Concrete Infrastructure Research Database

This database of in-progress and recently completed research related to concrete pavements and bridge decks across the US is partially a product of the former CP Road Map (or Long-Term Plan for Concrete Pavement Research and Technology). It is updated twice a year.

Research included is identified via the Transportation Research Board (TRB) list of Research in Progress (RiP), newsletters from across the concrete industry, and agency websites.

Find relevant projects using the search box below. Keywords and researchers are not shown in the table but are included in searches. (You can customize your search by clicking the down arrow to the right of the search box and/or click the “Date” header to sort results by date.)

End DateTitle
10/1/2013October 2013A Method to Assess the Use of New and Recycled Materials in Pavementshttps://cptechcenter.org/ncc-projects/a-method-to-assess-the-use-of-new-and-recycled-materials-in-pavements/Recycled materials, Pavements, Environmental impacts, State of the practice, Sustainable transportation, Durability, Pavement performance, Pavement designThe growing need for increased use of recycled as well as new materials in pavements has emerged due to the continuous decrease in natural resources and increased impact that the current state of practice has on the environment. Many transportation agencies are striving to make their practices and policies more "sustainable". Sustainable construction practices have been favored by the Federal and State Departments of Transportation (DOT's) as well as industry. However, the impacts of using new and recycled materials in pavements - particularly on long-term pavement durability and performance - are often unknown. The Michigan Department of Transportation (MDOT) does not have a system in place for evaluating any new or recycled materials as it relates to performance. This research will help identify methodologies to effectively determine the impacts of new recycled materials in pavement design and create a system for evaluating those materials.Muhammed Emin Kutay, Neeraj Buch, Syed Haider, Armagan Korkmaz, Anas Jamrah, Sudhir Varma
7/1/2014July 2014A Mobile Concrete Laboratory to Support Testing in 2014 on Internal Curing and High Early Strength Patcheshttps://cptechcenter.org/ncc-projects/a-mobile-concrete-laboratory-to-support-testing-in-2014-on-internal-curing-and-high-earl-strength-patches.--/Concrete curing; Concrete tests; Laboratory tests; PatchingThis project describes the use a mobile testing laboratory to obtain information during the 2014 construction season for the internally cured and rapid high early strength patching projects in 2014.Jason Weiss
2/1/2018February 2018A Simple and Nondestructive Evaluation Method to Achieve High-Quality Pervious Concrete Pavement Installationshttps://cptechcenter.org/ncc-projects/a-simple-and-nondestructive-evaluation-method-to-achieve-high-quality-pervious-concrete-pavement-installations/Pervious concrete, pavement, testing, PCP, compactionSomayeh Nassiri
11/1/2015November 2015A Targeted Approach to High-Volume Fly Ash Concrete Pavement (Phase I)https://cptechcenter.org/ncc-projects/a-targeted-approach-to-high-volume-fly-ash-concrete-pavement-(phase-i)/Concrete pavements; Fly ash; Innovation; Nanotechnology; Sustainable developmentFly ash, as a main by-product of coal-fired power plant, is one of the most used supplementary cementitious materials (SCMs) in concrete. Research is much needed to greatly advance understanding in the use of nanotechnology for high-volume fly ash concrete (HVFAC), especially when such concrete is intended for pavement applications. The primary objective of this project is to develop a viable nanotechnology approach to treat coal fly ashes based on their as-received characteristics before their use in sustainable concrete pavement. The use of nanotechnology to address weak interfaces in such sustainable concrete is a highly innovative approach.Sen Du, Xianming Shi
5/1/2013May 2013Accelerated Slab Replacement using Temporary Precast Panels and Self Consolidating Concretehttps://cptechcenter.org/ncc-projects/accelerated-slab-replacement-using-temporary-precast-panels-and-self-consolidating-concrete/Design, mix design, performance tests, precast concrete, self compacting, slabsThe research approach is to develop designs for the reusable temporary precast panels, engineer mixes for self-consolidating concrete (SCC), and validate performance and construction aspects of the system in the field.Kamal Tawfiq, Jamshid Armaghani
2/1/2019February 2019Accelerated Testing of Full-Scale Thin Bonded Concrete Overlay of Asphalthttps://cptechcenter.org/ncc-projects/accelerated-testing-of-full-scale-thin-bonded-concrete-overlay-of-asphalt/Accelerated tests; Concrete overlays; Heavy vehicles; Loads; Pavement performance; Service life; Serviceability; SimulationA research study was conducted with the goal of determining the expected performance life of thin bonded concrete overlay of asphalt (BCOA) in California. Eleven thin BCOA sections were built and tested with the Heavy Vehicle Simulators (HVS) in Davis, California. The performance of the sections in the HVS testing provided insight into the mechanics of the thin BCOA structures and the effects the different rapid-strength concrete materials, traffic, jointing, and base factors on their performance, including testing in both very wet and very dry conditions. Overall, the performance of the thin BCOA sections in the HVS testing was excellent. The eleven sections resisted the predefined HVS loading without cracking. In five of the sections, that loading was equivalent to 6 million single-axle loads and included load levels more than twice the legal limit in California, channelized traffic at the shoulder edge of the slabs, and a continuous water supply that simulated flooded conditions. The main conclusion from this research study is that a well-designed, well-built thin bonded concrete overlay with half-lane width slabs placed on top of an asphalt base that is in fair to good condition can provide 20 years of good serviceability on most of California’s non-interstate roadways.Angel Mateos, John Harvey, Fabian Paniagua, Julio Paniagua, Rongzong Wu
5/1/2019May 2019Advanced Reinforced Concrete Materials for Transportation Infrastructureshttps://cptechcenter.org/ncc-projects/advanced-reinforced-concrete-materials-for-transportation-infrastructures/Alternatives analysis;ÿCost effectiveness;ÿDurability;ÿInfrastructure;ÿLife cycle costing;ÿMaterials;ÿReinforced concrete;ÿSpecificationsThe objectives of this project are to: (1) identify novel materials that can be rapidly deployed in New Jersey’s reinforced concrete transportation infrastructure to improve the longevity and reduce the long-term costs of new and existing construction; (2) select cost-effective and structurally feasible materials in coordination with NJDOT for evaluation using experimental and computational methods to benchmark constructability, deterioration behavior across a range of mechanisms, and in-service structural performance among a diverse group of materials; (3) compare the economic impacts of different advanced materials across durability mechanisms and structural applications by performing life-cycle cost analyses; and (4) develop guidelines and specifications so that the materials can be rapidly deployed across the state in appropriate applications.Matthew J Bandelt
3/1/2016March 2016Advancing Steel Superstructures for ABChttps://cptechcenter.org/ncc-projects/advancing-steel-superstructures-for-abc/Bridge construction; Bridge superstructures; Steel bridges; Bridges and other structures; Construction; HighwaysThis project will test various schemes for accelerated bridge construction using steel superstructures. The testing will make recommendations for the optimal solution(s) to broaden acceptance.Professional Services Industries, Inc.
8/1/2015August 2015Aggregate Freezing-Thawing Performance using the Iowa Pore Index Methodhttps://cptechcenter.org/ncc-projects/aggregate-freezing-thawing-performance-using-the-iowa-pore-index-method/Aggregates; Concrete aggregates; Concrete pavements; Freeze thaw durability; Pavement performance; Pores (Geology); Winter maintenanceNon-durable aggregate leads to premature pavement deterioration often known as D-cracking. Repair of such distress may be costly and the agencies often end up with early replacement of the pavement. Differentiating the durable and nondurable aggregate is crucial, however, challenging. Frost durability of coarse aggregate has been reported to be related to its pore structure and available test methods to identify pore structure are not cost-effective. Iowa pore index test has been used by Iowa Department of Transportation for three decades as a supplemental decision-making tool, however, the method has never been standardized due to the lack of data relating its results to aggregate freezing-thawing durability. The research will use the Iowa pore index test to characterize concrete coarse aggregate and analyze the relationship between the Iowa pore index test and aggregates freezing-thawing performance.Fatih Bektas, Wenjing Cai, Kejin Wang
1/1/2016January 2016Air Void Analysis: Linear Traverse versus Imaged Methodshttps://cptechcenter.org/ncc-projects/air-void-analysis:--linear-traverse-versus-imaged-methods/linear traverse, spacing factor, hardened airThis study compares air distributions found by the traditional linear traverse method to the distribution found by using an off-the-shelf image analysis program.Will Lindquist, Rodney Montney
1/1/2012January 2012Alkali Content of Fly Ash - Measuring and Testing Strategies for Evaluating Compliancehttps://cptechcenter.org/ncc-projects/alkali-content-of-fly-ash---measuring-and-testing-strategies-for-evaluating-compliance/Fly ash, Alkali silica reactions, Quality control, Sodium, Potassium, Specifications, Cracking, Iowa, Alkali contentSodium and potassium are the common alkalis present in fly ash. Excessive amounts of fly ash alkalis can cause efflorescence problems in concrete products and raise concern about the effectiveness of the fly ash to mitigate alkali-silica reaction (ASR). Fly ash marketing agencies occasionally provide materials that just miss the criteria for alkali content given in Iowa Department of Transportation (IowaDOT) IM 491.17. Since usage is only from an approved list (certified sources) this leads to disputes that can be difficult to resolve. This is especially problematic when the alkali content of a given source of fly ash only changes by a small amount but the change causes the source to cross a specification limit. This immediately prompts the marketing agency to question the precision of the alkali determinations and/or the validity of the specification limit. This proposed research project is aimed helping to resolve these issues. Specifically, it plans to: (1) review the existing methods of fly ash alkali measurement; (2) reviewing models used to estimate alkali content of the various sources of fly ash commonly used in Iowa; (3) ascertaining how the measured alkali content of a fly ash impacts its ability to mitigate ASR; and (4) evaluating existing pavements in Iowa that were constructed using high-alkali fly ash, for ASR-induced cracking. The scope of the project is limited to the examination of fly ash sources that are commonly used by the Iowa DOT. Special attention will be given to fly ashes obtained from power stations that utilize alkali-bearing materials in their normal operating procedures. The objectives of this project are to: (1) determine if and at what content level fly ash with soda dosing has increased potential for alkali silica reactivity (ASR) as well as any other potential performance impacts in the concrete both during mixing and placing as well as long-term (good or bad); (2) evaluate field concrete containing high-alkali fly ash and moderately reactive fine aggregate to see if ASR-related distress has occurred; (3) determine a better method for determining available alkali in fly ashes with soda dosing. The method should be relatively simple and rapid in order to provide a quality control (QC) tool for the fly ash marketer and quality assurance (QA) test for the Department of Transportation (DOT); and (4) perform a literature review and/or a survey to determine if there are other materials and methods for emission control that may impact the mid-west power plants and their fly ash chemistry. A specification content limit or performance level should be determined and recommended.Scott M Schlorholtz
5/30/2015May 2015Alkali Silica Reaction (ASR) In Cement Free Alkali Activated Sustainable Concretehttps://cptechcenter.org/ncc-projects/alkali-silica-reaction-(asr)-in-cement-free-alkali-activated-sustainable-concrete/Alkali silica reactions, Compressive strength, Portland cement concrete, Fly ash, Durability, Concrete, Shrinkage, CrackingIncreased awareness in this decade on the significance of developing sustainable materials for construction has renewed the interest in exploring Alkali Activated Concrete (AAC), a concrete that contains no cement but only industrial by-products such as fly ash and slag, as a low energy alternative to the conventional concrete. Preliminary studies to evaluate the potential of alkali activated slag/fly ash as a sustainable alternative to Portland cement concrete is quite promising. Strength comparable to Portland cement concrete has been obtained in AAC under laboratory conditions. Through a UTRC2 grant, principal investigator's (PI‰Ûªs) research group has successfully developed AAC with compressive strengths as high as 60 MPa using slag or class C fly ash as the sole binder, and sodium silicate solution as the activator. However, transfer of this technology to the field has not received the expected momentum, primarily due to two major technical concerns: (1) potential for higher shrinkage and increased cracking, and (2) uncertainty associated with the possible Alkali Silica Reaction (ASR) related durability issues. Conducting experimental studies focusing on the detailed assessments of the durability performance is the most powerful mean to overcome these barriers.Zihui Li, Robert J. Thomas, Diego Lazama, Sulapha Peethamparon
1/9/2019January 2019An Approach to Characterize the Wearability of Concrete Pavement Surface Treatmentshttps://cptechcenter.org/ncc-projects/an-approach-to-characterize-the-wearability-of-concrete-pavement-surface-treatments/Abrasion resistance; Concrete pavements; Freeze thaw durability; Gravel; Limestone aggregates; Repeated loads; Service life; Silicates; Silicon; Surface treating; WearFor a concrete pavement, the permeation specifications for the surface have a crucial influence on its durability. In this accelerated laboratory research, a surface treatment that combines lithium silicate chemistry with a reactive silicon catalyst was tested to typify the product longevity under traffic and against salt scaling. River gravel and limestone aggregates were used in two different mixture designs. Abrasion testing was conducted according to ASTM standards in which mass loss was recorded at different time intervals. A modification was employed using a diluted deicer simulated by 4 wt.% CaCl₂ solution during 15 cycles of freeze/thaw testing. A model was proposed to relate the abrasion efficiency against load cycles of a treated surface to represent the longevity of a concrete pavement. Based on the abrasion coefficient and the texture wavelength of the pavement, it is shown that the life cycle under abrasion of a concrete pavement can be modeled. During the experimental procedures, the untreated concrete specimens were used as the control sample.Carl N. Abou Sleiman, Xijun Shi, Dan G. Zollinger
3/23/2018March 2018An Assessment of the Models to Predict Pavement Performancehttps://cptechcenter.org/ncc-projects/an-assessment-of-the-models-to-predict-pavement-performance/Asphalt concrete pavements; Composite pavements; Evaluation and assessment; Pavement performance; Portland cement; Regression analysis; Pavement Condition Index; Pavement prediction models; Road conditions; Highways; Maintenance and Preservation; Pavements; Planning and ForecastingData collected by the Iowa Department of Transportation (DOT) regarding road conditions across the state of Iowa were used to model pavement condition index (PCI). The data were for calendar year 2013, with the exception of updated PCI values from 2014 and 2015 and indicators of the resurfacing of road segments in 2014 and 2015. The data file provided by the Iowa DOT consisted of nearly 4,000 observations. Eighteen different road conditions and measures were considered as possible model inputs. Of the 18 measures, 11 were used in the final prediction of PCI in 2014 and 2015 for portland cement, composite, and asphalt cement pavement types. These measures included International Roughness Index (IRI), friction value, age, average daily traffic, PCI value in 2013, number of lanes, daily temperature change, surface type, pavement thickness, speed limit, and reconstructed kips. Series of multiple regression models were developed for the different pavement types, including aggregated pavement types with combined data. The results reveal that all 11 variables except age have a statistically significant relationship with PCI. The efficacies of the derived models, as measured by R2 values, range from 61% to 83%. Additional analyses also show that the efficacies of the derived models, as measured by root mean square error (RMSE) values, range from 6.29 to 9.52. The authors can interpret the RMSE values as indicating that approximately 95% of all prediction values should fall within 12.58 and 19.04 of the PCI values predicted by the models. Therefore, it is concluded that linear predictive models, which involve distress and descriptive characteristics of road conditions, provide a reasonable basis for estimating PCI. However, these models can be further improved by examining nonlinear effects.William Duckworth, Ravi Nath, Victor Ekpoke
5/1/2011May 2011Analysis of Bridge Deck Cracking Datahttps://cptechcenter.org/ncc-projects/analysis-of-bridge-deck-cracking-data/CrackingA review of mechanisms, analysis of MnDOT bridge construction data, and recommendations for treatment and prevention of cracking.David L. Rettner, Melanie S. Fiegen, Mark B. Snyder, Kevin A. MacDonald
9/3/2012September 2012Analysis of Construction Quality Assurance Procedures on Federally Funded Local Public Agency Projectshttps://cptechcenter.org/ncc-projects/analysis-of-construction-quality-assurance-procedures-on-federally-funded-local-public-agency-projects/Quality assurance, Construction management, Construction projects, Best practices, Governments, Local government agenciesThis study investigates construction quality assurance practices used on locally administered Federal-aid highway projects. The study covers various types, sizes, and scopes of transportation projects delivered by local public agencies. The study involves collecting, organizing, and analyzing data from various State highway and local public agencies. The research product is a report outlining current quality assurance practices on local public agency projects, including areas of weakness and successful practices.Linda Karen Konrath, Leslie Ann McCarthy, Sidney Scott
3/13/2018March 2018Application of a PCM-Rich Concrete Overlay to Control Thermal Induced Curling Stresses in Concrete Pavementshttps://cptechcenter.org/ncc-projects/application-of-a-pcm-rich-concrete-overlay-to-control-thermal-induced-curling-stresses-in-concrete-pavements/PCM concrete overlay; moderate temperature gradient, mitigate curling stresses.This study aims to evaluate the application of a Phase Change Material (PCM) rich concrete overlay to reduce curling stresses in concrete pavements. Curling stresses are the results of temperature gradient in pavements, and are comparable to the stresses that are induced by traffic loads. The weather conditions, which have a cyclic nature, are the source of curling stresses, and they cause cyclic tensile and compressive stresses in pavements. This phenomenon causes fatigue damage in concrete pavements and reduces their service life. The PCMs have a high latent heat of fusion and can increase the thermal inertia of concrete. When PCM is used in a concrete overlay, it tends to moderate the temperature gradient in the slab, and thus mitigate the curling stresses. The efficiency of the proposed PCM-rich overlay was evaluated under the real climatic conditions of three different cities in the US. The findings of this research demonstrated that the cumulative fatigue Damage Index (DI) resulted from repetitive curling stresses can be up to 22% in a concrete slab with the service life of 35 years. However, using a 7.6 cm bonded concrete overlay with 25 vol% PCM can moderate the curling stresses so much that the effect of curling induced fatigue damage would be virtually negligible.Naser P Sharifi, Kamyar C Mahboub
6/9/2014June 2014Application of Imaging Techniques to Evaluate Polishing Characteristics of Aggregateshttps://cptechcenter.org/ncc-projects/application-of-imaging-techniques-to-evaluate-polishing-characteristics-of-aggregates/Aggregates, Friction, Imaging systems, Polishing (Aggregates), Evaluation and assessment,The primary objective of this research is to identify approaches that can be used for aggregate pre-evaluation in order to reliably distinguish between different aggregates with different frictional characteristics.Reynaldo Roque, Abolfazl Ravanshad, Sanghyun Chun
8/8/2012August 2012Appropriate Implementation of Pavement Preservation Treatmentshttps://cptechcenter.org/ncc-projects/appropriate-implementation-of-pavement-preservation-treatments.--/Composite pavements; Hot mix asphalt; Implementation; Pavement management systems; Pavements; Portland cement concrete; Preservation; Surface treatingThe objectives of this research study are to develop a list of appropriate pavement preservation treatments for use on hot mix asphalt (HMA), Composite and portland cement concrete (PCC) pavements on the New Jersey Department of Transportation (NJDOT) state-maintained road network; recommend pavement management system inputs for pavement preservation treatments; develop NJDOT specifications for each pavement preservation treatment; document the constraints on pavement preservation treatments on material suppliers and contractors, and develop and facilitate pavement preservation treatment training and implementation.Nick Vitillo, Hao Wang, Michael Boxer, Brian Tobin, Carl Rascoe, Dan Roberts
5/1/2014May 2014Assessment of High Early Strength Limestone Blended Cement for Next Generation Transportation Structureshttps://cptechcenter.org/ncc-projects/assessment-of-high-early-strength-limestone-blended-cement-for-next-generation-transportation-structures/Limestone, Blended cement, Blends, Precast concrete, Shrinkage, High early strength cement, Creep, Setting (Concrete), Permeability, InfrastructureThis research effort is aimed at evaluating the effects of increasing ground limestone addition rates and in particular high fineness blended cements developed for high early strength in precast concrete construction. Assessment of key material properties (e.g., setting time, strength development, shrinkage, creep, permeability) relevant to the construction, operation, and maintenance of transportation structures will be the focus. Results will be used to better understand the implications of changes in cement compositions and to provide guidance of how these changes can or should be accommodated in state and federal specifications for precast concrete elements intended for transportation structures.Ahmad Shalan, Lawrence F. Kahn, Kimberly Kurtis, Elizabeth Nadelman
09/01/17September 2017Assessment of Limestone Blended Cements for Transportation Applicationshttps://cptechcenter.org/ncc-projects/assessment-of-limestone-blended-cements-for-transportation-applications/Limestone, Cement, Portland cement, Performance tests, Assessments, Performance based specificationsThe objective of this project is to compare the performance of limestone blended cements to conventional portland cements in concretes designed to meet Georgia Department of Transportation (GDOT) specifications for various types of concrete.Kimberly E. Kurtis, Lawrence F. Kahn, Ahmad Shalan, Behnaz Zaribaf, Elizabeth Nadelman
06/30/14June 2014Automated Measurement of Concrete Slump Using the Verifi Systemhttps://cptechcenter.org/ncc-projects/automated-measurement-of-concrete-slump-using-the-verifi-system/Fresh concrete, Slump test, Admixtures, Temperature, Automation, Cooperation, InfrastructiorThis study will evaluate the performance of an automated system of measuring the fresh properties of concrete in truck mixer. The automated system called ‰"Verifi" enables the evaluation of slump and temperature variations as well as monitoring of the amount of water and/or dispersant added to the mixture. This collaboration is essential for future quality management of infrastructure materials.Kamal H. Khayat, Nicolas Ali Libre
7/1/2019July 2019Base Stabilization Additives - Effect on Granular Equivalency (GE)https://cptechcenter.org/ncc-projects/base-stabilization-additives---effect-on-granular-equivalency-(ge)/Life cycle analysis; Life cycle costing; Pavement designBase stabilization additives are used to increase the strength and stiffness of road foundations in weak and susceptible soils. Numerous additives exist for improving performance of aggregate base layers, however, most independent studies have focused on non-proprietary additives. Additives are being used to stabilize base/subbase/subgrade layers, but engineering methods for pavement thickness design need to be better defined. In particular, determining granular equivalency (GE) factors for various proprietary geomaterial stabilizers will benefit Minnesota Department of Transportation (MnDOT) and county engineers by establishing design parameter values and a means for comparing additive effectiveness and cost. The proposed research has three main goals: (1) evaluate the performance of selected proprietary additives by conducting laboratory and field tests; (2) prepare pavement designs and construction specifications based on the test results; and (3) analyze the benefits of additives in terms of pavement construction cost savings and long-term service life.Bora Cetin
09/11/14September 2014BCOA-MEhttps://cptechcenter.org/ncc-projects/bcoa-me/concrete overlays, whitetopping, designThis pooled fund study developed an improve procedure for the design of bonded concrete overlays of existing asphalt pavements (whitetoppings). Major advances included consideration of the seasonal support provided by the underlying asphalt layer, and devlopment of fatigue cracking models based on panel size.Julie Vandenbossche
10/1/2013October 2013Best Field Practices for the Use of Self Consolidating Concrete (SCC) in Nevada DOT Projectshttps://cptechcenter.org/ncc-projects/best-field-practices-for-the-use-of-self-consolidating-concrete-(scc)-in-nevada-dot-projects/SCCThe sensitivity of the SCC mix design to local materials and different admixtures poses a serious challenge to its implementation in NDOT projects. Also different construction applications require different performance criteria for SCC mixtures. This research will evaluate SCC properties and implementation in NDOT projects.Aly Said, Pramen P Shrestha, Kojo Nkuako
12/1/2016December 2016Best Practices for Concrete Pumpinghttps://cptechcenter.org/ncc-projects/best-practices-for-concrete-pumping,/Air voids; Best practices; Properties of materials; Pumped concrete; Rheological propertiesPumping is one of the major placement techniques used in the concrete industry to deliver concrete from the mixing truck to the formwork. Although concrete pumping has been used to place concrete since the 1960s, there is still a lack of exact knowledge supported by research evidence as to what affects concrete pumpability and how pumping changes concrete properties.Kyle A. Riding, Jan Voshalik, Dimitri Feys, Travis Malone, Will Lindquist
11/25/2014November 2014Better Concrete Mixes for Rapid Repair in Wisconsinhttps://cptechcenter.org/ncc-projects/better-concrete-mixes-for-rapid-repair-in-wisconsin/Concrete pavements; Costs; Freeze thaw durability; Inventory; Materials; Mix design; Pavement maintenance; Pavement performance; Procedures; Specifications; Time dependenceConcrete pavements in Wisconsin have shown varying signs of deterioration due to age, environment, loading and other detrimental factors. Considering the enormous cost and effort required to remedy pavement deficiencies, it is crucial that a concerted effort be made to develop and implement practical, effective and economical methods and specifications for more durable concrete mixes for rapid repair. Due to high user delay costs for closing highways for repairs, very short closure periods are specified, requiring concrete that has a high strength gain and very fast cure times. Often times, this work needs to be done in the window of a single night closure. Due to the repair techniques used, concrete used in rapid repairs have been found to have unsatisfactory durability and performance resulting in reduced service lives. As a result, the Wisconsin Department of Transportation (WisDOT) is pursuing a research study of concrete materials and mix designs in order to achieve rapid repairs of concrete pavements that meet expected performance and service lives. The research objectives are to evaluate current practice in rapid repair of concrete pavements in Wisconsin and to recommend changes where appropriate. Four major deliverables will be provided: (1) A basic inventory of current materials, concrete mixes and procedures for rapid repair being used by WisDOT and other highway agencies; (2) Identification of high quality performing concrete rapid repair mixes that are capable of providing long life and good performance in a wet freeze-thaw climate typical for Wisconsin; (3) A field review and performance analysis on recent Wisconsin rapid repair projects to evaluate how repairs are performing; and (4) A categorization of technologies and methods available for installation, guidance for mix design and placement, and cost estimates on the concrete mixes being evaluated for rapid repair.Steven M. Cramer, Le T. Pham, Mark B. Snyder
6/15/2014June 2014Biocement for Road Repairhttps://cptechcenter.org/ncc-projects/biocement-for-road-repair/Wastes, Pavement maintenance, Cracking, Cost effectiveness, Stabilizers, Dust control, Unpaved roads, Paving, LimestoneRoad repair is an expensive operation every year. This cost can be greatly reduced if waste materials from mining and biofuel industries can be used to substitute conventional materials for road repair or construction. The objective of this project is to develop methods to produce a new construction material, biocement, using waste products and apply the new material for road repair and construction. Two types of waste will be used in this study. One is limestone fines produced from a limestone mine in Iowa. Another is organic acids, a byproduct produced from pyrolysis-based biofuel manufacturing process. The limestone fines and organic acids can be used to produce biocement under ambient temperature in an inexpensive way. The cost-effective biocement can be used as a substitute for expensive cement for roads repair and construction. Biocement grout, or biogrout, can be injected directly into cavities or cracks in pavement for road repair. As the viscosity of biogrout is low, biogrout can penetrate better into the road pavement than cement grout. Biocement mixed aggregate can be used for base or subbase for road construction. Biocement solution can also be applied directly onto shoulders as a stabilizer on unpaved roads as a dust control agent. The focus of this project will be on the development of cost-effective biocement products and its effectiveness for road repair. Once the methods for biocement production and its applications are established in lab-scale, field experiments will be carried out as a following up study.Jian Chu, Zhiyou Wen
5/2/2017May 2017Blast Furnace Slag Usage and Guidance for Indianahttps://cptechcenter.org/ncc-projects/blast-furnace-slag-usage-and-guidance-for-indiana/Construction projects; Leaching; Pollutants; SlagThe objective of the proposed research is to understand the extent of blast furnace slag (BFS) usage for completed INDOT projects, factors that control BFS leaching, review and recommend remediation strategies, and identify applications where future usage restrictions or sitting criteria are needed, if any. Completion of this project will equip INDOT staff with information to make decisions about future BFS usage.Andrew Whelton
10/3/2018October 2018Bond Characterization of UHPC Overlays for Concrete Bridge Decks: Laboratory and Field Testinghttps://cptechcenter.org/ncc-projects/bond-characterization-of-uhpc-overlays-for-concrete-bridge-decks:-laboratory-and-field-testing/Bond strength (Materials); Bridge decks; Concrete overlays; Field tests; Laboratory tests; Ultra high performance concreteThis paper aims to characterize the bond behavior and performance of UHPC-class materials as overlays on bridge deck concrete substrates. The study includes laboratory testing, field testing, and microstructural analysis using scanning electron microscopy (SEM). The laboratory portion examines the direct tension bond strength between UHPC and substrate concrete with different substrate surface preparations; namely, hydrodemolition and scarification. The field testing examines the tensile bond strength of the first UHPC bridge deck overlay in the United States. Lastly, microstructural analysis is used to investigate consolidation of the overlays, the substrate surface condition, and the hydration products and porosity at the interface between the overlay and substrate. The paper discusses correlation between bond strength and consolidation, mechanical interlock, chemical bond, and substrate surface condition and preparation.Zachary B. Habera, Jose F. Munoz, Igor De la Varga, Benjamin A. Graybeal
11/5/2015November 2015Bridge Deck Concrete Surface Resistivity for Performance Based Testshttps://cptechcenter.org/ncc-projects/bridge-deck-concrete-surface-resistivity-for-performance-based-tests/Bridge decks; Concrete; Durability; Infrastructure; Performance based specifications; Resistivity methodMajor steps have been taken with concrete reinforcing steel to address corrosion issues in Utah’s bridges. However, improving bridge deck concrete should remain a priority to extend concrete bridge deck service life. Concrete surface resistivity and bulk resistivity, are very easy to implement, non-destructive tests which can identify several important parameters, including concrete permeability and can potentially be correlated to applied tension loads, pore size distribution, internal relative humidity and accurately detect setting time.Thomas Hales
5/8/2017May 2017Bridge Deck Overlays Using Ultra-High Performance Concretehttps://cptechcenter.org/ncc-projects/bridge-deck-overlays-using-ultra-high-performance-concrete/Best practices; Bridge decks; Concrete bridges; Contraction; Overlays (Pavements); Skid resistance; Thermal expansion; Ultra high performance concreteOverlays are placed on existing concrete bridge decks for reasons that include increasing cover for the deck reinforcing steel, improving rideability, and improving skid resistance. To increase service lives of bridge deck overlays, and subsequently the underlying concrete deck, this research project will investigate the possibility of using ultra-high performance concrete (UHPC) to overlay existing concrete bridge decks. UHPC has been shown to have exceptional durability and strength properties that have the potential to greatly improve the sustainability of overlaying concrete bridge decks by extending the service lives of both the overlay and the concrete deck. The research project consists of a comprehensive literature review to identify best practices for traditional overlay materials that might also be used for UHPC overlays and development of practices that will ensure a strong durable bond between the UHPC overlay and the substrate material. It is crucial that this bond is able to withstand stresses and deformation caused by shrinkage of the UHPC, thermal expansion and contraction of the deck and overlay, and movements caused by loads applied to the bridge. Laboratory experiments will be conducted to verify that the practices identified are effective at maintaining the bond between a UHPC overlay and existing concrete decks. The implementation phase of the project will entail documenting the best practices for UHPC overlay application to existing concrete decks in the form of design recommendations. Field implementation is expected in on a New Mexico Department of Transportation project in late 2018.Craig Newtson, Brad Weldon
7/1/2013July 2013Bridge Decks: Mitigation of Shrinkage Crackinghttps://cptechcenter.org/ncc-projects/bridge-decks:-mitigation-of-shrinkage-cracking/deck cracking, shrinkage, expansive concrete, SRA, lightweight aggregates, deck model, parametric study, finite element model, bridge, cracking, durability, mitigationThe goal of this study (i.e., Phase- III) is to develop ‘robust’ shrinkage mitigation strategies by combining knowledge of materials level testing with lab-scale structural testing, and develop guidelines for Illinois Department of Transportation (IDOT) for implementation of a holistic approach that lessens premature cracking in concrete bridge decks in Illinois. The workplan below primarily focuses on the materials part of the research. A separate workplan is being submitted by SLU on the structural part of the work. A joint effort will be made to combine the small-scale materials lab test data with large-scale structural test data in order to ultimately develop guideline for field application.Ardavan Ardeshirilajimi, Di Wu, Piyush Chaunsali, Paramita Mondal, Ying Tung Chen, Mohammad Mahfuzur Rahman, Ahmed Ibrahim, Will Lindquist, Riyadh Hindi
5/29/2019May 2019Bridge Element Deterioration for Midwest Stateshttps://cptechcenter.org/ncc-projects/bridge-element-deterioration-for-midwest-states/Asset management;ÿBridge construction; Bridge design; Bridge management systems;ÿ Bridge members;ÿData analysis;ÿData collection;ÿDeterioration;ÿMaintenance;ÿState departments of transportation;ÿState of the practiceThe objective of this pooled fund research is to have multiple Mid-west departments of transportation (DOTs) pool resources and historic Mid-west DOT bridge data related to element level deterioration, operation practices, maintenance activities, and historic design/construction details. This data will provide the basis for research to determine deterioration curves. A select number of deterioration curves will provide needed utility for the time-dependent deterioration of bridge elements to be used in making estimates of future conditions and work actions. This effort will pool data and through the analysis and research processes create results that will improve accuracy of various bridge management and asset management applications that the member DOTs use (BrM, Agile Assets, and other). This study will be sequenced into three tiers based on the priorities of the DOTs: Tier 1 National Bridge Elements (NBE) & National Bridge Inventory) (1) Develop element level deterioration curves for Reinforced Concrete Deck from data that will provide the basis for research to determine the deterioration curves (2) Develop element level deterioration curves for Reinforced Concrete Slab from data that will provide the basis for research to determine the deterioration curves (3) Develop deterioration curves for NBI items from data that will provide the basis for research to determine the deterioration curves (4) Develop element level deterioration curves for Reinforced Concrete Deck after a major preservation activity such as mill and overlay with rigid concrete wearing course (5) Develop predicted improvement in condition of Reinforced Concrete Deck element after a major preservation activity such as mill and overlay (6) In addition to probabilistic deterioration curves, also develop deterministic deterioration curves that better may fit with field observations Tier 2 Bridge Management Elements (BME) (7) Develop element level deterioration curves for each type of wearing surface (bare concrete, sealed concrete, thin polymer overlay, PPC overlay, ridged concrete overlay, Polymer Modified Asphalt overlay, and asphalt overlay with membrane) from data that will provide the basis for research to determine the deterioration curves (8) Develop element level deterioration curves for Strip Seal Deck Joints and Modular Deck Joints from data that will provide the basis for research to determine the deterioration curves (9) Determine defect level deterioration curves that describe defect development and progression (e.g., cracking and delamination) (10) Develop defect level deterioration curves for Paint system (protective steel) effectiveness (11) Develop defect level deterioration curves for Steel Girder corrosion, and correlate to Paint system effectiveness; specifically, how long from new paint to 75% and 50% effective and end of life (12) Develop element level deterioration curves for substructure elements in harsh environments (i.e., pier caps under expansion joints, pier columns in spray zone from snow plows, etc.) Tier 3 (similar Agency Defined Elements (ADE) & Inspection related) (13) From research results, determine what type of inspection information (nondestructive testing) Mid-west DOTs have that translates into information on element level defects (GPR, Thermograph, other) (14) Use DOT past data and research and analysis results to determine the reliability of Infrared Thermography and Ground Penetrating Radar (GPR) for defect reporting (to describe delamination and deterioration) of concrete bridge decks.Lynn Hanus
4/1/2018April 2018Calcium Sulfoaluminate Cementhttps://cptechcenter.org/ncc-projects/calcium-sulfoaluminate-cement/Calcium sulfates; Cement; Concrete industry; Durability; Pavement maintenance; Repairing; Highways; Materials; PavementsIn the North American market, calcium sulfoaluminate (CSA) cement is primarily used as a rapid pavement repair material. This article provides an overview of the unique features and benefits of CSA cement, the durability of CSA cement concrete, and ongoing and potential applications within the concrete industry.Robert J Thomas, Marc Maguire, Andrew D Sorensen, Ivan Quezada
7/15/2015July 2015Calibrating the Iowa Pore Index with Mercury Intrusion Porosimetry and Petrographyhttps://cptechcenter.org/ncc-projects/calibrating-the-iowa-pore-index-with-mercury-intrusion-porosimetry-and-petrography/Pavement performance, Winter maintenance, Freeze thaw tests, Durability, Pore size distribution, Test procedures, Crushed rockThe Iowa Pore Index (IPI) test is a fast, non-destructive, inexpensive, and environmentally friendly test used by several Midwestern state departments of transportation to determine the volume ratio of macropores to micropores in a coarse rock aggregate. When combined with x-ray diffraction and x-ray fluorescence, this method has been shown to be effective in predicting the performance of aggregates in portland cement concrete. The test has the potential to replace mercury porosimetry and be integrated into any petrophysical laboratory. This research aimed to understand the geological factors (depositional environment, facies, grain and pore types, texture, and paragenesis) responsible for the results of the IPI test. Samples of various geologic ages were collected around Iowa to represent different combinations of accepted and rejected porosity and clay contents. The pore index of each sample was calibrated quantitatively via helium and mercury porosimetry and qualitatively via thin section petrography. The findings show that even the most homogeneous sources have at least three different rock types. Petrographic analysis showed that limestones with a sparite matrix, peloidal grains, and a low matrix-to-allochem ratio (i.e., grainy) are better for road construction than limestones with a micrite matrix, skeletal grains, and a high matrix-to-allochem ratio (i.e., muddy). Dolostones with fine to coarse grains, crystal-supported euhedral to subhedral rhombs, and porous intercrystalline areas are more desirable than dolostones with very fine grains and a tightly interlocking crystal mosaic in anhedral form. Several linear models were developed to relate IPI to helium porosity. Limestones with a helium porosity less than ~7% and dolostones with a helium porosity greater than ~13% were found to be desirable for use in road construction. The critical range of pore-throat size was found to be between 0.02 and 0.1 µm. Coarse aggregates with modal pore throat sizes above this range were found to be desirable for use in road construction.Franciszek Hasiuk, Muhammad Firdaus Ahmed Ridzuan, Peter Taylor
1/6/2017January 2017Calibration of the AASHTO Pavement Design Guide to SC Conditions - Phase IIhttps://cptechcenter.org/ncc-projects/calibration-of-the-aashto-pavement-design-guide-to-sc-conditions---phase-ii/Calibration; Data collection; Pavement design; Pavement distress; Pavement maintenanceThe overarching goal of this multi-phase research effort is to reduce design bias and increase precision of the model predictions used in Mechanistic Empirical Design Guide (MEPDG) with full consideration of South Carolina local conditions. The objective of Phase II will be to build upon the studies in Phase I to obtain local calibration factors and improve distress predictions by collecting new data of high priority.Sarah Gassman
08/09/14August 2014Carbonate Aggregate in Concretehttps://cptechcenter.org/ncc-projects/carbonate-aggregate-in-concrete/carbonate aggregates, concreteStudy to characterize Minnesota's aggregates and to investigate whether or not some aggregates rejected by the current MnDOT criteria can potentially be used in pavement concrete.Fatih Bektas, Kejin Wang, Jiaxi Ren
6/1/2017June 2017Case Study Report on Full-Depth Repairhttps://cptechcenter.org/ncc-projects/case-study-report-on-full-depth-repair/Full Depth Repair, deteriorated joints, partial and full slab replacementFull-depth repair (FDR) is a well-established technique applied to existing jointed plain and jointed reinforced concrete pavements (JPCP and JRCP) that includes both partial slab replacement and full slab replacement to address any variety of serious distress. FDR provides for the long-term repair of structurally and/or functionally deteriorated joints, working cracks, shattered slabs, and multiple slab distress. When combined with other needed concrete pavement restoration (CPR) techniques, FDR can significantly increase pavement service life before structural overlay or reconstruction is required. FDR can also increase the life of a pavement to be overlaid by providing high joint load transfer efficiency (LTE) to restore stability and control reflection cracking severityMichael Darter
1/1/2017January 2017Characterization and Performance of Zero-Cement Concretehttps://cptechcenter.org/ncc-projects/characterization-and-performance-of-zero-cement-concrete/Admixtures; Binders; Bridge decks; Concrete; Fly ash; Girders; Hydration; Portland cementThis study has investigated the feasibility of using five different types of class C fly ashes (FAs) sourced from Labadie, Jeffrey, Kansas City, Thomas Hill, and Sikeston power plants in the state of Missouri to synthesize zero-cement concrete (ZCC) for different structural and repair applications. Alkali activator (Alk) consisting of sodium silicate (SS), Na2SiO3, and sodium hydroxide (SH), NaOH were used to synthesize the ZCC. Slag, crumb rubber, and air-entraining admixture (AEA) were used in a few mixtures as additives to improve the durability of the ZCC.Eslam Gomaa, Simon Sargon, Cedric Kashosi, Ahmed Gheni, Mohamed ElGawady, William Schonberg
9/1/2017September 2017Characterization of Bases and Subbases for AASHTO ME Pavement Designhttps://cptechcenter.org/ncc-projects/characterization-of-bases-and-subbases-for-aashto-me-pavement-design/Aggregates; Aggregates by source; Asphalt; Cold in-place recycling; Concrete; Emulsions; Hot mix asphalt; Materials; Materials at high or low temperatures; Pavement layers; Portland cement concrete; Recycled materials; Soil cement; Stabilized materials; Subbase (Pavements); Values in measurementThe goal of this research is to identify material level 1, level 2, and level 3 inputs and properties for Graded Aggregate Base (GAB), Cement Stabilized Aggregate Base (CSAB), Cement Modified Recycled Base (CMRB), Soil-Cement, Cold in Place Recycling (CIR) with Foam, CIR with Emulsion required for use in the MEPDG. In addition, the research will investigate relationship between laboratory and field testing properties for each material type by comparing lab results to field results.Serji Amirkhanian
12/21/2016December 2016Characterization of environmental loads related concrete pavement deflection behavior using Light Detection and Ranging technologyhttps://cptechcenter.org/ncc-projects/characterization-of-environmental-loads-related-concrete-pavement-deflection-behavior-using-light-detection-and-ranging-technology/Environmental load-related deflection; Light Detection; (LiDAR) system.Repeated deflection behavior resulting from temperature and moisture variations across concrete pavement depth causes curling and warping of Portland cement concrete (PCC) pavement systems. Although curling and warping issues have been investigated extensively, there are no standardized methods or procedures currently available to characterize the degree/magnitude of this in situ environmental load-related deflection. This study discusses the development of a detailed procedure for assessing environmental load-related deflection of concrete pavement using a Light Detection and Ranging (LiDAR) system. LiDAR systems have been recognized as an advanced technology for transportation infrastructure inspection but have not been widely investigated for measuring environmental load-related deflection of concrete pavements. In this study, field surveys were conducted on six identified concrete pavement sites in Iowa by scanning the concrete slab surfaces using the stationary LiDAR instrument. Based on dense point cloud data obtained by the LiDAR instrument, a data processing algorithm was developed to obtain the degrees of environmental load-related deflection. The degrees of deflection obtained were correlated to variations in pavement performance, mix design, pavement design, and construction details at each site. The results and findings from this study describe a potentially novel method of using LiDAR system for environmental load-related deflection characterization of concrete pavement.Shuo Yang, Halil Ceylan, Kasthurirangan Gopalakrishnan, Sunghwan Kim, Peter C Taylor, Ahmad Alhasan
7/1/2015July 2015Characterization of Portland Cement Concrete Coefficient of Thermal Expansion in South Carolinahttps://cptechcenter.org/ncc-projects/characterization-of-portland-cement-concrete-coefficient-of-thermal-expansion-in-south-carolina/Coefficients; Failure; Pavement design; Portland cement concrete; Road construction; Thermal expansionThe objective of this study is to provide specific inputs and guidance in the selection and specification of coefficient of thermal expansion (CTE) for portland cement concrete (PCC) pavement design and construction. The new pavement design methodology has the potential to provide pavement designs that will perform more predictably than current designs and avoid potential issues that might cause premature pavement failure. By appropriately calibrating the new American Association of State Highway and Transportation Officials (AASHTO) pavement design methodology, the Department will be able to avoid costly premature pavement failures and better optimize its pavement investments.Trent H. Dellinger, Amir Poursee
6/2/2019June 2019Characterization of Recycled Concrete Aggregate after Eight Years of Field Deploymenthttps://cptechcenter.org/ncc-projects/characterization-of-recycled-concrete-aggregate-after-eight-years-of-field-deployment/Base course (Pavements);ÿChemical properties;ÿConcrete aggregates;ÿHeavy metals;ÿLeachate;ÿRecycled materials;ÿSubgrade materialsRecycled concrete aggregate (RCA) is a high-quality substitute for virgin aggregate as base or subgrade material in pavement construction. However, heavy metal leaching and/or production of high pH leachate are environmental risks commonly associated with the use of RCA. To characterize changes in physical and chemical properties after use, RCA base course and subgrade soil samples were recovered from the Minnesota road research (MnROAD) field site after eight years and compared to the original RCA physical and chemical characteristics. RCA samples were analyzed to determine their mineralogy, carbonate content, acid neutralization capacity (ANC), material pH, and trace element leaching potential. ANC was higher in the recovered RCA and higher for the fine-grained RCA particles than the coarse particles, which was confirmed by extensive carbonation of the fines fractions during field deployment. Material pH of RCA and subgrade soil samples were significantly higher than leachate pH measured in previous and current field investigations of this site, suggesting that conventional laboratory techniques do not represent field conditions and should be modified to better represent field conditions.Bharat Madras Natarajan, Zoe Kanavas, Morgan Sanger, Jared Rudolph, Jiannan Chen, Tuncer Edil, Matthew Ginder-Vogel
12/01/15December 2015Characterizing and Quantifying the Shrinkage Resistance of Alkali Activated (Cement Free) Concrete and Evaluating Potential Methods for Reducing Early Age Cracking In Pavements and Bridgeshttps://cptechcenter.org/ncc-projects/characterizing-and-quantifying-the-shrinkage-resistance-of-alkali-activated-(cement-free)-concrete-and-evaluating-potential-methods-for-reducing-early-age-cracking-in-pavements-and-bridges/Concrete, Shrinkage, Alkali aggregate reactions, Cracking, Raw materials, Energy consumption, Sustainable development, Climate change, PollutantsConcrete is one of the most commonly used construction materials for building nation‰Ûªs infrastructure such as roadways, bridges, tunnels, and buildings, with a per-capita consumption of more than two tons. The most energy consuming and expensive component of concrete is Portland cement, which accounts for more than 70% of the raw material cost towards producing concrete. One metric ton of Portland cement production consumes about 5,792,000 BTU of energy. In addition to the cost and vast energy consumption, cement manufacturing processes releases significant amount of into CO2 the atmosphere. The chemical reactions of raw materials during pyro-processing produce about 0.54 tons of CO2 for every ton of cement manufactured. Another 0.43 tons of per CO2 ton of cement is released from the fuel used for burning the raw materials. Thus it is not surprising that cement manufacturing process accounts for 4-5% of global CO2 emission and it touches on wide range of sustainability issues including climate change, pollution, solid waste land filling and resources depletion. A solution to address these environmental and energy challenges is to develop a sustainable alternative binding material that can replace the whole or at least part of the cement used in concrete. Significant effort has been invested in developing alternative binding materials by activating commonly available industrial by-products, such as Fly ash (FA) and Granulated blast furnace slag (GGBFS) using alkalis. The resulting concrete is called as alkali activated concrete (AAC) (also known as cement free /Geopolymer concrete).Sulapha Peethamparan, Robert J Thomas
10/21/2017October 2017Characterizing Strength and Thermal Properties of Concrete for Implementation of Pavement Mechanistic-Empirical Design in New Mexicohttps://cptechcenter.org/ncc-projects/characterizing-strength-and-thermal-properties-of-concrete-for-implementation-of-pavement-mechanistic-empirical-design-in-new-mexico/Coarse aggregates; Mechanistic-empirical pavement design; Pavement performance; Rigid pavements; Thermal expansion; Thermal propertiesThe format of the design and performance prediction of rigid pavements was reformed with the advent of Pavement mechanistic-empirical (ME) design procedure, which now serves as the state-of-the-art tool in pavement design. Various state agencies have either completed or in the process of calibration of distress prediction models and characterization of concrete materials to provide accurate inputs required by t was found that the concrete strength and thermal properties including elastic modulus, modulus of rupture and coefficient of thermal expansion (CTE) are the most important input data that affect the design and performance of rigid pavements. Accurate rigid pavement design is heavily dependent on accuracy of these material inputs. This study is part of a New Mexico Department of Transportation (NMDOT) research project that focuses on the development of guidelines for characterizing Portland cement concrete (PCC) materials for paving mixes being used in New Mexico. Concrete mixes with 5 different coarse aggregates were tested for these pivotal concrete properties at the curing age of 7, 14, 28 and 90 days, and for CTE at 28 days. The laboratory test results represent level 1 PCC material inputs. The data collected offered an excellent opportunity to validate and refine the ME default level 2 models for estimating flexural strength and elastic modulus based on compressive strength data. The data demonstrated a slight deviation from the nationally calibrated models. CTE values of concrete based on aggregate type were established for these paving mixes. Further analysis verified the benefit of using the level 1 inputs over the default level 3 inputs for accurate pavement design and performance prediction. It was also highlighted that transverse cracking is the most significantly affected performance parameter between the pavement designed with level 1 and level 3 material inputs.Gauhar Sabih, Rafiqul A Tarefder
3/1/2018March 2018Chemical Deicers and Concrete Pavement: Impacts and Mitigationhttps://cptechcenter.org/ncc-projects/chemical-deicers-and-concrete-pavement:-impacts-and-mitigation/Anti-icing; Calcium chloride; Concrete pavements; Deicing chemicals; Deterioration; Freeze thaw durability; Magnesium chloride; Mitigation strategies; Highways; PavementsThis Tech Brief focuses on a recently recognized form of deterioration on concrete pavements referred to as chemical deicer distress. It is gaining attention due to the increased frequency and severity of its appearance, which is related to the increased use of aqueous solutions of calcium chloride (CaCl₂) and magnesium chloride (MgCl₂) for pavement deicing (Sutter et al. 2008; Weiss and Farnam 2015). The resulting pavement distress often first appears as a “shadowing” at the pavement joints, which progresses into disintegration of the concrete (Taylor, Sutter, and Weiss 2012). This Tech Brief summarizes the use of chemical anti-icers and deicers, reviews how hydraulic cement paste (HCP) is traditionally protected from freeze-thaw damage, describes physical and chemical distress mechanisms in the presence of aqueous CaCl₂ or MgCl₂ brine solutions, and discusses strategies that can be employed to mitigate this distress.Tom Van Dam
1/1/2012January 2012Class F Fly Ash Assessment for Use in Concrete Pavementhttps://cptechcenter.org/ncc-projects/class-f-fly-ash-assessment-for-use-in-concrete-pavement/Concrete pavements; Durability; Evaluation; Fly ash; Mix design; Pavement performance; Paving; Specifications; Strength of materials; SCMThe Wisconsin Department of Transportation (WisDOT) currently specifies Class C fly ash for use as a partial replacement for Portland cement in concrete pavements. Class F fly ash sources were eliminated from WisDOT specifications in the 1990s due to high values of loss on ignition (LOI) which led to difficulties in establishing and maintaining a proper entrained air void system in the concrete used in paving applications. A recent study that looked at the use of Class F fly ash demonstrated its potential usage in WisDOT specifications. However, research is needed to evaluate the feasibility of expanding current specifications to allow for use of Class F fly ash in concrete paving applications with southern Wisconsin aggregates. In order for Class F fly ash to be a viable alternative as a supplemental cementitious material, its use must produce mixes that meet current performance standards in respect to strength (including early strength) and durability, when compared with a commonly used Class C fly ash. The main objective of this study is to evaluate whether the locally available Class F fly ash from Elm Road Generating Station, operated by WE Energies and located in Oak Creek, Wisconsin, will provide satisfactory performance in concrete pavement, in comparison with a Class C fly ash from Columbia Energy Center currently in use. The study will also provide mix design guidance related to acceptable proportions of Class F fly ash that can be used in paving applications without negatively impacting performance.Konstantin Sobolev, Mohamadreza Moini, Rani Pradoto, Marina Kozhukhova, Ismael Flores-Vivian, Scott Muzenski, Habib Tabatabai, Hani H Titi
2/1/2019February 2019Closed-Form Solution for Curling Responses in Rigid Pavementshttps://cptechcenter.org/ncc-projects/closed-form-solution-for-curling-responses-in-rigid-pavements/Concrete pavements; Elastic analysis; Rigid pavements; Slabs; Structural analysisClosed-form expressions for calculating stresses and displacements of partially restrained concrete pavement caused by a linear temperature gradient are presented. Translational and rotational linear elastic springs along the slab edges defined the partial restraint. In addition to plate theory behavior, the model assumes linear elastic concrete and an infinitely long slab resting on a Winkler foundation. The solutions of curling stresses and displacements were validated using the finite-element (FE) method and quantified the effect of semirigid connections, slab and foundation material properties, and slab thickness and width on them. Rotational and translational restraints, which can be related to joint condition in concrete pavement, had significant influence on the magnitude and location of maximum curling stresses and deflections.Jamie Hernandez, Imad L Al-Qadi
06/30/14June 2014Colored PCC Deteriorationhttps://cptechcenter.org/ncc-projects/colored-pcc-deterioration/colored concrete, joint deterioration This objective of this study is to investigate the causes for early deterioration of colored concrete pavements in Minnesota. Dtermination will be made whether the distress is caused by construction practices or materials related issues.Tom Burnham, Ally Akkari, Gerard Moulzolf, Larry Sutter
10/17/2013October 2013Comparison of Fresh Concrete Air Content Test Methods & Analysis of Hardened Air Content in Wisconsin Pavementshttps://cptechcenter.org/ncc-projects/comparison-of-fresh-concrete-air-content-test-methods-&-analysis-of-hardened-air-content-in-wisconsin-pavements/Air content, Fresh concrete, Test procedures, Concrete pavements, Service life, Durability, Admixtures, Alternatives analysis, WisconsinA recent study sponsored by the Wisconsin Department of Transportation (WisDOT) has revealed that the air contents in fresh concrete measured by pressure meter method are lower than those in the hardened concrete of the same pavement concrete. In addition, observation of air entrainment in hardened concrete shows interconnected and irregular void patterns that could lead to a decrease in durability and pavement life. Determining accurate air contents on fresh concrete in the field will allow the WisDOT and paving industry to optimize properties of the concrete mix in regards to strength, durability, and economy. The objective of this research is to evaluate accuracy of test methods for measurement of air content in fresh concrete in comparison to air content in the hardened concrete of the same type, and to determine the hardened air content and air void dispersion in Wisconsin’s concrete pavement. The results will recommend proper method and procedure to determine air content in fresh concrete on WisDOT projects, recommend values for concrete properties to be used by WisDOT in the Standard Specifications for Highway and Structure Construction and the applicable Standard Special Provisions, and to report potential changes in practice and benefits in terms of performance and cost savings.Le Pham, Steven Cramer
9/8/2018September 2018Comparison of Response for Three Different Composite Pavement Sections to Environmental Loadshttps://cptechcenter.org/ncc-projects/comparison-of-response-for-three-different-composite-pavement-sections-to-environmental-loads/Overlay compositesComposite pavement structures are constructed mainly either as Portland cement concrete (PCC)-over-PCC or hot mix asphalt (HMA)-over-PCC. Several successful in-service projects have been reported in Europe. The design and construction of these sections in the United States, however, still require effort. The current study includes the analysis of the response of three different composite pavement sections to the environmental loads. These sections were constructed in May of 2010 at the Minnesota Road Research Facility. The sections are constructed in three individual cells, Cell 70, a HMA-over-PCC with recycled concrete aggregate (RCA), Cell 71, exposed aggregate concrete (EAC)-over-RCA and Cell 72, EAC-over-economical concrete. All cells were heavily instrumented with thermocouples, moisture sensors, and static and dynamic strain gauges. This study characterises the structural response of HMA-over-PCC pavements and also PCC-over-PCC to the environmental loads.Somayeh Nassiri, Feng Mu, Mathew Geary, Julie M Vandenbossche
2/1/2019February 2019Comparison of Spacing Factors as Measured by the Air-Void Analyzer and ASTM C457https://cptechcenter.org/ncc-projects/comparison-of-spacing-factors-as-measured-by-the-air-void-analyzer-and-astm-c457/Air voids; Concrete pavements; Freeze thaw durability; Spacing; Specifications; Test proceduresThe Kansas Department of Transportation (KDOT) began using the Air-Void Analyzer (AVA) in 2001 and first incorporated an AVA spacing factor requirement into paving specifications beginning in late 2002. In 2005, a statewide investigation to evaluate the AVA and specifications began with the collection of 100-mm diameter hardened concrete samples taken at or near locations where the spacing factor was determined with the AVA. The hardened concrete samples were tested to determine the spacing factor in accordance with ASTM C457, a well-established test method used to determine spacing factors in hardened concrete. A total of 270 data pairs were collected to evaluate KDOT’s current use of the AVA and ASTM C457 tests and to determine if a correlation (either direct or pass-fail criteria) exists between spacing factors obtained with the two methods. Results of the study indicate that average spacing factors obtained with the AVA were 1.67 times higher than average spacing factors determined using ASTM C457. A strong direct correlation was not identified between the two test methods although pass-fail criterion that limits agency risk of accepting concrete with an inadequate air-void system was identified.Will Lindquist, Rodney Montney
9/1/2009September 2009Concrete Bridge Deck Crack Sealant Evaluation and Implementationhttps://cptechcenter.org/ncc-projects/concrete-bridge-deck-crack-sealant-evaluation-and-implementation/bridge deck cracking, sealants, crack sealers, maintenancePerform field testing and evaluation of 12 crack repair products over a 3 year period that came from recommendations found in a previous MnDOT project titled "Crack and Concrete Deck Sealant Performance."Matthew S Oman
6/14/2016June 2016Concrete Grinding Residue: Its Effect on Roadside Vegetation and Soil Propertieshttps://cptechcenter.org/ncc-projects/concrete-grinding-residue:-its-effect-on-roadside-vegetation-and-soil-properties/Backslopes; Diamond grinding; Environmental impacts; Foreslopes; Roadside flora; Vegetation controlDiamond grinding of Portland Cement Concrete (PCC) highway surfaces, a maintenance operation carried out to extend the pavement service life, generates a high-pH and high alkalinity slurry (water, concrete and aggregate residue), referred to as Concrete Grinding Residue (CGR). The objective of the proposed research is to gain a stronger understanding of the CGR effects on soil, water infiltration, and vegetation through an in-situ, statistically rigorous study that will analyze inslope and/or backslope soil samples and assess soil and vegetation properties before and after placement of the CGR. Based on the study findings, Minnesota Department of Transportation's (MnDOT's) Office of Environmental Stewardship will: l) be able to better assess the need for soil amendments, either prior to or after CGR placement; 2) be in a better position to recommend possible changes to CGR slurry offloading or placement practices; and 3) be able to better assess the need for possible changes to inslope/backslope seed mixes.Halil Ceylan, Yang Zhang, Bora Cetin, Sunghwan Kim, Bo Yang, Chenyi Luo, Robert Horton, Kasthurirangan Gopalakrishnan
12/1/2016December 2016Concrete Pavement Blowup Considering Generalized Boundary Conditionshttps://cptechcenter.org/ncc-projects/concrete-pavement-blowup-considering-generalized-boundary-conditions/Blowups; Elastic foundationsAn analytical expression for static stability of a rectangular slab with two simply supported and two elastically restrained edges is presented. The linear elastic isotropic slab can represent a rigid pavement resting on an elastic foundation and loaded by a uniform in-plane axial load per unit length along the edges. The partially restrained edges are connected to the ground by translational and rotational elastic springs; an appropriate magnitude of the springs can capture classical boundary conditions such as free, simply supported, and clamped edges. Results from classical boundary conditions and a finite-element model were used to validate the proposed stability equation. The generalized boundary conditions were found to change the critical load by a factor of two and greatly affected the first buckling mode shape of a typical concrete pavement. The critical load was not sensitive to the slab’s geometry if the length was four times longer than the width, but this was not the case for small aspect ratios. Finally, the translational spring was found to be a defining factor in determining the influence of the other variables on the critical load.Jaime A Hernandez, Imad Al-Qadi
10/1/2014October 2014Concrete Pavement Mixture Design and Analysis (MDA): Factors Influencing Drying Shrinkagehttps://cptechcenter.org/ncc-projects/concrete-pavement-mixture-design-and-analysis-(mda):-factors-influencing-drying-shrinkage./Cement paste; Concrete pavements; Drying; Literature reviews; Mix design; ShrinkageThis literature review focuses on factors influencing drying shrinkage of concrete. Although the factors are normally interrelated, they can be categorized into three groups: paste quantity, paste quality, and other factors.Peter Taylor, Xuhao Wang
5/1/2016May 2016Concrete Pavement Quality Control Testing Requirements Needed for the Super Air Meterhttps://cptechcenter.org/ncc-projects/concrete-pavement-quality-control-testing-requirements-needed-for-the-super-air-meter/Air content; Air voids; Concrete pavements; Freeze thaw durability; Measuring instruments; Paving; Quality controlConcrete freeze-thaw durability is prominently linked to the air void system within the concrete. Concrete pavements in Kansas undergo repetitive freeze-thaw cycles. Total air content measurements currently used on fresh concrete do not provide any indication of the air void size distribution. The Super Air Meter (SAM) addresses this issue by providing the air content and an additional number, the SAM number, which is claimed by the manufacturer to correlate to the concrete hardened air void spacing factor.Kyle A Riding, Mohammed T Albahttiti
1/1/2018January 2018Construction and Rehabilitation of Concrete Pavements under Traffichttps://cptechcenter.org/ncc-projects/construction-and-rehabilitation-of-concrete-pavements-under-traffic/National advancements in concrete pavement construction, rehabilitation With advancements in materials, equipment, placement procedures, and project management techniques, the construction and rehabilitation of concrete pavements can be effectively accomplished under traffic. Many projects have been constructed under varying levels of traffic, ranging from temporary closures to the maintenance of high traffic volumes adjacent to or through the projects. However, the current state of the practice in constructing or rehabilitating concrete pavements under traffic relies primarily on a few high-profile and well-documented projects. This study identified practices from projects representing a wider range of conditions and techniques. Information on existing practices and advancements in concrete pavement construction and rehabilitation was gathered through literature reviews and a survey of state transportation agencies, including that of the District of Columbia and the Illinois Tollway. Furthermore, sixteen case examples were reported to illustrate successful projects conducted under a variety of scenarios.Shreenath Rao, Deepak Raghunathan
7/1/2019July 2019Construction Incentives - Are They Working?https://cptechcenter.org/ncc-projects/construction-incentives---are-they-working?/Construction management; Disincentives; Incentives; Local government agenciesThis research project is targeted toward local road agencies rather than MnDOT. MnDOT currently uses incentive/disincentive (I/D) contracting based on construction completion dates; whereas, the local agencies are interested in exploring I/D contracting for higher initial pavement quality such as higher density or better ride quality. The local agencies are also interested in knowing if the I/D method results in the better contractors being selected for the job.Mohamed Diab
3/29/2018March 2018Construction Techniques for Electrically Conductive Heated Pavement Systemshttps://cptechcenter.org/ncc-projects/construction-techniques-for-electrically-conductive-heated-pavement-systems/Airport runways; Aprons (Airports); Concrete pavements; Deicing; Heat radiation; Heating systems; Paving; Technological innovations; Des Moines International AirportIce and snow accumulation on airport paved surfaces has the potential to cause fatal accidents and monetary loss due to flight delays and cancellations. Traditional de-icing methods involving the application of chemicals or salt and employing large machines can create negative environmental and structural impact on airport infrastructure systems. These methods are also considered to be labor intensive and a safety hazard, especially in congested areas such as aprons. Heated pavement systems using electrically conductive concrete (ECON) have been proposed as a promising alternative technology for preventing ice accumulation and mitigating the adverse effects of using traditional snow removal methods. The objective of this study is to present information and experience about the design, construction procedures, and performance of heated pavement systems using jointed plain concrete pavements for the construction of large-scale heated airport pavements. It is based on detailed field demonstration of the electrically conductive concrete (ECON) heated pavement system (HPS) at the north general aviation (GA) apron of the Des Moines International Airport (DSM) in Iowa, in collaboration with contractors, and airport staff representatives. The expected outcome of this study will help the construction industry to better understand optimal ECON construction methods.Hesham Abdualla, Halil Ceylan, Kristen S Cetin, Sunghwan Kim, Peter C Taylor, Mani Mina, Bora Cetin, Kasthurirangan Gopalakrishnan, Sajed Sadati
8/14/2018August 2018Contextual Heat Island Assessment for Pavement Preservationhttps://cptechcenter.org/ncc-projects/contextual-heat-island-assessment-for-pavement-preservation/Global Warming Potential (GWP); Pavement preservationPavement preservation (PP) is a planned set of construction and material interventions that can extend the pavement’s service life and may also impact sustainability through Heat Island (HI) mitigation. The HI mitigation potential can vary from location-to-location and with time. For agencies to widely adopt the PP, it is necessary to quantify the benefits based on the context of the project. A method to calculate the Global Warming Potential (GWP) for the HI effect was developed and illustrated for four cities in the US: Chicago, Austin, San Diego and Philadelphia, for hypothetical pavements with three preservation options: chip seals, a concrete inlay, and an asphalt concrete inlay. The use phase GWP with respect to HI was estimated for all cases given a 2-, 5-, 7- or 10-year service life. Overall, the HI in the use phase was found to dominate the total GWP relative to the materials and construction phases. The HI GWP savings increase over time, with the 10-year savings being greatest for San Diego using the concrete inlay (22.5 kg CO₂-eq/m²) and smallest for Chicago with a chip seal (8.0 kg CO₂-eq/m²). The savings were found to increase in areas that have a more pronounced HI and could offset GWP in the other phases. The proposed method allows agencies to estimate HI GWP for a specific preservation strategy, location and service life.Sushobhan Sen, Jeffery Roesler
7/1/2014July 2014Continuous Long-Term Health Monitoring Using Ultrasonic Wave Propagationhttps://cptechcenter.org/ncc-projects/continuous-long-term-health-monitoring-using-ultrasonic-wave-propagation/Reinforced concrete, Bridge decks, Nondestructive tests, Structural health monitoring, Delamination, Ground penetrating radar, Acoustic emission, Reinforcing barsMany different techniques of health monitoring and nondestructive testing (NDT) methodologies have been employed to detect rebar and overlay delamination in reinforced concrete bridge decks. NDT to monitor delamination in concrete bridge decks was initially done by acoustic sounding techniques such as chain dragging and hammer sounding. These relatively simple methods can only be employed by trained and experienced inspectors, require a lot of time, and yet provide only a qualitative assessment of the condition of the specimen. Recently, due to advancements in imaging technologies, acoustics, seismic measurements, and electromagnetics; NDT methods such as Ground Penetration Radar (GPR), Ultrasonic testing, and Impact Echo have gained popularity. Other NDT techniques also utilized to monitor concrete bridge deck delaminations include: radiography, infrared thermography, and acoustic emission, each with its own benefits and drawbacks. Radiography is expensive and requires radioactive protection, thus only highly trained and licensed personnel can carry out these methods, and it still poses potential safety hazards. Applications of infrared thermography are limited due to their heat differential requirements, which also creates application time constraints. Acoustic emission method requires load control, which limits it to be used primarily in lab research (Ghorbanpoor et.al. 2003). The proposed methodology is intended to provide a continuous health monitoring method for reinforced concrete bridge decks. The ultimate goal of the project is to develop a novel method using ultrasonic wave propagation (UWP) to identify the onset of rebar delaminations and to provide continuous health monitoring for the structure.Ece Erdogmus
5/1/2014May 2014Corrosion Sensitivity of Concrete Mix Designshttps://cptechcenter.org/ncc-projects/corrosion-sensitivity-of-concrete-mix-designs.--/Absorption; Admixtures; Corrosion resistance; Durability; Fly ash; Mix design; Permeability; Reinforced concrete; Silica fume; Slag cementThis study compared the durability of concrete mixtures containing supplementary cementitious materials (SCMs) by evaluating the permeability, absorption, and corrosion resistance of seven mix designs and two types of reinforcement. Permeability and alkalinity are contributing factors to the durability of portland cement concrete and can strongly influence the service life and corrosion resistance of the embedded steel. In reinforced concrete systems, the ingress of chloride ions increases the probability of corrosion of the reinforcing steel. Reducing the permeability of concrete enhances its durability by hindering the ingress of chloride ions from reaching the embedded steel surface and initiating corrosion. SCMs such as Class F fly ash, silica fume, and slag cement are widely used in concrete in an effort to reduce permeability. In addition, the alkaline environment of concrete enables the formation of a passive film on the surface of the steel. As long as this protective environment is maintained, the corrosion rate of the reinforcing bar will be insignificant for the majority of applications. The results of this study indicated that the use of SCMs can reduce the permeability and absorption of the concrete, leading to more durable structures than those with plain concretes; therefore, their continued use in structures by the Virginia Department of Transportation is recommended. However, different SCMs have varying levels of durability, and the agency should consider this information when selecting SCMs for specific applications. The absorption test results in this study provided a reasonable correlation with the corrosion test results. Therefore, the absorption test should be more closely investigated as a means of evaluating the corrosion protection provided by SCMs. This study also demonstrated that the corrosion-resistant reinforcement plays the most vital role in minimizing corrosion. SCMs provide durable concretes and in combination with the corrosion-resistant reinforcement ensure reinforced concrete structures with longer service lives.Stephen R Sharp, Celik Ozyildirim, David W Mokarem
8/16/2014August 2014Cost Analysis on the Reuse of Concrete Residualshttps://cptechcenter.org/ncc-projects/cost-analysis-on-the-reuse-of-concrete-residuals/Demolition, Wastes, Benefit cost analysis, Diamond grinding, Best practices, Sustainable development, Concrete,Concrete hydrodemolition and diamond grinding/grooving operations performed for the North Carolina Department of Transportation (NCDOT) generate large amounts of concrete residuals. Currently these residuals can be classified by the North Carolina Department of Water Resources (NCDWR) as Class A Residuals and are treated as ‰ÛÏinert debris‰Û thus allowing them to be reused instead of being disposed at Publicly Owned Treatment Works (POTW) and Municipal Solid Waste (MSW) sites. A benefit-cost analysis is needed in order to investigate potential savings from other alternative options to disposal such as the use of the material as liming amendments on NCDOT right of way highways, Class B residual sites and agricultural applications. These alternative methods of disposal need to satisfy current federal guidelines and state regulations and contractors disposing of the concrete residual materials need to be aware of these regulations as well. The objectives of this project will be to provide NCDOT with a Benefit-Cost Model (BCM) using Multi-Criteria Analysis that would enable the estimation of the costs of disposing and/or reusing concrete residual material that is produced by the hydrodemolition and diamond grinding/grooving processes. In addition to the BCM, a tool will be developed that can be used by contractors undertaking such projects to better estimate their costs and to allow them to compare alternatives for the disposal/reuse of the concrete residual material. The researchers will also develop a risk analysis for the comparison of several feasible alternatives to disposal of concrete residuals, a tool for contractors to use to estimate their anticipated costs for disposal or reuse of concrete particulars, and recommendations on acceptable methods for handling concrete residuals after monetary, environmental factors and risk have been considered. Recommendations for guidelines and/or specifications that could be provided to contractors for use on future NCDOT projects will be provided. As part of this work the researchers will use literature and case studies to identify the best practices for the disposal/reuse of the concrete residual material both from North Carolina and other states. By surveying Department of Transportation (DOT) personnel and contractors identify the attributes that contribute to the costs of the various alternatives. Using these attributes the BCM will be developed and eventually tested on NCDOT projects selected to serve as case studies. These case studies will allow the model to be refined to be accurately implemented on future NCDOT projects. This project will directly support the sustainability and safety initiatives mandated by the MAP-21 legislation.Nicholas Tymvios, Tara L Cavalline, Christopher Albergo
6/20/2011June 2011Cost-Effective Base Type and Thickness for Long-Life Concrete Pavementshttps://cptechcenter.org/ncc-projects/cost-effective-base-type-and-thickness-for-long-life-concrete-pavements/base, drainable base, concrete pavement, drainageIdentify ways of optimizing the use of base layer materials and the design of base layer thicknesses for Portland cement concrete pavements.Erol Tutumluer, Yuanjie Xiao, W. James Wilde
8/6/2018August 2018Cotton-Derived Composite Materials for Climate Resilient Transportation Infrastructurehttps://cptechcenter.org/ncc-projects/cotton-derived-composite-materials-for-climate-resilient-transportation-infrastructure/Cotton cellulose-based concrete; strength and durability; use of cotton fiber and its derivatives.The authors aimed to develop high performance and economically facile natural fiber-reinforced transportation infrastructure. The main three tasks of this project include: (1) preparation of cotton cellulose-based concrete; (2) characterization of cotton cellulose-based concrete for strength and durability; and (3) investigation of possible enhancement of other pavement materials through the use of cotton fiber and its derivatives. The results showed that the tensile strength and modulus values of cotton-derived concrete composites after 28 days are comparable with the control specimens without added cotton. The composite materials prepared from cotton and its derivatives also showed high load endurance properties with high ductility values as compared to control samples, which are extremely crucial in climate resiliency. The data collected in this research also demonstrated the high load resistance and elastic deformation properties of other cotton cellulose-derived particulate composites such as flowable fluids, and geopolymers. Moreover, the addition of raw cotton to highly plastic swelling clay significantly reduced the swell potential. Overall, using renewable natural fibers, mainly cotton and its derivatives, the authors demonstrated that the properties of conventional construction infrastructure can be adapted to climate change. Therefore, the results of this project are extremely promising. Importantly, the simplicity of the preparation method and the relative abundance and low cost of cotton fibers make this technology an attractive approach worthy of being further investigated.Noureddine Abidi, Priyantha W Jayawickrama, Rohan S Dassanayake, Manil Hettiwatte
6/1/2018June 2018Crushed Hydraulic Cement Concrete Adjacent to Underdrainshttps://cptechcenter.org/ncc-projects/crushed-hydraulic-cement-concrete-adjacent-to-underdrains/Blending; Cement content; Crushed aggregates; Drainage structures; Field studies; Geotextiles; Hydraulic cement; Subdrains; ValidationThe objectives of this field study are as follows: (1) to confirm the validity under field conditions of Crushed Hydraulic Cement Concrete (CHCC) behavior (fines migrate and tufa precipitates but geotextile continues to function as a filter and does not prevent water from flowing through) observed in the laboratory in a prior study; (2) to develop a threshold percentage for the blending of CHCC with virgin aggregate, and (3) to provide recommendations to Virginia Department of Transportation (VDOT) to generate specifications to allow the use of CHCC/virgin aggregate blends as unbound aggregate when geotextile is present in the drainage system.Burak Tanyu
11/1/2018November 2018Curing Concrete Paving Mixtureshttps://cptechcenter.org/ncc-projects/curing-concrete-paving-mixtures/Binders; Concrete curing; Concrete pavements; Curing agents; Curing and setting agents; Hydration; Mixtures; PavementsProper curing of a newly placed concrete pavement is an essential step to ensure that the concrete as designed, batched, and placed reaches its full potential. Improper curing can result in inadequate hydration and reduced concrete strength and can negatively affect the near surface concrete properties including increased permeability, decreased wear resistance, and increased risk of plastic shrinkage cracking.This Tech Brief focuses specifically on approaches commonly used for curing cast-in-place concrete pavements. The most common method is the application of membrane-forming curing compounds, although fogging, plastic sheets, wetted materials, and insulated blankets may also be used depending on the type of project and the ambient conditions during and after placement. Also discussed briefly is internal curing using prewetted lightweight aggregate. In the context of this Tech Brief, two curing steps are considered: 1) initial curing applied during or immediately after the concrete is placed under less-than-favorable conditions, and 2) conventional curing applied once the concrete has undergone initial set.Tom Van Dam
5/23/2017May 2017Data Collection for Local Calibration of the AASHTOWare Pavement ME Design Performance Models for Mississippihttps://cptechcenter.org/ncc-projects/data-collection-for-local-calibration-of-the-aashtoware-pavement-me-design-performance-models-for-mississippi/Calibration; Data collection; Mechanistic design; Pavement performance; Test sections; AASHTOWare (Software)The Mechanistic-Empirical Pavement Design Guide (MEPDG) method for designing pavement structures utilizes mechanistic materials properties combined with other inputs to predict pavement performance using user inputs. Pavement performance models are used for this prediction of pavement performance. The pavement performance models are based upon national predictive models that are likely not applicable to Mississippi. This research project is designed to provide the required information for the calibration of these performance models for Mississippi materials and conditions. A number of test pavement sections will be visited, evaluated, sampled, and tested. Following these activities site reports will be prepared for each individual site that provides the information required for this calibration of the pavement performance models to local conditions.Allen Cooley
7/1/2015July 2015Design and Evaluation of Modified Centerline Rumble Stripshttps://cptechcenter.org/ncc-projects/design-and-evaluation-of-modified-centerline-rumble-strips/Rumble strips, Center lines, Head on collisions, Fatigue (Physiological condition), Pavement performance, Deterioration, Field testsCenterline rumble strips are primarily installed on the centerline of undivided two-lane and two-way roadways to alert drivers who are moving out of their intended travel lane. The main purpose of the centerline rumble strips is to reduce cross-over crashes such as head-on crashes, opposite-direction sideswipe crashes, and front-to-side crashes, which are usually caused by inattentive, distracted, drowsy, or fatigued drivers. Despite the safety benefit, several pavement performance concerns associated with the centerline rumble strips have been reported (Torbic 2009). In particular, the centerline rumble strips milled over or adjacent to the centerline joint (even if it is hardly distinguishable), which is a damage-sensitive region of pavement, can increase or accelerate deterioration and degradation of the pavement structure. It also requires more maintenance and attention due to potential safety concerns. To reduce pavement damage, the centerline rumble strips design has been modified from a single strip over the centerline joint to dual strips straddling the joint in our state. The modified design could decrease pavement damage; however, there is still a pressing need to improve the centerline rumble strips design. To maximize the safety benefits of the centerline rumble strips and minimize pavement damage, a series of research activities needs to be performed. Firstly, configurations and dimensions of the centerline rumble strips built or tested by other states need to be collected. Surveying the corresponding lane widths required or suggested by other Departments of Transportation (DOTs) is also necessary. This will result in findings that can be used to improve the current dual rumble strips so as to satisfy expected structural performance as well as roadway safety requirements. Then, the proposed centerline rumble strips design will be evaluated and compared with the current design through structural model simulations and actual field tests. With the limited time and scope of this stage, this proposal primarily intends to first, collect data and practices from other states in order to recommend modifications to our current rumble strip design, and second, evaluate the recommended design through model simulations that compare the newly proposed design with current rumble strip design practices. Field test evaluation of the modified design can then be planned in a follow-up research effort.Yong-Rak Kim, Taesun You, Laurence R Rilett
7/1/2016July 2016Design and Performance of Cost-Effective Ultra High Performance Concrete for Bridge Deck Overlayshttps://cptechcenter.org/ncc-projects/design-and-performance-of-cost-effective-ultra-high-performance-concrete-for-bridge-deck-overlays/Bridge decks; Concrete overlays; Overlays (Pavements); Pavement design; Pavement performance; Service life; Ultra high performance concrete; Bridges and other structures; Design; Highways; MaterialsThe main objective of this research was to develop a cost-effective ultra-high performance concrete (UHPC) for bonded bridge deck overlays. The high durability and mechanical properties of such repair material can offer shorter traffic closures and prolong the service life of the bridge deck. The UHPC was optimized using supplementary cementitious materials (SCMs), proper combinations of sands, and adequate selection of fiber types and contents. . Early-age and long-term deformation caused by concrete, humidity and temperature gradients, as well as cracking and delamination were monitored over time. Test results indicate that there was no surface cracking or delamination in UHPC overlays after more than 200 d of casting. After laboratory investigations, a life cycle cost analysis (LCCA) was determined for the selected concrete mixtures with different mixture compositions and performance characteristics. Results indicate that, based on both deterministic and probabilistic results, UHPC overlay with minimum 25 mm (1 in.) thickness is a more cost-effective option compared with other commonly used materials, such as latex-modified concrete and conventional bonded concrete overlays.Kamal H Khayat, Mahdi Valipour
2/26/2010February 2010Design Guides/Sustainability (SI-09-41)https://cptechcenter.org/ncc-projects/design-guides-sustainability-si-09-41/Sustainable development, Handbooks, Highways, Decision making, Transportation professionals, Education and training methodsThis project will develop a sustainable highway framework that will culminate and be packaged into a Sustainable Highways Sourcebook. The Sustainable Highways Sourcebook will contain the sustainable highways framework as the decision analysis tool and will contain a series of educational and resource materials that will allow for an understanding of what a sustainable highway can be an how to implement a sustainable highway or street through planning development design materials choice and implementation. These products will be aimed at transportation professionals decision makers various stakeholders and the public.CH2M Hill
12/1/2017December 2017Design of a 3-D Magnetic Mapping System to Locate Reinforcing Steel in Concrete Pavementshttps://cptechcenter.org/ncc-projects/design-of-a-3-d-magnetic-mapping-system-to-locate-reinforcing-steel-in-concrete-pavements/Concrete pavements; Field tests; Mapping; Mathematical models; Reinforcing steel; Sensors; Spatial analysis; System design; TomographyThis report outlines the design, fabrication, and testing of a 3-D magnetic mapping system used to locate reinforcing steel in concrete pavements developed at Kansas State University (KSU) in 2006. The magnetic sensing functionality is based on the principles of magnetic tomography which use time-varying magnetic fields to induce magnetic returns from nearby ferrous objects. The purpose of this device is to provide a process for inspecting the depth and orientation of embedded steel bars.Nathanael W Holle
7/1/2016July 2016Design of Ultra High Performance Concrete for Thin Overlayshttps://cptechcenter.org/ncc-projects/design-of-ultra-high-performance-concrete-for-thin-overlays/Fibers; Greenhouse gases; Overlays (Pavements); Pavement performance; Service life; Ultra high performance concreteThe main objective of this research is to develop a ultra high performance concrete (UHPC) as a reliable, economic, low carbon foot print and durable concrete overlay material that can offer shorter traffic closures due to faster construction and long-term service life. This project aims at maximizing the performance of a thin layer of pavement material by reaching to an optimized composition of SCMs and proper types and amounts of fibers. Quarterly Progress (Apr-Jun 2016): The Task Order was executed by Missouri Department of Transportation (MoDOT) on July 8, 2016. Federal Regulations changed on June 30, 2016, which has caused a change in the F&A rate to go from 52.5% to 55%. This change will be documented via a letter that includes a new budget document. There will not be a formal supplemental agreement executed.Kamal H Khayat, Mahdi Valipour
9/1/2013September 2013Designing Quieter Pavement Surfaceshttps://cptechcenter.org/ncc-projects/designing-quieter-pavement-surfaces/Pavement design, Quiet pavements, Asphalt concrete pavements, Tire/pavement noise, Pavement maintenance, Overlays (Pavements), Laboratory tests, TextureThis project outlines a work plan for the design and maintenance of quieter asphalt and concrete pavements. A literature review will determine the state of the art in designing quieter pavements and contributing factors. An extensive pavement-noise database will be compiled, comprising a variety of asphalt and concrete surfaces with corresponding noise measurements over time. The effect of different overlay asphalt mixtures will be evaluated for flexible pavements (both open and dense mixtures will be considered) and the effect of different surface treatments (such as diamond grinding) for rigid pavements. This database will be analyzed using statistical techniques and will focus on identifying all relevant design parameters influencing noise. Laboratory design procedures to evaluate noise will be developed and correlated against mixture design parameters for a range of different asphalt mixtures. Close proximity and far-field noise tests in the field on both asphalt and concrete pavements will be correlated against laboratory measures towards establishing laboratory test procedures. Following these tasks, a set of preliminary guidelines will be developed to provide the districts with recommendations on and assistance in selecting appropriate candidate projects for low-noise surfaces and for designing surfaces to provide long-term noise reductions. A case study will be completed to recommend strategies for addressing noise complaints in an urban setting. In addition, a number of new and existing pavements across Texas will be monitored. Results from the case study and field tests will be used to validate and refine the District guidelines.Jorge A Prozzi
6/3/2016June 2016Determining Optimum Air-Void Spacing Requirement for a Given Concrete Mixture Design Using Poromechanicshttps://cptechcenter.org/ncc-projects/determining-optimum-air-void-spacing-requirement-for-a-given-concrete-mixture-design-using-poromechanics/Air voids; Concrete; Freeze thaw durability; Mix design; Spacing; Frost resistance; Poroelasticity; Poromechanical behaviorThe frost resistance of concrete is a function of the concrete constituent properties, entrained air-void system parameters and environmental exposure history. However, only a single maximum value for the void spacing factor is specified for all types of concrete by code writing bodies for successful protection against freezing damage. The advent and utilisation of new materials over the recent years warrant reevaluation of the validity of this single pass/fail criterion established more than 50 years ago. Here, a poromechanical model, capable of incorporating concrete constituent properties, environmental exposure and air-void spacing factor, has been used to determine the role of various concrete constituents and air-void system on the damage propensity of concrete exposed to freezing temperatures. It is found that a maximum threshold of acceptance, for instance a 0.2 mm spacing factor, may not be adequate for all concrete mixture designs subject to various cooling conditions. The model also suggests that concrete with low-porosity, low-permeability mortar matrix, a characteristic property of mortar containing supplementary cementitious materials and/or low water to cement ratio, can perform satisfactorily under freezing temperatures even with a spacing factor greater than the recommended value. If utilised for design, this model will give more freedom to practitioners in ensuring concrete durability by controlling multiple factors including the concrete mixture components and proportions rather than just satisfying a single pass/fail criterion for void spacing factor for all concrete mixtures.Syeda Rahman, Zachary Grasley
8/15/2015August 2015Determining Optimum Thickness for Long-Life Concrete Pavement in Ohiohttps://cptechcenter.org/ncc-projects/determining-optimum-thickness-for-long-life-concrete-pavement-in-ohio/Concrete pavements, Service life, Thickness, Pavement performance, Bridge decks, FailureThe main objective of this study is to provide guidance on the selection of concrete slab thickness required to achieve long term performance considering the effect of slab dimensions, concrete slab support, and climatic conditions on critical stresses. The study will include proposed changes to the design, construction, and material procedures/specifications that, if adopted and implemented, will significantly increase portland cement concrete (PCC) pavement lifetimes and reduce maintenance costs. Although concrete pavement has shown its evidence for a long last time in service, sometimes it still experiences functional failure and premature failure. The Ohio Department of Transportation (ODOT) has conducted extensive research focused on improving concrete pavement performance. The rigid pavement design procedure in the 1993 American Association of State Highway and Transportation Officials (AASHTO) Guide for the Design of Pavement Structures, in which a slab thickness can be selected and will result a great improvement in concrete terminal serviceability, is a good example of improving concrete pavement performance. However, other factors also play a major role in concrete pavement performance.Shad Sargand, Anwer Al-Jhayyish, Issam Khoury, Roger Green
6/1/2015June 2015Developing a Comprehensive Pavement Condition Evaluation System for Rigid Pavements in Georgiahttps://cptechcenter.org/ncc-projects/developing-a-comprehensive-pavement-condition-evaluation-system-for-rigid-pavements-in-georgia/Jointed plain concrete pavement; JPCP; Continuously reinforced concrete pavement; CRCP; Faultmeter; Faulting measurement The objective of this project is to develop standardized pavement condition evaluation systems for Georgia’s rigid pavements, including continuously reinforced concrete pavement (CRCP) and jointed plain concrete pavement (JPCP).Yichang Tsai, Yi-Ching Wu
8/1/2014August 2014Developing a Low Shrinkage, High Creep Concrete for Infrastructure Repairhttps://cptechcenter.org/ncc-projects/developing-a-low-shrinkage,-high-creep-concrete-for-infrastructure-repair.--/Adhesion; Admixtures; Compressive strength; Creep; Durability; Repairing; Shrinkage; Tensile strengthThis project will focus on optimizing time dependent strains for concrete repair. Initial focus will be on developing laboratory concrete mixtures for repairs using pre-saturated lightweight aggregate to take advantage of internal curing because of its documented reduced shrinkage. Furthermore, mineral and chemical admixtures will be investigated to enhance concrete properties such as: high early strength, creep, shrinkage, tensile strength and adhesion. Testing will include compressive and tensile creep, shrinkage, and strength and durability testing, all following the available ASTM standard. Additionally, small scale mock repairs will be produced with similar geometry to those in the field and monitored at the Utah State University Materials Lab, and finite element models will be developed to investigate additional simulated repair performance based on the materials testing. Finally, upon selecting candidate field mixtures and candidate field repairs, in-service monitoring will be performed on Utah Department of Transportation (UDOT) projects with control and developed admixtures.Ivan Quezada, Marc Maguire, Robert J Thomas
10/8/2013October 2013Developing Improved Opportunities for the Recycle and Reuse of Materials in Road Bridge and Construction Projectshttps://cptechcenter.org/ncc-projects/developing-improved-opportunities-for-the-recycle-and-reuse-of-materials-in-road-bridge-and-construction-projects/Wastes, Recycled materials, Road construction, Bridge construction, Opportunities, ImprovementsThe objective of this project is to develop opportunities to improve the recycling and reuse of waste materials for road and bridge construction projects. This study is not about conducting laboratory materials testing. This study focuses on learning what factors influence the participation of recyclers and materials producers in increasing the use of recycled materials for road and bridge construction.Ralph Ellis, Duzgun Agdas, Kevin Frost
04/30/24April 2024Developing Performance Specification for High Performance Concretehttps://cptechcenter.org/ncc-projects/developing-performance-specification-for-high-performance-concrete/Field studies, High performance concrete (HPC), Laboratory studies, Mechanical properties, Multiple criteria decision making, Performance based specifications, Physical propertiesIn the past, achieving high strength was considered by TxDOT as the main design criteria to formulate high performance concrete. TxDOT considers mix design options 1-4 in item 421 as high performance concrete (HPC) and these options were developed for ASR mitigation and not for other durability aspects. Very little work has been done to determine if these options are adequate to provide long-term durability often needed when HPC is specified. The main objective of this study is to develop performance specification for high performance concrete in order to ensure high performance in terms of durability. The researcher team will conduct a combination of both field investigation and laboratory study in order to achieve this objective. The researcher team will use both conventional and innovative new lab testing methods to determine the key performance characteristics (i.e., prescribing acceptable limits of permeability, shrinkage, surface resistivity, and chloride ingress - basis for developing performance specification) followed by developing specific prescriptive requirements in order to formulate wide varieties of prescriptive mixes that can meet the durability requirements matching with different exposure conditions.Anol Mukhopadhyay, Andy Naranjo, Jason Tucker, Rachel Cano, Christopher Miller, Lianxiang Du, Kevin Moyer
4/8/2016April 2016Developing Ultra-High-Performance Concrete Mix Designs for Arizona Bridge Element Connectionshttps://cptechcenter.org/ncc-projects/developing-ultra-high-performance-concrete-mix-designs-for-arizona-bridge-element-connections/Admixtures; Bridge construction; Curing and setting agents; Ductility; Durability; Mix design; Strength of materials; Ultra high performance concreteThe Arizona Department of Transportation (ADOT) is looking to develop a successful, non-proprietary formula for mixing ultra-high-performance concrete (UHPC). It wishes to have such material available for Accelerated Bridge Construction (ABC) bridge closure pours due to its durability, ductility, strength, and fast set-up, curing, and strength gain. ADOT wishes to join Federal Highway Administration (FHWA) and other organizations to develop non-proprietary, and therefore more economical, UHPC mixtures that stand to accelerate its bridge projects.Barzin Mobasher
7/1/2014July 2014Development and Evaluation of Portable Device for Measuring Curling and Warping in Concrete Pavementshttps://cptechcenter.org/ncc-projects/development-and-evaluation-of-portable-device-for-measuring-curling-and-warping-in-concrete-pavements/Concrete pavements, Curling, Traffic loads, Fatigue (Mechanics), Performance measurement, Pavement performance, Measurement, Quality assurance, Quality controlThe temperature and moisture variations across the depth of the Portland cement concrete (PCC) pavements result in a unique deflection behavior that has been recognized as curling and warping of the pavements since mid-1920. The repeated slab curvature changes due to curling and warping, when combined with traffic loading, can accelerate fatigue failures including top-down and bottom-up transverse, longitudinal, and corner cracking. It is of paramount importance to measure the actual magnitude of curling and warping taking place in concrete pavements in order to develop performance measures and critical threshold magnitudes as well as gain a better understanding of their relationship to diurnal and seasonal temperature/moisture changes and long-term pavement performance. Although several approaches and devices have been proposed for measuring curling and warping for in-service concrete pavements, they have certain limitations that inhibit their use for routine inspection for quality control (QC) and quality assurance (QA) of concrete pavements. The primary objective of the proposed research is to develop an economical and simple device for measuring curling and warping in concrete pavements with accuracy comparable to or better than the existing methodologies. To meet this objective, the proposed curling measurement device will be portable and easy to operate with just one person, and will provide reliable measurements. The first-generation crude prototype of the proposed device has already been developed to support our ongoing research efforts at Iowa State University (ISU), focusing on investigating the impact of curling and warping on concrete pavements. This Midwest Transportation Center (MTC) proposal focuses on development of a standardized curling and warping measurement device and test procedure for routine use by improving the first generation crude prototype through technical requirements identified from both the literature and field evaluations.Halil Ceylan, Robert F Steffes, Kasthurirangan Gopalakrishnan, Sunghwan Kim, Shuo Yang, Kailin Zhuang
9/1/2015September 2015Development of a Numerical Simulation Tool for Continuously Reinforced Concrete Pavementshttps://cptechcenter.org/ncc-projects/development-of-a-numerical-simulation-tool-for-continuously-reinforced-concrete-pavements/Continuously reinforced concrete pavements; Finite element method; Foundations; Geometric configurations and shapes; Mechanistic-empirical pavement design; Pavement joints; Reinforcing steel; Simulation; Temperature gradients; Traffic loadsThe accurate modeling of the main features of continuously-reinforced concrete pavements (CRCP) is of primary importance in a mechanistic-empirical pavement design procedure. The use of the finite element (FE) method as a comprehensive tool for modeling the responses of rigid pavements, CRCP in particular, has been limited because of the complexity of calculations in modeling material nonlinear behaviors, which are difficult to describe mathematically and computationally. Significant amount of research has been conducted to improve the design of CRCPs under traffic, environmental, and thermal loads. To develop a reliable model that better represents the behavior of CRCP, a clear understanding of the design features that impact CRCP responses is essential. Researchers from the University of Texas at El Paso developed NYSLAB to analyze the response of comprehensively jointed concrete pavements (JCPs) under different geometric configurations, foundation models, temperature gradient profiles and traffic loads.Cesar Carrasco, Soheil Nazarian, Nancy Aguirre
1/8/2019January 2019Development of a QC/QA Process for Caltrans Automated Pavement Condition Survey Datahttps://cptechcenter.org/ncc-projects/development-of-a-qc-qa-process-for-caltrans-automated-pavement-condition-survey-data/Condition surveys; Data quality; Pavement management systems; Quality assurance; Quality controlThe California Department of Transportation (Caltrans) awarded a contractor a three-year contract to collect, analyze, and report pavement condition of the state highway system for 2018 and 2019 using automated pavement condition survey (APCS). The contract covers 12 Caltrans districts with roughly 52,000 lane miles of on-system roadways and 6,000 lane miles of off-system roadways. Before investing significant resources on statewide APCS data collection, Caltrans and the contractor initiated a pilot study. The purpose is to establish a workable process for data quality control (QC) and quality assurance (QA), making sure the data collected closely reflect the field condition. The pilot study was conducted on selected routes in Caltrans District 12.Haiping Zhou, Zhongren Wang, Robert Sherrick, Scott Mathison
9/5/2013September 2013Development of an Overlay Design Procedure for Composite Pavementshttps://cptechcenter.org/ncc-projects/development-of-an-overlay-design-procedure-for-composite-pavements/Pavement design, Composite pavements, Concrete overlays, Asphalt concrete, Thickness, Traffic loads, Falling weight deflectometers, Portland cement concrete,A majority of Ohio Department of Transportation's (ODOT's) 4-lane and interstate highways are composite pavement; with the vast majority being Portland cement concrete (PCC) pavement overlaid with asphalt concrete (AC). Each year, ODOT rehabilitates several hundred miles of existing AC/PCC pavements by additional overlay. It is important to have an effective means to evaluate the existing AC/PCC pavements and to design the overlay thickness required to carry anticipated future traffic loading. The pavement overlay thickness design procedure currently exercised by ODOT works well for both flexible and rigid pavements, but it tends to produce overly conservative designs for composite pavements. For composite pavements with relatively thick asphalt overlays, the current design procedure consistently recommends very high overlay thickness that is deemed structurally unnecessary. Research is needed to evaluate and verify the assumptions used for composite pavements in the current overlay design procedure and provide modifications as needed or to develop a new deflection based overlay design procedure for composite pavements. The proposed study investigates the possible cause(s) and finds solution(s) to address the problem within the composite overlay design procedure and to verify and validate the revised procedure through actual pavements. The goals and objectives of this project are to: (1) develop and validate a Falling Weight Deflectometer ‰ÛÜ(FWD) deflection-based overlay design procedure for composite pavements and incorporate it into the most current version of ODOT's overall design software; and (2) provide ODOT with the ability to mechanistically determine the effective thickness of the PCC slab portion of a composite pavement for use in the U.S. Army Corps of Engineers' equation for the design of unbonded concrete overlays.Liangbo Hu, Eddie Chou
1/18/2017January 2017Development of Calcined Clays as Pozzolanic Additions in Portland Cement Concrete Mixtureshttps://cptechcenter.org/ncc-projects/development-of-calcined-clays-as-pozzolanic-additions-in-portland-cement-concrete-mixtures/Clay soils; Compressive strength; Diffraction; Mortar; Portland cement; Pozzolanic actionThe objectives of this research are to (1) evaluate the quality of various clay sources available in Florida in terms of their chemical and mineralogical composition and amorphous content through the use of x-ray fluorescence and x-ray diffraction techniques; (2) explore different calcination temperatures and accompanying phase transformation for various clay samples through the use of x-ray diffraction or other techniques; (3) evaluate the reactivity of calcined pozzolanic materials in combination with ordinary Portland cement through the use of mortar compressive strength.A Zayed, N Shanahan, A Sedaghat, Y Stetsko, B Lorentz
5/18/2018May 2018Development of Cost-Effective Ultra-High Performance Concrete (UHPC) for Colorado's Sustainable Infrastructurehttps://cptechcenter.org/ncc-projects/development-of-cost-effective-ultra-high-performance-concrete-(uhpc)-for-colorado?s-sustainable-infrastructure/Admixtures; Bridge construction; Compressive strength; Cost effectiveness; Infrastructure; Silica; Sustainable development; Ultra high performance concreteThis report presents the development of ultra-high performance concrete (UHPC) using locally available materials that reduce construction costs compared with commercial products. With the aim of achieving a specified compressive strength of 20 ksi, a UHPC mixture is formulated. The implications of various constituent types are examined with an emphasis on silica compounds (silica fume, silica powder, silica sand, finer silica sand, pyrogenic silica, and precipitated silica), including steel and polypropylene fibers. Bond tests are conducted to evaluate the development length of the UHPC. Cost analysis shows that the prototype UHPC is up to 74% less expensive than commercial products.Yail Jimmy Kim
7/17/2017July 2017Development of High Performance Rapid Patching Materials for Pavement Repairhttps://cptechcenter.org/ncc-projects/development-of-high-performance-rapid-patching-materials-for-pavement-repair/Alkali silica reactions; Asphalt mixtures; Cracking; Deterioration; Freeze thaw durability; Patching; Pavement distressConcrete pavement distresses resulting from freeze/thaw (F/T) deterioration, alkali-silica reaction (ASR), and chemical attacks may cause different forms of deterioration, including scaling, cracking, breaking, chipping, and fraying. Concrete pavements exhibiting severe distresses such as transverse cracks, shattered slabs, and corner breaks require patching are commonly observed in concrete pavement in Nebraska. Due to the opening requirement of the pavement to traffic after the placing of repair concrete, it is essential to achieve high early strength. To ensure high early strength, the current patching mix (i.e., PR in the Nebraska Department of Roads [NDOR] specification 1002.02) requires a minimum cement content of 752 or 799pcy for PR1 and PR3 mixes respectively. Besides the high associated cost, the high cement content tends to result in a less stable mix with a high drying shrinkage, high autogenous shrinkage, high heat of hydration and cracking potential. The mixes also exclude the use of fly ash, which makes it vulnerable to various deteriorations, particularly ASR. In order to reduce the material cost and premature failures of pavement repair, patching materials that develops early strength and is durable is needed. This study is to improve the current rapid patching materials. The research team will particularly focus on mix design in terms of aggregate gradation, cement type and content, water-to-cement ratio (w/c), and incorporation of proper chemical admixtures to achieve sufficient early-age strength that is comparable to the current NDOR PR mixes, yet more durable and resist to deteriorations such as ASR.Jiong Hu, Yong-Rak Kim
4/30/2019April 2019Development of Performance Curves for Whitetopping in Minnesotahttps://cptechcenter.org/ncc-projects/development-of-performance-curves-for-whitetopping-in-minnesota/Asphalt pavements; Condition surveys; Mathematical prediction; Pavement maintenance; Pavement management systems; Pavement performance; Performance measurement; Rehabilitation (Maintenance); WhitetoppingWhitetoppings, now commonly referred to as bonded concrete overlays on asphalt (BCOA), are growing in popularity as an option for rehabilitating existing asphalt pavements. It was the objective of this study to develop predictive performance models, based on measured performance of existing whitetopping projects in Minnesota, which will eventually be adopted into MnDOT’s pavement management project selection process. In this project, 26 whitetopping projects in service throughout Minnesota were examined to determine their historical performance to date. Each of the projects were visited periodically from 2015 to 2018 to gather supplemental performance data. Based on this and other historical data, performance curves were developed to highlight the current trends in Minnesota whitetopping performance in terms of MnDOT pavement index parameters. An analysis of the effect of specific design parameters on performance was also carried out. Finally, two predictive performance models, based on only International Roughness Index (IRI), were developed for undoweled whitetoppings in Minnesota.Thomas Burnham, Bernard Izevbekhai, Joseph Gallagher, Santiago Huerta
2/1/2019February 2019Development of Predictive Performance Models and Calibration of Mechanistic Empirical Design Method for Optimized Transportation Infrastructure Management, Considering Life-Cycle Costs and Environmental Impactshttps://cptechcenter.org/ncc-projects/development-of-predictive-performance-models-and-calibration-of-mechanistic-empirical-design-method-for-optimized-transportation-infrastructure-management,-considering-life-cycle-costs-and-environmental-impacts/Calibration;ÿData analysis;ÿEnvironmental impacts; ÿInfrastructure;ÿLife cycle costing; ÿMathematical models;ÿ Mathematical prediction;ÿMechanistic-empirical pavement design;ÿOptimization; Pavement cracking; ÿPavement management systems; ÿPavement performance;ÿRigid pavementsThe United States spends $150 billion per year to maintain its vast transportation network of 4.11-million lane-miles of roads. Vehicles that drive along these roads consume 213 billion gallons of fuel per year. Due to such staggering financial and environmental costs, it is important for transportation planners to optimize current infrastructure. In California, pavement maintenance is extremely costly. Effective pavement management systems take into account cracking and roughness. The quality of these features directly impacts vehicle fuel consumption. This research has two main objectives: (1) Developing predictive performance models needed for optimized network level management of rigid transportation infrastructure. These performance models are developed by conducting big data analysis of field data collected from Caltrans Pavement Management System. (2) Calibrating Mechanistic-Empirical Design Guide for rigid pavements in California and developing models for longitudinal cracking specific to California and few other states.Ashkan Saboori, John Harvey
9/1/2017September 2017Development of Rational CPCD Pavement Design Procedureshttps://cptechcenter.org/ncc-projects/development-of-rational-cpcd-pavement-design-procedures/Pavement designThe usage of CPCD (Concrete Pavement Contraction Design) has been quite limited in Texas since the TxDOT policy of utilizing CRCP was enacted in 2010. That policy was based on rather poor performance of CPCD built on poor slab support and/or without dowels. The new requirement of CoTE of concrete for CRCP will undoubtedly increase the use of CPCD in Texas. The current TxDOT pavement design method for CPCD is based on the method in the AASHTO 93 Pavement Design Guide, which was developed from the findings in the AASHO Road Test. However, the pavement structures evaluated in the AASHO Road Test are quite different from those currently in use in Texas. Accordingly, the distress types and their mechanisms observed in the AASHO Road Test are quite different from those observed in Texas, which implies that the current TxDOT pavement design method for CPCD may not be the most accurate and efficient one to be used in Texas. An improved CPCD design procedure is needed that accurately reflects the pavement behavior and performance in Texas. An improved procedure will result in more realistic and optimized pavement structures. This design procedure could be used for the development of catalog design, if TxDOT deems desirable.Moon Won
3/1/2013March 2013Development of Specifications for Engineered Cementitious Composites (ECC) for Use in Bridge Deck Overlayshttps://cptechcenter.org/ncc-projects/development-of-specifications-for-engineered-cementitious-composites-(ecc)-for-use-in-bridge-deck-overlays/ECCThis research will investigate multiple sources for making ECC, examine the material properties and then investigate its production and performance on a large scale. Further, specifications for designing, producing, placing, and finishing ECC material for bridge deck overlay in Nevada will be developed.Elie Y Hajj, David H Sanders, Nicholas D Weitzel
9/23/2016September 2016Development of Specifications for High-Performance Fiber Concrete for Nevada (NDOT 366-16-803)https://cptechcenter.org/ncc-projects/development-of-specifications-for-high-performance-fiber-concrete-for-nevada-(ndot-366-16-803)/Bridge decks; Bridge design; Economic efficiency; Fiber reinforced concrete; High performance concrete; SpecificationsBridge decks are the weakest link among the various bridge components, lasting approximately 30 years. According to the American Association of State Highway and Transportation Officials (AASHTO) Load and Resistance Factor Design (LRFD) specifications, a bridge deck should be expected to last for 75 years. Bridge decks are exposed to excessive traffic and chloride elements. The chloride elements can seep through cracks within the bridge decks, causing corrosion in the steel. High durability concrete has been used to improve the serviceability of structures.Jiong Hu
3/31/2015March 2015Development of Standard Operating Procedure for Analysis of Ammonia Concentrations in Coal Fly Ashhttps://cptechcenter.org/ncc-projects/development-of-standard-operating-procedure-for-analysis-of-ammonia-concentrations-in-coal-fly-ash/Fly ash, Ammonia, Laboratory tests, Standard operating procedures, Field tests, Evaluation and assessment, State of the practice, FloridaThe objectives of this project include conducting a detailed assessment of the current practices used for ammonia analysis in coal fly ash, necessary side-by-side laboratory testing of AFA samples using current methodologies, examining new analytical procedures, developing a draft standard operating procedure, conducting field tests of the standard operating procedure in cooperation with likely end-users, and finalizing the standard operating procedure based on the stakeholder and Florida Department of Transportation (FDOT) feedback.Timothy Townsend, John Schert, Tim Vinson
12/31/15December 2015 Documentation of INDOT’s Experience with the Construction of Bridge Deck’s Containing Internal Curing in 2013https://cptechcenter.org/ncc-projects/documentation-of-the-construction-of-indot's-experience-with-the-bridge-deck's-containing-internal-curing-in-2013/Bridge construction, Bridge decksThis project outlines work to document the construction of four internally cured bridge decks during the summer of 2013. The project will include documentation, measurement of fresh concrete properties, collection of samples for long-term testing including diffusion samples as well as one series of frames to measure cracking.Jason Weiss
4/28/2017April 2017Durability Analysis of Recycled Asphalt Pavement as Partial Coarse Aggregate Replacement in a High-Strength Concrete Mixturehttps://cptechcenter.org/ncc-projects/durability-analysis-of-recycled-asphalt-pavement-as-partial-coarse-aggregate-replacement-in-a-high-strength-concrete-mixture/Admixtures; Coarse aggregates; Durability tests; Freeze thaw durability; High strength concrete; Permeability; Reclaimed asphalt pavements; Recycled materials; Thermal expansionThe strength reduction associated with the replacement of the virgin coarse aggregate in concrete with recycled asphalt pavement (RAP) limits the use of the RAP concrete to nonstructural applications. Recent research has suggested that RAP concrete might retain sufficient strength for structural applications if high-strength concrete mixture designs were used. Before these high-strength RAP concrete mixtures can be used in transportation infrastructure applications, their durability must be proven. This study evaluated the chloride permeability, the freeze-thaw durability, and the coefficient of thermal expansion of high-strength RAP concrete mixtures. The results indicated that the chloride permeability of the high-strength concrete, as measured by the surface resistivity, was unaffected by the replacement of up to 50% of virgin coarse aggregate with RAP. Furthermore, the freeze-thaw durability of high-strength RAP concrete was improved over high-strength concrete with 100% virgin coarse aggregate. The optimal RAP fraction in terms of the freeze/thaw durability was 35% by mass. Finally, the coefficient of thermal expansion was minimally affected by the replacement of up to 50% of virgin coarse aggregate with RAP. On the basis of these results, the durability of high-strength concrete with RAP coarse aggregate was deemed sufficient for transportation infrastructure applications.R J Thomas, Andrew J Fellows; Andrew D Sorensen
8/8/2018August 2018Durability of Cementitious Systems Incorporating Calcined Low-Grade Kaolin Clayshttps://cptechcenter.org/ncc-projects/durability-of-cementitious-systems-incorporating-calcined-low-grade-kaolin-clays/Cement; Chemical properties; Durability; Kaolin; Physical properties; Service life;The project aims to (1) Investigate the effects of the chemical and physical characteristics, and of the replacement levels of calcined low-grade kaolin on strength evolution in cementitious systems, (2) Establish the impact of low-grade kaolin characteristics and substitution levels on the durability of cementitious systems exposed to aggressive conditions during service life.Abla Zayed
02/01/15January 2015Durability, Ductility, and Bond Strength of Portland Cement Concrete with Recycled Asphalt Pavement as Partial Replacement for Coarse Aggregatehttps://cptechcenter.org/ncc-projects/durability,-ductility,-and-bond-strength-of-portland-cement-concrete-with-recycled-asphalt-pavement-as-partial-replacement-for-coarse-aggregate/Recycled materials, Coarse aggregates, Portland cement concrete, Asphalt mixtures, Admixtures, Durability tests, Ductility,This research project has three main objectives. First, to determine the durability of the recycled asphalt pavement (RAP) mixture and compare the results to those obtained for normal concrete mixes. Second, to determine the ductility of the RAP mixture and compare the results to those obtained for normal concrete mixes. Third, to determine the bond strength between the RAP mixture and reinforcing steel and compare the results to those obtained for normal concrete mixes.Andrew Sorensen
07/31/19July 2019Durable and Sustainable Concrete through Performance-Engineered Concrete Mixtureshttps://cptechcenter.org/ncc-projects/durable-and-sustainable-concrete-through-performance-engineered-concrete-mixtures/Admixtures; Compressive strength; Concrete pavements; Durability; Highway maintenance; Infrastructure; Limestone; Mix design; Quality assurance; Quality control; Sustainable developmentAs funds to construct, maintain, and preserve our highway infrastructure become increasingly stretched, it is imperative that the criteria for selection of concrete mixtures and acceptance of placed concrete reliably ensure durability. Over the past several decades, research has led to new understanding of deterioration mechanisms, advancements in concrete mixture design, and better field and laboratory tests to aid in quality assurance/quality control (QA/QC). American Association of State Highway and Transportation Officials (AASHTO) PP 84, “Standard Practice for Developing Performance Engineered Concrete Mixtures” provides guidance to agencies aiming to improve the durability, economy, and sustainability of their infrastructure using both prescriptive and performance specification provisions and emerging technologies. Although developed for pavement concrete mixtures, the approach outlined in AASHTO PP 84 can be extended to include specifications for performance-engineered concrete mixtures utilized for other infrastructure (bridges, lower grade uses, etc.) as well. The scope of work in this project supports an initial effort to move towards a specification for performance-engineered concrete mixtures by (1) utilizing existing data to identify areas in need of improvement, (2) targeting the establishment of performance-related criteria using several Performance-engineered concrete mixtures (PEM) QA/QC tests and approaches of interest to North Carolina Department of Transportation (NCDOT), and (3) providing a “roadmap,” outlining recommended tasks towards implementation of performance measures, performance goals, and QA/QC protocol in other areas. Existing data from previous concrete research projects for NCDOT were leveraged with new, targeted data to efficiently develop proposed specifications for three areas of interest to improve durability of future concrete infrastructure: surface resistivity, early age strength for opening to traffic, and shrinkage. Guidance for other performance and prescriptive (including water-cementitious ratio and paste content) is also presented for consideration. Suggested specification provisions developed as part of this project are suitable for use by NCDOT on several upcoming projects targeted as pilot projects for PEM research. Additional study to evaluate the performance of concrete mixtures that include the combination of both fly ash and portland limestone cement (PLC) was also performed. Findings of this work align with previous findings by the research team, indicating significant durability performance benefits in mixtures that contain the two materials. Performance improvements were particularly noted at the current allowable fly ash replacement (30%), which has been increased in recent years. The enhanced durability, sustainability and economy of these mixtures provides additional justification for use of PLC and higher fly ash contents. Findings of this study should allow NCDOT to specify and use of more durable, sustainable concrete mixtures in North Carolina highway infrastructure. Ultimately, paired with other efforts aligned with the national PEM initiative, findings this project should result in cost savings associated with construction costs, QA/QC costs, reduced maintenance costs, and extended life of concrete pavements and bridges.Tara Cavalline
9/15/2016September 2016Durable High Early Strength Concretehttps://cptechcenter.org/ncc-projects/durable-high-early-strength-concrete/Concrete bridges; Concrete pavements; High strength concrete; Mix design; Service lifeThe objective of this research project is to develop high early strength concrete mixture criteria or designs that can do the following: (1) satisfy current Kansas Department of Transportation (KDOT) minimum strengths for opening to traffic in 4 to 24 hours; and (2) provide a 20-year pavement or 50-year bridge service life.Christopher Jones
7/1/2018July 2018Early Detection of Near-Surface Void Defects in Concrete Pavement Using Drone-based Thermography and GPR Methodshttps://cptechcenter.org/ncc-projects/early-detection-of-near-surface-void-defects-in-concrete-pavement-using-drone-based-thermography-and-gpr-methods/Air voids; Concrete curing; Concrete pavements; Drones; Flaw detection; Ground penetrating radar; Nondestructive tests; Quality control; ThermographsNear-surface (i.e., less than 4 in deep) voids that are 1/2” or larger in diameter (in both horizontal and vertical directions) is a common consolidation issue during the construction of concrete pavements. This issue was observed by Nebraska Department of Transportation (NDOT) in concrete pavements constructed by different contractors, on different roads (highways and local roads), and with different thicknesses (9-14 in). These voids can be caused by improper vibration, overly dry mix, and/or long wait time between concrete batches (Legg 1974). These large voids or concentrations of smaller voids can be detrimental to the durability and/or strength of the pavements (Freeman and Zollinger 2008). Being able to detect these voids at an early stage will enable NDOT to direct timely correction orders during the construction process. As a result, costlier repair and maintenance actions can be avoided. Non-destructive testing (NDT) methods, including ground penetrating radar (GPR) and Thermography have been used in detecting concrete defects for a long time, including the detection of pavement delamination, deterioration, spalling and pumping issues (Sebest and Scullion 2005; Morcous and Sekpe 2010) with varying levels of success. However, very few reports were found on using these two NDT approaches to detect defects during the hydration time due to many constraints and challenges, including weak compression strength during the early hydration process for heavy inspection vehicles or equipment. The primary project goal is to develop a reliable and efficient early detection tool for near-surface voids and to enhance NDOT’s capacity of quality control during concrete pavement construction. More specifically, early detection means during the curing stage, 2 to 72 hours after the concrete pavement is casted in place. This will give NDOT field personnel sufficient time to request corrections before the contractors complete the job.E Erdogmus, G Morcous, Zhigang Shen
9/30/2013September 2013Early-Age Fiber-Reinforced Concrete Properties for Overlayshttps://cptechcenter.org/ncc-projects/early-age-fiber-reinforced-concrete-properties-for-overlays/Asphalt concrete pavements; Concrete overlays; Cracking of asphalt concrete pavements; Fatigue limit; Fiber reinforced concrete; Finite element method; Pavement joints; Rehabilitation (Maintenance)A common pavement rehabilitation technique for rutted or cracked hot - mixed asphalt concrete roadways is to mill the surface and then overlay with up to 6 inch es of a portland cement concrete (PCC) layer. More recent advancements in research has proven that a feasible top wearing surface can be made at this 2 inch (50 mm) thin layer if it is comprised of f iber reinforced c oncrete (FRC). FRC has increasingly being used in UTW overlays since it has been proven through experimental lab and field testing improve the fatigue life and reduce deflections of jointed concrete overlay slabs. Cracking and debonding of the overlay structure can initiate as a result of drying shrinkage, and temperature shrinkage, slab settlements, or external load. Temperature - induced curling and cracking has been researched many times and is currently recognized as one of the major failure mechanisms in concrete pavements. Slabs are designed to have joints cut at spacing sizes proportional to the thickness. These jo ints are cut in order to provide a specific location for thermal and humidity - induced cracking while also keeping net curling lift - off deflections to a minimum. It has experimentally been verified that with FRC overlays and pavements, not every joint crack s upon the first thermal cycle. Yet the few joints that do crack at early ages produce the lowest load transfer efficiency and widest crack widths at later ages. There are no known publications or research performed which has studied why or how the addition of fiber - reinforcement in a thin concrete overlay affects the joint cracking and slab curling. A full - scale test pavement of a 50 mm thick FRC overlay was constructed in July 2009, which has been subjected only to environmental loading since then.. This is a unique pavement section as well because it has no mid - panel slab cracking except in pre - placed constructed debonding zones. The cracking of joints was monitored at early ages between 3 and 20 days as well as climatic temperature data of the air and in 4 depths within the pavement structure. Existing temperature and joint opening models overpredict the actual crack widths measured from the field. The proposed research will attempt to improve prediction of crack width for thermally - loaded FRC pavements. The early - age properties of FRC as measured in this research will be utilized in a co hesive zone finite element analysis of the same The main objective of this research is to perform experimental tests to determine the hardened properties of fiber- reinforced concrete as they change with time at early-ages. These properties and their function with time can be implemented into finite element modeling to improve overlay prediction at early ages.Amanda Bordelon, Min Ook Kim
09/01/19September 2019Economical and Crack-Free High Performance Concrete with Adapted Rheologyhttps://cptechcenter.org/ncc-projects/economical-and-crack-free-high-performance-concrete-with-adapted-rheology/Crack-free; Early-age cracking; Eco-Crete; Packing density;Shrinkage mitigating Strategies, Supplementary cementitious materials; Structural performance; Life cycle assessmentThe main objective of this study is to develop, characterize, and validate the performance of a new class of environmentally friendly, economical, and crack-free high-performance concrete referred to as Eco and crack-free HPC that is proportioned with high content of recycle materials. Two classes of Eco-HPC are designed for: (I) pavement (Eco-Pave-Crete); and (II) bridge infrastructure (Eco-Bridge-Crete). Eco-HPC mixtures were designed to have relatively low binder content up to 350 kg/m3 and develop high resistance to shrinkage and superior durability.Kamal H Khayat, Iman Mehdipour, Hani Nassif, Zeeshan Ghanchi, Chaekuk Na, Kaan Ozbay, Jeffery S Volz
5/25/2017May 2017Effect of Coarse Aggregate Type on Chloride Ion Penetration in Concretehttps://cptechcenter.org/ncc-projects/effect-of-coarse-aggregate-type-on-chloride-ion-penetration-in-concrete/Bridge decks; Chloride content; Chlorides; Coarse aggregates; Ions; Rapid Chloride Penetration Test; Bridges and other structures; Highways; Materials; Pavements;Long-term durability and sustainability of crucial infrastructure systems such as bridges and pavements are of utmost importance for the economic health of any society. Understanding factors that affect long-term deterioration of reinforced concrete structures can help enhance durability and sustainability of these systems. This paper investigates the effect of the type of coarse aggregate used in concrete on chloride ions penetrability. Twelve coarse aggregate types of different geologic formations (sedimentary, igneous, and metamorphic) were used to prepare fresh concrete in which silica fume and class C fly ash were used. All mix parameters including gradation and volumes of different aggregates were held constant in different mixes with the only variable being the aggregate type. The Rapid Chloride Penetration Tests were conducted on concrete specimens made with various aggregate types at ages of 28, 56, 91 and 365?days. Analysis of test results showed that the aggregate type as well as aggregate absorption rates have significant influence on the electrical charges passed through concrete, especially in early ages of concrete containing aggregates with sedimentary rock origin and relatively high absorption. These specimens exhibited the highest RCPT results indicating higher capacity to allow chloride ion penetration when compared to specimens with igneous and metamorphic rock aggregate of lower absorption values. This influence (discrepancy) diminishes with time for both aggregate type and absorption rates in terms of the magnitude of measured total charge passed.Hani H Titi, Habib Tabatabai
11/21/2018November 2018Effect of Curing Methods on Quality of Concrete Joints: Experimental and Modelinghttps://cptechcenter.org/ncc-projects/effect-of-curing-methods-on-quality-of-concrete-joints:-experimental-and-modeling/Absorption; Concrete curing; Concrete pavements; Durability; Pavement joints; Three dimensional flowJoint deterioration in concrete pavements is predominantly related to penetrability of concrete and environmental conditions. Saw-cutting as the last procedure in the construction sequence of concrete pavements may compromise the durability of joints due to insufficient curing and uncontrolled evaporation at an early age. Capillary absorption is considered fundamental to understanding the durability performance of porous building materials. Thus, the aim of this study is to develop an analytical model based on Katz-Thompson relationship to determine the absorption capacity of joints in concrete pavements according to an absorption test customized to the joint geometry of pavements. The experimental program involved absorption and mercury-intrusion porosimetry tests conducted on cores extracted from saw-cut concrete slabs with different curing scenarios. The absorption trends were modeled based on the unsaturated flow theory with three dimensional (3D) finite-element software. The results indicated that the unsaturated flow model reliably simulated fluid transport at joint locations in concrete with accurate predictions relative to experimental results.M Tiznobaik, M T Bassouni
12/1/2018December 2018Effect of Dowel Bar Arrangements on Performance of Jointed Plain Concrete Pavement (JPCP)https://cptechcenter.org/ncc-projects/effect-of-dowel-bar-arrangements-on-performance-of-jointed-plain-concrete-pavement-(jpcp)/Concrete pavements; Dowels (Fasteners); Finite element method; Load transfer; Longitudinal cracking; Pavement cracking; Pavement maintenance; Pavement performance; Spalling; Transverse crackingA full-scale jointed plain concrete pavement (JPCP) with two different dowel bar arrangements, namely, standard and special method, was constructed and evaluated under actual traffic-environmental condition in Florida. For standard dowel bar arrangement, dowel bars spaced at 304.8 mm (12 in), while three dowel bars spaced at 304.8 mm (12 in) only within the wheel paths were installed for special dowel bar arrangement. Field performance evaluation was conducted in terms of longitudinal crack, transverse crack, corner crack, spalling, and load transfer efficiency (LTE). Also, a three-dimensional (3-D) finite element (FE) model was developed to evaluate change in structural response characteristics due to different dowel bar arrangements under the critical loading condition.Kukjoo Kim, Sanghyun Chun, Sangyoung Han, Mang Tia
1/1/2015January 2015Effect of Early-Age Concrete Elastic Properties on Fatigue Damage in PCC Pavements Containing Fibershttps://cptechcenter.org/ncc-projects/effect-of-early-age-concrete-elastic-properties-on-fatigue-damage-in-pcc-pavements-containing-fibers/Portland cement concrete, Fatigue (Mechanics), Failure, High early strength cement, Elasticity (Mechanics), FibersThis research may result in decreased construction time and time for opening to traffic, resulting in potential cost savings through use of shorter periods of traffic control, as well as potential for enhancing highway user satisfaction and decreasing user complaints, plus other cost savings.Mohsen A Issa
3/1/2019March 2019Effective Instrumentation Plan and Analysis Methodology for Full-Scale Field Tests of Concrete Pavementshttps://cptechcenter.org/ncc-projects/effective-instrumentation-plan-and-analysis-methodology-for-full-scale-field-tests-of-concrete-pavements/Concrete pavements;ÿData analysis;ÿField tests;ÿInstrumentation;ÿStrain gages;ÿStrain measurement;ÿTest proceduresThis study focused on the development of an effective methodology for instrumentation and data analysis to more accurately measure and to assess strain profiles from full-scale test slabs in consideration of the effects of localized traffic wander and missing data within an array of sensors. An effective instrumentation plan and analysis methodology were identified, and their applicability was evaluated using analytical results and a full-scale field experiment. The results indicated that sensor spacing significantly affected maximum strains interpolated, and load-induced strain profiles from strain gauges were highly influenced by localized wheel wander. The accuracy of predicted maximum strain was not affected by one missing data point; however, it would be greatly reduced if data from two sensors at the center of the array were missed. An array of uniformly spaced six gauges with 15 cm (6 in.) intervals around the wheel path was used and an interpolation methodology was developed to accurately capture the load-induced maximum strain based on strain profiles obtained from a full-scale concrete slab, taking into account the effects of localized traffic wander and missing data.Sangyoung Han, Kukjoo Kim, Sanghyun Chun, Mang Tia
7/1/2019July 2019Effectiveness of Geotextiles/Geogrids in Roadway Construction; Determine a Granular Equivalent (GE) Factorhttps://cptechcenter.org/ncc-projects/effectiveness-of-geotextiles-geogrids-in-roadway-construction-determine-a-granular-equivalent-ge-factor/Geogrids; Geotextiles; Road constructionThe objective of this project is to evaluate the performance benefit and cost effectiveness of geogrid in road systems by addressing five questions: (1) What strength enhancement is offered by the use of geogrids? (2) In which layer in a pavement structure is geogrid most effective? (3) How should geogrids be in the MnPave software application? (4) How would it be possible to evaluate the effectiveness and reliability of proprietary geogrid design? (5) How would it be possible to evaluate cost versus benefits of geogrids in different soil conditions?Junxing Zheng
06/30/15June 2015Effects of Coarse Aggregate on the Physical Properties of Florida Concrete Mixeshttps://cptechcenter.org/ncc-projects/effects-of-coarse-aggregate-on-the-physical-properties-of-florida-concrete-mixes/Florida, Road construction, Coarse aggregates, Admixtures, Durability, Portland cement concrete, Pozzolan, SlagThis research will investigate the use of new sources and current sources of coarse aggregates produced in Florida, which will be used to implement recommendations for revision to the Florida DOT (FDOT) Standard Specification for road and bridge construction, particularly sections 901 and 346, Pozzolans and Slag, and Portland Cement Concrete. The research will investigate the strength, physical, thermal, and durability properties of the aggregate materials and their suitability for use in concrete.Christopher C Ferraro, Caitlin M Tibbetts, Michael C Perry, Benjamin E Watts, Jerry M Paris
8/1/2014August 2014Efficacy of the Bacteria Encapsulation Concrete Self-Healing Method in a Harsh Environmenthttps://cptechcenter.org/ncc-projects/efficacy-of-the-bacteria-encapsulation-concrete-self-healing-method-in-a-harsh-environment/Concrete construction, Compressive strength, Reinforcing steel, Tensile strength, Corrosion, Moisture content, Air content, Cracking,Concrete is the most widely used material in construction, offering advantages in terms of moisture and fire resistance, versatility, cost, energy-efficiency, and environmental impact. Concrete provides a relatively high level of compressive strength; its tensile strength, however, is fairly low, and concrete members crack on the tension side under the application of small loads. Hence, most concrete systems generally incorporate reinforcing steel to resist tensile. While reinforcing steel receives a certain level of protection against corrosion from the surrounding concrete, the corrosion of reinforcing steel is still a predominant factor undermining the longevity of the vast concrete-based infrastructure. The presence of both air and water is required for corrosion activity to start, and, after tensile crack formation, it will accelerate. However, corrosion may be slowed down considerably if the diffusion of oxygen and harmful ions, such as chloride ions, through the concrete could be reduced. The new concept of self-healing concrete was introduced over the past decade, and many researchers are still investigating the feasibility of the process at a laboratory scale. There are two objectives for the self-healing concrete: (1) recovery of strength after the formation of cracks and (2) sealing the cracks to prevent further concrete deterioration, such as that resulting from corrosion. Several approaches for concrete self-healing are proposed in the literature, such as bacteria encapsulation, mineral admixture, chemical in glass tubing, etc. Most of the proposed methods focused on the second objective and showed promising results for eliminating or reducing the cracks that form first, when the concrete is still relatively young, under dry or wet conditions. However, very few studies have been done to show the versatility and repeatability of some the most promising approaches, such as bacterial encapsulation.Goli Nossoni, Daniel Hussey, Marisa Budziszewski
4/19/2017April 2017Enhancing Mechanical Properties of Pervious Concrete Using Carbon Fiber Composite Reinforcementhttps://cptechcenter.org/ncc-projects/enhancing-mechanical-properties-of-pervious-concrete-using-carbon-fiber-composite-reinforcement/Carbon fibers; Composite materials; Mechanical properties; Porous pavements; Reinforced concrete; Reinforcement (Engineering); Salvage; Pervious concreteCured carbon fiber composite material (CCFCM) is available from manufacturing lines; however, excess CCFCM has no reuse applications at present. Postindustrial CCFCM was mechanically refined and used as reinforcement to improve the mechanical properties of pervious concrete (PC). Four PC mixtures were included in the study, which contained 0 (control), 3, 4, and 5% CCFCM by volume. Infiltration rates of all CCFCM mixtures were above the acceptable level of 1,200  cm/h. Paired t-tests showed that all CCFCM mixtures significantly outperformed the control mixture in terms of split tensile strength by 57–84% and flexural strength by 36–65% in 28-day testing. Load-displacement curves of CCFCM mixtures indicated increases of 41–54% in toughness indices. Mass loss due to Los Angeles machine abrasion (Cantabro) ranged from 16 to 31% for CCFCM mixtures, while the control lost 50% of its original mass. Overall, within the tested range, up to 4% CCFCM addition to PC presented the optimal result across the entire experimental scope. Higher CCFCM contents may be possible if used as a replacement of aggregate rather than an additive to the mixture.Harry Rodin, Milena Rangelov, Somayeh Nassiri, Karl Englund
9/1/2017September 2017Establishing Best Practices for Construction and Design of Cement Treated Materialshttps://cptechcenter.org/ncc-projects/establishing-best-practices-for-construction-and-design-of-cement-treated-materials/Base course (Pavements); Cement treated soils; Failure; Laboratory tests; Mix design; Performance testsTxDOT has been constructing pavement structures with cement-treated materials for many years; however, premature failures, such as rutting and cracking, occasionally occur during or shortly after construction. To ensure cement-treated base (CTB) durability and adequate performance over the pavement design life, it is critical to have a better understanding and knowledge of the significance of material mixture designs, construction, and inspection techniques. This project will look at the existing TxDOT guidelines and provide a comprehensive evaluation of how they compare to other published guidelines and recent literature. Particularly, this project will evaluate the potential benefits of new technologies such as inverted pavement structure and super slurry on the properties of the CTB. This evaluation includes developing new rheological testing standards and specifications for evaluating best slurry mixes to maximize performance of the most common TxDOT recycled base material. The project will include an extensive laboratory evaluation of performance and durability of CTB material prepared using traditional on-site and in-plant mixing and compare it to the newly proposed slurry-based mixing. These tests will provide the basis for the new mix design specifications and laboratory testing, along with developing baseline curves for in-situ inspection and evaluating field performance.Reza S Ashtiani
8/9/2012August 2012Evaluate and Develop Innovative Pavement Repair and Patching: Taconite-Based Repair Optionshttps://cptechcenter.org/ncc-projects/evaluate-and-develop-innovative-pavement-repair-and-patching:-taconite-based-repair-options.--/Asphalt pavements; Concrete pavements; Patching; Pavement maintenance; Paving; Potholes (Pavements)The research notes that Taconite-based pavement repair options provide such benefits as longer-lasting/more efficient repairs. Additionally, Taconite-based pavement repair is seen to provide important near- and long-term cost-savings, reduced traffic delays, and increased safety for drivers. Immediate use and deployment of Taconite-based pavement repair would include the repair/maintenance of Hot Mix Asphalt (HMA) and Portland Concrete Cement (PCC) pavements (e.g., pothole repair). The research, which involves laboratory and field tests, does comparative testing against propane/infrared-based (IR) heating for: a) wintertime utility access and/or repair of pavement; and b) hot in-place recycling of HMA. Also included are cost-benefit analyses, designed to aid decision-makers withn municipal, county and state governments, as well as the private sector.Lawrence M Zanko, David M Hopstock, Will DeRocher
03/01/20March 2020Evaluate, Modify and Adapt the Concrete Works Software for Iowa's Usehttps://cptechcenter.org/ncc-projects/evaluate,-modify-and-adapt-the-concrete-works-software-for-iowa's-use/Computer programs, Concrete bridges, Cracking, Mass concrete, Temperature The early-age thermal development in mass concrete has a significant impact on the performance and long-term serviceability of mass concrete structures, such as bridge foundations. Great efforts have been made on predicting and controlling the thermal development in mass concrete. ConcreteWorks has been increasingly used for this purpose. However, previous research in Iowa indicated that, although user-friendly, the public ConcreteWorks program has some features that do not fit Iowa concrete well. The present research aimed at modifying the ConcreteWorks software for Iowa’s use, particularly for the prediction of thermal behavior of mass concrete elements with a smallest dimension of 6.5 feet or less. In this study, the input and output parameters of ConcreteWorks that need to be modified for Iowa’s use were identified. The key properties (heat of hydration, thermal conductivity, mechanical properties, etc.) of typical Iowa concrete mixes required by ConcreteWorks for thermal predictions were tested. The Iowa environmental data and Iowa Department of Transportation (DOT) temperature differential limits were incorporated into the modified ConcreteWorks program. An initial soil temperature model was added. Thermal analyses were conducted on a real-time mass concrete project (the I-35 NB to US 30 WB [Ramp H] bridge) using both the unmodified and modified ConcreteWorks software as well as 4C-Temp&Stress software, and the predicted temperature developments were compared with those monitored from the field site. The results indicate that the modified ConcreteWorks software predicts the early-age temperature profile, maturity, and strength of Iowa mass concrete quite well. As many default data in the public ConcreteWorks software are replaced with Iowa concrete values, the modified software is even more user-friendly and reliable for Iowa’s use. A hands-on workshop on learning how to use ConcreteWorks was welcomed by Iowa engineers. Recommendations are made in this report for effective use of the modified ConcreteWorks software in Iowa and for further research in this area. Kejin Wang, Yogiraj Sargam, Kyle Riding, Mahmoud Faytarouni, Charles Jahren, Jay Shen
04/31/2016April 2016Evaluating Electrical Resistivity as a Performance based Test for Utah Bridge Deck Concretehttps://cptechcenter.org/ncc-projects/evaluating-electrical-resistivity-as-a-performance-based-test-for-utah-bridge-deck-concrete/Admixtures; Bridge decks; Cement; Concrete bridges; Electrical resistivity; Modulus of elasticity; Nondestructive tests; Permeability; Water cement ratioConcrete surface resistivity, American Association of State Highway and Transportation Officials Spec (AASHTO Spec) and bulk resistivity, are easy to implement, non-destructive tests which can identify several important parameters, including concrete permeability and can potentially be correlated to applied tension loads, pore size distribution, alkali silica reaction, sulfate attack, internal relative humidity accurately detect setting time. This project seeks to synthesize national literature and past projects, focusing on performance metrics. Concrete mixtures and specimens from around the state of Utah will be investigated to identify relevant phenomena using several variations of concrete constituents, including multiple aggregate types, common supplementary cemetitious materials, w/c ratios and curing styles. All mixtures will be mixed by ready mix companies and precasters within the state of Utah. Mechanical and durability properties will be investigated, including (but not limited to) strength, elastic modulus, chloride ion permeability, freeze thaw, surface resistivity and bulk resistivity. Relationships between measured variables will be identifified and variability associated with the resistnace measurement techniques. This project will seek to estimate acceptable levels of performance metrics (i.e., concrete permeability) including the synthesized literature and past Utah Department of Transportation (UDOT) projects quantifying bride deck performance metrics.Amir Malakooti, Marc Maguire, Robert J Thomas
10/1/2011October 2011Evaluating the Financial Cost and Impact on Long Term Pavement Performance of Expediting Michigan's Road Construction Workhttps://cptechcenter.org/ncc-projects/evaluating-the-financial-cost-and-impact-on-long-term-pavement-performance-of-expediting-michigans-road-construction-work/Pavement performance, Michigan, Incentives, User delay costs, Road construction, CostsThis research studies whether the Incentive/Disincentive for expediting construction captures the true cost and identify its impacts on the long-term pavement performance for projects that have been expedited vs. conventional scheduling. The analysis results highlight the effectiveness of Accepted for Traffic and Interim Completion incentive/ Disincentive clauses; they also debate the effectiveness of the lane rental incentive/disincentive clauses, in achieving their goal by accelerating project schedules and reducing user delay cost.Mohamed El-Gafy
5/1/2013May 2013Evaluation of Alternative Pozzolanic Materials for Partial Replacement of Portland Cement in Concretehttps://cptechcenter.org/ncc-projects/evaluation-of-alternative-pozzolanic-materials-for-partial-replacement-of-portland-cement-in-concrete/Alternatives analysis, concrete, durability, materials, portland cement, pozzolan, rheological propertiesThis research will investigate the use of new sources of pozzolanic materials, which will be used to implement recommendations for revisions to the FDOT Standard Specifications for road and bridge construction, particularly Section 929, Pozzolans and Slag. The research will investigate the plastic, rheological, heat generating, chemical, physical and durability properties of the alternative materials and their suitability for use in concrete.Christopher C Ferraro, Timothy Townsend, Mang Tia, Jerry Paris
03/12/21March 2021Evaluation of Bonded Concrete Overlays on Asphalt Pavementshttps://cptechcenter.org/ncc-projects/evaluation-of-bonded-concrete-overlays-on-asphalt-pavements/Concrete overlays, Cracking of concrete pavements, Durability, Life cycle costing, Mechanistic-empirical pavement design, Pavement maintenance, Rutting, Service life, Thickness This report presents representative performance prediction curves for bonded concrete overlays on asphalt (BCOAs). The representative performance prediction curves are based on comprehensive laboratory and field investigations for determining best practices for scoping, design, material selection, construction, maintenance, repair, and rehabilitation of BCOA pavements. This report will be of immediate interest to construction and maintenance engineers. Linda M. Pierce, Sarah E. Stolte, Nick Weitzel, Jose Medina, Tom Van Dam, Kevin Senn, Jeff Roesler, Gail M. Scott, Sushobhan Sen, Omar A. Jadallah, Ken Maser, Adam Carmichael, Kelly Smith, Kurt Smith
8/9/2012August 2012Evaluation of Concrete and Mortars for Partial Depth Repairshttps://cptechcenter.org/ncc-projects/evaluation-of-concrete-and-mortars-for-partial-depth-repairs/partial depth repairs, cpr, patchingEvaluate the effect of chemical admixtures on a standard MnDOT patching mix, to develop improved guidelines for evaluation of pre-bagged commercial patching mixtures to ensure durability if possible, and to recommend effective construction practices while using these types of patching materials.Eshan V Dave, Jay Dailey, Eric Musselman
12/15/2016December 2016Evaluation of Corrosion Inhibiting Materials Applied by Impregnation (Pressure Injection) Methods to Prevent Corrosion of Post-Tensioned Tendonshttps://cptechcenter.org/ncc-projects/evaluation-of-corrosion-inhibiting-materials-applied-by-impregnation-(pressure-injection)-methods-to-prevent-corrosion-of-post-tensioned-tendons/Corrosion; Impregnation (Engineering); Materials; Posttensioning; Pressure; Tendons (Materials)The goal of this project is to evaluate the long term effectiveness and the service life of the material(s) actually used for impregnation of tendons and identify other materials that could produce better end results. In addition, the project will evaluate the effects of the impregnation methods on the physical characteristics of the tendon system to determine applicability to bonded tendons.Ivan Lasa
12/11/2017December 2017Evaluation of Durability and Structural Performance of Concrete with Embedded Inductive Coilshttps://cptechcenter.org/ncc-projects/evaluation-of-durability-and-structural-performance-of-concrete-with-embedded-inductive-coils/Coils (Electromagnetism); Durability; Electric power transmission; Electric vehicle charging; Inductance; Load tests; Paving; Portland cement concreteA major impediment to public acceptance of electric vehicles is their very limited travel range. An exciting potential solution to this problem is In-Motion Electric Wireless Power Transfer. This proposal addresses initial investigations of the problem from the perspective of the actual civil infrastructure. In order for the future adoption of this technology, roadways will need to be modified to allow the transmission of power to vehicles as they travel. Successful adoption of In-Motion Wireless Power Transfer will require advances in the efficiency of the overall electrical system, improvements in tracking of the actual vehicles, and significant developments in the civil infrastructure. This proposal will address the durability and constructability of coils in Portland cement concrete. The stringent electrical specifications will be monitored while repeated cycles of simulated truck tire loadings are inflicted on constructed specimens.Marvin W Halling
11/1/2016November 2016Evaluation of In-Place Concrete Strength by Coringhttps://cptechcenter.org/ncc-projects/evaluation-of-in-place-concrete-strength-by-coring/concrete cores; compressive strengthThe objective of this project is to develop an ALDOT procedure to evaluate core strength results obtained under various conditions. The procedure will account for the most significant variables that may affect the core strength and for the number of core results obtained from the structure. Experimental work will be performed to evaluate the effect of concrete age on core strength & of core L/D ratio on concrete strength for strengths greater than 6,000 psi.Aaron R Grubbs, Adam C Carroll, Anton K Schindler, Robert W Barnes
4/1/2011April 2011Evaluation of Long-Term Pavement Performance and Noise Characteristics of the Next Generation Concrete Surfacehttps://cptechcenter.org/ncc-projects/evaluation-of-long-term-pavement-performance-and-noise-characteristics-of-the-next-generation-concrete-surface/Next Generation Concrete Surface, concrete pavement, diamond grinding, quieter pavements, on board sound intensity measurementsThis report documents the performance of the first Next Generation Concrete Surface (NGCS) built by the Washington State Department of Transportation (WSDOT). On-board sound intensity (OBSI) measurements increased from initial levels of 100.6 dBA to 104.4 dBA in 30 months. The increase in noise level was attributed to the loss of aggregate and general roughening of the concrete surface by studded tires.Keith W Anderson, Jeff S Uhlmeyer, Tim Sexton, Mark Russell, Jim Weston
1/1/2016January 2016Evaluation of Lower Quality Recycled Portland Cement Concrete Pavement for Paving Applicationshttps://cptechcenter.org/ncc-projects/evaluation-of-lower-quality-recycled-portland-cement-concrete-pavement-for-paving-applications/Base course (Pavements); Concrete pavements; Hot mix asphalt; Pavement layers; Portland cement concrete; Recycled materials; Subgrade (PavementsThe primary objective of this project is to investigate the suitability of recycled concrete aggregate (RCA) for the cement-treated base layers, hot-mix asphalt concrete pavement layer, and stabilized subgrade materials.Mustaque Hossain
09/30/14September 2014Evaluation of Materials for Partial Depth PCC Repairshttps://cptechcenter.org/ncc-projects/evaluation-of-materials-for-partial-depth-pcc-repairs/partial depth repairs, cpr, patchingEvaluate performance of various materials used for partial depth PCC repairs at MnROAD.Eddie Johnson, Ben Worel, Tom Burnham
2/1/2018February 2018Evaluation of MIT-SCAN-T2 for Thickness Quality Control for PCC and HMA Pavementshttps://cptechcenter.org/ncc-projects/evaluation-of-mit-scan-t2-for-thickness-quality-control-for-pcc-and-hma-pavements/ Field tests; Nondestructive tests; Pavement performance; Portland cement concrete; Quality control; Thickness; MIT Scan-2 system Thickness is currently a pay item for PCC pavements and a quality control item for both PCC and HMA pavements. A change in pavement thickness of 0.5 in. can result in a change of multiple years of service. Current thickness measurements are performed by destructively coring the finished pavement and measuring the thickness of the core. Many times this is performed at the end of the project construction and only five representative samples are collected for each lot. Devices such as the MIT-SCAN-T2 are excellent examples of non-destructive technology capable of accurately measuring the pavement thickness. The objective was to evaluate the MIT-SCAN-T2 as a non-destructive pavement thickness measuring device for quality control and quality assurance purposes. A ruggedness study was performed in the laboratory to determine factors of influence on thickness measurements. Field evaluations were performed to test the device in actual production conditions. The ruggedness test showed the presence of steel-toe boot, surface area, plate manufacturer, and depth as potentially significant factors. However, the influence of these factors on the measured depth was large, causing significant errors in the depth readings. An additional factorial was performed with a control sample and additional runs, varying only one factor at a time. The readings obtained with this factorial were significantly more accurate, with an error of 0.2 in. for the control sample. These results show that the device is capable of accurately measuring thickness if used within the parameters recommended by the manufacturer. The field results support the finding of the ruggedness study. If all of the negative influencing factors are controlled the MIT-SCAN-T2 can accurately measure the in-place depth of pavement. If any of these factors are present, then results can be skewed heavily.Zachary Collier, Amar Raghavendra, TysonRupnow, Patrick Icenogle,
10/27/2014October 2014Evaluation of Mix Designs and Test Procedures for Pervious Concretehttps://cptechcenter.org/ncc-projects/evaluation-of-mix-designs-and-test-procedures-for-pervious-concrete.--/Compressive strength; Concrete; Flexural strength; Infiltration; Mix design; Permeability; PorosityPervious concrete is a mixture of cement, aggregate, and water that provides a level of porosity which allows water to percolate into the sub-grade. It differs from the conventional concrete since it usually contains a smaller amount of fine aggregate. There is typically single size aggregate in pervious concrete which results in larger air void than conventional concrete. The District Department of Transportation (DDOT) constructed pavements in selected street alleys using pervious concrete on a pilot basis. DDOT does not currently have its own specifications for pervious concrete. As a result, this research was aimed at developing and testing five design mixes of pervious concrete to identify the appropriate mix which would provide the maximum compressive strength with an acceptable permeability rate and flexural strength. The tests were conducted on the five design mixes using three different types of compaction methods (self-consolidating, half-rodding and Standard Proctor Hammer). Based on the results, a design mix with a compressive strength of 3,500 pounds per square inch (psi) with a maximum coefficient of permeability of 57.82 inches per hour (in/hr) was selected. The maximum modulus of rupture of the selected mix was determined to be 565 psi. The in-situ infiltration tests conducted at 3 locations in the District of Columbia (DC) with the optimal pervious concrete mix yielded average infiltration rates between 86.1 and 208.7 in/hr. This falls within the typical infiltration rate of pervious concrete (i.e., 100 to 200 in/hr, on average).Rezene Medhani, Wasi Khan, Stephen Arhin
7/1/2013July 2013Evaluation of PCC Pavement and Structure Coring and In-situ Testing Alternativeshttps://cptechcenter.org/ncc-projects/evaluation-of-pcc-pavement-and-structure-coring-and-in-situ-testing-alternatives/concrete, coring, in-place strength, non-destructive evaluationThe objective of this research is to improve interpretation of core sample test results to predict in-place concrete strength. The effect of core condition (including presence of embedded rebar) and core conditioning procedures (dry and wet) on the measured compressive strength of the core sample will be considered. Another objective of the research to evaluate the utility of practical non-destructive testing methods for estimating in-place concrete strength that could be done to reduce the amount of required coring, or provide an estimate of in situ strength for locations that cannot be cored, such as in precast pre-stressed beams. Results from this study will assist IDOT to establish procedures to estimate in-place strength of concrete with greater accuracy, where such information could be used by IDOT to improve implementation of pay-for-performance specifications for PCC construction.John S. Popovics, Agustin Spalvier, Kerry S. Hall
05/01/14May 2014Evaluation of Pervious Concrete Mixes in Areas Subject to Snow Plow Operations and Abrasive and Salt Applicationhttps://cptechcenter.org/ncc-projects/evaluation-of-pervious-concrete-mixes-in-areas-subject-to-snow-plow-operations-and-abrasive-and-salt-application/Pervious ConcreteThis research is intended to monitor field sites and conducting laboratory tests on durability and effectiveness of the pervious concrete.Ning Xie, Stephen Mery, Yudong Dang, Michelle Akin, Xianming Shi
3/1/2018March 2018Evaluation of Precast Concrete Pavement Systems and Cast-in-Place—Phase I: Identification of Accelerated Concrete Pavement Rehabilitation Methodshttps://cptechcenter.org/ncc-projects/evaluation-of-precast-concrete-pavement-systems-and-cast-in-place:-phase-i:-identification-of-accelerated-concrete-pavement-rehabilitation-methods/Cast in place concrete; Evaluation and assessment; Pavement maintenance; Performance based specifications; Portland cement concrete; Precast concrete pavements; Rehabilitation (Maintenance)The purpose of this project is to: (1) Evaluate the laboratory and field performance of several precast and Cast In-Place (CIP) rapid Portland Cement Concrete (PCC) pavement rehabilitation technologies or systems; (2) Establish a performance criteria for evaluating and approving precast and CIP systems under full-scale accelerated testing conditions applied using a Heavy Vehicle Simulator (HVS); (3) Develop a system/material approval procedure (MAP) which incorporates the performance criteria developed (previous goal) and populate NJDOT’s qualified products list (QPL) to include the best performing systems/materials; and (4) Develop system/material-specific specifications that will ensure success of selected materials.Yusuf Mehta
8/1/2014August 2014Evaluation of Recycled Aggregates Test Section Performancehttps://cptechcenter.org/ncc-projects/evaluation-of-recycled-aggregates-test-section-performance/Pavement distress, Sustainable development, Recycled materials, Test sections, Road construction, Concrete pavements, Aggregates, Freeze thaw durability, Degradation failures, Minnesota,Sustainable development is promoted by using recycled material such as recycled concrete aggregates (RCA) in construction. Several sections of concrete pavement made with RCA now exist in the Minnesota Department of Transportation (MnDOT) network. However, the long-term performance of such sections has not been formally evaluated against the performance of similar conventional concrete pavements. The variables of interest include such things as mean times between repairs or maintenance, rate of friction degradation, ride quality loss, amount of freeze-thaw degradation, aggregate alkali reaction, and other distresses. It is necessary to perform such an evaluation to get an accurate idea of the cost effectiveness of using RCA. While a reduction in initial cost may be realized by using RCA, there is the possibility that long-term costs, that is lifecycle costs, may be higher for the RCA pavements. If the lifecycle costs of RCA pavements are found to be lower than those for conventional pavements, this could lead to an increased use of RCA in pavement construction.Farhad Reza, W. James Wilde
10/17/2016October 2016Evaluation of Recycled Base Aggregateshttps://cptechcenter.org/ncc-projects/evaluation-of-recycled-base-aggregates/Asphalt pavements; Blending; Concrete aggregates; Deformation; Economic benefits; Environmental impacts; Pavement distress; Pavement performance; Recycled materialsWhile the Wisconsin Department of Transportation (WisDOT) has been using Recycled Asphalt Pavement (RAP) and Recycled Concrete Aggregate (RCA) for their economic and environmental benefits for over thirty years, there has been great interest in using them in recent years due to expected economic and environmental benefits. However, studies to support these benefits are inconclusive. Some laboratory studies indicate that, under certain conditions, RAP and RCA are more resilient, with higher durability than typical natural aggregates; but, RAP also showed temperature sensitivity and larger permanent deformations, and RCA exhibits tufa (type of limestone) formation, with a potentially lower ability to drain. Another long term (2009-2013) study found recycled and natural aggregates performed similarly; however, there are now reports of rutting and cracking. The general impression of roads constructed with recycled materials is that they are performing adequately. But we need a quantitative review of Wisconsin roads - using recycled materials compared with roads constructed with natural materials. This study needs to include a collection and comparison of pavement distress surveys for us to make wise decisions in the future. This study will conduct surveys to collect and analyze pavement distress for roadways constructed using recycled versus natural materials. If the research shows recycled materials have negative attributes, alternative techniques, such as blending aggregates, will be examined to determine if they can produce satisfactory results.Hani H. Titi, Habib Tabatabai, Jessie Ramirez, Mohammad Sooman
7/1/2017July 2017Evaluation of Reducing Cement Content in NDOR Class R Combined Aggregate Gradationshttps://cptechcenter.org/ncc-projects/evaluation-of-reducing-cement-content-in-ndor-class-r-combined-aggregate-gradations/Aggregate gradation; Air voids; Blending; Cement content; Granular materials; OptimizationTo encourage more use of locally available aggregates, Nebraska Department of Roads (NDOR) Materials and Research recently introduced a new blend aggregate band named 47B Revised (47BR). While results showed that mixes with this new blend can satisfy NDOR requirements, there is a fairly large amount of voids in the aggregate particle skeleton. As a result, a relatively high amount of cement (approximately 600pcy) is currently used in these mixes to compensate the high void content, which increase the cost of these mixes. A further study is needed to improve the cost effectiveness of the current 47BR mixes by allowing contractors and ready-mixed concrete producers to apply mixture designs with lower cement content. The reduced cement content can be achieved by reducing the void content in the aggregate granular skeleton through the change of aggregate proportion and/or the introduction of a third kind of aggregate (e.g., intermediate size aggregate) to optimize the gradation.Jiong Hu, Yong-Rak Kim
12/1/2013December 2013Evaluation of Resistivity Meters for Concrete Quality Assurancehttps://cptechcenter.org/ncc-projects/evaluation-of-resistivity-meters-for-concrete-quality-assurance/Concrete resistivity, Life cycle analysis, Quality assurance, Concrete, Concrete construction, Durability, DistressThe objective of this study is to develop appropriate test protocols for implementation of the surface resistivity test method as a quality assurance tool for new construction and for potential evaluation of existing structures in Missouri. Resistivity testing is currently the single simplest and lowest cost technique available to improve concrete lifecycle. Missourians will benefit through better quality, lower permeability concrete increasing concrete lifecycle, reducing durability distresses, and required reconstruction. Quarterly Progress Report (Oct-Dec 2013): The Request for Proposals was posted to the Research website on November 5, 2013. Proposals were due Thursday December 5, 2013 and two proposals were received. The technical advisory team met on December 19, 2013. The proposal from UMKC led by Dr. John Kevern was selected. Dr. Kevern began developing his work plan and budget to be included in the Task Order. The contract will be signed and executed at the beginning of this upcoming quarter.John T. Kevern, Ceki Halmen, Dirk P. Hudson
2/1/2014February 2014Evaluation of Test Sections Built with Recycled Aggregateshttps://cptechcenter.org/ncc-projects/evaluation-of-test-sections-built-with-recycled-aggregates/recycleThis study is designed to evaluate test sections at MnROAD where two-lift and monolithic recycled aggregates pavements have been built. It will also evaluate test sections identified in the network.Farjhad Reza
7/1/2013July 2013Evaluation of the Long-Term Performance and Benefit of Using an Enhanced Micro-Milling Resurfacing Methodhttps://cptechcenter.org/ncc-projects/evaluation-of-the-long-term-performance-and-benefit-of-using-an-enhanced-micro-milling-resurfacing-method/Micromilling, Resurfacing, Pavements, Preservation, Performance evaluations, Friction courseThe objective of this project is to examine the suitability of micromilling for pavement preservation by comparing the performance of pavement preservation methods in which friction courses are directly placed on micro milled and conventionally-milled surfaces. Yichang (James) Tsai, Zhaohua Wang, April Gadsby
12/1/2018December 2018Experimental Simulation and Quantification of Migration of Subgrade Soil into Subbase under Rigid Pavement Using Model Mobile Load Simulatorhttps://cptechcenter.org/ncc-projects/experimental-simulation-and-quantification-of-migration-of-subgrade-soil-into-subbase-under-rigid-pavement-using-model-mobile-load-simulator/Concrete pavements; Fines (Materials); Pavement joints; Pavement performance; Rigid pavements; Saturated soils; Subbase (Pavements); Subgrade (Pavements)Rigid pavement structure typically consists of a surface layer (concrete), underlying granular layers (subbase and/or base), and a compacted subgrade soil layer. Because the subgrade is saturated during wet seasons, cyclic loading caused by heavy traffic may lead to pumping of fine particles from the subgrade into the granular layers, redistribution of materials underneath the slabs, and gradual ejection of materials through pavement joints. This phenomenon results in faulting and can be a major contributor to pavement failure in wet regions. The objective of this study was to simulate and quantify the migration of subgrade soil into the subbase at rigid pavement joints. The cyclic traffic loading was simulated on a geometrically scaled model of rigid interstate highway pavement using a one-third-scale model mobile load simulator (MMLS3), an accelerated pavement testing device. Nonplastic saturated silt and partially saturated aggregate subbase were used as subgrade and subbase layers, respectively.Behnoud Kermani, Shelley M. Stoffels, Ming Xiao, Tong Qiu
9/5/2017September 2017Experimental Study on Anti-Icing and Deicing Performance of Polyurethane Concrete as Road Surface Layerhttps://cptechcenter.org/ncc-projects/experimental-study-on-anti-icing-and-deicing-performance-of-polyurethane-concrete-as-road-surface-layer/Deicing; Polymer concrete; Polyurethane resins; Shear tests;This study aims to investigate deicing and anti-icing performance of an innovative pavement surface layer that replaces asphalt binder with polyurethane, using laboratory tests. The ice-mixture composite specimens were prepared using asphalt binder and polyurethane with the same aggregate type and gradation. The deicing and anti-icing performance of polyurethane concrete at different freezing time was compared to the traditional asphalt concrete. It was found that polyurethane concrete has similar thermal conductivity but much greater specific heat as compared to asphalt concrete. Compared to asphalt concrete, polyurethane concrete can significantly retard the ice-formation time. The pull-off strength and interface shear strength at the interface of ice and polyurethane concrete is about 50% and 55% of those at the interface of ice and asphalt concrete. The work of rupture to break ice layer on polyurethane concrete is about 50% of the work required on asphalt concrete with the same ice layer thickness. The findings demonstrate the potential of using polyurethane concrete on roadways in cold regions to provide better anti-icing and deicing performance and enhance traffic safety at winter seasons.Jun Chen, Xie Ma, Hao Wang, Pengyu Xie, WeiHuang
05/30/14May 2014Extending the Usage of High-Volume Fly Ash in Concretehttps://cptechcenter.org/ncc-projects/extending-the-usage-of-high-volume-fly-ash-in-concrete/Additives, Admixtures, Cracking, Fly ash, Freeze thaw durability, Surface treating, X-ray computed tomographyConcrete mixtures that contain a high volume of fly ash (greater than 30%) have become more desirable for the increase in sustainability and economy of these mixtures. Extensive work has been completed by the principal investigator (PI) Volz for the Missouri Department of Transportation under several previous projects to show that there are many applications where high volume fly ash can be used to provide satisfactory performance. However, several additional additives had to be included in the concrete mixture to improve the reactivity and subsequent strength gain of the mixture. While these additives did improve the performance of the mixtures, there was still a measurable difference between the high volume fly ash mixtures and concretes that use traditional volumes of fly ash. Furthermore, during the durability testing of these mixtures, there was poor performance of these mixtures in the ASTM C 672 salt scaling test. These differences in performance in these materials provide significant barriers between low and high dosages of fly ash that will not allow their usage in bridge decks, pavements, sidewalks, or any element with a time sensitive strength gain. Recent work has been completed by Silva, Cheung, and Roberts of W.R. Grace to introduce a new and promising method of pre-treating fly ash by soaking it in water or other solutions before using it in concrete. This treatment allows the fly ash mixtures investigated to show improved early and later age reaction rates and subsequent strength gain. This methodology needs to be investigated with a larger number of fly ash sources and also the mechanisms need to be better understood. If the benefits of this method could be achieved in a practical manner, then this would greatly improve the ability to use high volume fly ash concrete and would address several of these critical issues with delayed strength and setting. Even if these issues are addressed then there will still be problems with the subsequent scaling of these mixtures. While there are a number of different ways to address this problem, it would be better if there was a greater understanding of the mechanisms of salt scaling with high volume fly ash and why it is more severe than low volumes. In order to investigate this, the research team will use X-ray computed tomography techniques to image samples during freezing and thawing cycles. This technique can make 3D maps of materials with a scale of 1 micron and has been a significant focus of research of PI Ley at OSU. This technique will allow direct observations to be made of the crack initiation sites and their subsequent growth under freezing cycles. Once the scaling mechanism is better understood, then this will give much greater insight to guide future solutions.Jeffery S. Volz
9/15/2018September 2018Feasibility Study of 3D Printing of Concrete for Transportation Infrastructures TR-756https://cptechcenter.org/ncc-projects/feasibility-study-of-3d-printing-of-concrete-for-transportation-infrastructures-tr-756/Feasibility analysis; Infrastructure; Mix design; Printers; Technological innovations; Three dimensional displaysThere is a growing interest in 3D concrete printing worldwide. Through automation, digitalization, and process planning, 3D printing technology permits to create concrete structures having complex geometry (various shapes/cross-sections) with high precision. It also enables concrete construction under extreme conditions that are difficult and/or very costly for conventional concrete formwork setup, placing, and/or consolidation. Many breakthroughs have been made in 3D concrete printing already, and one of them is the recent development in printing of reinforced concrete, which has opened a new door for further innovations and applications of 3D printed concrete. In spite of significant progress of this technology, studies on 3D concrete printing for the applications in transportation infrastructures are still very limited. This proposed project is to explore the feasibility to fill this gap. Research has indicated that in addition to the proper printing equipment and automation design tools, a core for successful 3D printed concrete is to have a desirable robust “ink” – an engineered concrete mixture. The focus of this proposed project is to develop a printable, functional concrete mixture. It is expected that this explorative study will bring many 3D printing related innovations to Iowa and offer a revolutionary perspective on the future structural concrete design and construction of transportation infrastructures as well as on emergency road/bridge repairs.Kejin Wang
10/1/2018October 2018FHWA Research and Technology Evaluation: Precast Concrete Pavementhttps://cptechcenter.org/ncc-projects/fhwa-research-and-technology-evaluation:-precast-concrete-pavement/Precast concrete pavement (PCP)This evaluation assesses the outcomes of the Federal Highway Administration’s (FHWA’s) investment in precast concrete pavement (PCP). The evaluation team determined the benefits and costs of individual PCP projects and, where possible, extrapolated findings from the data based on overall themes. Additionally, the evaluation team determined the outcomes and impacts of FHWA research, demonstrations, workshops, and related activities and developed recommendations to facilitate the continued adoption of the technology. FHWA’s efforts were found to be largely successful and contributory to the development and adoption of PCP. FHWA has overseen initial research and prototypes and has helped the use of PCP technology become routine in some States. PCP is an effective and efficient way to conduct roadway maintenance, repairs, and reconstruction. Benefits significantly exceed costs in high-volume areas or unique roadway sections that would lead to significant detours if closed for long periods of time. PCP also allows for innovative maintenance practices and cost savings, such as the reuse of concrete panels for temporary repairs.Greg Bucci, Matthew Keen, Kaitlin Coppinger, JoeCondon
2/1/2018February 2018Fiber (Steel) Reinforced Concrete for Improved Performance of Transportation Infrastructurehttps://cptechcenter.org/ncc-projects/fiber-(steel)-reinforced-concrete-for-improved-performance-of-transportation-infrastructure/Steel fiber reinforced concrete, establish optimal mix designs, implementation, validate design procedures for SFRCSteel fiber-reinforced concrete (SFRC) provides improved tensile performance of concrete. This improved performance can be used in slabs to reduce the volume of conventional steel reinforcement, create longer spans, or reduce slab thickness. Use of SFRC can lead to a reduction in structure weight and improvements in the safety and speed of construction. These benefits can result in cost savings in both the short term (construction labor) and the long term (improved quality and durability). To maximize the benefits of SFRC, it is necessary to establish optimal mix designs, identify target projects for implementation, and validate design procedures for SFRC. This project investigated the application of SFRC in pavements and bridge decks to reduce the amount of traditional steel used and to improve service level performance. The project consisted of four main tasks. The first was a review of the literature on SFRC applications to elevated slabs and slabs-on-grade. This was followed by case studies on implementation of SFRC for pavement and bridge decks. Results of the case studies informed the development of an experimental test program. Finally, all results were compiled to develop design recommendations and an implementation plan. The report summarizes the project findings and provides recommendations for the implementation of SFRC in Arizona Department of Transportation infrastructure.Anna C. Birely, Philip Park, Joshua A. McMahon, Xijun Shi, Younho Rew
1/1/2019January 2019Fiber-Reinforced Concrete in Bridge Decks TR-767https://cptechcenter.org/ncc-projects/fiber-reinforced-concrete-in-bridge-decks-tr-767/Benefit cost analysis; Bridge decks; Cracking; Fiber reinforced concrete; Field tests; High performance concrete; Laboratory tests; Mix design; Service lifeThe main objective of this research project is to design and evaluate the use of fibers in HPC mixes to prevent or reduce early-age cracking in bridge decks. This will be achieved through a systematic investigation supported by laboratory and field tests to ensure that the developed concrete mixes will meet both short- and long-term properties of interest. This project will begin with a comprehensive literature search and survey, which will supplement the knowledge and experience of the research team in working with fiber-reinforced concrete (FRC). A set of HPC mixes, including standard HPC, HPC with fibers, and HPC with fibers and admixtures will then be developed using fibers of different type, geometry, and dosage.Behrouz Shafei
7/1/2016July 2016Field Implementation and Monitoring of Behavior of Economical and Crack-Free High-Performance Concrete for Pavement and Transportation Infrastructure Constructions - Phase IIhttps://cptechcenter.org/ncc-projects/field-implementation-and-monitoring-of-behavior-of-economical-and-crack-free-high-performance-concrete-for-pavement-and-transportation-infrastructure-constructions-phase-ii/Asphalt mixtures; Cracking; Field tests; High performance concrete; Infrastructure; Mix design; Pavement performance; Sustainable transportationEconomical and crack-free high-performance concrete (Eco-HPC) is a new class of environmentally friendly and cost-effective high-performance concrete (HPC) that is made of low binder content, high volume of supplementary cementitious materials (SCMs), and shrinkage mitigating materials. The initial phase of research that involved an extensive laboratory investigation indicated that the designed Eco-HPC can secure high resistance to shrinkage cracking, and high strength and durability.Kamal H. Khayat, Iman Mehdipour, Zemei Wu
7/1/2016July 2016Field Implementation of High-Volume Recycled Materials for Sustainable Pavement Constructionhttps://cptechcenter.org/ncc-projects/field-implementation-of-high-volume-recycled-materials-for-sustainable-pavement-construction/Concrete aggregates; Field tests; Monitoring; Recycled materials; Road construction; Sustainable transportationThe objective of this study was to evaluate the feasibility of producing sustainable concrete materials for rigid pavement construction using high volume of recycled materials. The goal was to replace 50% of all solid materials in the concrete with recycled materials and industrial by-products. This included the replacement of cement with at least 50% supplementary cementitious materials (SCMs) and aggregate with 50% recycled concrete aggregate (RCA).Kamal H. Khayat, Seyedhamed Sadati
7/1/2016July 2016Field Implementation of Super-Workable Fiber-Reinforced Concrete for Infrastructure Constructionhttps://cptechcenter.org/ncc-projects/field-implementation-of-super-workable-fiber-reinforced-concrete-for-infrastructure-construction/Bridge construction; Bridge members; Fiber reinforced concrete; Infrastructure; Performance based specifications; Self compacting concrete; Substructures; Superstructures; WorkabilityA fiber-reinforced super-workable concrete (FR-SWC) made with 0.5% micro-macro steel fibers and 5% calcium oxide (CaO)-based expansive agent was used for the new deck slab of Bridge A8509. The selected FR-SWC had a targeted slump flow of 20 in. at the casting location. Multiple trial batches were performed, in collaboration with the concrete supplier, to adjust the mixture composition to meet the targeted performance criteria. This was followed up by casting the fibrous concrete in a mock-up slab measuring 10 × 10 ft that was prepared to simulate the tight rebar and the roadway crown slope in the transverse direction. The results indicated the necessity to lower the concrete slump from the intended value for FR-SWC to hold the 2% crown slope of the bridge deck in the transverse direction. The final mixture that was selected following the trial batches and mock-up placement had a slump consistency of 8 ± 2 in. (FRC). Six sensor towers were installed in the slab within 18 ft to the East and West sides of the intermediate bent to monitor in-situ properties of the concrete.Kamal H. Khayat, Ahmed Abdelrazik
10/1/2017October 2017Field Testing of an Ultra-High Performance Concrete Overlay on Bridge Deckshttps://cptechcenter.org/ncc-projects/field-testing-of-an-ultra-high-performance-concrete-overlay-on-bridge-decks/Ultras High Performance Concrete Overlay on Bridge DecksBridge decks are commonly rehabilitated using overlays, depending on the cause of deck deterioration, available budget, and desired service life of the rehabilitated structure. One emerging solution for bridge deck rehabilitation is thin, bonded, ultra-high performance concrete (UHPC) overlays. As an overlay material, UHPC can provide both structural strength and protection from ingress of contaminates using a 1 inch to 2 inch layer of material.The first U.S. deployment of UHPC as a bridge deck overlay was completed in May 2016 on a reinforced concrete slab bridge located in Brandon, Iowa. A few months after installing the UHPC overlay, a field inspection of the bridge identified some locations along the deck where delamination may have occurred. To address this concern, a field study was conducted in November 2016 to evaluate the bond between the UHPC overlay and the substrate concrete bridge deck. Researchers from the Federal Highway Administration's (FHWA) Turner-Fairbank Highway Research Center (TFHRC) synthesized photographic evidence, conducted a field inspection of the bridge deck surface using a chain drag, and conducted physical testing of the UHPC-concrete interface bond using the direct tension bond pull-off test. Tested samples were taken back to TFHRC, and the UHPC-concrete interface was subsequently analyzed using scanning electron microscopy (SEM). The pull-off test data indicated that the UHPC overlay and the existing concrete bridge deck were intact, which was confirmed by SEM analysisZachary B. Haber, Jose F. Munoz, Benjamin A. Graybea
3/31/2017March 2017Forensic Investigation of Continuously Reinforced Concrete Pavements in Fair and Poor Conditionhttps://cptechcenter.org/ncc-projects/forensic-investigation-of-continuously-reinforced-concrete-pavements-in-fair-and-poor-condition/Continuously reinforced concrete pavements; Deterioration by environmental action; Nondestructive tests; Pavement cracking; Pavement maintenance; Structural deterioration and defectsContinuously reinforced concrete pavement (CRCP) sections contain longitudinal and transverse reinforcement that spans the entire pavement section. This paper presents the investigation result of two CRCP sections that exhibited closely spaced cluster cracks. One of the CRCP sections was in relatively poor condition because of distress in the form of several punchouts. In the forensic pavement investigation conducted jointly by a research team and the Georgia Department of Transportation, both nondestructive and destructive tests were used to investigate CRCP performance. It was concluded that the cluster-cracking mechanism was related to material and environmental factors. It was also concluded that the relatively poor CRCP section experiencing punchouts was due to poor concrete compaction and other construction issues. A long-term monitoring program was recommended by the investigation team to further identify signs of punchout distress and provide any needed rehabilitation.Mi G. Chorzepa, Catherine Johnson; S. Sonny Kim, Stephan Durham
3/1/2019March 2019Forensic Investigation of Distresses Found in Jointed Plain Concrete Pavementshttps://cptechcenter.org/ncc-projects/forensic-investigation-of-distresses-found-in-jointed-plain-concrete-pavements/Concrete pavements; Cracking of concrete pavements; Forensic science; Load transfer; Pavement distress; Pavement joints; Unreinforced concreteJointed plain concrete pavement (JPCP) is commonly used in roadway construction as an economical choice when distributed steel reinforcement is not necessary. The performance of JPCP depends on the joint load transfer efficiency and design parameters such as slab thickness, concrete strength, and dowel/joint spacing. This paper investigates two JPCP sections, State Route (SR)-22 in good condition and Interstate Highway (I)-75 in poor condition. The distress in the I-75 section is mainly depicted by longitudinal (or linear) cracks running the full depth through the concrete slabs. To understand the cause of distress, a forensic investigation was conducted jointly by a research team and the Georgia Department of Transportation. As part of the investigation, both nondestructive and destructive tests were performed using a falling weight deflectometer ground penetration radar, corings, and laboratory tests including petrographic analysis. Three sources of distress were considered in this study: environmental, traffic load, and material-related cracking mechanisms.Mi G. Chorzepa, Catherine Johnson; S. Sonny Kim, Stephan Durham
8/13/2014August 2014Forensic Study of Early Failures with Unbonded Concrete Overlayshttps://cptechcenter.org/ncc-projects/forensic-study-of-early-failures-with-unbonded-concrete-overlays/ Concrete overlays; Costs; Pavement design; Pavement distress; Pavement maintenance; PavingThe Ohio Department of Transportation (ODOT) has constructed over 350 lane miles of Unbonded Concrete Overlays (UBCO). For the most part these overlays have performed as expected. However, occasionally an UBCO is constructed which performs below expectations. The objective is to determine the mechanisms of failure responsible for each distress evident at the time of the study. The goal being to tie these mechanisms to the design, construction and/or materials practices or standards that can be modified to gain better performance and eliminate or delay these types of problems in the future. The research is expected to result in a better understanding of how to design and construct an unbonded concrete overlay. Ultimately, this research is expected to produce cost savings by preventing premature distress formations in unbonded concrete pavement overlays and reducing future maintenance costs to those projects through improved performance of the overlays.Shad Sargand, Roger Green, Junqing Zhu, Issam Khoury
4/19/2017April 2017Four High Performance Nonproprietary Concrete Deck Configurations for Movable Bridgeshttps://cptechcenter.org/ncc-projects/four-high-performance-nonproprietary-concrete-deck-configurations-for-movable-bridges/Admixtures; Bridge decks; Concrete pavements; Fiber reinforced polymers; Finite element method; High performance concrete; Movable bridgesFour high performance nonproprietary concrete bridge deck configurations are presented for Louisiana’s movable bridges as an alternative to traditional steel grid decks, which have exhibited durability problems. These concrete decks are as light and as deep as the traditional steel grid decks and meet the maximum weight limitation of 0.96 kN/m2 imposed by the capacity of the mechanical systems that operate the movable bridges. The four concrete deck configurations feature unique nonproprietary concrete mixtures that possess high strength and low unit weight. The development of each concrete mixture is presented. All reinforcement is corrosion resistant and consists of glass fiber reinforced polymer (GFRP) bars and a two-way carbon fiber mesh. Several nonlinear finite element analyses are performed to simulate the behavior of all four concrete deck configurations from the onset of loading to failure and to ensure that the developed deck configurations meet AASHTO’s load and deflections requirements. AASHTO’s ultimate load demand is met regardless of whether the deck system is made continuous for live loads. Two deck configurations meet AASHTO’s deflection requirements when continuity for live loads is established. The failure mode of the concrete deck panels is dominated by shear. The presented deck configurations offer the departments of transportation various feasible options and thus more flexibility for to how to address problems related to the deterioration of steel grid decks using locally available materials, and provide guidance as to what experimental testing to perform in the future.Hadi Baghi, Fatmir Menkulasi, Carlos Montes, Jean Paul Sandrock Jr., Sergio Gomez
2/28/2018February 2018Freeze Thaw and Deicer Salt Scaling Resistance of Concrete Prepared with Alkali Aluminosilicate Cementhttps://cptechcenter.org/ncc-projects/freeze-thaw-and-deicer-salt-scaling-resistance-of-concrete-prepared-with-alkali-aluminosilicate-cement/Alkali; Cement; Concrete; Deicing chemicals; Freeze thaw durability; Scaling (Concrete); Aluminosilicates; Highways; Materials; Pavements;Concrete materials were prepared with a cement based primarily on the alkali aluminosilicate chemistry. Two aspects of concrete performance were emphasized and compared against those of ordinary Portland cement (OPC) concrete: freeze-thaw durability, and deicer salt scaling resistance. Test results indicated that the concrete prepared with the alkali aluminosilicate cement (AAC) produced excellent freeze-thaw durability; its dicer salt scaling resistance, however, was lower than that provided by the OPC concrete. Efforts were made to improve the deicer salt scaling resistance of the AAC concrete through refinement of the AAC composition. The use of an air-entraining agent was found to enhance the deicer salt scaling resistance of the AAC concrete. Modification of the AAC chemistry with polyethylene glycol, tartaric acid, or a combination of sodium benzoate and triisopropanolamine was found to also improve the AAC concrete resistance to deicer salt scaling with minimal effect on compressive strength.Faris Matalkah, Parviz Soroushian
6/6/2014June 2014Full-Depth Reclamation (FDR) for Suburban/Urban and Local Roads Applicationhttps://cptechcenter.org/ncc-projects/full-depth-reclamation-fdr-for-suburban-urban-and-local-roads-application/Full-depth reclamation, Cost effectiveness, Rehabilitation (Maintenance), Urban highways, Rural highways, Guidelines, Road construction, ReconstructionFull depth reclamation (FDR) is widely recognized as a cost-effective rehabilitation method for road reconstruction, and can provide increased structural capacity when additional stabilizing agents are used. While this method has been extensively used and evaluated in the rehabilitation of county and state roads, it has received less attention as a rehabilitation alternative for urban and suburban streets. The objective of the project is to evaluate the advantages and limitations of using FDR for urban and suburban streets and to propose guidelines for implementing FDR as a rehabilitation procedure for street applications. A literature review and survey will be conducted followed by an experimental to identify the most suitable and cost effective technology to be applied to street rehabilitation.Marcella Hartman, Mugur Turos, Debaroti Ghosh, Mihai Marasteanu
3/10/2015March 2015Further Validation of ASR Testing and Approach for Formulating ASR Resistant Mixhttps://cptechcenter.org/ncc-projects/further-validation-of-asr-testing-and-approach-for-formulating-asr-resistant-mix/Admixtures, Alkali silica reactions, Mix design, Aggregates, Fly ash, Test procedures, Concrete cylinders, Hydraulic cementThe main objectives of this project is to further validate the aggregate-solution method and the accelerated concrete cylinder testing (ACCT) and validate the approach (developed in research project 0-6656) of developing alkali silica reaction (ASR) resistant concrete mix. Developing Alkali-silica reaction (ASR) resistance mix is a combined approach of aggregate -solution testing measuring Ea (activation energy) and threshold alkalinity (THA) and concrete testing. The specific objectives are as follows: (1) Validate the usefulness of threshold alkalinity in determining alkali loading for different aggregate sources which could potentially be used to modify mix design option 7. In option 7 of Texas Department of Transportation (TxDOT) Item 421, it is recommended that the total alkali contribution from cement in the concrete should not exceed 3.5 lbs per cubic yard of concrete when using hydraulic cement alone. With the eventual loss of Class F fly ash sources, the department needs to investigate other methods to determine potential reactivity of aggregates in terms of alkali threshold (current test methods are not appropriate for this analysis) in order to be prepared in the event Class F fly ash is no longer readily available. (2) Further validation of ACCT (testing period, expansion limits, level of alkali loadings, appropriate level of soak solution chemistry, suitable specimen dimension etc.) method - Use the TxDOT field exposure block data to calibrate the ACCT method. (3) Suitability of ACCT to test job mix. (4)Validation of the combined approach using both aggregate-solution and concrete testing for formulating ASR resistant mix.Anol Mukhopadhyay, Kai-Wei Liu, Mostafa Jalal
3/1/2014March 2014Georgia Long-Term Pavement Performance (GALTPP) Program - Maintaining Georgia's Calibration Sites and Identifying The Potential for Using MEPDG For Characterization of Non-standard Materials and Methods (Phase 1)https://cptechcenter.org/ncc-projects/georgia-long-term-pavement-performance-(galtpp)-program-?-maintaining-georgia?s-calibration-sites-and-identifying-the-potential-for-using-mepdg-for-characterization-of-non-standard-materials-and-methods-(phase-1)/Calibration; Data collection; Field tests; Geographic information systems; Laboratory tests; Mathematical prediction; Mechanistic-empirical pavement design; Pavement distress; Pavement performanceThe Georgia Department of Transportation (GDOT) has initiated a Georgia Long-Term Pavement Performance (GALTPP) monitoring program 1) to provide data for calibrating the prediction models in the AASHTO Mechanistic-Empirical Pavement Design Guide (MEPDG) and 2) to monitor sites for evaluating the effect of various materials and methods on pavement performance. A total of 38 flexible pavement sites (17 LTPP and 21 non-LTPP) and 23 rigid pavement sites (11 LTPP and 12 non-LTPP sites) sites were selected for the MEPDG calibration and various field and laboratory testing, including condition surveys in accordance with LTPP Distress Identification Manual, Falling Weight Deflectometer (FWD), etc., were conducted on the non-LTPP sites. Yi-Ching Wu, Yichang (James) Tsai
6/1/2014June 2014Grains of Gain. Roads & Bridges, Volume 52, Issue 5, 2014, pp 52-55https://cptechcenter.org/ncc-projects/grains-of-gain.-roads-&-bridges,-volume-52,-issue-5,-2014,-pp-52-55/Artificial aggregates; Concrete pavements; Evaluation; Fine aggregates; Mix design; Portland cement concrete; Proportioning; Skid resistance; StudiesManufactured fine aggregates are a product created when rocks are crushed using a mechanical crusher. With the depletion of sources of natural sands, the usage of manufactured fine aggregates has increased. Manufactured fine aggregates have properties that differ from natural sands; for this reason, the plastic and hardened properties of concrete produced using manufactured fine aggregates differ from the properties of concrete made with natural sands. The main concrete properties affected by the usage of manufactured fine aggregates are skid resistance, workability, and finishability. The aim of this research project was to investigate how manufactured fine aggregates could be used in concrete pavements without causing workability or skid related issues. To improve the workability of concrete made with manufactured fine aggregates, the use of the optimized mixture proportioning method developed by the International Center for Aggregate Research (ICAR) was investigated. Results obtained from this testing were used to make recommendations.Marc Rached, David W. Fowler
12/1/2018December 2018Greenhouse Gas Reduction Opportunities for Local Governments: A Quantification and Prioritization Frameworkhttps://cptechcenter.org/ncc-projects/greenhouse-gas-reduction-opportunities-for-local-governments:-a-quantification-and-prioritization-framework/Alternatives analysis; Climate change; Decision support systems; Economic factors; Greenhouse gases; Infrastructure; Life cycle analysis; Life cycle costingUnder Senate Bill 375, California counties and cities must develop greenhouse gas (GHG) reduction targets and specific actions to achieve them. Many of these Climate Action Plans (CAPs) are being updated now, and some existing CAPs reflect a lack of consistent methodology, relevant information, and data to support robust GHG reduction targets, and lack clarity on the likelihood of success or economic costs of mitigation. Local jurisdictions and agencies responsible for managing roadways and associated right of ways, parking, complete streets, and other transportation infrastructure assets and related operation and maintenance may play a crucial role in GHG reduction goals.Alissa Kendall, John Harvey
1/1/2013January 2013Ground Tire Rubber (GTR) as a Component Material in Concrete Mixtures for Paving Concretehttps://cptechcenter.org/ncc-projects/ground-tire-rubber-(gtr)-as-a-component-material-in-concrete-mixtures-for-paving-concrete/Tires, Mix design, Admixtures, Concrete pavements, Compressive strength, Flexural strength, Cracking, Shrinkage, Laboratory tests, Life cycle costing, Ground tiresThis research was done to investigate if the problems associated with flexibility and temperature sensitivity (expansion and contraction) in roadway concrete pavements can be addressed by replacing some of the fine or coarse aggregate component with crumb rubber, specifically, Ground Tire Rubber (GTR). The research also intended to find out the general effects of adding the GTR to the conventional pavement concrete, in terms of the mechanical properties and workability, requiring several laboratory tests to be conducted as part of the study. Finally, the research was required to evaluate the practical implementation at a ready mix plant, of the proposed use of GTR as a component in the concrete. It was found from the study that the modulus of elasticity of concrete is reduced when GTR is used in concrete, thus the pavement concrete becomes more flexible. Based on the results of the tests for the coefficient of thermal expansion (CTE), it was not conclusive from this study, that adding GTR will significantly affect the expansion and contraction in the concrete pavement.John O.Sobanjo, Kamal S. Tawfiq, Richard Twumasi-Boakye, Sylvester Inkoom, Sheldon Gibbs
11/1/2014November 2014High Early-Strength High-Performance Concrete for Rapid Pavement Repairhttps://cptechcenter.org/ncc-projects/high-early-strength-high-performance-concrete-for-rapid-pavement-repair/High performance concrete, State departments of transportation, Pavement performance, Mix design, Specifications, Durability, Repairing, Literature reviewsThe objective of this study is to (1) review and survey the current materials, concrete mixes and procedures for rapid repair being used by different departments of transportation (DOTs) and other state highway agencies. The review/survey will include benefits, disadvantages, costs and longevity of each method. The findings of literature/survey will be used as a basis for definition of minimum strength and durability requirements of rapid repairs and selection of the most reliable methods for experimental program; (2) evaluate performance of different rapid repair methods and introduce high performance mixtures for rapid repair. Different mixtures with adequate longevity and for different opening times will be introduced to be applied in different projects. The final definition of test parameters, level of performance and costs will be provided; and (3) categorize technologies and methods available for installation, and provide a manual guidance for material specification, mix design, casting and curing of the rapid repairs.Nader Ghafoori, Meysam Najimi, Matthew Maler
1/1/2019January 2019High Performance Concrete with Post-Tensioning Shrinking Fibershttps://cptechcenter.org/ncc-projects/high-performance-concrete-with-post-tensioning-shrinking-fibers/Durability;ÿFiber reinforced concrete;ÿHigh performance concrete;ÿMechanical properties;ÿPolymer fibers;ÿPosttensioningThis research improves upon the technique of reinforcing concrete with dispersed fibers by having the fibers axially shrink after curing to produce a dispersed multi-axial post-tensioned state. Such reinforcing has the potential to increase the crack resistance and durability of the concrete. Preliminary benchtop testing with natural chitosan polymer fibers have confirmed the viability of the technique, where certain configurations show significant strengthening with the shrinking fibers. The proposed research would expand the knowledge base by examining larger scale chitosan samples, exploring steel and nitinol shape memory fibers that produce a similar effect, studying the underlying mechanical principles and exploring direct applicability to transportation structures.Dryver Huston
6/15/2015June 2015High-Volume Recycled Materials for Sustainable Pavement Constructionhttps://cptechcenter.org/ncc-projects/high-volume-recycled-materials-for-sustainable-pavement-construction/Concrete pavements, Recycled materials, Concrete, Infrastructure, Sustainable development, Paving,The proposed study aims at developing sustainable concrete materials for infrastructure applications. The main objective of the proposed research project is to maximize the content of recycled materials (at least 50% of the mass of solids) in concrete pavement in an effort to reduce the overall material cost of pavement construction as well as enhancing the sustainability aspects of these operations.Kamal H. Khayat, Seyedhamed Sadati
2/1/2016February 2016Hydrologic Performance of Four Permeable Pavement Systems Constructed over Low-Permeability Soils in Northeast Ohiohttps://cptechcenter.org/ncc-projects/hydrologic-performance-of-four-permeable-pavement-systems-constructed-over-low-permeability-soils-in-northeast-ohio/Clay soils; Drawdown (Hydraulics); Hydrology; Impervious soils; Pavement performance; Porous pavements; Runoff; Permeability (material), Stormwater management, Peak flow, Filtration, Permeability (soil), Pavement condition, Concrete pavements, Water storagePermeable pavements benefit urban hydrology through detention of stormwater in the aggregate base and subsequent exfiltration to the underlying soil. The majority of previous research has focused on permeable pavements constructed in sandy soils and/or treating only direct rainfall. Four permeable pavements employing internal water storage (IWS) zones and situated over low-permeability soils were intensively monitored for their hydrologic performance in northern Ohio. Volume reduction varied from 16 to 53% for permeable pavements with low drawdown rates (<0.35  mm/h) and loading ratios (Watershed Area+Permeable Pavement Area divided by Permeable Pavement Area) exceeding 5∶1. Postconstruction drawdown rates were similar to saturated hydraulic conductivity (Ksat) measured during construction, suggesting that lateral exfiltration and evaporation were relatively minor contributors to volume reduction. Stormwater was completely captured (i.e., no discharge from the permeable pavements) during 4–80% of observed storm events. Average depth of abstraction ranged from 3.0 mm (site with highest loading ratio) to 25.2 mm (site treating only direct rainfall). Substantial peak flow mitigation was observed for all rainfall events not producing surface runoff (i.e., untreated bypass). Under these conditions, peak flow was diminished by more than 80% for seven events exceeding the 1-year, 5-min design rainfall intensity for Cleveland, Ohio. Lower loading ratios, reduced surface runoff, an IWS zone, and higher underlying soil Ksat directly impacted volume reduction and peak flow mitigation. Overall, permeable pavement mitigated negative hydrologic impacts of impervious surfaces even when sited over low-conductivity clay soils.Ryan J. Winston, Jay D. Dorsey, Alessandra P. Smolek, William F. Hunt
2/28/2018February 2018Identify Best Practices in Pavement Design, Materials, Construction and Maintenance in Wet Freeze Climates Similar to Michiganhttps://cptechcenter.org/ncc-projects/identify-best-practices-in-pavement-design,-materials,-construction-and-maintenance-in-wet-freeze-climates-similar-to-michigan/Best practices; Climate; Freezing; Literature reviews; Materials selection; Pavement design; Pavement maintenance; Pavements; Paving; Wet weatherThe intent of this research is to identify best practices for pavements in wet-freeze climates. For the purposes of this report, a best practice is a procedure that has been shown by research or experience to produce improved results and that is established or proposed as a standard suitable for widespread implementation. This project identified the criteria used to determine locations around the country and the world with a similar wet-freeze climate as that of Michigan. This project documented the process of conducting the literature review, the method of analysis pertaining to the discovered information, and the organization of the report.Zhanping You, Chris Gilbertson, Thomas Van Dam
1/1/2016January 2016Impact of Curling and Warping on Concrete Pavementhttps://cptechcenter.org/ncc-projects/tr-668-impact-of-curling-and-warping-on-concrete-pavement-active/Concrete pavements; Curling; Field studies; Laser radar; Pavement performance; Portland cement concrete; Quality assurance; Quality control; Recommendations; WarpagePortland cement concrete (PCC) pavement undergoes repeated environmental load-related deflection resulting from temperature and moisture variations across the pavement depth. This phenomenon, referred to as PCC pavement curling and warping, has been known and studied since the mid-1920s. Slab curvature can be further magnified under repeated traffic loads and may ultimately lead to fatigue failures, including top-down and bottom-up transverse, longitudinal, and corner cracking. It is therefore important to measure the “true” degree of curling and warping in PCC pavements, not only for quality control (QC) and quality assurance (QA) purposes, but also to achieve a better understanding of its relationship to long-term pavement performance.Halil Ceylan, Shuo Yang, Kasthurirangan Gopalakrishnan, Sunghwan Kim, Peter Taylor, Ahmad Alhasan
5/15/2018May 2018Impact of Curling and Warping on Concrete Pavement: Phase 2https://cptechcenter.org/ncc-projects/impact-of-curling-and-warping-on-concrete-pavement-phase-2/Concrete pavements; Curling; Laser radar; Mix design; Pavement performance; Portland cement concrete; WarpageThe impacts of curling and warping on long-term pavement performance are not well understood. While some recent studies have pointed to a strong connection between the two, others have stated that these findings may not be as significant as first thought. At the same time, we continue to seek out more cost-effective ways of designing and constructing pavements without sacrificing performance. In order to do this, the curling and warping relationship must be better understood. Phase I by Dr. Ceylan and his research team, “Impact of Curling and Warping on Concrete Pavement” (Phase I), field investigations were performed at six identified sites in Iowa highways to better understand the curling and warping behavior of portland cement concrete (PCC) pavements in Iowa and provide recommendations to mitigate PCC curling and warping. A stationary light detection and ranging (LiDAR) device was used to scan the slab surfaces. The degree of curling and warping along longitudinal, transverse, and diagonal directions were calculated for the predetermined slabs based on the point clouds acquired using LiDAR. The results and findings were correlated to pavement performance, mix design, pavement design, and construction-related variations at each site. the curling and warping literature suggested that water absorption of coarse aggregate is one of the significant mix design variables affecting warping degree/magnitude, but little reported information currently exists on water absorption of coarse aggregate used in Iowa PCC pavements to validate this literature review finding. Thus, a more comprehensive follow-up study on the impact of curling and warping on Iowa concrete pavement is recommended.Halil Ceylan
1/1/2011January 2011Impact of Environmental Factors on Pavement Performance in the Absence of Heavy Loads https://cptechcenter.org/ncc-projects/impact-of-environmental-factors-on-pavement-performance-in-the-absence-of-heavy-loads/LTPP, Pavement performance, Damage, Environmental factors, JPCP, ACP, Subgrade, SPS-8, Truck loadings, Cost allocationThe objectives of this study were to identify and quantify the effects of environmental factors and pavement design on pavement performance in the absence of heavy loads; establish what the environmental effects are and develop recommendations for mitigating these effects through effective designs, materials selection, and construction; estimate the portion of total pavement damage caused by environmental factors; and establish a database of pavement design features, materials properties, and performance to be used in the future for similar analyses. Site-by-site analyses of the Long-Term Pavement Performance program’s Specific Pavement Study (SPS)-8 sections were conducted. Next, researchers determined the effect of environmental factors in SPS-8 and companion sections from other SPSs and General Pavement Studies (GPSs) on the performance of flexible and rigid pavements. Finally, an estimate of the portion of pavement damage caused by environmental factors was made through a comparison of the pavement damage of low-traffic SPS-8 sections with higher-traffic companion SPS and GPS sections. Results showed an average of 36 and 24 percent of total damage was related to environmental factors for flexible and rigid pavements, respectively, at an age of 15 yr.Leslie Titus-Glover, Michael I. Darter, Harold Von Quintus
12/1/2018December 2018Impact of Local Calibration Using Sustainable Materials for Rigid Pavement Analysis and Designhttps://cptechcenter.org/ncc-projects/impact-of-local-calibration-using-sustainable-materials-for-rigid-pavement-analysis-and-design/Admixtures; Concrete pavements; Fine aggregates; Mechanistic-empirical pavement design; Pavement performance; Rigid pavements; Sustainable development; Thermal propertiesA catalog of locally appropriate Mechanistic-Empirical Pavement Design Guide (M-EPDG) inputs was developed for North Carolina Department of Transportation (NCDOT) rigid pavements using 18 concrete mixtures produced with two ordinary portland cements (OPCs), portland limestone cement (PLC), two fly ashes, and local aggregates. Equivalent mechanical and thermal performance was found between mixtures using OPC and PLC, supporting use of these sustainable cements. Tests for coefficient of thermal expansion (CTE), thermal conductivity, and heat capacity revealed default values are very conservative for North Carolina use. Varying coarse aggregate type did not greatly influence performance. However, fine aggregate type (manufactured or natural sand) significantly influenced concrete thermal properties.Tara L. Cavalline, Brett Q. Tempest, Edward H. Blanchard; Clayton D. Medlin, Rohit R. Chimmula, Clark S. Morrison
7/1/2018July 2018Impact of Water/Cementitious-Based Concrete Mix Design Specification Changes on Concrete Pavement Qualityhttps://cptechcenter.org/ncc-projects/impact-of-water-cementitious-based-concrete-mix-design-specification-changes-on-concrete-pavement-quality/Admixtures; Air content; Concrete pavements; Design standards; Mix design; Pavement management systems; Permeability; Ride quality; Specifications; Water cement ratioThis research investigated the impact of MnDOT implementing a w/cm-based specification for concrete pavements. Pavement sections constructed before and after the specification implementation were examined to assess permeability, compressive strength and air-void system parameters. Pavement management system data was examined to identify changes in ride quality associated with the specification change. The results show the change to a w/cm-based specification resulted in concrete with lower permeability, higher strength, and increased air content. The ride quality for those pavements appears to be better and the rate of degradation of ride quality appears to be slower.Lawrence Sutter, Gerard Moulzolf, Maria Masten
9/1/2016September 2016Implementation of ASTM C157: Testing of Length Change of Hardened Concretehttps://cptechcenter.org/ncc-projects/implementation-of-astm-c157:-testing-of-length-change-of-hardened-concrete/Acceptance tests; Bridge decks; Concrete tests; Implementation; Mix design; ShrinkageThe Kansas Department of Transportation (KDOT) has a history of using tests such as concrete strength, permeability, and air void structure as design and acceptance criteria on concrete paving and bridge deck projects. In 2012, the KDOT Concrete Research group concluded a study on testing the length change of hardened concrete according to ASTM C157 (2008), commonly referred to as free shrinkage. This free shrinkage test was reviewed as a possible design or acceptance test for construction projects, primarily relating to bridge decks where even minimal cracking is detrimental.Andrew Jenkins
3/31/2015March 2015Implementation of Concrete Pavement Mixture Design and Analysis (MDA) Track of Concrete Pavement Road Maphttps://cptechcenter.org/ncc-projects/implementation-of-concrete-pavement-mixture-design-and-analysis-(mda)-track-of-concrete-pavement-road-map/Concrete pavements; Implementation; Mix design; Specifications; TrainingThe work to be covered by this pooled fund addresses focused activities under the Concrete Pavement Road Map (CP Road Map) Track 1, Mix Design and Analysis. The activities are intended to meet some of the needs identified by the track.
10/19/2018October 2018Implementation of Precast Concrete Segments for Electrified Roadwayhttps://cptechcenter.org/ncc-projects/implementation-of-precast-concrete-segments-for-electrified-roadway/Precast electrified panelsA major impediment to broad public acceptance of electric vehicles is their limited travel range. An exciting potential solution to this problem is In-Motion Electric Wireless Power Transfer. This is essential for the development of connected and autonomous vehicles. Durability of the Civil-Electrical Infrastructure has been studied in recent research. The next logical step toward adoption is integration in a successful demonstration project. In order for the future adoption of this technology, roadways will need to be modified to allow the transmission of power to vehicles as they travel. Successful adoption of In-Motion Wireless Power Transfer will require advances in the efficiency of the overall electrical system, improvements in tracking of the actual vehicles, and significant developments in the civil infrastructure. This proposal will address the constructability of coils in a proposed precast system. The stringent electrical specifications will be monitored while utilized in an actual closed loop working system.Marvin Halling
05/01/15May 2015Implementation of Self-Consolidating Concrete for Prestressed Applications (Phases I & II, funded separately)https://cptechcenter.org/ncc-projects/implementation-of-self-consolidating-concrete-for-prestressed-applications-(phases-i-&-ii,-funded-separately)/Self-consolidating concrete; prestressed concrete; bridgesThis research project consists of implementing the research previously conducted by Auburn University for ALDOT on self-consolidating concrete's application in the precast & prestressed concrete industry on an actual ALDOT project. In the demonstration project, a bridge would be constructed using girders made from SCC and conventional concrete for side-by-side comparison. Phase I of the project consisted of developing a draft special provision for the use of SCC, selecting a test bridge, evaluating new fresh property test methods from previous research, monitoring the fabrication of the girders, and monitoring the pre-erection structural performance of the girders. Phase II of the project consisted of monitoring the construction of the demonstration bridge, load testing of the bridge, monitoring in-place structural performance of the bridge, and making recommendations for the final revisions to ALDOT's SCC spec.Samuel D. Keske, Robert W. Barnes, Anton K. Schindler, Brandon R. Johnson, Morgan A. Ellis, D. Eric Miller, Tyler L. Neal
02/01/20February 2020Implementation Support for Second Strategic Highway Research Program (SHRP2) Renewal R06E Real-Time Smoothness Measurements on Portland Cement Concrete Pavements During Constructionhttps://cptechcenter.org/ncc-projects/implementation-support-for-second-strategic-highway-research-program-(shrp2)-renewal-r06e-real-time-smoothness-measurements-on-portland-cement-concrete-pavements-during-construction/Construction, Highways, Pavements, Quality control (QC), Smoothness, Specifications, WorkshopsThe Second Strategic Highway Research Program (SHRP2) R06E project, Real-Time Smoothness Measurements on Portland Cement Concrete Pavements during Construction, advanced real-time smoothness measuring technologies through unbiased field evaluations and demonstrations and the development of draft model specifications and guidelines. Furthermore, the study validated technologies designed to improve quality control and the paving process and enhanced understanding of the construction artifacts that affect smoothness. The Federal Highway Administration (FHWA), through the SHRP2 Solutions Implementation Assistance Program, funded additional work to continue development and implementation, with the goal to eventually achieve routine use of real-time smoothness measuring technologies by owner agencies and paving contractors. This report summarizes the implementation tasks performed in support of R06E. Tasks included developing an equipment loan program involving real-time smoothness measuring technologies, holding a showcase and conducting workshops, conducting case studies of projects that took advantage of the equipment loan program, refining the specifications developed under R06E, and engaging in a wide array of marketing and outreach activities.Gary Fick, David Merritt, Peter Taylor, Todd Hanke, Helga Torres, Robert Rasmussen
9/1/2015September 2015Implementation: Investigation of Alternative Supplementary Cementing Materials (SCMs)https://cptechcenter.org/ncc-projects/implementation:-investigation-of-alternative-supplementary-cementing-materials-(scms)/Admixtures; Cement; Classification; Concrete construction; Fly ash; Materials; Pozzolan; Properties of materialsSupplementary cementing materials (SCMs) provide many benefits to concrete mixtures in terms of cost, long-term strength, and durability. Class F fly ash is the most widely used SCM in Texas, but its availability is dwindling. Given the importance of Class F fly ash as a means to improve concrete durability, it is important to find alternative materials that can maintain the high quality and durability of concrete in Texas. TxDOT project 0-6717: Investigation of Alternative Supplementary Cementing Materials (SCMs), completed in August 2014, identified sources of Class F fly ash alternatives that can be used in Texas concrete and developed best practices in testing these materials. Due to their higher availability and lower cost new sources of materials present better opportunities for Class F fly ash replacement than those initially tested. Implementation of the experimental protocols developed in project 0-6717 on these new materials will enable their use in Texas concrete. The objectives of this implementation project are to: (I) procure additional Class F fly ash alternatives not tested in the original project, including natural pozzolans, industrial byproducts. and reclaimed and remediated fly ashes; (2) chemically and physically characterize the materials; (3) determine optimum dosage amounts based on workability, reactivity/strength, and durability (4) test performance in concrete mixtures; and (5) make recommendations regarding their suitability for use in Texas. The testing will follow the recommendations from project 0-6717, with attention paid in particular to workability, admixture interaction, early and long-term strength, and resistance to alkali silica reaction and sulfate attack.Saif Al-Shmaisani, Ryan Kalina, Michael Rung, Raissa Ferron, Maria Jeunger
9/1/2015September 2015Implementing Rubblization and Drainage Improvement Techniques on Severely Distressed Concrete Pavements: Technical Reporthttps://cptechcenter.org/ncc-projects/implementing-rubblization-and-drainage-improvement-techniques-on-severely-distressed-concrete-pavements:-technical-report/Comminution; Concrete pavements; Drainage; Implementation; Pavement design; Pavement distress; Pavement maintenance; Recommendations; Test sections; WorkshopsRubblization of old concrete pavement has not been widely used in Texas. In this implementation study, a review was made of Texas experience with this approach including both successes and failures. The lessons learned were incorporated into workshop materials developed as part of this study. A review was also completed on the recommended pavement evaluation procedures developed in the original 0-4687 project. These were updated and demonstrated on three sections, which are under consideration for rubblization, in the Beaumont, Dallas, and Paris Districts. The design recommendations for each are presented in this report.Tom Scullion
9/1/2016September 2016Improvement of Climate Data for Use in MEPDG Calibration and Other Pavement Analysishttps://cptechcenter.org/ncc-projects/improvement-of-climate-data-for-use-in-mepdg-calibration-and-other-pavement-analysis/Pavement Analyses, Climate Effects, Mechanistic-Empirical Pavement Design Guide (MEPDG), Ground-based Weather Station (GBWS), ModernEra Retrospective Analysis for Research and Applications (MERRA), North American Regional Reanalysis (NARR)This study compares the predicted distresses of asphalt concrete (AC) and jointed plain concrete pavement (JPCP) using four different climate data sources: (1) ground-based weather station (GBWS) data, (2) the North American Regional Reanalysis (NARR) data, and (3 and 4) the Modern-Era Retrospective Analysis for Research and Applications (MERRA) versions 1 and 2 (MERRA-1 and MERRA-2) data. The results indicate that pavement performance predictions generated using these data showed disagreement among some of the climate data sources, especially for MERRA-2. Comprehensive diurnal and time-series analyses of the raw climate data found significant disagreements in the percent sunshine data.Stephan A. Durham, Bora Cetin, Charles Schwartz, Barton Forman, Leela Sai Praveen Gopisetti
8/1/2017August 2017Improving Concrete Patching Practices on Iowa Roadways TR-731https://cptechcenter.org/ncc-projects/improving-concrete-patching-practices-on-iowa-roadways-tr-731/Concrete pavements; Highway maintenance; Patching; Portland cement concretePortland cement concrete (PCC) pavements are subject to distress from a variety of mechanisms including traffic loads, thermal movement, freezing and thawing, materials related distress, and construction issues. Standard practice for maintaining PCC pavements includes concrete patching using partial depth and full depth repairs. States spend large amounts of money and time every year performing partial and full depth repairs of PCC pavements. The performance of partial and full depth repairs is important for cost savings and safety of the roadways.Todd Nelson
12/3/2018December 2018Improving Constructability and Durability of Concrete Pavementshttps://cptechcenter.org/ncc-projects/improving-constructability-and-durability-of-concrete-pavements/Asphalt concrete pavements; Concrete construction; Pavement designConcrete pavements can be cost-effective as they have been reported to exhibit long service lives. Although the majority of pavements in Oregon are asphalt concrete, many interstate pavements are concrete. Performance of these concrete pavements has generally been excellent. Several pavement projects are now being designed and constructed with Portland cement concrete. To ensure long service lives and cost-effectiveness, the construction of these pavements must be straightforward and without undue challenges. The concrete mixture can have a significant influence on constructability and long-term performance and well-proportioned concrete mixtures will result in improved constructability and performance. The objective of this research is to develop performance engineered mixtures (PEM) for concrete pavements in Oregon, thereby ensuring constructability and long-term performance of these concrete pavements. It is anticipated that this research will generate sufficient data on materials and concrete mixture proportions such that draft specifications can be developed for slipform concrete paving mixtures using materials available to the Oregon construction market.David Trejo
4/1/2018April 2018Improving the Foundation Layers for Concrete Pavements: Field Assessment of Variability in Pavement Foundation Propertieshttps://cptechcenter.org/ncc-projects/improving-the-foundation-layers-for-concrete-pavements:-field-assessment-of-variability-in-pavement-foundation-properties/Concrete pavements; Field tests; Foundations; Pavement layers; Quality assurance; Quality control; Service life; Spatial analysis; Subgrade (Pavements); Design; Highways; PavementsNon-uniform support conditions under pavements can have detrimental effects on the service life of pavements. Generally, pavement design considers the foundation as a layered medium with spatially uniform material properties and support conditions. But, soil engineering parameters generally show significant spatial variation. In this report, field testing was conducted at several pavement foundation construction sites in a dense grid pattern with relatively close spacing (i.e., < 1 m) over a small area (< 10 m x 10 m) and in a sparse sampling pattern (> 5 m apart) over a large area (> 100 m) to characterize spatial variability. Results from selected field studies were analyzed for a more in-depth analysis of spatial variability and assessment of anisotropy. The measurement parameter values assessed include elastic modulus determined from the light weight deflectometer (LWD) test, penetration index of subbase and subgrade layers using dynamic cone penetrometer (DCP) test, and dry unit weight and moisture content determined from the nuclear gauge (NG) test method. Spatial variability analysis on dense gridded test sections showed that different anisotropic major directions could be expected in different test areas. Comparisons of directional semivariogram models from dense and sparse datasets from the same project are also provided in this report.The longer ranges in the sparse dataset compared to shorter ranges calculated using the dense grid dataset suggests that there is a nested structure in the data with both short and long range spatial continuity of the measured properties. In summary, the data and analysis demonstrate that spatial variability in pavement foundation layers can be quantified using semivariogram modeling, but is anisotropic and depends on test spacing.Jia Li, David White, Pavana K.R. Vennapusa
3/1/2018March 2018Influence of Aggregate and Proportions on Flowing Concrete Characteristicshttps://cptechcenter.org/ncc-projects/influence-of-aggregate-and-proportions-on-flowing-concrete-characteristics/Air voids; Cast in place concrete; Flow; Fresh concrete; Piles (Supports); Plastic flow; Cast in drilled hole; bridge pilesCast-in-drilled-hole (CIDH) piles are often constructed to depths that are inaccessible, and internal vibration is not performed over the length of the pile. Because of this, the likelihood of voids occurring increases. Many state highway agencies use inspection pipes to detect if voids are present along the length of the pile. High reinforcement densities and concrete void detection inspection pipes can congest CIDH piles. Although concrete void detection and reinforcement spacing are critical to ensuring adequate CIDH pile structural performance, eliminating concrete voids can also ensure expected performance. This research will assess the influence of coarse aggregate (CA) type and mixture proportions on concrete workability for CIDH pile applications. Results indicate that identifying an optimal paste volume-to-aggregate void ratio (PV/AV) can be used to proportion flowing concrete (FC) mixtures with adequate slump flow and stability. Concrete containing rounded CA achieved higher slump flow values than concrete with crushed CA at the same paste volume. However, increasing PV/AV also decreased stability. Stability was increased by increasing the FA-to-CA ratio (FA/CA).David Trejo, Greg Hendrix
1/9/2019January 2019Influence of Aggregate Gradation and Nominal Maximum Aggregate Size on the Performance Properties of OGFC Mixtureshttps://cptechcenter.org/ncc-projects/influence-of-aggregate-gradation-and-nominal-maximum-aggregate-size-on-the-performance-properties-of-ogfc-mixtures/Aggregate gradation; Friction course; Open graded aggregates; Pavement performance; Porous pavementsThe effect of aggregate gradation and nominal maximum aggregate size (NMAS) on the performance properties of open-graded friction courses (OGFC) mixtures was investigated in this research. Several tests which included porosity, surface texture, indirect tensile strength (ITS), shear strength, and Cantabro abrasion loss were used to compare eight different aggregate gradations having two NMAS (9.5 mm and 12.5 mm) all from one aggregate source. For each NMAS, the gradations varied by adjusting the percent passing the No. 4 (4.75 mm) sieve. The results indicated that aggregate gradation does influence the behavior of OGFC mixtures. An increase in percent passing the No. 4 sieve showed significant decreases in porosity, which were more pronounced for the 12.5 mm NMAS compared with the 9.5 mm NMAS. Conversely, the increase in the percent passing the No. 4 sieve generally resulted in increases in the mixture performance properties as measured by the ITS, Cantabro loss, and shear strength. The results of this study provide laboratory-based evidence that adjusting the OGFC gradation by increasing the allowable percent passing the No. 4 sieve toward the higher end of the current specification range (e.g., near 30% for 12.5 mm NMAS) could potentially have positive effects on mixture durability while also maintaining adequate permeability for water drainage.Haripriya Nekkanti, Bradley J. Putman, Behrooz Danish
9/26/2017September 2017Influence of Concrete Mixture Parameters on Chloride Test Measurementshttps://cptechcenter.org/ncc-projects/influence-of-concrete-mixture-parameters-on-chloride-test-measurements/Admixtures; Chlorides; Coarse aggregates; MeasurementThe American Concrete Institute (ACI) and most state highway agency (SHA) organizations limit the amount of chlorides in fresh concrete to lower the risk associated with corrosion of steel reinforcement. It is often required to measure the chloride concentration of concrete powder samples to ensure that the published chloride limits are not exceeded. However, the standard documents provide no information on number of samples required for chloride testing for different concrete mixtures. This study explores the influence of concrete material proportions and the admixed chloride levels on the mean and variability of the chloride test results. Results from this research indicate that the maximum size and proportion of the coarse aggregate and the admixed chloride level significantly influence the chloride test results. Based on the estimated variability of chloride measurements from this research, a method to determine the number of samples for chloride testing is presented for different concrete mixtures.Naga Pavan Vaddey, David Trejo
1/1/2012January 2012Influence of Rock Salt Impurities on Limestone Aggregate Durabilityhttps://cptechcenter.org/ncc-projects/influence-of-rock-salt-impurities-on-limestone-aggregate-durability/Rock Salt, Limestone Aggregate, Aggregate Durability, Freeze-Thaw CyclesNon-durable coarse aggregate in concrete pavement can break down under repeated freeze-thaw cycles. Application of rock salt may increase the severity of exposure conditions because of trace compounds, such as calcium sulfate, in rock salt. Concrete and saw-cut limestone specimens were also subjected to wet-dry cycles in varying salt solutions to examine the influence of trace compounds in rock salt. Subsequently, limestone aggregate in concrete was subjected to freeze-thaw cycling in two methods: salt-treating the aggregate before batching concrete, and half-immersing concrete specimens in rock salt solution during freeze-thaw cycling.Kyle A. Riding, Jonathan Varner, Cale Armstrong
6/1/2019June 2019Innovative Techniques and Materials for Preventing Concrete Shrinkage Crackinghttps://cptechcenter.org/ncc-projects/innovative-techniques-and-materials-for-preventing-concrete-shrinkage-cracking/Admixtures;ÿCracking of concrete pavements;ÿField studies;ÿRecommendations;ÿShrinkage;ÿSpecifications;ÿTechnological innovationsThe objectives of this research are: (1) To identify and measure major components of shrinkages (chemical, autogenous, and drying shrinkages) in New Jersey concretes; (2) To identify and investigate different methods most functional, practical, and effective for controlling shrinkage cracking applicable for New Jersey infrastructure concrete mixes; (3) To determine what effects the techniques and methods used to control shrinkage cracking have on other fresh and hardened concrete properties; (4) To investigate field performance of the New Jersey mixes and compare concrete mixes with different shrinkage cracking potentials and concrete mixes with and without shrinkage control methods; (5) To compare the test results and observations obtained from the lab and field investigations and provide rational recommendations for the New Jersey concrete industry to effectively control shrinkage of New Jersey infrastructure concrete; and (6) To develop guidelines and specifications for the identified new techniques and materials in as directed by the New Jersey Department of Transportation (NJDOT) Technical Advisory Panel (TAP).Gilson Lomboy
7/1/2013July 2013In-Place Response Mechanisms of Recycled Layers Due to Temperature and Moisture Variationshttps://cptechcenter.org/ncc-projects/in-place-response-mechanisms-of-recycled-layers-due-to-temperature-and-moisture-variations/Pavement layers, Recycled materials, Full-depth reclamation, Subbase (Pavements), Moisture content, Freeze thaw durability, Pavement design, New EnglandMany states have adopted the use of recycled pavement layers in highway rehabilitation. Techniques such as full depth reclamation (FDR) with or without stabilization additives, plant mix cold recycled asphalt pavement (RAP), blending RAP with unbound sub base layers and substitution of unbound sub base layers with RAP are being used effectively. However, the properties of these recycled pavement layers change significantly with variations in temperature and moisture conditions during different seasons. To obtain good performing rehabilitated pavements throughout their design lives, it is imperative to select the best combination of virgin materials, recycled materials, stabilizing additives and construction methods for a particular location. For such selection, an understanding of the in-place properties of pavement layers and their relationship to the principal pavement response mechanisms is needed. Currently, significant knowledge gaps exist regarding variations in performance related properties that result from seasonal changes in temperature and moisture content. The main objective of this research is to determine the in-place properties of pavement cross-sections containing recycled materials common to the New England region, and to relate changes in those properties to variations in temperature and moisture. The study will focus primarily on obtaining field data from base layers (as opposed to asphalt surface layers) that have been constructed with different types of unbound or bound recycled layers such as full depth reclamation (with or without stabilizing additives), plant mix recycled asphalt pavement (PMRAP), or foamed asphalt. The research team will work with the New England Transportation Consortium (NETC) advisory board members to identify appropriate field sites where the pavement design is clearly documented and where pavement performance can be linked to factors such as traffic loadings, moisture regimes and freeze-thaw effects. Laboratory testing will also be included to complement the analysis of in-place test data and instrumentation monitoring.Jo Daniel
3/1/2018March 2018Instantaneous Crack Width Calculation for Steel Fiber-Reinforced Concrete Flexural Membershttps://cptechcenter.org/ncc-projects/instantaneous-crack-width-calculation-for-steel-fiber-reinforced-concrete-flexural-members/Cracking; Cracking of concrete pavements; Fiber reinforced concrete; Flexure; Steel fibers; Stiffness; Highways; Materials; PavementsA rational and simple method is presented in this paper to determine instantaneous crack widths of steel fiber-reinforced concrete members subjected to flexure. By adding fibers to concrete, the postcracking stiffness of a concrete structure can increase significantly. The model builds upon previous work conducted by the authors by considering the beneficial effect of the fibers across a crack to the tension stiffening relationship of steel fiber-reinforced concrete. The model reported herein is shown to give reliable predictions of reported experimental values.Ali Amin, R. Ian Gilbert
10/31/2018October 2018Internal Curing of Bridge Decks and Concrete Pavement to Reduce Crackinghttps://cptechcenter.org/ncc-projects/internal-curing-of-bridge-decks-and-concrete-pavement-to-reduce-cracking/Bridge decks; Concrete; CrackingWisconsin Department of Transportation (WisDOT) has been successfully managing 12,000 total centerline miles of highway system and 5,293 state-owned bridges. The 2016 data shows 98.1 percent of the backbone system and 79.2 percent of the non-backbone system in fair and above condition. Currently 96.9 percent of State owned or maintained bridges have a good rating or fair rating1. Even though the condition of majority transportation system in Wisconsin is in fair or above condition, WisDOT has struggled to control cracking on bridge deck and concrete pavement in our High-Performance Concrete (HPC) and conventional concrete bridge (Grade A) construction projects (Standard Specification Sec. 501 and Sec. 415). Higher strength, lower water to cement ratio (w/c) concrete has been promoted for over 20 years due to the desire for increased strength and reduced permeability.Jose Pacheco
2/1/2014February 2014Internal Curing of High-Performance Concrete Using Lightweight Aggregates and Other Techniqueshttps://cptechcenter.org/ncc-projects/internal-curing-of-high-performance-concrete-using-lightweight-aggregates-and-other-techniques.--/Concrete curing; Freeze thaw durability; High performance concrete; Lightweight aggregates; Mix designInternally cured concrete has been rapidly emerging over the last decade as an effective way to improve the performance of concrete. Internal curing (IC) holds promise for producing concrete with an increased resistance to early-age cracking and enhanced durability (Bentz and Weiss, 2011). IC is a simple and effective way to cure concrete. Proper internal curing supplies water that is necessary to relieve stress buildup due to self-desiccation. Typically this is done using pre-wetted lightweight aggregates (LWAs), as this is the most commercially available application at the present time. IC has shown reduced autogenous and drying shrinkage cracking, improved fluid absorption resistance, improved compressive strength, and reduced ion diffusion. It is becoming increasingly clear that internal curing has great potential for the concrete industry to create a longer lasting, more sustainable product. This report specifically examines the freeze-thaw resistance of internally cured concrete. It is shown that internally cured concrete, using the recommended mixture proportions (i.e., pre-wetted fine LWAs to replace only the water lost due to chemical shrinkage) is freeze-thaw resistant. Internal curing has shown, as outlined in this report, to be a simple and cost-effective way to create longer lasting, more durable concrete. The initial cost of a bridge deck concrete can increase in price anywhere from 3 to 10 $/yd3. However, this percentage when compared with the cost of a bridge is typically negligible, especially when considering an increased service life and reduced maintenance cost. Colorado Department of Transportation (CDOT) can benefit from this research by applying what has been presented in this study to create longer lasting, more durable bridge decks.Wesley A. Jones, Mitch W. House, W. Jason Weiss
7/15/2016July 2016Internal Curing of Pervious Concrete Using Lightweight Aggregateshttps://cptechcenter.org/ncc-projects/internal-curing-of-pervious-concrete-using-lightweight-aggregates/Concrete curing; Curing agents; Durability; Lightweight aggregates; Pavement maintenance; Porous materials; Porous pavements; Pervious concrete; Highways; Maintenance and Preservation; Materials; PavementsPervious concrete is an important stormwater management technique for the urban environment. Surface raveling is the single most common distress caused primarily by plastic drying and paste shrinkage. Internal curing is one mechanism to provide additional moisture to elevate internal humidity and reduce shrinkage and is most commonly provided through prewetted lightweight aggregates (PLWA). This study evaluated how fine PLWA influence properties when used to completely replace the small portion of conventional fine aggregate present in pervious concrete. Samples were placed at a fixed void content to not confounded results with changes in density. Strength, degree of hydration, shrinkage, and freeze–thaw testing all showed substantial improvements over the control mixture, strongly suggesting that internal curing become routine for pervious concrete. John T. Kevern, Qiwei C. Nowasell
1/1/2014January 2014Internally Cured Concrete for Pavement and Bridge Deck Applicationshttps://cptechcenter.org/ncc-projects/internally-cured-concrete-for-pavement-and-bridge-deck-applications/Aggregates, bridge decks, concrete curing, concrete pavements, field tests, laboratory tests, lightweight materialsThe objective of this project is to conduct a laboratory and field testing program to evaluate performance and usability of internally cured concrete using lightweight aggregates for bridge decks and pavements under Florida conditions.Mang Tia, Thanachart Subgranon, Kukjoo Kim, Andrea Medina Rodriguez, Abdullah Algazlan
4/1/2017April 2017Investigating Frost Heave Deterioration at Pavement Joint Locationshttps://cptechcenter.org/ncc-projects/investigating-frost-heave-deterioration-at-pavement-joint-locations/Base course (Pavements); Concrete pavements; Foundation engineering; Freeze thaw durability; Frost heaving; Geosynthetics; Geotextiles; Moisture content; Pavement layersFrost heave of foundation materials causes severe joint deterioration in concrete pavements. Sufficient freezing depth, continuous water supply, and frost susceptible geomaterials are the three necessary factors leading to frost heave. To investigate the frost actions of deteriorated pavements with frost heaves at joint locations, the longitudinal pavement surface profiles were plotted by measuring vertical heaves crossing transverse joints. Specimens were cored to determine the moisture conditions at different layers. Ice lenses were found at layer interfaces, and frozen base layers with low permeability contributed to trapping water within joint spaces. Another objective of this study was to determine the local freeze-thaw conditions in pavements. Temperature sensors were installed during the reconstruction to estimate the frost penetration depths, lengths of freezing and thawing periods, and number of freeze-thaw cycles at different depths. Up to 1.1 m frost penetration depth was found, and it showed various lengths of freezing periods. The last objective was to evaluate the frost-heave and thaw-weakening susceptibility of the reconstructed foundation materials. Results indicated that all three geomaterials were medium frost-heave susceptible, and the soft subgrade showed high thaw-weakening susceptibility.Yang Zhang, David J. White, Pavana K. R. Vennapusa, Alex E. Johnson, Maxim M. Prokudin
2/1/2019February 2019Investigation and Evaluation of Iowa Department of Transportation Bridge Deck Epoxy Injection Processhttps://cptechcenter.org/ncc-projects/investigation-and-evaluation-of-iowa-department-of-transportation-bridge-deck-epoxy-injection-process/Bridge decks; Concrete overlays; Delamination; Service life; SpecificationsSince the 1970s, the Iowa Department of Transportation (DOT) has used concrete overlays as a means of restoring its bridge decks and, as a result, the service life of the deck is commonly extended many years. This procedure has proven to be both effective and economically attractive. Despite that, concrete overlays cannot be considered a permanent repair as they are subjected to harsh conditions, similar to the original bridge decks. As time passes, the overlays often become delaminated from the original deck at or near the bond interface, leading to cracking and the intrusion of water and chloride ions, which accelerate the deterioration. A preservation solution involving the injection of epoxy resin into the cracks and voids has been developed and this solution has been implemented with success across Iowa. Even so, the length of additional service life and the most effective methods and materials of injection remain unknown.Terry J. Wipf, Brent Phares, Justin M. Dahlberg, Ping Lu
4/1/2019April 2019Investigation into enhancing and evaluating curing efficiency of joints in concrete pavementshttps://cptechcenter.org/ncc-projects/investigation-into-enhancing-and-evaluating-curing-efficiency-of-joints-in-concrete-pavements/Concrete curing; Concrete pavements; Durability; Microstructure; Pavement joints; Test sectionsSigns of premature deterioration of concrete pavements are often indicated by shadowing, resulting from a network of micro-cracks in the vicinity of joints, which causes significant loss of material over time. In Canada, the construction sequence of concrete pavements typically involves continuous casting, applying curing compound and subsequently saw-cutting, which may compromise the durability of joints, due to insufficient curing and uncontrolled evaporation. The aim of this study was to assess the effect of overfilling joints with curing compound immediately after saw-cutting (early- and late-cuts) on improving the quality of concrete microstructure at joint regions in laboratory slabs and trial field sections. The study involved an absorption test customised to the joint geometry of pavements, mercury intrusion porosimetry and microscopy tests that were conducted on cores. The results indicated that overfilling the joints with curing compound immediately after late saw-cutting significantly improved the microstructure and durability of joint zones.Mohammad Tiznobaik, Mohamed T. Bassuoni
11/1/2009November 2009Investigation of Jointed Plain Concrete Pavement Deterioration at Joints and the Potential Contribution of Deicing Chemicalshttps://cptechcenter.org/ncc-projects/investigation-of-jointed-plain-concrete-pavement-deterioration-at-joints-and-the-potential-contribution-of-deicing-chemicals/Concrete pavements; Deicing chemicals; Deterioration; Life cycle costing; Pavement joints; Service lifeThe objectives of this research project are to: (1) determine the causes of anomalous concrete joint deterioration nationwide; (2) quantify any contributions to joint deterioration due to deicing chemicals and develop estimates of service reduction and life cycle costs; and (3) develop recommendations based on research results for minimizing future joint deterioration on both existing pavements and new construction including possible repair methodologies and specification modifications.Lawrence Sutter, Peter Taylor, Jan Olek, Jason Weiss
09/30/15September 2015Investigation of Optimized Graded Concrete for Oklahoma - Phase 2https://cptechcenter.org/ncc-projects/investigation-of-optimized-graded-concrete-for-oklahoma---phase-2/Admixtures, Coarse aggregates, Cracking, Durability tests, Oklahoma, Optimization, Shrinkage, WorkabilityOklahoma has started to implement ‰"optimized graded concrete‰". These concrete mixtures are designed to use less cement, and proportionately more aggregate with a more optimized and continuous distribution of aggregate sizes. This allows a concrete mixture to achieve increased workability and strength through using less mortar (sand, cement and water). Cement is the most expensive ingredient in concrete, the largest contributor to the carbon footprint, and can also lead to increased cracking through shrinkage. Both the initial cost and long term performance of concrete would benefit from the reduction of cement content in concrete mixtures. The primary focus of this research will be to investigate the interplay between gradation and mortar content in a concrete mixture and how that impacts the necessary performance requirements for structural concrete: workability, strength, and durability. In addition the research team will also be available to work with any contractors that are implementing optimized graded concrete in the field. This is an important step in the validation of the research completed in the laboratory and is essential to the implementation of this new approach. Finally, the team will work with ODOT to create a new specification that will help implement optimized graded concrete for structural concrete in the state of Oklahoma.Marllon D. Cook, J. Nick Seader, M. Tyler Ley, Bruce W. Russell
09/15/19September 2019Investigation of Physical and Dynamic Properties of High Porous Concretehttps://cptechcenter.org/ncc-projects/investigation-of-physical-and-dynamic-properties-of-high-porous-concrete/Concrete, Education and training, Mix design, Pavement design, Porous materials, Porous pavements Highly porous concrete is a promising new technology that can be applied to avoid flooding on pavements, parking lots, and highways. The concrete mixture design allows this material to be highly porous (up to 30% in air voids) and permeable that allows water penetrate through the pavement during heavy rain periods. This would help to increase safety and reduce the number of accidents during harsh weather conditions. Hence, this study will investigate and design samples with different grain sizes and chemical composition to optimize the mechanical, physical, and dynamic properties of the material to use in Louisiana's climate conditions. In addition, this research study is designed to engage Baton Rouge Community College students to develop research skills and use basic engineering principles to solve real-world problems associated with improving the durability and safety of local transportation infrastructure. Ildar Akhmadullin, Marwa Hassan
7/1/2017July 2017Investigation of Quality Control/Quality Assurance Data to Review Current Specifications for Portland Cement Concrete Pavement Acceptance in Kansashttps://cptechcenter.org/ncc-projects/investigation-of-quality-control-quality-assurance-data-to-review-current-specifications-for-portland-cement-concrete-pavement-acceptance-in-kansas/Compliance; Compressive strength; Concrete pavements; Quality assurance; Quality control; Road construction; Specifications; ThicknessQuality control (QC) and quality assurance (QA) attributes of highway construction must be measured and achieved throughout each project. Statistical specifications are commonly used to ensure compliance of QC and QA attributes, and attribute data must be reviewed periodically to improve specifications for agencies and contractors. The Kansas Department of Transportation (KDOT) typically considers concrete compressive strength and slab thickness to be QC attributes for portland cement concrete (PCC) pavements.Shuvo Islam, Xingdong Wu, Mustaque Hossain
12/15/2016December 2016Investigation of the Relationship Between Formation Factor and Water Content of Fresh Concretehttps://cptechcenter.org/ncc-projects/investigation-of-the-relationship-between-formation-factor-and-water-content-of-fresh-concrete/Admixtures; Concrete; Durability; Moisture content; Quality assurance; Quality control; Service lifeEach year approximately 10 billion tons of concrete is produced, making concrete the largest manufactured product globally. The majority of this production is in the form of ready mix concrete. There are about 5,500 ready mixed concrete plants and about 55,000 ready mixed concrete mixer trucks that deliver concrete to points of placement. The quality control (QC) and quality assurance (QA) of this large operation have major economic, social and environmental implications. Current protocols for assessing the quality of fresh concrete during construction do not provide information on critical parameters that are related to long-term durability of structures. Compressive strength tests are typically performed weeks after the placement of concrete, and they do not provide adequate information about the future performance of structures in terms of their durability because they mainly check if the desired mechanical properties are satisfied. Therefore, there is a need for improved and practical QC/QA protocols to (1) confirm that the fresh concrete delivered to the construction site is the concrete that is specified and ordered, and (2) ensure that the delivered fresh concrete mixture will satisfy the performance specifications for long-term durability. Formation factor of concrete is a unique parameter that can satisfy both needs. Formation factor of concrete is directly related to critical performance indicators such as water-to-cementitious material ratio or porosity of concrete and provide information about both durability and mechanical performance of structures during their service life. The main objective of this research is to investigate the relationship between the formation factor and water content of fresh ordinary portland cement concrete. This research will establish the groundwork for the future development of an in-situ measurement device for measuring formation factor of fresh concrete mixtures at job sites for improved QC and QA protocols. These protocols will provide significant improvements in the quality of the concrete used in transportation structures.O. Burkan Isgor, Hossein Sallehi, Pouri Ghods
10/11/2018October 2018Laboratory Assessment of Nine Methods for Nondestructive Evaluation of Concrete Bridge Decks with Overlayshttps://cptechcenter.org/ncc-projects/laboratory-assessment-of-nine-methods-for-nondestructive-evaluation-of-concrete-bridge-decks-with-overlays/NDE overlay; Bridge decks; NDE methodsOverlay systems have been extensively used to extend the service life of concrete bridge decks. There is, however, a lack of systematic studies on nondestructive evaluation (NDE) of concrete bridge decks with various overlays. This study assesses nine NDE methods for evaluation of concrete bridge decks with seven different types of overlays through laboratory concrete specimens. The nine NDE methods are sounding, ultrasonic surface waves (USW), impact echo (IE), ultrasonic testing (UT), impulse response (IR), ground-penetrating radar (GPR), electrical resistivity (ER), half-cell potential (HCP), and infrared thermography (IRT). The seven types of overlays are epoxy, latex modified concrete, silica fume modified concrete, polyester polymer, asphalt with a liquid membrane, asphalt with a sheet membrane, and asphalt without a membrane. Eight concrete specimens with various defects were built and nondestructively evaluated to acquire the detailed information of all embedded defects before placing overlays. One concrete specimen was kept bare as a reference, and the other seven specimens were covered with seven different overlays, respectively. Half of each overlay was bonded to the underlying concrete specimens, whereas the other half was debonded. NDE tests were carried out on the top of overlays.Shibin Lin, Dewei Meng, Hajin Choi, Sadegh Shams, Hoda Azari
06/24/15June 2015Laboratory Evaluation of 100% Fly Ash Cementitious Systems Containing Ekkomaxxhttps://cptechcenter.org/ncc-projects/laboratory-evaluation-of-100-fly-ash-cementitious-systems-containing-ekkomaxx/Laboratory tests, Fly ash, Concrete, Cementitious Materials, Concrete hardening, Fresh concreteThe objectives of this research are to fully characterize the concrete containing Ekkomaxx for fresh and hardened properties, determine the first, second, and third level interactions and determine all main effects. From the results a specification may be developed for the use of Ekkomaxx products in the Louisiana Department of Transportation (LADOTD) projects.Bill King
6/1/2018June 2018Laboratory Evaluation of Corrosion Resistance of Various Metallic Dowel Barshttps://cptechcenter.org/ncc-projects/laboratory-evaluation-of-corrosion-resistance-of-various-metallic-dowel-bars/Chlorides; Concrete pavements; Corrosion; Corrosion resistance; Corrosion tests; Dowel bar retrofit; Epoxy coatings; Laboratory studies; Stainless steel; Zinc coatingsThis report presents corrosion study findings related to corrosion resistance of eight types of metallic dowel bars.The best corrosion performance was achieved by type 316L solid stainless steel (SS) dowel bars. . As expected, the worst corrosion performance was observed with the uncoated carbon steel dowel bars. Most of them produced the corrosion-induced concrete cracks. The hot-dip galvanized and zinc-clad dowel bars are classified as the second worst performance group. Even though the zinc-coating layers performed well as the sacrificial cathodic protection systems for the bare steel exposed at the artificial defect sites, the consumption rates of the zinc mass were too excessive, leading to the premature depletion of the zinc layers in the areas with elevated chloride concentration. Therefore, these zinc-based dowel bars are recommended only for infrequently salted roadways and mild service conditions. For major roadways, where repairs and/or traffic disruption are not feasible, high grades of solid SS dowel bars are recommended, even though this means very high initial costs. Considering the unavailability of the SC bars and the good performance of EC dowel bars at a much lower price, it is recommended that high-quality EC dowel bars be continuously used in the majority of the major roadways subject to heavy deicing salts provided that damage touchups and stringent quality assurance/quality control practices are implemented in the field to minimize initial coating defects until they are buried in concrete.Seung-Kyoung Lee
02/28/15February 2015Laboratory Fatigue Evaluation of Continuously Fiber Reinforced Concrete Pavementhttps://cptechcenter.org/ncc-projects/laboratory-fatigue-evaluation-of-continuously-fiber-reinforced-concrete-pavement/Continuously reinforced concrete pavements, Fiber reinforced concrete, Fibers, Load tests, Failure, Pavement performance, Mechanics, HardnessThis study presents the first approach to develop a new concrete pavement structure reinforced only with fibers. This research will identify probable combinations of fibers (dosage and length combinations) that will adequately perform repeated load fatigue tests. While fibers and high dosage fiber combinations have been previously used in concrete, these combinations have never before been use in a Department of Transportation (DOT) pavement structure. The major difference between previous applications and the current objective is number and level of load applications. The fundamental objective of this research is to determine how Continuously Fiber Reinforced Concrete Pavements (CFRCPs) behave under highway-type loading. The specific objectives of this study are to characterize the fresh and hardened properties of CFRCP concrete, determine the comparative fatigue resistance of different fibers and differing fiber blends and dosage rates, perform a detailed economic analysis of all pavement types through a cost-benefit analysis and provide recommendations for future research, including full scale loading and possible field implementation sites.Matthew Mulheron, John T. Kevern, Tyson D. Rupnow
9/1/2016September 2016Laboratory Investigation of the Use of Volcanic Ash in Concretehttps://cptechcenter.org/ncc-projects/laboratory-investigation-of-the-use-of-volcanic-ash-in-concrete/Admixtures; Bleeding (Pavements); Durability; Evaluation; Laboratory tests; Materials tests; Permeability; Volcanic ashSupplementary cementitious materials (SCMs) are commonly used in Kansas Department of Transportation (KDOT) concrete pavements and bridge decks to improve strength and permeability characteristics. The supplementary cementitious materials allowed under current KDOT specifications are all by-products of industrial processes. Volcanic ash is a natural product that has been used as a mineral admixture in concrete. The purpose of this study was to evaluate Kansas sources of volcanic ash for use in concrete as an SCM. This report will discuss all three stages of the study: material testing of the volcanic ash, testing the cementitious properties of Kansas volcanic ash, and evaluating the effects of volcanic ash on the properties of concrete such as strength and permeability.Jennifer Distlehorst, Andrew Jenkins
01/01/15January 2015Laboratory Study of Optimized Concrete Pavement Mixtureshttps://cptechcenter.org/ncc-projects/laboratory-study-of-optimized-concrete-pavement-mixtures/mix proportionThis project will evaluate the feasibility of expanding current specifications in sustainable concrete paving applications with the goal of producing guidelines for optimized concrete mix design. This study will provide WisDOT with information on the beneficial use of sustainable, blended cementitious systems capable of improving concrete performance. The specifications of new pavement mixtures can provide WisDOT with savings that include more cost-effective designs, more effective use of materials, and overall longer pavement life.Konstantin Sobolev, Mohamadreza Moini, Steve Cramer, Ismael Flores-Vivian, Scott Muzenski, Rani Pradoto, Ahmed Fahim, Le Pham, Marina Kozhukhova
6/1/2013June 2013Laser Scanning Aggregates for Real-Time Property Identificationhttps://cptechcenter.org/ncc-projects/laser-scanning-aggregates-for-real-time-property-identification/Lasers, Technological innovations, Aggregates, Literature reviews, Properties of materials, Training, Laboratory tests, ImplementationThe objectives of this research proposal have been divided into two phases to address the major issues of concern. Phase I includes a thorough literature review and assessment of laser technology to be utilized for real-time characterization of aggregate properties in the laboratory, while Phase II addresses field implementation and training of personnel.Beena Sukumaran, Ravi Ramachandran, Michael I. Lim
3/1/2018March 2018Life-Cycle Cost Analysis for Traditional and Permeable Pavementshttps://cptechcenter.org/ncc-projects/life-cycle-cost-analysis-for-traditional-and-permeable-pavements/Hot mix asphalt; Life cycle costing; Pavement maintenance; Paving; Permeability; Porous pavements; Portland cement concrete; Finance; Highways; Maintenance and Preservation; Materials; Pavements;Cost is an important factor for owners and communities when considering the selection of pavement types for parking lots and sidewalks. Sustainabilty has also become an important factor. Permeable pavements, which have been shown to be more sustainable than traditional pavement types, are an attractive option given their advantages of reducing rainwater runoff, recharging ground water, and reducing the costs associated with treating storm water. A comprehensive study was conducted to analyze and compare the life-cycle costs of two conventional impermeable pavements (hot-mix asphalt and portland cement concrete) and two permeable pavements (porous asphalt and pervious concrete). The study analyzed the alternatives in 20-year, 30-year, and 40-year analysis periods. In addition to initial construction and maintenance costs, stormwater treatment costs were included in the life cycle cost analysis for all alternatives in areas that have combined sewer and storm systems. The results show that hot mix asphalt has the lowest initial construction costs, while permeable pavements are considerably more economical than impermeable pavements in terms of maintenance costs. If stormwater treatment costs are accounted for, permeable pavements are more economical for 20-year and 30-year period analysis. In the 40-year analysis period, portland cement concrete is the most economical followed by porous asphalt, hot-mix asphalt, and then pervious concrete.Talal Rehan, Yan Qi, Anne Werner
10/1/2014October 2014Load Rating on Bibb Graves Concrete Arch Bridgehttps://cptechcenter.org/ncc-projects/load-rating-on-bibb-graves-concrete-arch-bridge/bridge load rating, historic bridges, concrete arch bridgeThis project serves to determine the bridge load rating of the historic Bibb Graves Bridge. Several spans of the bridge are affected by ASR. Previous research projects have attempted to remediate the problem, to no avail.Travis H. Le J.. Michael Stallings
3/1/2013March 2013Long -Life Slab Replacement Concretehttps://cptechcenter.org/ncc-projects/long--life-slab-replacement-concrete/Concrete, cracking, rehabilitation, maintenance, service life, slabsThe objectives of this project are to (1) identify the factors or parameters contribuitng to the cracking of concrete replace slabs on FDOT projects and (2) recommend changes to FDOT specifications and/or procedures that will minimize the occurrence of cracking of concrete used for Florida DOT slab replacement projects.Abla Zayed, Kyle Riding, Christopher C. Ferraro, Andre Bien-Aime, Natallia Shanahan, Daniel Buidens, Thomas Meagher, Victor Tran, Justin D. Henika, Jerry M. Paris, Caitlin M. Tibbetts, Benjamin E. Watts
02/01/20February 2020Long Term Performance of Overlays: Thin Epoxy Overlay vs. Traditional Rigid Overlayhttps://cptechcenter.org/ncc-projects/long-term-performance-of-overlays:-thin-epoxy-overlay-vs.-traditional-rigid-overlay/Bond strength (Materials); Bridge decks; Chloride content; Epoxy coatings; Evaluation and assessment; Laboratory tests; Overlays (Pavements); Pavement performance; Service life The objectives of the project included: (1) evaluate the bond strengths of two types of overlays (i.e. thin epoxy overlay and LSDC overlay) and investigate the change in bond strength over time with on-site testing; (2) understand the long term performance of epoxy overlays and rigid overlays via accelerated lab testing; (3) investigate how existing chloride that has been sealed in a deck by an epoxy overlay migrates and how that might relate or contribute to additional deck deterioration; (4) identify factors that affect the initial and long term performance of overlays; and 5) estimate the expected service life for these two types of overlays. The following tasks were performed for this work. These tasks were developed to allow for the evaluation of the performance of epoxy overlays compared to the performance of LSDC overlays using both on-site and lab testing. Task 1. information collection: collect needed information on bridges to be tested. Task 2. field testing: on-site pull-off testing and visual inspection. Task 3. laboratory testing: accelerated freeze-thaw and salt treatment lab testing. Task 4. reporting. Ping Lu, Katelyn Freeseman, Yuxiang Tan, Kejin Wang
7/1/2013July 2013Longer Lasting Bridge Deck Overlayshttps://cptechcenter.org/ncc-projects/longer-lasting-bridge-deck-overlays/Bridge decks, Service life, State of the art, Repairing, Durability tests,The objectives of this project are to research the current state-of-the-art practices for bridge deck repair and overlay; identify specific bridge decks within Kentucky which have achieved extended life and evaluate the materials/processes that were utilized; identify products that may appear more durable for bridge deck overlay projects within the same geographic region as Kentucky; and develop guidance for the Kentucky Transportation Cabinet in selecting appropriate bridge deck replacement technologies.David Hunsucker, Kean HAshurst Jr,, Brad W. Rister, David Allen, Eileen Grady
12/1/2017December 2017Magnetic Tomography - Assessing Tie Bar and Dowel Bar Placement Accuracyhttps://cptechcenter.org/ncc-projects/magnetic-tomography-?-assessing-tie-bar-and-dowel-bar-placement-accuracy/Accuracy; Location; Reinforced concrete pavements; Reinforcing bars; Road construction; Tie barsThe Kansas Department of Transportation (KDOT) constructs portland cement concrete pavements (PCCP) for new highway expansions and/or for replacement of existing highway pavement using slip-form paving operations. Typical concrete pavement construction in Kansas requires reinforcing steel across the joints. Correct placement of reinforcing steel in the PCCP is critical for good performance and long life of highways. However, once immersed in the concrete paste, steel placement is difficult to measure with nondestructive methods. Sometimes the steel bars are inserted (placed) using automated equipment. If the insertion process isn’t accurate, such that the steel bars are mislocated, costly remedial action can be required.Cliff Hobson
3/1/2017March 2017Magnetized Water Effect on Compressive Strength and Dosage of Superplasticizers and Water in Self-Compacting Concretehttps://cptechcenter.org/ncc-projects/magnetized-water-effect-on-compressive-strength-and-dosage-of-superplasticizers-and-water-in-self-compacting-concrete/Compressive strength; Magnetic materials; Self compacting concrete; Superplasticizers; Water; Water cement ratio; Highways; Materials; Pavements;The use of self-compacting concrete (SCC) has been established; however, novel methods for optimizing and providing suitable workability are still developing. The effect of magnetized water on SCC, by keeping the dosage of superplasticizer constant and reducing the ratio of water-to-cement, was investigated. Results showed a 10% decrease in the amount of water required and a 12% increase in compressive strength. Moreover, the effect of magnetized water on the dosage of superplasticizer in SCC, for making a specific spread diameter (600±10  mm) was studied. Results indicated that use of magnetized water in self-compacting concrete can reduce superplasticizer dosage by up 30%.Amirsalar R. Esfahani, Mohammad Reisi, Benjamin Mohr
8/31/2018August 2018Material Constituents and Proportioning for Roller-Compacted Concrete Mechanical Propertieshttps://cptechcenter.org/ncc-projects/material-constituents-and-proportioning-for-roller-compacted-concrete-mechanical-properties/Coarse aggregates; Compressive strength; Fracture mechanics; Materials; Mechanical properties; Mix design; Portland cement concrete; Roller compacted concrete; Roller compacted concrete pavementsRoller-compacted concrete (RCC) is increasingly becoming an alternative pavement type because of its construction expediency, reductions in material and construction costs, sustainability benefits, and overall structural capacity. Current RCC pavement mix design procedures select mix constituents and proportions based on strength requirements, workability, and field density. Discrepancies in mechanical properties are known to exist between field and laboratory compacted specimens. In order to move toward designing and constructing performance-based RCC mixtures—the effects of various mixture constituents, proportions, and compaction methods must be quantified. The gap between laboratory and field properties must be minimized as well. A wide range of RCC aggregate gradations were batched, tested, and found to impact RCC properties—especially compressive strength. Jeffrey R. LaHucik, Jeffery R, Roesler
12/29/2017December 2017Measurement of entrained air-void parameters in Portland cement concrete using micro X-ray computed tomographyhttps://cptechcenter.org/ncc-projects/measurement-of-entrained-air-void-parameters-in-portland-cement-concrete-using-micro-x-ray-computed-tomography/Air content; Air entrained concrete; Air voids; Concrete pavements; Freeze thaw durability; Image processing; X-ray computed tomography Highways; Materials; PavementsThe entrained air-void system in concrete is closely related to freeze-thaw durability in concrete pavements or other structures. For either research or forensic purposes, reliable and economical methods for the quantification of entrained air are desirable. This study explores the potential of using micro X-ray computed tomography (μCT) to measure entrained air-void parameters in concrete. A series of small cores (6 mm dia.) were retrieved from larger (100-mm-dia.) cores from two different concrete pavements, representing both adequate and marginal air contents, and scanned at a resolution of 7.5 μm/pixel. A systematic procedure based on image processing is proposed to address practical difficulties such as void/solid thresholding, air-type discernment (entrained air-voids vs. voids in aggregate) and the separation of bubbles within close proximity to each other (e.g. clustered air-voids). Air content and specific surface were measured directly from the three-dimensional (3D) reconstructed X-ray images, while values for paste content were derived from manual point counts performed on two-dimensional (2D) slices obtained from the 3D images. The derived values for air content, specific surface and paste content were used to calculate Powers’ spacing factor. To assess the issue of local fluctuations of material constituents and the limited dimensions of the small cores, uncertainty associated with the sample volume of concrete under measurement was also estimated. Based on the results in this study with regard to the work involved in sample preparation, data analysis and uncertainty bounds, μCT has been found to be a viable option for measurement of spacing factor and specific surface, but due to limitations imposed by the dimensions of the sample size (6-mm-dia. cores), the method is not appropriate for bulk air content determination.Haizhu Lu, Karl Peterson, Oleksiy Chernoloz
3/1/2018March 2018Mechanical and Durability Properties of Concrete Produced with Treated Recycled Concrete Aggregatehttps://cptechcenter.org/ncc-projects/mechanical-and-durability-properties-of-concrete-produced-with-treated-recycled-concrete-aggregate/Admixtures; Concrete aggregates; Durability; Mechanical properties; Mortar; Recycled materials; Recycled concrete aggregate; Highways; Materials; PavementsThe presence of attached mortar is the main reason for lower quality of recycled concrete aggregate (RCA) compared to that of natural aggregate. Hence, its use is limited up to 30% replacement of natural aggregate at present. The attached mortar of the RCA can be removed by mechanical treatment, acid treatment, thermal treatment (500 to 750°C [932 to 1382°F]), and microwave treatment. There are difficulties—such as achieving high temperature and treating larger quantities of RCA with acid and a microwave oven—in applying these treatments at field level. Hence, the present study focuses on a combination of heating (250°C [482°F]) and mechanical treatment to improve the quality of the RCA. This method removed 70 to 80% of attached mortar of the RCA. Properties of RCA such as bulk density, specific gravity, water absorption, and crushing value were discussed in detail. Post-treatment, it was observed that the properties of treated RCA improved compared to untreated RCA, but still they were found to be poorer than natural aggregate. The experimental studies were carried out to overcome the aforementioned drawbacks of the recycled aggregate concrete by incorporation of mineral admixtures. It was found that the use of mineral admixtures in concrete produced with treated RCA enhances both the mechanical and durability properties. Thus, the concrete produced with treated RCA and mineral admixture will lead to sustainable development.V. Bhasya, B. H. Bharatkumar
6/15/2016June 2016Mechanical Integrity and Sustainability of Pre-stressed Concrete Bridge Girders Repaired by Epoxy Injection - Phase Ihttps://cptechcenter.org/ncc-projects/mechanical-integrity-and-sustainability-of-pre-stressed-concrete-bridge-girders-repaired-by-epoxy-injection---phase-i/Cracking; Epoxy resins; Girders; Life cycle analysis; Mechanical properties; Prestressed concrete bridges; Simulation; Sustainable developmentThe project objectives are to: (1) Explain in which conditions the strength of cracked concrete can be recovered by epoxy injection; (2) Design the injection method for optimal mechanical performance; (3) Interpret mechanical tests performed on cracked and repaired pre-stressed concrete beams; (4) Assess the mechanical integrity of pre-stressed bridge girders for a variety of crack and injection patterns; (5) Predict the mechanical behavior of repaired concrete in the long-term, under typical loading and weathering conditions; (6) Simulate the life cycle of a typical pre-stressed girder; (7) Assess the sustainability of pre-stressed concrete bridge girders repaired by epoxy injection.Chloe Arson, Koochul Ji
3/15/2018March 2018Mitigating Pavement Reflective Cracking Using A Ductile Concrete Interlayerhttps://cptechcenter.org/ncc-projects/mitigating-pavement-reflective-cracking-using-a-ductile-concrete-interlayer/Fatigue (Mechanics); Fiber reinforced concrete; Load tests; Pavement components; Pavement interlayers; Reflection cracking; Repairing Overlays are constructed over existing pavement structures as a repair measure. When an overlay is placed on an existing pavement, under thermal, shrinkage or traffic induced loadings, cracking of the overlay often takes place at locations where there are joints or cracks in the underlying pavement due to stress concentration. This phenomenon is known as reflective cracking. Reflective cracking in the overlay allows water to penetrate the pavement structure and contributes to many forms of pavement deterioration, including increased roughness, spalling and decreased fatigue life. Therefore, to achieve an effective and durable pavement repair using overlay system, reflective cracking needs to be suppressed. A ductile high-performance fiber reinforced concrete (HPFRC) interlayer is proposed in this research to mitigate the reflective cracking problem in pavement overlays. It is hypothesized that by adding a thin layer of highly ductile HPFRC material between the existing pavement and overlay, reflective cracking can be arrested by the ductile interlayer.Qian Zhang, Mohammad Khattak
1/12/2019January 2019Mitigation of Differential Settlement at Highway Bridge Approacheshttps://cptechcenter.org/ncc-projects/mitigation-of-differential-settlement-at-highway-bridge-approaches/Bridge approaches; Geotechnical engineering; Highway bridges; Safety; Settlement (Structures); State departments of transportationDifferential settlement in the transition zone between the bridge structure and the approach embankment often creates a "bump" which is a potential safety hazard and comfort issue for drivers. Studies conducted by departments of transportation (DOTs) around the country suggest that about 25 percent of the 600,000 bridges in the US are affected by bridge approach settlement, or the "bump at the end of the bridge." The settlements can result in unsafe driving conditions, rider discomfort, structural deterioration of bridges and long-term maintenance costs. Identifying additional geotechnical or structural means to mitigate this issue, which may or may not be employed in conjunction with preloading, is of benefit to many State DOTs.Steven Bartlett
5/1/2018May 2018MnPAVE-Rigid 2.0https://cptechcenter.org/ncc-projects/mnpave-rigid-2.0/Concrete pavements; Mechanistic-empirical pavement design; Rigid pavements; SoftwareThis project implemented additional features into MnPAVE-Rigid, leading to a new version of MnDOT’s rigid pavement design software. The database of American Association of State Highway Transportation Officers (AASHTO) mechanistic-empirical (M-E) pavement design projects was expanded to account for additional design inputs. A new codebase using the Java scripting language was developed to provide MnDOT with direct control over the software. The representation of traffic loads was expanded to use design lane factors and an axle load spectra estimator to reflect truck proportions from MnDOT traffic reports; in turn, new reliability criteria were adopted for traffic volumes. The project effort included sensitivity studies of the AASHTO M-E software for all stages of the project, from investigating new design inputs, to debugging the original damage calculation, validating the database of AASHTO M-E projects, and testing the implementation of new features. The project is fully documented in this final report, which includes a software user’s guide, the database of all AASHTO M-E design projects, and the full Java source code.Derek Tompkins
1/10/2017January 2017Modelling the Evolution of Strength and Modulus of Cementitiously Stabilised Materials for Different Curing Conditionshttps://cptechcenter.org/ncc-projects/modelling-the-evolution-of-strength-and-modulus-of-cementitiously-stabilised-materials-for-different-curing-conditions/Cement; Compressive strength; Concrete curing; Modulus of rupture; Stabilized materials; Stiffness; Strength of materials; Tensile strengthThe strength and modulus of cementitiously stabilised materials (CSM) are important in pavement design and analysis. This study presents tests and models that can predict the growth of strength and stiffness of CSM under varying conditions. Specimens of nine different mixtures were tested to evaluate the strength gain after curing from 3 to 360 days under 100% relative humidity (RH) at 20°C (the so-called standard condition) using unconfined compressive strength (UCS), modulus of rupture (MOR), and indirect tensile (IDT) strength tests. Additional IDT specimens were prepared from 3 to 56 days of curing at various RH values and temperatures (the so-called variable conditions) for tensile strength and modulus growth. Using the laboratory results, a strength growth model was developed to predict the UCS, MOR, and IDT strength under the standard condition. Also, the IDT strength and modulus models were developed to predict the IDT strength and modulus under the variable conditions.Jingan Wang, Xiaojun Li, Haifang Wen, Balasingam Muhunthan
8/7/2018August 2018Moisture Detection of Stored Rapid-Setting Cementitious Materialshttps://cptechcenter.org/ncc-projects/moisture-detection-of-stored-rapid-setting-cementitious-materials/Airport runways; Moisture damage; Monitoring; Cement composites; Materials storage; Moisture sensors; Rapid setting patch materialsStorage of airfield damage repair (ADR) materials on site is essential for rapid repair operations. However, ADR materials may have limited shelf lives and are prone to degradation in the presence of moisture. This study investigated methods of storage to reduce moisture damage and to monitor moisture present in ADR materials. Various techniques were evaluated to reduce moisture in storage containers, and Super Sacks® of materials were installed with sensors to monitor moisture. Two common ADR materials, Rapid Set Concrete Mix® and Utility Fill 1-Step 750®, were included in the testing procedure. Two different sensors were tested for monitoring moisture: a standard soil moisture probe and an engineered Radio Frequency Identification Reader (RFID) moisture detector. Absorpole desiccants were found to be the most beneficial of the techniques tested in reducing humidity and removing water from the storage container. The RFID moisture detector was found to be able to detect moisture events better than the soil moisture sensor, which was unable to detect moisture events even when stored outside. Recommendations for future storage conditions and monitoring are provided. This study demonstrates the capability of moisture monitoring in cementitious material Super Sacks and provides groundwork for further optimization of storage protocols.Jameson Shannon, William D. Carruth, Gregory J. Norwood, Harold T. Carr
8/25/2017August 2017National Road Research Alliance: A Research Study on Partial and Full Depth Repairs of Concrete at MnROADhttps://cptechcenter.org/ncc-projects/national-road-research-alliance:-a-research-study-on-partial-and-full-depth-repairs-of-concrete-at-mnroad/Concrete; MaintenanceThe National Road Research Alliance (NRRA) is a pooled fund that will help direct and compliment the use of the MnROAD test track for local, regional and national research, tech transfer and implementation needs. This project will study partial and full depth repairs of concrete at MnROAD.Terry Kraemer
6/1/2016June 2016New Methodology for Evaluating Incompatibility of Concrete Mixes in Laboratory: A Feasibility Studyhttps://cptechcenter.org/ncc-projects/new-methodology-for-evaluating-incompatibility-of-concrete-mixes-in-laboratory:-a-feasibility-study/Admixtures; Aggregates; Concrete mixers; Feasibility analysis; Recycled materials; Shrinkage; Water cement ratioThe current specifications encourage the use of supplementary cementitious materials (SCMs) and as much as possible recycled materials in portland cement concrete. The use of SCMs, especially along with low water-to-cementitious material ratio, low total cementitious material content and cements with a low C3A content and low alkali, can produce some incompatibility in the paste due to the fact that they are not optimized for sulfate content when used with SCMs, or that have anhydrite or hemi-hydrate as the main sulfate source. This situation can create a concrete mixture that is sensitive to changes in ambient temperature, admixture dosage, cement and SCM properties, creating problems in the curing process, developing some early cracking, and compromising the performance of the structure. The following five factors are considered as the most significant factors contributing to the stability of the mixes: (1) type of cement, (2) type of chemical admixture, (3) dosage of chemical admixture, (4) type of SCMs, and (5) testing temperature. A study is proposed to develop an easy to use, relatively inexpensive laboratory test and equipment to determine potential concrete mixture incompatibilities among the aggregates and the above five parameters. The proposed equipment is a miniaturized free-free resonant column (FFRC, ASTM C215) device that has been used by many agencies with success. We have prototyped a fully-automated computer-controlled FFRC device that at user-defined time intervals collects data without the need for a technician. The computer used for this device, can also be readily used to gather temperature measurements from thermocouples. Therefore, the proposed test setup can collect the shear and compression wave velocities as well as the thermal maturity of the material up to an age of 72 hours. It will also utilize a thermal and/or digital imaging processes to estimate the patterns of heat dissipation and shrinkage of the concrete during curing. The proposed device will be assembled and tested for accuracy and precession and will be tested with a number of mixed with different levels of SCM and cement content, among other factors, to establish the feasibility of the system.Soheil Nazarian
1/1/2014January 2014Nitrogen Dioxide Sequestration Using Demolished Concrete and Its Potential Application in Transportation Infrastructure Developmenthttps://cptechcenter.org/ncc-projects/nitrogen-dioxide-sequestration-using-demolished-concrete-and-its-potential-application-in-transportation-infrastructure-development/Sustainable development, Infrastructure, Nitrogen dioxide, Demolition, Crushed aggregates, Volatile organic compounds, Wastes, Concrete, Environmental impactsAchieving environmental sustainability of the United States (US) transportation infrastructure via more environmentally sound construction is not a trivial task. This proposal, which addresses this critical area (Focus Area 3), is aiming at transforming concrete, the material of choice for many transportation projects, into less environmentally harmful and better performing component of the US infrastructure. This will be extremely relevant to construction of pavements, bridges, tunnels, airports, marine installations and other transportation projects. Simultaneously, the project will address one of the most pressing public health issues, such as NO? emissions from cement kilns, by developing new applications of crushed concrete aggregates (CCA), which are already contributing to resource conservation and elimination of solid waste disposal issues. NO? emissions can cause various environmental and health problems. They contribute to the formation of acid rain, atmospheric particles, and various other toxic substances resulting in health problems, visibility reduction, eutrification and global warming. One of the most prevalent problems with NO? emissions is the formation of ground level ozone, which is produced by NO? (NO+NO?) reacting with volatile organic compounds (VOCs) and CO in the presences of sunlight. Ground level ozone can damage lung tissue and reduce lung function. It is a significant problem nationwide as millions of Americans live in areas that do not meet the health standards for ozone. Among many sources of NO? emissions cement kilns are very significant contributors. They emit over 219,000 tons/year of NO?, which amounts to approximately 20% of all industrial emissions. High temperatures reached in cement kilns are favorable for NO? emissions and cannot be avoided.Alexander Orlov
4/11/2018April 2018Numerical Simulation of the Initial Particle Parking Structure of Cement/Geopolymer Paste and the Dissolution of Amorphous Silica using Real-Shape Particleshttps://cptechcenter.org/ncc-projects/numerical-simulation-of-the-initial-particle-parking-structure-of-cement-geopolymer-paste-and-the-dissolution-of-amorphous-silica-using-real-shape-particles/Anm material model ; irregular shape particles; cement/geopolymer pastes.Many particle-based numerical models have been used to simulate the hydration process of cementitious materials. Most of those models employ regular shape particles, like the commonly used spheres, to represent cement, slag, or fly ash, which neglects the influence of particle shape. To deal with this issue, this study extended the Anm material model and used irregular shape particles to simulate the initial particle parking structures of cement/geopolymer pastes. The irregular shapes of cement, slag and fly ash particles were characterized by spherical harmonic series. Compared to the initial particle structures simulated using spherical particles, those using irregular shape particles had total surface areas and bulk specific surface areas with up to 37.40% and 36.84% larger, respectively. However, the pore size distributions of the simulated initial particle structures did not show significant influence of particle shape. As a demonstration to illustrate the influence of particle shape on dissolution, the initial particle parking structure of amorphous silica in alkaline solution was generated using irregular shape particles, and was used as input to simulate the dissolution of silica particles. The Lattice Boltzmann method was used to simulate the transport process of aqueous ions and thermodynamics was employed to consider the rate of dissolution of silica. The dissolved fractions of silica at different temperatures in the simulations agreed well with experimental measurements. The influences of continuous stirring, concentration of alkali and particle shape on the dissolution kinetics of silica were investigated numerically.Yibing Zuo, Zhiwei Qian, Edward J. Garboczi, Guang Ye
6/1/2019June 2019Optimization of Advanced Cementitious Material for Bridge Deck Overlays and Upgrade, Including Shotcretehttps://cptechcenter.org/ncc-projects/optimization-of-advanced-cementitious-material-for-bridge-deck-overlays-and-upgrade,-including-shotcrete/Bridge Decks; Cement;ÿLiterature reviews; Mathematical models; Optimization;ÿ Overlays (Pavements);ÿ Rehabilitation (Maintenance);ÿ Shotcrete;ÿUltra high performance concreteDeterioration of bridge decks is a major issue for bridge owners. The need for cost-effective and durable rehabilitation methods has been documented by many researchers. The primary causes of deck deterioration include vehicle traffic, environmental effects (i.e. freeze-thaw, salt spray), and maintenance practices (snow plows, de-icing chemical treatments). Deterioration is featured by delamination, cracking, corrosion of reinforcing steel, abrasion, scaling, and other mechanisms. Ultra-High strength concrete (UHPC) overlays are gaining in popularity as a rehabilitation material due to the high compressive strength, higher tensile capacity compared to normal strength concrete, low permeability, and low shrinkage.Islam Mantawy
3/1/2019March 2019Optimized Performance of UHPC Bridge Joints and Overlayshttps://cptechcenter.org/ncc-projects/optimized-performance-of-uhpc-bridge-joints-and-overlays/Bridges;ÿJoints (Engineering);ÿLaboratory tests;ÿMix design;ÿOptimization;ÿOverlays (Pavements);ÿUltra high performance concreteThe objective of this research is to capitalize on the existing knowledge and literature by compiling various ultra-high performance concrete (UHPC) mix design strategies and establishing empirical composition-property relationships that can be used to develop UHPC mixtures for expansion joints and overlays with optimum durability and structural performance. In addition, the research team will address a critical knowledge gap of linking formulation and rheology of UHPC mixtures with different fiber types, which allow designing highly flowable mixtures. The resulting optimum UHPC mixtures will be laboratory tested and further improved. Potential impact on the state of practice could be significant by promoting the use of low-cost non-proprietary UHPC to extend the life of concrete bridges, and by familiarizing the industry and transportation agencies in the region with this valuable technology.Paramita Mondal, Farshad Rajabipour
9/10/2018September 2018Passive Wireless Sensors for Monitoring Behavior of Recycled Aggregate Concretehttps://cptechcenter.org/ncc-projects/passive-wireless-sensors-for-monitoring-behavior-of-recycled-aggregate-concrete/Accuracy; Concrete aggregates; Data collection; Feasibility analysis; Radio frequency identification; Recycled materials; Sensors; Strain measurement; Structural health monitoring; Temperature measurementThis project studied the feasibility of applying new Radio Frequency Identification (RFID) technology – particularly passive tag technology – to infrastructure projects that incorporate recycled concrete aggregates. The goals were to advance the technology for passive RFID wireless system for embedment in concrete to monitor the behavior of the material under loading, and other structural health monitoring scenarios. RFID tabs with temperature and strain measurement were studied, and the performance constraints that affect data logging were assessed. When RFID tags are embedded into concrete, the attenuation of the electromagnetic wave through concrete is correlated with the embedment depth, moisture content, concrete density, and aggregate mineralogy. The study considered these and other variables that affect passive RFID systems and suggest an approximate equation to estimate the attenuation. The project assessed the accuracy and data logging rates to validate the strain readings from passive RFID systems with other independent instruments. The early age monitoring of recycled aggregate concrete will be conducted with the RFID system. This project is a precursor to a field test at O’Hare International Airport to demonstrate the survivability of RFID systems for real-world operation in aggressive weather conditions.David Lange
1/1/2015January 2015Pavement Recycling: Shrinkage Crack Mitigation in Cement-Treated Pavement Layers - Phase 1 Laboratory Testinghttps://cptechcenter.org/ncc-projects/pavement-recycling-shrinkage-crack-mitigation-in-cement-treated-pavement-layers-phase-1-laboratory-testing/Cracking; Falling weight deflectometers; Field tests; Full-depth reclamation; Laboratory tests; Microcracking; Pavement design; Pavement performance; Rehabilitation (Maintenance); Stiffness; Structural testsThe California Department of Transportation (Caltrans) has been using full-depth reclamation (FDR) as a rehabilitation strategy since 2001. Most projects to date have used a combination of foamed asphalt and portland cement as the stabilizing agent. Recently though, the fluctuating and at times high cost of asphalt binder coupled with the relatively complex mix-design procedure for mixes that include foamed asphalt has generated interest in the use of portland cement alone as an alternative stabilizing agent. However, shrinkage cracking associated with the hydration and curing of the cement-treated layers remains a concern, especially with regard to crack reflection through asphalt concrete surfacings and the related problems caused by water ingress.S. Louw, D. Jones
7/29/2014July 2014Pavement Thickness Variation versus Observed Pavement Distresshttps://cptechcenter.org/ncc-projects/pavement-thickness-variation-versus-observed-pavement-distress/Pavement distress, Nondestructive tests, Thickness, Portland cement concrete, Quality assurance, Quality control, Pavement layers, Statistical analysis, Minnesota,Recent developments in non-destructive testing (NDT) technologies show a great potential for assessing thickness variation in concrete pavements and identification of subsurface damage. These technologies and associated evaluation methods - particularly MIRA ultrasonic tomography and 3D Radar step frequency ground penetrating radar - have immediate implications that can assist Minnesota Department of Transportation (MnDOT) engineers in quality assurance/quality assessments (QA/QC) assessments. However, additional value from thickness variation measurements can be captured if they are completed in a way that provides insight to the causes of pavement failures. This type of evaluation could lead to the development of guidelines for more economical and long lasting pavement solutions. In the proposed study, comprehensive thickness variability assessment on several existing portland cement concrete (PCC) pavements prior to rehabilitation will be conducted and compared to observed surface distress maps. Statistical analysis will be performed to determine correlations between key pavement components and observed distresses. Factors such as overall thickness deficiencies, significant thickness variation, and large variation in base layer properties will be considered. In addition, an evaluation of similar parameters in newly constructed pavements and comparison with existing pavement results will help in identifying the need, if any, for improved QA/QC construction protocols with regard to pavement thickness.Lev Khazanovich, Kyle Hoegh, Randal Barnes, Ryan Conway, Lucio Salles
02/01/15February 2015Performance and Design of Bridge Approach Panels in Wisconsinhttps://cptechcenter.org/ncc-projects/performance-and-design-of-bridge-approach-panels-in-wisconsin/bridge approachThis research is aimed to improve constructability and performance of approach slabs in Wisconsin and to determine if three expansion joints are needed or the newer design method will result in better performance. The objective is achieved by completing a national state-of-the-practice review, comparing the results of that review to current WisDOT practice, conducting a detailed on-site information collection campaign, and engineering-based reporting. The results of this research will develop a better understanding of the field performance of approach panels and recommended design changes including new standard design drawings, specifications, and construction/material manual changes that lead to improvements in performance, cost, and constructability of approach panels.Brent Phares, Justin Dahlberg
05/31/19May 2019Performance and Load Response of Rigid Pavement Systemshttps://cptechcenter.org/ncc-projects/performance-and-load-response-of-rigid-pavement-systems-/Life cycle costing; Load factor; Pavement design; Pavement performance; Portland cement concrete; Rigid pavements; Sensitivity analysis Pavement design techniques have advanced to incorporate modern technology and scientific-based models to improve pavement construction, performance, maintenance, and rehabilitation. The reliability of these models depends upon input data gathered in the field via pavement instrumentation. There is a demonstrated lack of rigid pavement instrumentation and experimental field data nationally, leading to a shortage of pavement field data required to examine, model, and simulate the interaction of pavement components in the field (such as pavement base material, slab, tie bar, etc.). In order to rely upon more scientific-based models to improve pavement systems (and ultimately reduce pavement life-cycle costs), more data is required to refine existing and new pavement performance models. Perhaps the most commonly used and popularly accepted model-based, modern approach to highway design is embodied in the Mechanistic-Empirical Pavement Design Guide (MEPDG), which incorporates models embedded in dedicated software (such as AASHTOWare Pavement ME Design) to predict pavement performance in greater detail than prior predictive models. Such dedicated software incorporates scientific data such as material mechanics, climate data, axle-load spectra, and other factors. Full implementation of the Mechanistic-Empirical Pavement Design by state departments of transportation (DOTs) requires customization or calibration/validation of the software for variables and pavement conditions at state and local levels. This in turn requires the collection of region-specific field data on climate, material properties, load response, and pavement performance for use in calibration and implementation of the software. Mechanistic-Empirical Pavement Design software uses these data inputs to more accurately simulate the load response of pavements and long-term pavement performance. Local calibration of the software involves comparing long-term performance simulation results to actual performance data at local sites (if possible) or from matching pavements in the Federal Highway Administration Long-Term Pavement Performance (LTPP) database. Several numerical models are available to predict pavement performance, and these models are an effective tool to predict the likelihood of pavement damage and longevity. These numerical models also enable improvements in road design methods, whether for new or rehabilitated pavements, that will help mitigate the problems of load-induced damage. However, most of these models have not been calibrated against actual field data obtained under realistic conditions. To enhance the effectiveness of these models and to assist in their application, instrumented test sections of pavement can be monitored and data gathered to monitor performance factors (such as soil pressure, pavement temperature, strains and deflections caused by daily changes in temperature within the pavement, along with air temperature, wind speed, relative humidity, solar radiation, and precipitation). The pavement construction process can also be monitored, and the materials used in the pavement can be tested in the laboratory or in the field (using non-destructive testing) to ascertain material property information. As pavement systems are highly nonlinear in their responses to loads and load related strains, field data collected via instrumentation helps indicate which parameters need to be emphasized in the models to describe pavement performance and response to conditions. Data from the laboratory tests (or from non-destructive field testing) is input to the model to predict the road response. The predicted response is then compared to the measured response. A sensitivity analysis also helps determine which parameters should be adjusted to best fit actual conditions. Also the LTPP database can be used for calibration in addition to data related to material properties, traffic data, and pavement performance data provided by other DOTs. In the long term, the calibrated model is used in conjunction with existing Mechanistic-Empirical design models and Mechanistic-Empirical Pavement Design software to improve the design method. The data can be put into a format directly useful to designers and engineers. Since 2001, the New York State Department of Transportation (NYSDOT) has significantly invested in instrumenting test pavement sections to acquire local data to improve calibration of Mechanistic-Empirical Pavement Design software. The instrumented field pavements in New York include Interstate 490, Interstate 90, and Interstate 86. The installed sensors are still functioning to an extent that permits data collection of additional useful scientific information, and I-490 is providing high-quality data that will positively impact future design, construction, and maintenance of roads. As NYSDOT progresses in its adoption of the Mechanistic-Empirical Pavement Design approach, the test sections it has invested in over the past decade will play a key role in the validation of that approach. In addition to collecting load response data, it will be possible to assess the long-term performance of these pavements. (Mechanistic-Empirical Pavement Design requires both.) An extended study will verify that the performance benefit is maintained in the long term and that these designs will save money in the long run. Additionally, on I-86, three different concrete pavement rehabilitation techniques were tested previously, with some differences in the performance. Extended study will provide a definitive conclusion of which method provides the best performance and is the most economical. Several states previously have conducted projects using instrumentation in pavement test sections to collect pavement performance data. In addition to the three I-86 sections instrumented to measure deflection, strain, and temperature in order to study different techniques of portland cement concrete (PCC) pavement rehabilitation, additional sections on I-490 and two sections on I-90 are being used to measure the effects of varying base types. Other states such as Ohio, Minnesota, and Delaware, among others, have instrumented concrete sections to collect data which can be used for analysis. The sharing of data from multiple DOTs and geographic regions (via resources such as the LTPP database) adds significant value to pavement performance modeling tools and to the body of scientific knowledge; this pooled approach among multiple sources/DOTs also offers a more efficient and economical manner than on an individual basis. The objectives of this study include: (1) Collecting load response and performance data and environmental monitoring at selected test pavements for four years. (2) Installing new instrumented sections as needed for a better understanding of rigid pavement response, including monitoring for the duration of the project. (3) Determining the impact of a base and other components (such as dowel bars, tie bars, etc.) on long-term performance of rigid pavement utilizing the data acquired and other nationally available data on the topic. (4) Documentation of the processes, procedures, and findings. (5) Finalization of the rigid pavement design catalog with local validation and calibration of mechanistic-empirical models. Shad Sargand, Tom Cackler
1/1/2013January 2013Performance Determination of Precast Concrete Slabs Used for the Repair of Rigid Pavementshttps://cptechcenter.org/ncc-projects/performance-determination-of-precast-concrete-slabs-used-for-the-repair-of-rigid-pavements.--/Degradation (Thermodynamics); Performance tests; Portland cement concrete; Precast concrete; Rehabilitation (Maintenance); Rigid pavements; TemperatureThe primary objective of this research is to determine the effect of temperature variation on the mechanical performance of the severely damaged rigid pavements repaired using precast portland cement concrete (PCC) slabs. The secondary objective will be to study the synergistic impact of load induced and temperature induced stresses on the mechanical performance of the repaired sections. This objective will be achieved through subjecting the precast panels to accelerated field loading to monitor the decay of performance at certain load intervals. Additionally, the project will calibrate the current generation of the performance model based on the collected field data. Measured field data and calculated pavement responses will be used to develop performance degradation plots for each permutation of the experiment design. These performance plots provide a valuable resource for field practitioners to efficiently and economically select the best available combination of repair technique and leveling material with respect to climatic data.Reza S. Ashtiani, Gabriel de Haro
10/1/2017October 2017Performance-Engineered Concrete Paving Mixtureshttps://cptechcenter.org/ncc-projects/performance-engineered-concrete-paving-mixtures/Admixtures; Concrete pavements; Field tests; Implementation; Pavement performance; Specifications; Training programsThe objective of this study is to focus on the successful deployment of performance engineered mixtures. This will involve building off the foundational work that Federal Highway Administration (FHWA) and the "PEM Champion States" have done, with emphasis on implementation, education and training, adjusting the specification values to relate accurately to good pavement performance in the field, and continued development of relating early age concrete properties to performance.Peter Taylor
5/21/2018May 2018Performance Evaluation, Material and Specification Development for Basalt Fiber Reinforced Polymer (BFRP) Reinforcing Bars Embedded in Concretehttps://cptechcenter.org/ncc-projects/performance-evaluation,-material-and-specification-development-for-basalt-fiber-reinforced-polymer-(bfrp)-reinforcing-bars-embedded-in-concrete/Basalt; Durability; Fiber reinforced concrete; Fiber reinforced polymers; Reinforcing bars; SpecificationsThe objective of this project is to complement existing fiber reinforced polymer (FRP) rebar specifications and to identify non-corrosive basalt fiber reinforced polymer (BFRP) rebar technologies for concrete reinforcement with suitable surface enhancements for the construction of durable and resilient infrastructure in Florida.Raphael Kampmann, Michelle Roddenberry, Fransico De Caso
8/15/2014August 2014Performance Monitoring of Preservation Treatments in Honoluluhttps://cptechcenter.org/ncc-projects/performance-monitoring-of-preservation-treatments-in-honolulu/Sealing compounds, Cracking, Slurry seals, Preservation, Tension, Surface treating, Rheometers, Pavement performance, Honolulu (Hawaii),This project will monitor the performance of different preservation treatments in Honolulu, Hawaii. The condition of the treated and control sections will be surveyed prior to the treatment application and then regularly at intervals between 3 and 4 months with the goal of quantifying the benefits of pavement preservation (PP). The treatments considered are fog seal, slurry seal, asphalt seal coat treatments currently available in Honolulu, thin lift overlay, and crack sealing. In addition, pavement temperature with depth will be monitored on one section to validate whether moduli may increase with depth for the Honolulu environment; a situation that is believed to result in high tensile strains near the surface of the pavement and thus affect the performance of pavement preservation treatments. Finally, the materials used for pavement preservation will be tested in the laboratory. Specifically, binders (including emulsion residues) will be tested with a Dynamic Shear Rheometer and a Viscometer, the Wet Track Abrasion will be used for slurry seals, and several performance tests will be carried out for thin lift overlay. The test results will be used to help in writing guidelines and potentially help explaining any unexpected behavior of the treatments.Adrian Archilla
09/01/17September 2017Performance of Fiber-Reinforced Self-Consolidating Concrete for Repair of Bridge Sub-Structures and Fiber-Reinforced Super-Workable Concrete for Infrastructure Constructionhttps://cptechcenter.org/ncc-projects/performance-of-fiber-reinforced-self-consolidating-concrete-for-repair-of-bridge-sub-structures-and-fiber-reinforced-super-workable-concrete-for-infrastructure-construction/Bridge substructures; Cast in place structures; Cracking; Feasibility analysis; Fiber reinforced concrete; Fibers; Flexural strength; Repairing; Self compacting concrete; ShrinkageThe proposed study seeks to investigate key engineering and structural properties of FR-SCC and fiber-reinforced super workable concrete (FR-SWC) for infrastructure repair and construction. FR-SCC is targeted for repair of sub-structure elements, while the FR-SWC is targeted for construction operations. The FR-SWC requires some consolidation and can be used in less congested structural elements where this consolidation with SCC or FR-SCC is not required. The FR-SWC is easier to produce than FR-SCC and is more cost-effective for use in infrastructure construction.Kamal H. Khayat, Ahmed Abdelrazik
9/1/2018September 2018Performance of Synthetic Fiber-Reinforced Concrete with Adapted Rheologyhttps://cptechcenter.org/ncc-projects/performance-of-synthetic-fiber-reinforced-concrete-with-adapted-rheology/Admixtures; Corrosion resistance; Cracking; Durability; Fiber reinforced concrete; Optimization; Rheology; Shrinkage; Synthetic fibers; Tensile strengthThe main objectives of this project can be summarized as follows: (1) Optimize the SRA-fiber system of SCC and SWC mixtures to achieve superior performance, including properties, autogenous shrinkage, restrained shrinkage, mechanical properties (tensile and compressive strength), frost durability, and transport properties. The investigation will include the Eclipse 4500 SRA, or equivalent, and two types of synthetic fibers (i.e., STRUX and SINTA from GCP). (2) Evaluate the effect of rheological properties of fiber alignment along the casting-flow direction of structural elements. The rheological properties of concrete will be modified using a viscosity modified admixture (VMA), such as V-MAR from GCP. The incorporation of VMA can improve the stability of the concrete mixture and distribution of the fibers. (3) Investigate the corrosion resistance of reinforcing bars in pre-cracked FR-SCC and FR-SWC mixtures. The cracking will be controlled to achieve different widths for mixtures with different fibers. The transport properties of the concrete matrix will also be investigated. (4) Evaluate the enhancement in tensile/flexural toughness and shrinkage/crack resistance of FRC made with partially replacement of the steel reinforcement in flexural members with different types of and combinations of the STRUX and SINTA fibers.Kamal Khayat
6/8/2019June 2019Performance Specifications Implementation Guidehttps://cptechcenter.org/ncc-projects/performance-specifications-implementation-guide/Asphalt mixtures;ÿ Concrete;ÿGuidelines;ÿImpacts;ÿImplementation;ÿ Performance measurement;ÿ Quality assurance; ÿSpecifications;ÿ Test proceduresMany public transportation agencies are in the process of implementing some type of performance specifications for asphalt mix and concrete. Reasons for doing so include a desire to improve long-term durability, encourage contractor innovation, better align design requirements with construction, and to have rational pay adjustments tied to predicted project life. Ongoing initiatives such as Balanced Mix Designs for asphalt mixes and Performance Engineered Concrete Mixes lend themselves to a performance specification approach by introducing higher level test methods that are intended to be more directly related to material performance than current methods. Introduction of these test methods and mix design criteria will have a major impact on existing quality assurance programs. Agencies will need to make informed decisions regarding applicability of new tests to process control and quality assurance. Lot and sublot sizes may need to be adjusted to account for test time and complexity. Quantity of material obtained for testing may need to be increased.Edward Harrigan
10/1/2016October 2016Permeability Reduction of Restrained Concrete in a Chloride-Rich Environmenthttps://cptechcenter.org/ncc-projects/permeability-reduction-of-restrained-concrete-in-a-chloride-rich-environment/Admixtures; Bridge decks; Chloride content; Permeability; Portland cement concrete; Test proceduresMississippi Department of Transportation (MDOT) is now requiring waterproofing (permeability reducing) admixtures in bridge deck overlays in an effort to improve the long-term performance of bridges. These admixtures reportedly reduce permeability of concrete by plugging pores and capillaries throughout the entire mass of concrete. These admixtures react with water and cement hydration by-products to either formulate coalescing polymer globules or crystalline structures that seal pores, capillary tracts and micro cracks in hardened concrete. This makes hardened concrete less permeable to water and chemicals that corrode the reinforcing steel and create costly repairs. While some manufacturers note that these chemicals exceed performance requirements of industry standards such as ASTM C494 Type S, limited data is provided to document their performance in a bridge deck. Bridge structures create a restrained system for concrete shrinkage and many Mississippi bridges are exposed to chloride ions when salt is broadcast on the decks in winter months. This laboratory study will use testing equipment and chloride ion exposure to simulate these field conditions. Data compiled from this study will provide MDOT Engineers with information needed to verify that ordinary portland cement (OPC) or portland limestone cement (PLC) combined with these admixtures will reduce the permeability of portland cement concrete (PCC) in bridges.Robert Varner
2/1/2019February 2019Permeable Pavement in Northern North American Urban Areas: Research Review and Knowledge Gapshttps://cptechcenter.org/ncc-projects/permeable-pavement-in-northern-north-american-urban-areas:-research-review-and-knowledge-gaps/Permeable interlocking concrete pavers; Permeable pavements; Pervious concrete; Research needsA majority of existing permeable pavement installations are related to parking lots and commercial areas with low speeds and light traffic loads. During the past two decades, a tremendous amount of progress has been made with regard to the application of permeable pavements regarding mix design, hydrologic design, water quality assessment and maintenance requirements. Review of the literature revealed, however, that there are still many important questions that must be answered before permeable pavements can be fully integrated in urban roads, especially in highways with high speeds and loads. This paper summarises the major research progress in the above listed areas and identifies research needs. Research needs are summarised under four topics: (1) structural and materials property, (2) hydrologic performance, (3) water quality and (4) maintenance. Research needs are further organised based on their immediate, short-term and long-term impact.Peter Weiss, Masoud Kayhanian, John Gulliver, Lev Khazanovich
4/1/2016April 2016Pervious Concrete Parking Stripshttps://cptechcenter.org/ncc-projects/pervious-concrete-parking-strips/Pervious concrete, pervious pavement, permeable pavement, storm water management, parking stripsPervious concrete parking strips were constructed adjacent to SR 203 through the urban core of Monroe, Washington. The parking strips will be monitored over a period of five years to measure performance with respect to infiltration capacity, service life, and any possible negative effects on the adjacent lanes of SR 203. A final report will be issued summarizing the performance of the parking strips at the end of the period.Keith W. Anderson, Mark Russell, Jeff S. Uhlmeyer, Jim Gardner
09/01/16September 2016Pervious PCChttps://cptechcenter.org/ncc-projects/pervious-pcc/pervious concrete, porous concrete overlayStudy on full-depth and pervious concrete pavements and a thin porous concrete overlay.Bernard Izevbekhai. Alexandra Akkari
05/31/14May 2014Phase II Evaluation of Waste Concrete Road Materials for Use in Oyster Aquaculture - Field Testhttps://cptechcenter.org/ncc-projects/phase-ii-evaluation-of-waste-concrete-road-materials-for-use-in-oyster-aquaculture---field-test/Waste products, Concrete aggregates, Recycled materials, Field tests, Aquaculture, Thickness, Chesapeake BayThe overall objective of this project was to determine the suitability of waste concrete from road projects as bottom conditioning material for on bottom oyster aquaculture in the Chesapeake Bay. The objectives for Phase 2 are to: (1) evaluate the potential introduction of organisms attracted to the reclaimed concrete aggregate (RCA) pile that may be potential predators of oyster spat; and (2) determine potential impacts or disruptions in the use of traditional harvesting gear on aquaculture areas conditioned with RCA. As appropriate, recommendations of thickness of native shell overburden will be provided to mitigate any identified impacts.Chunlei Fan, Kelton L. Clark
1/1/2019January 2019Polyester Polymer Concrete Overlayhttps://cptechcenter.org/ncc-projects/polyester-polymer-concrete-overlay/Polyester polymer concrete, PPC, rut filling, studded tire wear mitigation, concrete pavement wear Polyester polymer concrete (PPC) was used in a trial application as a possible repair strategy on a section of concrete pavement that suffered from extensive studded tire wear. The PPC was applied in three methods; (1) as a 1 inch thick inlay of the entire lane that was diamond ground to remove all rutting from studded tire wear, (2) as an inlay of just the wheel paths that were diamond ground, and (3) as a feathered overlay of the existing pavement which had no diamond grinding to remove rutting.Keith W. Anderson, Jeff S. Uhlmeyer, Mark Russell, Chad Simonson, Kevin Littleton, Dan McKernan, Jim Weston
1/15/2016January 2016Portland Cement Concrete Material Characterization for Pavement ME Design Implementation in Idahohttps://cptechcenter.org/ncc-projects/portland-cement-concrete-material-characterization-for-pavement-me-design-implementation-in-idaho/Cost effectiveness; Databases; Materials tests; Mechanical properties; Mechanistic-empirical pavement design; Portland cement concrete; Shrinkage; Tensile propertiesThis project will develop a database with Portland Cement Concrete (PCC) materials characterization data necessary for Idaho Transportation Department (ITD) use of American Association of State Highway and Transportation Officials Ware (AASHTOWare) Pavement Mechanistic-Empirical (Me) Design for PCC pavement design. This will be accomplished by characterizing materials used in PCC pavement by the Idaho Transportation Department. Types and proportions for main constituents of concrete paving mixtures across Idaho will be identified. Material from suppliers throughout the state will be gathered and tested for drying shrinkage, mechanical properties and indirect split tensile. A PCC-Me Database will be developed using the material testing results. The implementation of the new Pavement Me Design Guide will provide more economical pavement structures saving Idaho money.Somayeh Nassiri, Milena Rangelov, Ahmed Ibrahim, Fouad Bayomy, Ahmed Muftah, Bikash Sigdel
7/1/2018July 2018Precast Concrete Deck-to-Girder Connection Using UHPChttps://cptechcenter.org/ncc-projects/precast-concrete-deck-to-girder-connection-using-uhpc/Bridge decks; Girders; Panels; Precast concrete; Shear reinforcement; Structural analysis; Structural connection; Ultra high performance concreteThe method used in Nebraska for connecting precast concrete deck panels to concrete girders to create composite section is extending shear connectors (i.e., threaded rods) from the concrete girder into HSS-formed shear pockets in the deck panels, and then filling the pockets and haunch area using self-consolidating concrete (SCC). This method requires high level of quality control/quality assurance (QA/QC) in spacing the shear connectors during girder fabrication as well as shear pockets during panel fabrication to avoid any conflict between them during erection. It also requires shear connectors to achieve minimum embedment in the shear pockets to develop the design capacity, which necessitates adjusting connector’s height to compensate for girder camber.G. Morcous
7/1/2018July 2018Precast Concrete Panels for Rapid Full-Depth Repair of CRC Pavement to Maintain Continuity of Longitudinal Reinforcementhttps://cptechcenter.org/ncc-projects/precast-concrete-panels-for-rapid-full-depth-repair-of-crc-pavement-to-maintain-continuity-of-longitudinal-reinforcement/Precast Panels, Full Depth Repair, CRC PavementsThis Tech Brief describes a recently implemented method for rapid overnight full-depth repairs of continuously reinforced concrete (CRC) pavements using precast concrete panels. This method, developed by the Illinois Tollway, uses continuous longitudinal reinforcement throughout the repair area to make the method applicable for repairing multiple lanes or large areas, as well as for isolated repairs for long-term performance with minimal impact to traffic. The Illinois Tollway successfully utilized this method for a high traffic-volume expressway in the Chicago metropolitan area.Steve Gillen, Dan Gancarz, Shiraz Tayabji
9/26/2014September 2014Preliminary Evaluation of Cool-cretehttps://cptechcenter.org/ncc-projects/preliminary-evaluation-of-cool-crete/Bridge decks, Cracking of concrete pavements, Compressive strength, Concrete curing, Temperature, Corrosion, Additives,Cracking of concrete bridge decks is a problem throughout the country. The cracking leads to the penetration of water and road salts that accelerates corrosion of reinforcement in the deck which can further increase cracking and detrimental effects. States have to invest significant resources to repair and replace damaged decks caused by the cracking. A new additive for concrete has been developed that could greatly improve on some of the difficult issues that the curing process of concrete creates. The four objectives of this study are: (1) Measurement of internal temperatures during curing; (2) Measurement of strains during curing caused by restraint; (3) Testing for compressive strength and modulus of rupture material properties; and (4) Generation of thermal gradient through the deck samples to monitor effects. If Cool-crete shows superior behavior, it can be utilized as an option for better performing concrete in bridge decks as well as other locations susceptible to cracking.Eric Steinberg, Travis Ellison
8/1/2014August 2014Quantification of System-wide Life Cycle Benefits of Recycled Materials in Highwayshttps://cptechcenter.org/ncc-projects/quantification-of-system-wide-life-cycle-benefits-of-recycled-materials-in-highways/Road construction, Recycled materials, Life cycle analysis, Cost effectiveness, Environmental impacts, Waste products, MarylandThe Federal Highway Administration (FHWA) and various governmental agencies have developed fact sheets on various recycled materials and industrial byproducts for their use in highway construction applications. These fact sheets typically have addressed the engineering properties and environmental suitability issues relevant to various applications and in some cases incorporated design guidelines and construction specifications. What is lacking is direct information on sustainability assessment characteristics, i.e., greenhouse emissions, energy and water consumption and life cycle cost benefits. Agencies may track system-wide use of quantities for major recycled materials such as fly ash, recycled asphalt pavement, recycled concrete aggregate, foundry sand, coal combustion byproducts, steel slag, etc., but they cannot readily calculate the benefits accrued by substitution of these materials for conventional materials. Although state transportation departments have been in the forefront of introducing recycled materials, they have not been able to clearly convey the benefits in a quantitative and transparent manner using readily understood metrics. The first objective of this study is to develop/update fact sheets on various recycled materials and industrial byproducts that are used in highway construction. New information generated in recent years relative to their engineering properties and environmental impact questions will be added as well as relevant life cycle assessment data. The second objective of this study is to develop a tool by which the state system-wide material use quantities can be used to calculate the life cycle benefits associated with the incorporation of recycled materials and industrial byproducts to highway pavement construction. (1) Develop/update fact sheets on various recycled materials and industrial byproducts that are used in highway construction; (2) Identification of the most appropriate cost database for life cycle assessment parameters for each material; (3) Integration of cost effectiveness and environmental impact into current materials testing and evaluation; and (4) Determining the benefits accrued by use of recycled materials and industrial by products in construction through a highway rating system. Various states including Maryland Department of Transportation (DOT) plans to adopt a green materials management approach. This research project directly helps the DOTs build their capacity to sustain such efforts. The life-cycle analysis method evaluted through actual field projects in this research will provide an easy-to-use tool for DOT engineers to evaluate the impact of green materials and technologies in terms of environment, cost, and long-term performance. The successful implementation of this project could also lead toward the development of green materials registry and management at the DOTs. Recommendations provided in the final report can also lead to pilot implementation for full-scale evaluation of the developed life-cycle analysis tools.Ahmet H. Aydilek
11/1/2018November 2018Quantifying the Effects of Preservation Treatments on Pavement Performancehttps://cptechcenter.org/ncc-projects/quantifying-the-effects-of-preservation-treatments-on-pavement-performance/Preservation treatments, Pavement performance condition, cracking and faulting of concrete pavements ,service life, and life-cycle costsThis report presents a framework for quantifying the effects of preservation treatments on pavement performance, along with a guidance document to facilitate implementation of the framework. The proposed framework uses performance measures that quantify the changes in pavement performance in terms of condition (e.g., cracking and faulting of concrete pavements and cracking and rutting of asphalt pavements), service life, and life-cycle costs. Applicability of these measures was demonstrated using in-service pavement performance data. The guide also identifies alternate pavement performance measures (e.g., friction and composite pavement condition indices) and describes a process for assessing their appropriateness for use in quantifying the effects of preservation treatments on pavement performance. In addition, incorporating these measures in asset management systems would provide a means for selecting the appropriate preservation treatments and optimizing the allocation of resources..This project is the NCHRP Research Report 858Gonzalo R. Rada, James M. Bryce, Beth A. Visintine, R. Gary Hicks, DingXin Cheng
3/9/2018March 2018Quantifying the Range of Variability in the Flexural Strength of Fiber Reinforced Concrete Using Monte Carlo Simulationhttps://cptechcenter.org/ncc-projects/quantifying-the-range-of-variability-in-the-flexural-strength-of-fiber-reinforced-concrete-using-monte-carlo-simulation/Admixtures; Fiber reinforced concrete; Flexural strength; Mix design; Monte Carlo methodMany laboratory studies have shown erratic results in flexural strength among replicate specimens of Fiber reinforced concrete (FRC). As a result, repeatability of results was very challenging. Given this issue, it would be very difficult for design engineers to make reliable claims about the performance of a certain FRC element in the field. The objective of this project is to provide a better tool for FRC designers to be able to make more robust claims about the performance of an FRC element in transportation infrastructures. This will be carried out through statistically quantifying the range of variability in the flexural strength of FRC using Monte Carlo Simulation. The power of the obtained range of variability prediction tool will be examined through conducting flexural experiments on 8 concrete mixes. These mixes will have randomly selected fiber types, fiber dosages, and other concrete properties in order to examine the power of the developed tool for a wide range of mixes. Ranges of variability associated with several confidence levels will be tested.Ahmad Ghadban, Nadim Wehbe
10/10/2017October 2017Quantitative Measurements of Curing Methods for Concrete Bridge Deckshttps://cptechcenter.org/ncc-projects/quantitative-measurements-of-curing-methods-for-concrete-bridge-decks/Bridge decks; Chlorides; Concrete curing; Field tests; Lithium compounds; Silicates; Bridges and other structures; Highways; Materials; PavementsThis paper gives a quantitative comparison of how different curing methods impact the rate of drying and subsequent penetration of lime water and chloride penetration of concrete. Laboratory work is used to investigate a bridge deck concrete mixture cured by two different curing compounds, wet curing of different lengths, and then no curing. The results confirm that wet curing methods reduce the ingress of external chemicals more effectively. The wet curing for even one day provided significant improvement over both curing compounds and no curing. To confirm the findings in the field eight bridge decks were investigated that were cured with a curing compound and wet curing. The field investigation confirms the findings of the laboratory testing and emphasizes the importance of wet curing for long term durability of concrete. This paper provides important quantitative data that can be used to compare these methods and help with making decisions about different curing practices and the impact on the service life of concrete.Amir Hajibabaee, Moradllo Khanzadeh , Mehdi, Amir Behravan, M. Tyler Ley
9/1/2014September 2014Rapid Pavement Construction: Research on Thixotropy and Workability Loss of Vibration-free Concrete in View Accelerating Pavement Construction by Slipforminghttps://cptechcenter.org/ncc-projects/rapid-pavement-construction:-research-on-thixotropy-and-workability-loss-of-vibration-free-concrete-in-view-accelerating-pavement-construction-by-slipforming/Cement paste; Mix design; Road construction; Slip form paving; Thixotropy; WorkabilityThe main objective of this project is to identify critical constituent materials and mix design parameters that influence the thixotropy and workability loss of vibration-free concrete. The research will be mainly performed on cement-pastes, which is the source of thixotropy and workability loss. The influence of the aggregates will be investigated in a separate task. Understanding the time-dependent fresh concrete behavior is essential for the development of vibration-free concrete for slipforming, enhancing the opportunities for accelerated pavement construction. Furthermore, the obtained results can be related to other Research on Concrete Applications for Sustainable Transportation (RE-CAST) projects, such as project 1B on formwork pressure and 1C on the influence of casting procedures on the performance of concrete.Dimitri Feys
01/01/2016January 2016Rapid Replacement of Bridge Decks (Phases I-IV funded under different contracts)https://cptechcenter.org/ncc-projects/rapid-replacement-of-bridge-decks-(phases-i-iv-funded-under-different-contracts)/rapid repair; bridge deck; aging infrastructure; precast bridge decksThe earliest phases of this project date back to 1998, when research was initiated to identify effective & cost efficient design & construction strategies & procedures for rapid rehab or replacement of bridge decks, to include those decks which must be r/r-ed under conditions of concurrent traffic. Phase 1 consisted of identifying & analyzing the various strategies for such work, and making recommendations on which are the most appropriate for the specified conditions. Phase II consisted of monitoring & documenting the rapid replacement work on four Georgia DOT bridges in the Atlanta metro area; identifying design & construction problem areas, as well as corrective actions that should be taken to eliminate these in future rapid deck replacements. Phase III will consist of construction of two test bridges on I-59 in Collinsville, AL using two different types of rapid deck replacement technologies. Phase IV will consist of evaluating the structural performance of the decks constructed in Phase III. Phases III & IV have essentially been halted indefinitely due to delays in letting the construction project.Bryan Harvey, Hassan Abbas, G. Ed Ramey
6/30/2013June 2013Rapid Retrofit and Strengthening of Bridge Componentshttps://cptechcenter.org/ncc-projects/rapid-retrofit-and-strengthening-of-bridge-components/Carbon fibers; Highway bridges; Retrofitting; Strengthening (Maintenance)The objective of this study is to (1) repair four bridges with high-performance carbon fiber materials developed at University of Kentucky; and (2) develop a guide and specifications for the use of this material. The advantage of the carbon fiber material is ease of application by a single worker and reduction in repair time, resulting in lower repair costs.R. Graves
6/1/2013June 2013Real-Time Laser Scanning of Aggregate Materials in Highway Constructionhttps://cptechcenter.org/ncc-projects/real-time-laser-scanning-of-aggregate-materials-in-highway-construction/Absorption; Aggregates; D cracking; Quality control; Real time information; Specific gravityThe quality and service life of the roadways that make up the highway transportation infrastructure are dependent upon the selection and use of high quality aggregate materials. Five state transportation agencies participated in this Transportation Pooled Fund (TPF) study, which was designed to demonstrate the use of laser scanning as a means to assess, in real-time, the quality of aggregate used in highway construction. Participating states included Kansas, New York, Ohio, Oklahoma, and Pennsylvania.Warren H. Chesner, Nancy J. McMillan
10/1/2012October 2012Recycled Concrete Aggregate (RCA) for Infrastructure Elementshttps://cptechcenter.org/ncc-projects/recycled-concrete-aggregate-(rca)-for-infrastructure-elements/RCA, recycled concrete aggregate, RAC, recycled aggregate concrete, sustainability, aggregateThe objective of the research is to determine the implications of using recycled concrete aggregate (RCA) in the production of new concrete. Specifically, the study will evaluate the fresh and hardened properties, durability, and structural behavior of concrete containing RCA. The expected result from this study will be guidelines for evaluating, selecting, and specifying RCA concrete. These guidelines will provide both MoDOT and design engineers with a resource to design, test, and implement RCA in transportation-related infrastructure.Jeffery S. Volz, Kamal H. Khayat, Mahdi Arezoumandi, Jonathan Drury, Seyedhamed Sadati, AdamSmith, Amanda Steele
09/15/19September 2019Reduction of Structural Damage from the Thermal Expansion of Concrete Using Multifunctional Materialshttps://cptechcenter.org/ncc-projects/reduction-of-structural-damage-from-the-thermal-expansion-of-concrete-using-multifunctional-materials/Alloys, Bridges and other structures, Concrete, Cracking, Design, Highways, Materials, Pavements, Structural materials, Thermal expansionControl of thermal expansion is a critical goal of engineering design in a wide range of applications, particularly in cases where system components are small, are subject to large changes (gradients) in temperatures, or require extreme dimensional stability over a wide range of temperatures. In particular, the thermal expansion of concrete plays a significant role in the durability of the transportation infrastructure and causes misalignment, cracking, and structural failure. As such, the objective of this study is to improve the durability and extend the life of transportation infrastructure using multifunctional materials. This research aims to use high-performance materials such as shape memory components to address the issue of thermal expansion integrated into next-generation designs, to enhance the longevity and safety of these structures. As a result, the more specific objective of this research is to design and characterize the use of multifunctional materials that stabilize the changing structure due to thermal expansion. The characteristics of these materials will work in conjunction with the temperature dependence of concrete. This will require very specific properties from the materials, making trained shape memory alloys (SMAs) a likely candidate, to meet the characteristics required to address the problem statement. The methods to train the materials should be developed in a repeatable fashion, and their adaptability demonstrated as a function of temperature and stress from the thermal expansion of the concrete.Ibrahim Karaman, Darren Hartl
1/1/2013January 2013Reuse of Mine Waste Materials Amended with Fly Ash in Transportation Earthwork Projectshttps://cptechcenter.org/ncc-projects/re-use-of-mine-waste-materials-amended-with-fly-ash-in-transportation-earthwork-projects/Wastes, Fly ash, Earthwork, Highway maintenance, Mines, Colorado, Strategic planningEnvironmental sustainability and land stewardship are challenging but laudable constraints for all infrastructure development in the United States. Our nation‰'s prevalent energy concerns, which include the desire for energy independence coupled with a growing population requiring additional energy capacity, constrain energy available to repair and build new infrastructure. The Colorado Department of Transportation (CDOT) has identified the maintenance and improvement of roadways in addition to increased construction of local road systems as strategic goals in the statewide transportation plan (CDOT 2008). These goals will support an overarching objective in Colorado to enhance transportation safety while meeting future needs of increased transportation capacity.Mohammad H. Gorakhki, Sultan A. Alhomair, Christopher A. Bareither
03/01/20March 2020Role of Coarse Aggregate on Chloride Intrusion in HPC Bridge Deckshttps://cptechcenter.org/ncc-projects/role-of-coarse-aggregate-on-chloride-intrusion-in-hpc-bridge-decks/Bridge decks; Chlorides; Coarse aggregates; High performance concrete; Permeability; Test proceduresThe overall goal is to identify an effective test method to reduce uncertainty concerning the use of certain Iowa aggregate sources for manufacturing high performance concrete (HPC) for bridge decks. The research team's approach is to investigate typical Iowa HPC coarse aggregates and study the relationships between the aggregate properties, especially the pore system properties, and concrete permeability. The specific objectives of the proposed study include the following: (A) To examine the relationship between the coarse aggregate pore properties and concrete permeability/chloride ingress measured using different methods (e .g., natural chloride penetration and electrical methods); (B) To identify the properties (such as porosity, median pore throat diameter, etc.) that describe the main features of aggregate pore structure; (C) To critically evaluate test methods for quantifying key pore system properties of coarse aggregates effectively; and (D) To establish criteria for accepting Iowa coarse aggregates for the manufacture of low permeability HPC for Iowa bridge decks.Kejin Wang, Franek Hasiuk
8/15/2017August 2017Role of Supplementary Cementitious Material Type in the Mitigation of Calcium Oxychloride Formation in Cementitious Pasteshttps://cptechcenter.org/ncc-projects/role-of-supplementary-cementitious-material-type-in-the-mitigation-of-calcium-oxychloride-formation-in-cementitious-pastes/SCMs mitigate calcium oxychloride formationPremature deterioration has been observed at some joints in concrete pavements. This joint damage has been attributed, in part, to a deleterious chemical reaction between chloride-based deicing salts (e.g., calcium chloride) and calcium hydroxide from the cementitious matrix resulting in the formation of a compound referred to as calcium oxychloride. Calcium oxychloride formation can be mitigated in cementitious pastes through the replacement of cement with supplementary cementitious materials (SCMs) (e.g., fly ash or slag). Although various SCMs are beneficial in mitigating the formation of calcium oxychloride, little has been written to describe similarities or differences between the different types of SCMs relating to their ability to mitigate calcium oxychloride formation. This paper compares various SCM types. As the volume of supplementary cementitious materials replacing the cement increases, calcium hydroxide and calcium oxychloride amounts decrease. The supplementary cementitious materials reduce the calcium hydroxide and calcium oxychloride formed in the order calcined clay > silica fume ≫ fly ash > slag ≫ limestone. The contributions of the SCMs to reducing calcium hydroxide (CH) and calcium oxychloride (CAOXY) due to dilution and reaction are separated. The potential benefits of different SCMs in reducing calcium hydroxide amounts in paste can be predicted based on their pozzolanicity (determined from their response in pozzolanic tests based on isothermal calorimetry and thermogravimetric analysis).Prannoy Suraneni, Vahid Jafari Azad, O. Burkan Isgor, Jason Weiss
3/1/2017March 2017Seasonal Variations and In Situ Assessment of Concrete Pavement Foundation Mechanistic Propertieshttps://cptechcenter.org/ncc-projects/seasonal-variations-and-in-situ-assessment-of-concrete-pavement-foundation-mechanistic-properties/Freeze thaw cycles; Seasonal variations; California bearing ratio; Coefficient of subgrade reaction; Concrete pavements; Falling weight deflectometers; Foundations; Mechanical properties; Subbase (Pavements); Subgrade (Pavements)In cold climates, pavement surface and foundation layers are subjected to seasonal temperature variation and freeze–thaw cycles. The number and duration of freeze–thaw cycles in the foundation layers can significantly influence the pavement performance. Seasonal variation in foundation layers is accounted for in pavement design by empirically adjusting the foundation layer moduli values. This paper presents results from in situ falling weight deflectometer (FWD) and dynamic cone penetrometer (DCP) tests conducted over a two-year period at five sites in Iowa; at one of these sites, temperatures of the foundation layers were continuously monitored during the testing period. FWD testing was conducted to determine the modulus of subgrade reaction (k) values. DCP testing was conducted to estimate California bearing ratio (CBR) values of the subbase and subgrade. Temperature data were analyzed to determine freezing and thawing periods and frost penetrations. Seasonal variations observed in the foundation mechanistic properties were compared with the assumed design values. Empirical relationships between the different mechanistic properties are explored.Yang Zhang, Pavana K.R. Vennapusa, David J. White, Alex E. Johnson
10/10/2012October 2012Self-Consolidating Concrete (SCC) and High-Volume Fly Ash Concrete (HVFAC) for Infrastructure Elements: Implementationhttps://cptechcenter.org/ncc-projects/self-consolidating-concrete-(scc)-and-high-volume-fly-ash-concrete-(hvfac)-for-infrastructure-elements:-implementation/Self-Consolidating Concrete,SCC, HFVA, high volume fly ashThe objective of this project is to evaluate and monitor a bridge that has self-consolidating concrete for some of the precast/prestressed girders and an intermediate bent with 50% fly ash replacement. The bridge project will have both traditional and innovative beams and intermediate bents which allows the researchers to do direct comparisons. At the conclusion of the project, it will be determined if MoDOT should allow SCC and 50% fly ash replacement as options on MoDOT projects.John J. Myers, Eli S. Hernandez, Hayder Alghazali, Alexander Griffin, Kaylea Smith
08/31/14August 2014Simplified Design Table for Minnesota Concrete Pavementshttps://cptechcenter.org/ncc-projects/simplified-design-table-for-minnesota-concrete-pavements/designDevelop a design table based on Mechanistic Empirical Pavement Design Guide (MEPDG) procedureLev Khazanovich, Derek Tompkins
9/20/2016September 2016Soil-Cement Manual of Practice: Interconnected Framework for Pavement Design, Laboratory Mixture Design, and Construction Quality Control/Assurancehttps://cptechcenter.org/ncc-projects/soil-cement-manual-of-practice-interconnected-framework-for-pavement-design-laboratory-mixture-design-and-construction-quality-control-assurance/Handbooks; Mechanistic-empirical pavement design; Mix design; Pavement layers; Quality assurance; Quality control; Soil cement pavements; ThicknessDevelop a soil-cement manual of practice for Mississippi Department of Transportation (MDOT) that focuses on integrating pavement layer thickness design (MEPDG), laboratory mixture design, and construction quality control/assurance.Isaac Howard
12/31/2017December 2017SPR-3310: Investigation of Use of Slag Aggregate and Slag Cements in Concrete Pavement to Reduce Their Maintenance Costshttps://cptechcenter.org/ncc-projects/spr-3310:-investigation-of-use-of-slag-aggregate-and-slag-cements-in-concrete-pavement-to-reduce-their-maintenance-costs/Coarse aggregates; Compressive strength; Concrete pavements; Costs; Durability; Flexural strength; Fly ash; Freeze thaw durability; Maintenance; Slag; Wetting and drying testsThe air-cooled blast furnace slag (ACBFS), the by-product of the pig iron making process, is often used as coarse aggregate in portland cement concrete (PCC) pavements, especially in the areas located in the vicinity of the iron mills. The utilization of this by-product as an aggregate in concrete offers environmental and economic benefits in the form of elimination of waste, decrease in the disposal costs, and reduction in need for mining of the natural materials. However, concerns exist with relation of the influence of these aggregates on the long-term durability of pavement concretes, especially at locations exposed to freezing and thawing environment. The objective of this research was to evaluate the influence of using the ACBFS aggregate (slag aggregate) as a replacement for natural aggregates on the properties of pavement concrete designed to meet the standard specifications of the Indiana Department of Transportation.Kho Pin Verian, Parth Panchmatia, Jan Olek,
8/1/2015August 2015SPR-3403: Removing Obstacles for Pavement Cost Reduction by Examining Early Age Opening Requirementshttps://cptechcenter.org/ncc-projects/spr-3403:-removing-obstacles-for-pavement-cost-reduction-by-examining-early-age-opening-requirements/Accelerated tests; Concrete curing; Concrete pavements; Flexural strength; Pavement cracking; Tension; Traffic loadsThe risk of cracking in a concrete pavement that is opened to traffic at early ages is related to the maximum tensile stress that develops in the pavement and its relationship to the measured, age dependent, flexural strength of a beam. The stress that develops in the pavement is due to several factors including traffic loading and restrained volume change caused by thermal or hygral variations. The stress that develops is also dependent on the time-dependent mechanical properties, pavement thickness, and subgrade stiffness. There is a strong incentive to open many pavements to traffic as early as possible to allow construction traffic or traffic from the traveling public to use the pavement.Federico C. Antico, Hadi S. Esmaeeli, Igor De la Varga, Wesley Jones, Timothy Barrett, Pablo Zavattieri, W. Jason Weiss
3/1/2015March 2015SPR-3623: Early Detection of Joint Distress in Portland Cement Concrete Pavementshttps://cptechcenter.org/ncc-projects/early-detection-of-joint-distress-in-portland-cement-concrete-pavements/Concrete pavements; Deterioration; Electrical resistivity; Ground penetrating radar; Moisture content; Pavement distress; Pavement joints; Portland cement concreteINDOT (as well as several surrounding states) have observed that certain concrete pavements may show a susceptibility to joint deterioration. Unfortunately, by the time that this joint deterioration is observed it is often too late and costly partial depth repairs are needed. The deterioration is generally occurring in the joint behind the backer rod and joint sealant; as such, it is difficult to detect even if one is standing directly above the joint. This project investigated the use of electrical resistivity and ground penetrating radar as two techniques to detect premature joint deterioration. The thought process was that if the joint deterioration is determined at an early stage, low cost corrective actions can be taken to extend the life of the concrete.Jason Weiss, Dwayne Harris, Yaghoob Farnam, Robert Spragg, Paul Imbrock
12/31/16December 2016SPR-3808: Synthesis: Accelerating the Implementation of Research Findings to Reduce the Potential for Concrete Pavement Joint Deteriorationhttps://cptechcenter.org/ncc-projects/spr-3808:-synthesis:-accelerating-the-implementation-of-research-findings-to-reduce-the-potential-for-concrete-pavement-joint-deterioration/Concrete pavements, Deterioration, Implementation, Joints (Engineering), Pavement distressThis project will comprehensively review and synthesize all the suggested causes and phenomena associated with joint deterioration for purposes of developing a manageable solution to prevent and/or to mitigate this problem in the future.Jason Weiss, Jan Olek
5/30/2016May 2016SPR-3864: Performance of Deicing Salts and Deicing Salt Cocktailshttps://cptechcenter.org/ncc-projects/spr-3864:-performance-of-deicing-salts-and-deicing-salt-cocktails/Concrete pavements; Deicing chemicals; Pavement performanceDeicing salts are widely used for anti-icing and deicing operations in pavements. While historically sodium chloride may have been the deicer most commonly used, a wide range of deicing salts have begun to be used to operate at lower temperatures, to “stick to the road better” and to improve other aspects of performance such as environmental impact or corrosion resistance. It has been observed that some chloride based deicing salts can react with the calcium hydroxide in the mixture resulting in the formation of calcium oxychloride an expansive phase that can damage concrete pavements, especially at the joints. This report describes the two main objectives of this work. First, the report documents the development a standardized approach to use low temperature differential scanning calorimetry (LT-DSC) to assess the influence of cementitious binder composition on the potential for calcium oxychloride formation. Second, this work will assess the influence of blended salt cocktails on the formation of calcium oxychloride.Prannoy Suraneni, Jonathan Monical, Erol Unal, Yaghoob Farnam, Chiara Villani, Timothy J. Barrett, W. Jason Weiss
7/1/2016July 2016SPR-4004: Development of Subgrade Stabilization and Slab Undersealing Solutions for PCC Pavements Restoration and Repairshttps://cptechcenter.org/ncc-projects/spr-4004:-development-of-subgrade-stabilization-and-slab-undersealing-solutions-for-pcc-pavements-restoration-and-repairs/Pavements; Portland cement concrete; Slabs; Stability (Mechanics); Subgrade (Pavements)Project deliverables will include protocols for proposed stabilization and slab undersealing techniques that will be in the form suitable for implementation in INDOT’s specifications. In addition, the proposed field trials of the proposed solutions will provide a credible set of information that will help with the implementation efforts.Jan Olek
10/17/2016October 2016SPR-4112: Best Practices for Patching Composite Pavementshttps://cptechcenter.org/ncc-projects/spr-4112:-best-practices-for-patching-composite-pavements/Best practices; Composite pavements; Concrete pavements; Patching; Pavement management systems; Pavement performancePatching composite and, to a lesser extent, concrete pavements poses numerous constructability and performance issues. A synthesis of research and experience is needed to identify ways to facilitate proper construction and improve the ultimate performance of these patches. Developing these best practices will involve a survey of other states’ practices, literature review and review of Indiana Department of Transportation (INDOT) pavement management data before and after patching on selected projects in each district.Rebecca McDaniel
1/1/2017January 2017SPR-4116: Investigation of Design Alternative for the Subbase of Concrete Pavementshttps://cptechcenter.org/ncc-projects/spr-4116:-investigation-of-design-alternative-for-the-subbase-of-concrete-pavements/Concrete pavements; Geosynthetics; Geotextiles; Settlement (Structures); Smoothness; Soil compaction; Subbase (Pavements)The study will develop recommendations for new subbase designs based on a comprehensive review of the literature, a survey of best practices across the US and abroad and an experimental program focused on unstabilized layers alone and in combination with geotextiles.Marika Santagata, Philippe Bourdeau
9/1/2017September 2017SPR-4210: Determining the Optimal Traffic Opening Timing through an In Situ NDT Method for Concrete Early Age Properties Monitoringhttps://cptechcenter.org/ncc-projects/spr-4210:-determining-the-optimal-traffic-opening-timing-through-an-in-situ-ndt-method-for-concrete-early-age-properties-monitoring/Concrete curing; Concrete pavements; Construction scheduling; Costs; Failure; Mechanical properties; Nondestructive tests; Optimization; Sensors; Test proceduresThe aim of this project is to develop a reliable in situ testing method to determine the quality of concrete for traffic opening by using piezoelectric sensors coupled with electromechanical impedance (EMI) to determine early age properties of concrete. The potential benefits of using this non-destructive testing (NDT) include 1) reducing pre-mature failure of concrete pavement, patching and other concrete structures; 2) determining optimal traffic opening time based on reliable data of concrete property; 3) enabling cost and schedule savings due to reduced testing samples and testing time; and 4) eliminating construction worker safety issues on the job site and accident rates in opening zones.Na Lu
1/1/2018January 2018SPR-4213: Determining Concrete Patch Locations Other Than Visualhttps://cptechcenter.org/ncc-projects/spr-4213:-determining-concrete-patch-locations-other-than-visual/ Artificial intelligence; Classification; Ground penetrating radar; Patching; Pavement maintenance; Sensors; IIn this research, the fusion of data from two current Indiana Department of Transportation (INDOT) sensors (WayLink 3D Laser Imaging and GSSI ground penetrating radar) will be investigated and methods will be developed to use them to create a patching and classification table. The proposed approach is to use the 3D imaging system to create a 1 mm resolution image of the pavement surface and develop an artificial intelligence based technique, which may allow narrowing the patch search area in order to concentrate computational and human resources for analyzing the GPR data.James Krogmeier, Mark Bell
9/1/2018September 2018SPR-4320: Implementation of Epoxy Injection of Concrete Overlaid Bridge Deckshttps://cptechcenter.org/ncc-projects/spr-4320:-implementation-of-epoxy-injection-of-concrete-overlaid-bridge-decks/Bridge decks; Concrete overlays; Cost effectiveness; Epoxy coatings; Freeze thaw durability; Service life; Winter maintenance; Bridges and other structures; Highways; Maintenance and PreservationConcrete overlay has proven to be effective maintenance treatment as it prevents de-icing chemicals and water penetration into the original deck surface. Typically, over time, debonding develops at the boundary between the original deck and overlay which creates void. Displacing water and filling these cracks with epoxy helps eliminate freeze and thaw and reduces spalling requiring emergency patching, and thereby extending the bridge deck life span. This process is envisaged as an end of bridge deck life treatment. The ultimate goal is to forgo another costly deck rehabilitation project and save that money for a deck replacement, or superstructure replacement in the near future.Prince Baah
7/1/2018July 2018SPR-4326: Self-healing Cementitious Composites (SHCC) with Ultrahigh Ductility for Pavement and Bridge Constructionhttps://cptechcenter.org/ncc-projects/spr-4326:-self-healing-cementitious-composites-(shcc)-with-ultrahigh-ductility-for-pavement-and-bridge-construction/Bridges; Cement; Composite materials; Cost effectiveness; Cracking; Ductility; Durability; Pavement design; Pavement maintenance; Bridges aThe aim of this project is to develop a new class of self-healing cementitious composites (SHCC) with ultra-high ductility and durability that can autonomously heal cracks developed in the concrete, due to shrinkage, free-thaw damage, and service loading. The superior ductility and durability of SHCC can accommodate pavement and bridge structures deformation imposed by concrete shrinkage, temperature fluctuation, etc. As such, this class of SHCC materials provide a cost-effective solution to pavement and bridge rehabilitation as well as new construction projects.Na Lu
1/1/2019January 2019SPR-4327: Development of Compaction Control Guidelines for Aggregates Drainage Layers and Evaluation of In Situ Permeability Testing Methods for Aggregateshttps://cptechcenter.org/ncc-projects/spr-4327:-development-of-compaction-control-guidelines-for-aggregates-drainage-layers-and-evaluation-of-in-situ-permeability-testing-methods-for-aggregates/Aggregates; Compaction; Drainage; Guidelines; Pavement layers; Permeability; Quality assurance; Test proceduresObjective of this research is to improve the process for aggregate drainage layer construction within INDOT contracts. Results of the study will allow INDOT to move towards standardizing a performance based quality assurance approach for aggregate drainage layer construction.Peter Becker, Marika Santagata
1/1/2019January 2019SPR-4332: Performance Related Specification for Pavement Millinghttps://cptechcenter.org/ncc-projects/spr-4332:-performance-related-specification-for-pavement-milling/Milling; Pavement distress; Pavement layers; Specifications; Test proceduresThe objective of this research is to evaluate pavement damage that could occur during milling process. The primary deliverable for this research will be a technical report documenting more reliable milling procedures and specifications, testing methodologies, testing results, and findings.Seong-Hwan Cho, John Haddock
1/1/2019January 2019SPR-4336: Improvement of Scaling Resistance of Pavement Concrete Using Titanium Dioxide (Tio2) and Other Nano-additiveshttps://cptechcenter.org/ncc-projects/spr-4336:-improvement-of-scaling-resistance-of-pavement-concrete-using-titanium-dioxide-(tio2)-and-other-nano-additives/Concrete pavements; Durability; Fly ash; Mechanical properties; Nanostructured materials; Permeability; Scaling (Concrete); TitaniumObjective of this research is development of reliable and relatively inexpensive method of improving the scaling resistance of pavement concretes containing fly ash. Additional benefits may include increased resistance to chemical attack by deicing chemicals and increase in mechanical properties of concrete pavements. If successful, the proposed method of increasing scaling resistance of fly ash concrete will allow for extension of the construction window for usage of fly ash while, at the same time, increasing durability of concrete.Jan Olek
1/1/2019January 2019Stringless Pavinghttps://cptechcenter.org/ncc-projects/stringless-paving/concrete pavements, smoothness, roughnessString lines have traditionally been used to control paving machine elevation and steering on the grade. Stringless paving (sometimes referred to as “3-D paving”) is the process of constructing a pavement using non-contact, electronic guidance systems to guide the paver along the grade without the aid of string lines. Stringless paving allows contractors to eliminate hubs, pins, sensors or wands, clamps, and string lines (wires, cables, rope, etc.). This can produce significant savings of time and labor for establishing and maintaining the string line system, the elimination of stringline-related tripping hazards, and reductions in the required width of operating space for the paver. Additionally, stringless paving offers the potential for more accurate, smoother paving, especially in tight horizontal and vertical curves where stringlines can only simulate a smooth curve using straight line segments.Mark Snyder
08/31/19August 2019Subgrade Stabilization Alternativeshttps://cptechcenter.org/ncc-projects/subgrade-stabilization-alternatives/Highway engineering, Pavement design, Soil stabilization, Specifications, Subgrade (Pavements)Subgrade stabilization in the INDOT current standard specification is limited to the selection of materials type rather than strength and properties of the treated soil. With the adoption of the Mechanistic Empirical Design Guide, it is possible to consider in the input parameters the actual properties of the stabilized soil subgrade. The research addresses this issue by exploring the engineering properties of subgrade stabilization alternatives, so pavement engineers can design the pavement structure accordingly.Antonio Bobet
09/01/21September 2021Superabsorbent Polymers in Concrete to Improve Durabilityhttps://cptechcenter.org/ncc-projects/superabsorbent-polymers-in-concrete-to-improve-durability/bridge structures, Concrete, Durability, Internal curing, Mix design, pavement, Shrinkage, superabsorbent polymer This research examined and documented the use of internal curing by superabsorbent polymer (SAP) to improve the durability of Tollway bridge decks. The project included laboratory studies to characterize material behavior and properties, and field testing to measure slab performance and observe behavior with full scale truck mixers. David A. Lange, Kamal Khayat, Matthew D'Ambrosia, Nima Farzadnia, Yucun Gu, Karthik Pattaje, Jamie Clark, Chuanyue Shen, Ruofei Zuo
9/1/2008September 2008Surface characteristics for new PCChttps://cptechcenter.org/ncc-projects/surface-characteristics-for-new-pcc/surface characteristics, friction, noiseStudy of surface characteristics for new concrete pavements.Bernard Izevbekhai
3/1/2015March 2015Surface Resistivity as an Alternative for Rapid Chloride Permeability Test of Hardened Concretehttps://cptechcenter.org/ncc-projects/surface-resistivity-as-an-alternative-for-rapid-chloride-permeability-test-of-hardened-concrete/Concrete permeability, Surface resistivity, Rapid Chloride Permeability, Volume of Permeable Voids, Materials testingKansas experiences harsh winters that require frequent use of de-icing salts, making it critical to the long-term durability of concrete structures that the permeability is kept under control. Under current KDOT ecification, the Rapid Chloride Permeability (RCP) test, as described in ASTM Standard C1202 (2012), or the Volume of Permeable Voids method, described in ASTM Standard C642 (2013), more commonly known as the boil test, must be performed to evaluate concrete permeability. Surface resistivity testing was investigated as an alternative to these tests.Rodney Montney
06/30/14June 2014Sustainable Crack-Free, Environmental-Friendly Concrete "Crack Free Eco-Crete"https://cptechcenter.org/ncc-projects/sustainable-crack-free,-environmental-friendly-concrete-?crack-free-eco-crete/Concrete, Building materials, Sustainable development, Pollutants, Greenhouse gases, Environmental impacts, Waste products, Portland cementSince concrete is the most used construction material in the world, it accounts for a considerable part of CO2 emissions. This means that besides to its appreciable roles, it may be considered as a significant source of emission of greenhouse gases. The solution of this problem is to reduce the environmental impact of concrete and cement through the idea of Eco-Concrete. Besides to its environmental benefits, Eco-Crete is also important from the economical perspective. Because, incorporating high volumes of industrial by-products as replacements for Portland cement makes the Eco-Crete more energy efficient and cheap to produce.Kamal H. Khayat, Iman Mehdipour
3/1/2018March 2018Sustainable Mitigation of Stormwater Runoff Through Fully Permeable Pavementhttps://cptechcenter.org/ncc-projects/sustainable-mitigation-of-stormwater-runoff-through-fully-permeable-pavement/Asphalt pavements; Concrete pavements; Data collection; Mechanistic-empirical pavement design; Performance tests; Porous pavements; Runoff; Test beds; Permeable pavements; Environment; Highways; Hydraulics and Hydrology; PavementsThis report presents the implementation of new design method developed using mechanistic-empirical design approach by University of California Pavement Research Center (UCPRC) through building two test sections at California State University Long Beach (CSULB). The study includes a literature review, pavement design procedure, mix design, construction procedure, instrumentation, and collection of performance data of the permeable asphalt and concrete pavement sections for validation and structural design calibration of the new design approach. Fully permeable pavements are characterized as those in which all layers are porous, and the pavement structure serves as a reservoir to store water and minimize the negative impacts of stormwater spillover. The California Department of Transportation (Caltrans) has shown interest in developing fully permeable pavement design for use in territories that convey substantial truck activity as a potential stormwater management best management practice (BMP) to give low-effect infrastructure and proficient framework operation. A location was selected within CSULB for the construction of the test sections. Pressure cells and strain gages were installed during the construction of pavements for measuring the stress on the top of subgrade on both test sections and the strain at the bottom of surface layer to assess the performance of the fully permeable pavements. In the study, the traffic count was also determined. The data acquisition device CDaq was installed at the site to collect the data. The recorded data was analyzed using the MATLAB program code. The data from pressure cells and strain gages are analyzed, and graphs were plotted to study the pattern in the data sets. The stress and strain measurements and the cracking (both sections) and rutting (asphalt section only) will be used to calibrate the pavement structural design procedure and hydraulic performance will also be monitored.Avinash Ralla, Shadi Saadeh
11/16/2016November 2016Systematic Decision-Making Process for Composite Pavement Maintenancehttps://cptechcenter.org/ncc-projects/systematic-decision-making-process-for-composite-pavement-maintenance/Composite pavements; Decision making; Hot mix asphalt; Pavement maintenance; Portland cement concrete; Reflection crackingThe assessment of pavement condition rating (PCR) for hot mix asphalt (HMA) surfaces and exposed portland cement concrete (PCC) in composite pavements is an important component of the decision-making process for treating reflective cracking. Visual inspections such as PCR or falling weight deflectometer (FWD) have been conducted as current practices for reflective cracking treatment. However, these evaluation methods are not able to identify the severity of cracking in the underlying PCC slab. , field engineers often tend to rely solely on visual inspection of the HMA surface without performing actual milling operations. Therefore a systematic decision-making process is needed to select appropriate maintenance treatments for reflective cracking in composite pavements. In response to this need, this research proposes a framework for composite pavement maintenance decision making that consists of three modules: (1) field evaluations to assess the condition of the pavement at the joint, (2) development of a PCC pavement condition prediction model to determine the severity of PCC cracking at the joint in a composite pavement, and (3) a treatment selection table to help determine a possible mitigation strategy for the treatment of each reflective crack type. A case study is conducted to validate the proposed prediction model, with the results showing 0.77 accuracy. Therefore the proposed systematic decision-making process is able to provide field engineers with a more accurate treatment selection process for reflective cracking in composite pavements than is currently available. Furthermore, the proposed process can reduce maintenance costs by simplifying field test evaluation methods and alleviating the need for milling the HMA surfaces.Soojin Yoon, Kyubyung Kang, Yoojung Yoon, Makarand Hastak, Richard Ji
01/01/19January 2019Temperature Control Requirements for the Construction of Mass Concrete Membershttps://cptechcenter.org/ncc-projects/temperature-control-requirements-for-the-construction-of-mass-concrete-members/Mass concrete; thermal cracking;The main objectives of this project are: to measure in-place temperatures for some mass concrete members under construction; to develop an ALDOT procedure to designate various members as mass concrete members; to develop temperature control requirements for mass concrete construction for ALDOT; and to provide training to the ALDOT personnel in order to understand & implement temperature control requirements for mass concrete construction.Eric D. Gross, Andrew D. Eiland, Anton K. Schindler, Robert W. Barnes
3/11/2014March 2014Ten Year Performance Evaluation of Unbonded Concrete Overlay and Jointed Plain Concrete Pavement: A Toronto Case Studyhttps://cptechcenter.org/ncc-projects/ten-year-performance-evaluation-of-unbonded-concrete-overlay-and-jointed-plain-concrete-pavement-a-toronto-case-study/Canada; Case study; Conference; Damage; Durability; Evaluation (assessment); Joint (structural); Junction; Resurfacing; Rigid pavement; Rutting (wheel); Strengthening (pavement)Heavy, slow moving traffic can be extremely damaging to asphalt pavements. The City of Toronto was observing the rapid deterioration of the pavements at an urban intersection with high volumes of transit bus traffic. The heavy traffic was causing severe rutting and other safety concerns. In collaboration with the Cement Association of Canada, the City of Toronto elected to rehabilitate the high traffic intersection of Bloor Street and Aukland Road using Portland cement concrete. As part of this project, the city constructed its first unbonded concrete overlay and reconstructed an adjacent area as a conventional Jointed Plain Concrete Pavement. The rehabilitation activities were completed during the summer of 2003. Instrumentation was installed by University of Waterloo researchers to monitor and evaluate the long-term performance of the rehabilitated pavements. This paper presents an overview of the existing conditions, design, construction and instrumentation of the Bloor and Aukland site and a ten year performance evaluation of the rehabilitated pavements. The results of this study show that concrete overlays and inlays are excellent rehabilitation options for urban pavements subjected to high volumes of heavy traffic. Both the unbonded overlay and Jointed Plain Concrete Pavement sections have demonstrated excellent performance to date. The pavements are in very good condition visually, ride quality remains excellent and the recurrence of the regular rutting and shoving problems that were being observed prior to rehabilitation has been mitigated. Significant remaining life is expected from the concrete pavement sections at Bloor and Aukland. For the covering abstract of this conference see ITRD record number 201310RT334E.A. Kivi, S.L. Tighe, R. Fung, J. Grajek
1/1/2010January 2010Tension Testing of Ultra-High Performance Concretehttps://cptechcenter.org/ncc-projects/tension-testing-of-ultra-high-performance-concrete/Cement; Composite materials; Fiber reinforced concrete; Tensile properties; Tension tests; Ultra high performance concreteUltra-high performance concrete (UHPC) is a class of cementitious composite materials designed to exhibit exceptional mechanical and durability properties, including sustained postcracking tensile strength. Laboratory tests of structural elements have clearly indicated that UHPC components can exhibit tensile mechanical properties far in excess of those expected from conventional or fiber-reinforced concretes. This study developed a material scale direct tension test applicable to UHPC that relates the full range of uniaxial tensile behaviors through strain localization and can be completed on cast or extracted specimens. In order to demonstrate applicability, the test method was carried out in parallel with other UHPC tension test methods. This research model allowed for both development of a practical test method along with direct determination of the tensile mechanical properties of two commercially available UHPC-class materials.Benjamin A. Graybeal, Florent Baby
1/1/2019January 2019Thermoplastic Composites by 3D Printing and Automated Manufacturing to Extend the Life of Transportation Facilitieshttps://cptechcenter.org/ncc-projects/thermoplastic-composites-by-3d-printing-and-automated-manufacturing-to-extend-the-life-of-transportation-facilities/Automation; Composite materials; Concrete structures; Feasibility analysis; Fillers (Materials); Forming; Manufacturing; Precast concrete; Printers; Quality assurance; Recycling; Reinforcing materials; Service life; Specifications; Thermoplastic materials; Thermoplastic resinsThe objectives of this project are to: (a) Identify potential applications for large-scale 3D printing of forms and tooling for precast concrete parts in transportation using bio-based fillers and reinforcements and cost-effective thermoplastic materials. (b) Determine the feasibility of making 3D printed forms for optimized precast concrete parts and elements to extend durability and reduce cost. (c) Document the demonstration of large-scale 3D printing of precast concrete forms and assess the quality of the parts. Establish material and manufacturing specifications to assist the departments of transportation (DOTs) implement this technology in transportation applications. (d) Investigate the potential for recycling the 3D print forms and tooling, and reusing/reprinting the wood-filled thermoplastic material to make it a capital asset for precasters.Roberto Lopez-Anido, James Anderson, Douglas Gardner, Yousoo Han
11/1/2018November 2018Three-dimensional surface texture of Portland cement concrete pavements containing nanosilicahttps://cptechcenter.org/ncc-projects/three-dimensional-surface-texture-of-portland-cement-concrete-pavements-containing-nanosilica/Abrasion resistance; Concrete pavements; Friction; Macrotexture; Microtexture; Surface course (Pavements)Pavement surface texture is critical to tire/pavement interaction. Texture characteristics of concrete containing nanosilica pavement surface has not yet been directly investigated, although researchers have found that nanosilica improved pavement friction values and durability. Specimens with various nanosilica content are tested for three-dimensional (3D) texture height maps which are decomposed using discrete wavelet transform for the calculation of 3D texture indices for macrotexture and microtexture. It is found that 3D texture indices increase correspondingly with the increment of nanosilica content. Significant relationship with R² values between 0.80 and 0.99 is found between various texture indices and nanosilica content. The increased texture amplitude indicates enhanced pavement friction and then safety. The increment of core material volume implies more texture in the core region, which indicates better longevity of texture. The findings of this research agree with the results of other studies that nanosilica increased the abrasion resistance and frictional property of concrete surface.Qingfan Liu, Marcelo Gonzalez, Susan L. Tighe, Shalaby Ahmed
12/31/17December 2017Toward Performance Related Specifications for Concrete Pavementshttps://cptechcenter.org/ncc-projects/toward-performance-related-specifications-for-concrete-pavements/Performance based specificationsThe current level of construction activity provides INDOT with the opportunity to collect information from concrete paving projects which can be used to generate information that may be used to improve the standards and specifications in the next generation of pavements. INDOT is poised to utilize data from pavement projects to develop new approaches for contracting and specification (PRS and PWL specifications). This information may be used to provide high quality contractors with rewards for providing this quality.
1/1/2020January 2020Transportation Engineering and Road Research Alliance (TERRA)https://cptechcenter.org/ncc-projects/transportation-engineering-and-road-research-alliance-(terra)/tech transferThe purpose of this project is to exchange information regarding pavement research between the participating states to see if research funds can be better allocated.Debra Fick
1/22/2019January 2019Ultra-High-Performance Concrete (UHPC) Use in Florida Structural Applicationshttps://cptechcenter.org/ncc-projects/ultra-high-performance-concrete-(uhpc)-use-in-florida-structural-applications/Curing agents; Durability; Mixing; Structures; Test procedures; Ultra high performance concreteThis project will establish testing methods and determine the mixing, placing, curing, and durability requirements necessary to produce durable, non-proprietary ultra-high-performance concrete (UHPC), made using locally-sourced raw materials for different classes of structural use and exposure conditions.Kyle A. Riding
7/1/2013July 2013Unbonded Concrete Pavement/Overlay Monitoringhttps://cptechcenter.org/ncc-projects/unbonded-concrete-pavement-overlay-monitoring/Cast in place concrete; Concrete pavements; Cracking; Fiber optics; Frigid regions; Optimization; Overlays (Pavements); Pavement performance; SensorsAn instrumentation system including electric and optic sensors will have been installed by July 1, 2013 in 6 ft x 6 ft, 3 in-thick unbonded concrete panels and their existing substrates over an approximately 500 ft long distance in cell-40 at MnROAD - a pavement test track located near Albertville, MN. The unbonded concrete pavement/overlay panels will be loaded under a standard design truck or subjected to cold weather effects over the years. Their field performance will provide the required data for a widespread implementation of this potentially viable solution for aging highway pavement rehabilitation. Strain, crack width, temperature, and other environmental factors will be measured periodically to understand loading and environmental effects on the behavior and performance of the ultrathin panels and their interaction with substrates over time. Laboratory tests will also be conducted for calibration and optimization of the sensitivity, spatial resolution, and strain transfer effect of optical fiber sensors with various packaging materials (coatings). Major outcomes will include repeatable and precise installation procedures for various sensors in cast-in-place panel applications, packaging sensor performances in field application, verified sensor specification, and performance data of concrete panels. This project represents a collaborative effort among Missouri University of Science and Technology (Missouri S&T), North Dakota State University (NDSU), and the University of Minnesota (UMN), taking advantage of their experiences in continuous optical fiber sensing, discrete optical fiber sensing, and pavement engineering.Ying Huang, Genda Chen
10/1/2016October 2016Updated Analysis of Michigan Traffic Inputs for Pavement-ME Designhttps://cptechcenter.org/ncc-projects/updated-analysis-of-michigan-traffic-inputs-for-pavement-me-design/Analysis; Flexible pavements; Pavement design; Pavement performance; Rigid pavements; Traffic dataThe purpose of this study is to characterize traffic inputs in support of the new Mechanistic-Empirical Pavement Design Guide for the State of Michigan. These traffic characteristics include monthly adjustment factors (MAF), hourly distribution factors (HDF), vehicle class distributions (VCD), axle groups per vehicle (AGPV), and axle load distributions for different axle configurations. Weight and classification data were obtained from 41 Weigh-in-Motion (WIM) sites located throughout the State of Michigan to develop Level 1 (site-specific) traffic inputs.Syed Waqar Haider, Gopikrishna Musunuru, Neeraj Buch, Olga Selezneva, Praveen Desaraju, Joshua Li
09/15/19September 2019Use of Bagasse Ash as a Concrete Additive for Road Pavement Applicationshttps://cptechcenter.org/ncc-projects/use-of-bagasse-ash-as-a-concrete-additive-for-road-pavement-applications/Ash content, Durability, Highways, Life cycle costing, Materials, Mix design, Pavement design, Pavements, Pozzolan, Pozzolanic action, Waste productsThis research will investigate potential uses of sugarcane bagasse ash to reduce the cost and carbon footprint of concrete materials for road pavement construction and maintenance. Bagasse is the fibrous by-product of sugarcane stalks after they are crushed to extract their juice. Fortunately, bagasse ash has also been found to be a suitable supplementary cementitious material (SCM) due to its pozzolanic behavior. Hence, it can be used as an alternative to reduce cement consumption, similar to the current use of fly ash. Pozzolanic additives such as bagasse ash present several benefits, such as lower costs, lower environmental impacts, higher long-term compressive strength at the expense of a small reduction of the 28-day compressive strength, and improved durability. This study's goal is to develop new uses for bagasse ash as an SCM for concrete. In particular, the use of bagasse ash as a partial substitute for cement and fly ash will be investigated. An efficient production method to maximize the pozzolanic activity of bagasse ash will be developed, and the optimal amounts of bagasse ash to obtain desired concrete properties will be identified. The economic feasibility of bagasse ash used as an SCM will be explored through a preliminary life-cycle cost analysis.Gabriel Arce, Marwa Hassan, Maria Gutierrez-Wing
12/15/2018December 2018Use of Concrete Grinding Residue as a Soil Amendment TR-764https://cptechcenter.org/ncc-projects/use-of-concrete-grinding-residue-as-a-soil-amendment-tr-764/Alkalinity; Compressive strength; Concrete; Diamond grinding; Erosion control; Laboratory tests; Leaching; Runoff; Soil stabilization; Waste productsDiamond grinding is a widely-used rehabilitation technique usually referred to as resurfacing of Portland cement concrete (PCC) pavement. As a maintenance operation, diamond grinding can provide a smooth PCC surface with enhanced texture and skid resistance and reduced road noise. Typically, this operation uses a truck equipped with grinding heads at ground level to saw a thin layer of concrete, grinding it into fine particles, while mixing with water to cool blades and reduce dust. This process generates a slurry byproduct known as concrete grinding residue (CGR). The majority of current maintenance practice involves spreading of fresh CGR on roadsides, resulting in potential environmental concerns regarding vegetation growth.Bora Cetin
6/1/2014June 2014Use of Concrete Pavement Overlays on U.S. 58 in Virginiahttps://cptechcenter.org/ncc-projects/use-of-concrete-pavement-overlays-on-u.s.-58-in-virginia.--/Alternatives analysis; Bituminous overlays; Concrete overlays; Continuously reinforced concrete pavements; Costs; Rehabilitation (Maintenance)Asphalt overlays are typically used to extend the life of continuously reinforced concrete pavement (CRCP) because they can be placed in one or more layers while traffic uses the adjacent lane and can be opened to traffic in a short time. Hydraulic cement concrete overlays have also been used to extend the life of CRCP but have often not been considered an alternative to asphalt because of the higher cost and longer curing time. In 2012, the Virginia Department of Transportation (VDOT) rehabilitated a 4.8-mi section of the westbound lanes of a CRCP on U.S. 58 in Southampton County using a 4-in.-thick bonded concrete overlay and a 7-in-thick unbonded concrete overlay with a 1-in. asphalt separation layer. The four-lane, divided primary highway is an 8-in.-thick CRCP placed over a 6-in. cement-treated aggregate layer. Saw cutting was used to form joints at 6 ft by 6 ft panels for an unbonded overlay, and tie bars were used along the centerline of the pavement and along both shoulders. A concrete overlay was placed on the shoulders of the unbonded overlay, and asphalt was placed on the shoulders of the bonded overlay. Two layers of asphalt with a total thickness of 5 in. were placed on a 9.75-mi section of the eastbound lane of U.S. 58, which provided cost information that was used to compare the alternatives. Since traffic management was very different for the two projects, definitive conclusions on the total cost of asphalt versus concrete overlays could not be drawn. On the basis of material costs alone, concrete and asphalt can be competitive options for extending the service life of CRCP. Construction of the concrete overlays was successfully executed on time. The concrete was of high quality with good strength and low permeability. The bonded overlay is well bonded. The ride quality was much better than for the original pavement. Using the initial cost of materials in-place, the cost of the bonded and unbonded overlays was approximately the same, at an average of $36 to $38 per square yard. The unit cost of patching concrete pavements is approximately 6 times the cost of the bonded concrete overlay and approximately 4 times the cost of an unbonded overlay. VDOT's Materials Division should consider the use of bonded concrete overlays to extend the life of CRCPs that are in good condition and need little patching (<10%) prior to placement of the overlay and should consider the use of unbonded concrete overlays as an alternative to patching to extend the life of CRCP that needs more than 10 percent patching. Further, the Materials Division should advertise overlay projects allowing alternate designs using stone-matrix asphalt and hydraulic cement concrete to determine if they are competitive alternatives. VDOT's Traffic Engineering Division should explore innovative traffic management plans for pavement rehabilitation to reduce maintenance of traffic costs.Michael M. Sprinkel, Celik Ozyildirim, M. Shabbir Hossain, Mohamed K. Elfino, Chung Wu, Affan Habib
10/17/2016October 2016Use of Crushed Recycled Glass in the Construction of Local Roadwayshttps://cptechcenter.org/ncc-projects/use-of-crushed-recycled-glass-in-the-construction-of-local-roadways/Aggregates; Feasibility analysis; Glass; Paving materials; Recommendations; Recycled materials; Road construction; Sustainable development; Waste productsGlass cullet is produced from crushing waste glass collected in municipal and industrial waste streams to a uniform size. Currently, it is primarily used in Ohio in new glass container manufacturing; however, only clear glass cullet can be used. As a result, colored glass cullet has a relatively low market value as color sorting can be expensive. When market prices drop too low for long periods, some of the glass is sent to landfills instead of subsequent recycling because storage space can be limited or costly. One possible solution is using crushed glass in the construction of civil infrastructures. The Ohio Department of Transportation (ODOT) does not have a specification for using glass cullet as an aggregate. This is in part due to concerns with the propensity for glass to strip in the presence of moisture resulting in issues with asphalt binder sticking in the surface course and an overall lack of a consistent supply of product. Although ODOT has chosen not to pursue the incorporation of glass cullet in interstate and highway applications, some local public agencies (LPA) are of the opinion that there may be an appropriate application of this material in the local system. The potential to mix crushed glass cullet into aggregates exists for many applications including roadway and parking lot base or leveling courses, glasphalt, pipe bedding and backfill, drainage material, fill and concrete. Using a recycled product, like crushed glass, can have environmental benefits to projects seeking Leadership in Energy and Environmental Design (LEED) or National Green Building Standard (NGBS) certification. Because local roads have different traffic types, volumes, and patterns requiring the use of different types of mixtures and aggregates than those typically utilized for interstates and highways, research is needed to analyze the application of recycled crushed glass on local transportation projects. The goal of this research is to assess the feasibility of using crushed recycled glass as an aggregate in local roadway construction. The objective is to develop recommendations for implementing the use of crushed recycled glass in local roadway applications in Ohio that do not adversely affect the performance or durability of the pavement or structure. The results of this research will provide local officials with enhanced knowledge of recycled glass cullet and its potential for use in local transportation projects. The findings of this research will either validate or disprove the perception that utilizing glass cullet as part of an aggregate mix is feasible in local roadway construction and can lead to cost savings while maintaining performance. The results of this research may also produce environmental benefits as it could maximize the use of a recyclable material and lead to a reduction in landfills and wasteJunliang (Julian) Tao
1/12/2019January 2019Use of Geogrid in Pavement Systems to Provide Longer Service Life and Reduced Maintenancehttps://cptechcenter.org/ncc-projects/use-of-geogrid-in-pavement-systems-to-provide-longer-service-life-and-reduced-maintenance/Field tests; Geogrids; Laboratory tests; Pavement maintenance; Properties of materials; Service life In 2010, a section of roadway on Utah SR 30 near Emery, Utah was reconstructed using a geogrid-reinforced pavement system. This project was intended to demonstrate the effectiveness of geogrid in reducing cost, providing longer service life, and reducing long-term maintenance of the pavement system. This roadway carries between 200 to 300 coal trucks per day in each direction. A test section was constructed first to evaluate the effectiveness of four different biaxial geogrids. While this test section has performed well, much of the remaining roadway section has required significant multiple maintenance procedures to keep it functional. The primary objectives of this research project are to evaluate forensically the test section and the rest of the roadway to determine why the test section has performed well but the rest has not; evaluate the performance of each of the four geogrids; determine the benefit, if any, provided by the geogrid to the pavement system; and develop methods to evaluate the use of geogrid on other pavement systems.Evert Lawton, Pedro Romero
3/1/2018March 2018Use of Lightweight Sand for Internal Curing to Improve Performance of Concrete Infrastructurehttps://cptechcenter.org/ncc-projects/use-of-lightweight-sand-for-internal-curing-to-improve-performance-of-concrete-infrastructure/Internal Curing, dry shrinkage, compressive strength, LWSThe goal of this project was to develop an effective methodology to use saturated lightweight sand (LWS) for internal curing to enhance concrete performance and prolong service life of concrete structures. High-performance concrete (HPC) mixtures approved by MoDOT for pavement and bridge deck structures were used for the baseline mixtures. Five different types of saturated LWS employed at various contents were investigated to evaluate the optimum dosage of LWS and maximize its effectiveness on enhancing concrete performance. The content of LWS was varied to ensure the introduction of internal curing water that can secure up to 150% of the water consumed by chemical shrinkage during cement hydration (As per ASTM C1761). Performance improvement from the LWS focused mainly on reducing autogenous and drying shrinkage and the resulting cracking potential without sacrificing durability and cost competence. Proper combinations of internal and external curing were found to enhance shrinkage mitigation. Under 7 days of initial moisture curing, HPC made with the LWS3 resulted in the lowest overall shrinkage. The Bridge-LWS2-150% exhibited the best performance in mitigating autogenous shrinkage where the concrete maintained 160 micro-strain of expansion even after 175 days of age. The lowest drying shrinkage was obtained with the BridgeLWS3-50% mixture (340 micro-strain) at 175 days subjected to 28 days of moist curing. For the paving HPC, the lowest drying shrinkage at 155 days was obtained with the Paving-LWS3-150% mixture (265 micro-strain) subjected to 28 days of moist curing. Concrete proportioned with the LWS2 expanded shale LWS exhibited the best compressive strength, regardless of the curing regime. For the paving HPC, the lowest drying shrinkage at 155 days was obtained with the Paving-LWS3-150% mixture (265 micro-strain) subjected to 28 days of moist curing.Kamal H. Khayat, Weina Meng, Mahdi Valipour, Matthew Hopkins
5/10/2016May 2016Use of Lime Kiln Dust for Treated Subgradeshttps://cptechcenter.org/ncc-projects/use-of-lime-kiln-dust-for-treated-subgrades/Alternatives analysis; Kiln dust; Limestone; Soil stabilization; Subgrade (Pavements)The objective of this research study is to investigate lime kiln dust materials for stabilization in comparison with lime. Four soils with which lime is scheduled to be used will be selected.Jamal Kakrasul, Robert L. Parsons, Jie Han
2/1/2014February 2014Use of Nevada's Natural Pozzolan to Mitigate Alkali-Silicate Reactivityhttps://cptechcenter.org/ncc-projects/use-of-nevada?s-natural-pozzolan-to-mitigate-alkali-silicate-reactivity/Alkali silica reactions; Alternate fuels; Carbon dioxide; Cement; Fly ash; Pollutants; Pozzolan; Sustainable development; Thermal efficiencyAlkali-silica reactivity is one of the most recognized deleterious phenomena in Portland cement concrete resulting in cracks, spalling, and other deleterious mechanisms. The aim of this study was (i) to assess the extent of reactivity of the aggregates, quarried from seven different sources, suspected of being conducive to ASR, and (ii) to compare the effectiveness of industrial (Class F fly ash) and natural pozzolans in mitigation of alkali-silica reactivity of the studied aggregates. To this end, seven aggregate sources, four natural pozzolan sources, and one source of Class F fly ash were used. ASTM Type V Portland cement was replaced at four levels of 15, 20, 25, and 30% by different pozzolan types and sources. A uniform water-to-cementitious materials ratio of 0.47 was used. Beam shaped mortars were tested for ASR-induced expansion for eight weeks. In addition, companion mortar cubes cured for 90 days in a salt-water environment and in a controlled moisture room were tested in compression. The findings of this investigation revealed that the ASR mitigation of the studied aggregates depended on the aggregate source, natural pozzolan source and content, and immersion age. For nearly all natural and industrial pozzolans used in this study, 15% by weight of Portland cement was sufficient to mitigate alkali-silica reactivity of the studied reactive aggregates. The loss in strength of the studied mortars also depended on aggregate and natural pozzolan types and sources, and reduced with increases in Portland cement substitution level. Overall, the four natural pozzolan sources used in this study exhibited similar to better performance, in comparison to that of the Class F Fly ash, in suppressing the alkali-silica reactivity of the reactive aggregates.Nader Ghafoori, Arash Kian
5/8/2017May 2017Use of Rice Hull Ash (RHA) as a Sustainable Source of Construction Materialhttps://cptechcenter.org/ncc-projects/use-of-rice-hull-ash-(rha)-as-a-sustainable-source-of-construction-material/Alkali silica reactions; Compressive strength; Concrete; Durability; Pozzolan; Tensile strengthRice hull ash (RHA) is a cementitious material, which may contain about 75% silica in an amorphous form and has an extremely high surface area. RHA is also economically beneficial, but its performance as a construction material has been investigated very little. High silica content makes it a probable pozzolanic material for concrete by following the Roman Concrete technology. The main objective of the proposed study is to assess the usage of rice hull ash (RHA) as a construction material. Specific objectives are given as: (i) evaluate chemical, physical and strength and expansion properties of RHA-modified concrete based on curing time and environmental conditions; and (ii) assess the feasibility of using RHA as an alternative modifier to enhance performance properties of soft asphalt binders. These objectives will be accomplished by testing RHA-modified samples in laboratories. Strength properties (compressive, tensile, elastic modulus, etc.) and alkali-silica reactivity (ASR) properties of RHA-modified concrete at different curing time will be evaluated. Rheological properties of RHA-modified asphalt binders will be determined by following the routine and Superpave test protocols. The benefits of the proposed study are (a) reuse of waste materials in transportation construction projects, (b) enhance training opportunity for students in the Mississippi Delta region, (c) help local farmers and asphalt industries to be economically sustainable, and (d) build a future workforce.Zahid Hossain
3/15/2018March 2018Use of Rice Husk Ash (RHA) in Flowable Fill Concrete Mix Materialhttps://cptechcenter.org/ncc-projects/use-of-rice-husk-ash-(rha)-in-flowable-fill-concrete-mix-material/Admixtures; Ash content; Concrete; Durability; Feasibility analysis; Flowable fill; Mix design; Pozzolan; Waste products; Construction; Highways; Maintenance and Preservation; Materials; PavementsRice hull (RH) is one of the main agricultural residues obtained from the outer covering of rice grains during the milling process. RH constitutes 20% of about 700 million tons of paddy produced in the world. When burnt, 20% of RH is transformed into rice husk ash (RHA). RHA is a cementitious material, and locally produced RHA in Arkansas contains about 75% silica in an amorphous form and has an extremely high surface area. RHA is also economically beneficial in producing concrete, but its performance as a construction material has been investigated very little. Based on the preliminary data of the research team of this project, locally produced RHA is not capable of producing “regular” concrete of compressive strength of greater than 3000 psi. Rather, low strength concrete such as Flowable Fill Concrete (FFC) can be produced using the “as is” RHA. However, the usage, test protocols and procedures of FFC are different from “regular” concrete. Arkansas Department of Transportation (ARDOT) has ranked this problem statement in its Top 10 Problems for possible solution in 2018-2019. The main objective of the proposed study is to assess the feasibility of the use local RHA in producing FFC. Specific objectives are to: (i) prepare FFC and determine their workability and flow behavior, (ii) evaluate the effect of curing time and environmental conditions on strength properties and durability of RHA-modified FFC, and (iii) evaluate the optimum dosages of RHA as pozzolan in preparing FFC.Zahid Hossain
8/14/2018August 2018Vertical Impedance Scanner for Concrete Bridge Deck Assessment without Direct Rebar Attachmenthttps://cptechcenter.org/ncc-projects/vertical-impedance-scanner-for-concrete-bridge-deck-assessment-without-direct-rebar-attachment/Detecting corrosion bridge decksThis project will develop and implement a multichannel vertical impedance scanner with large area electrode to detect corrosion in bridge decks without direct rebar connection. In Stage 1, a trailer with improved electrodes will be constructed that could be quickly unfolded and deployed by a single person in the field to scan a 12-ft-wide lane. Through improved electronics, simultaneous parallel measurements will be demonstrated. DGPS and LiDAR measurements will be incorporated. Additional software will be developed for combining DGPS and Lidar data and distance measurements. Automated mapping routines will be developed for presentation of impedance data to end users. At least six decks with overlays (epoxy or bituminous) will be tested. Passes at multiple speeds will be performed to understand appropriate rates for data collection both in terms of spatial coverage and localizing specific types of defects. The collected data will inform recommendations for the use of the technology. Preliminary specifications will be developed for the technology based on the test results. In Stage 2, results from Stage 1 work will be used to revise the multi-channel system with improved probes and computer algorithms. All system components will be connected through a networking device and controlled through a custom graphical user interface running on an attached laptop. Success will be achieved when the apparatus is controlled using a laptop and data acquisition using six channels across the full width of a traffic lane is performed faster than 1500 ft2/minute. The design of critical prototype features will be documented.Brian Mazzeo
7/1/2016July 2016Waterproofing Options for Bridge Deckshttps://cptechcenter.org/ncc-projects/waterproofing-options-for-bridge-decks/Bridge decks; Laboratory tests; Performance; Waterproofing; Waterproofing materialsThe increased use of deicing chemicals requires that some bridge decks be waterproofed to maintain their good condition. A variety of options are available, each of which has varying degrees of effectiveness, cost, and longevity. There are a range of waterproofing options including waterproofing membranes, polymer asphalts and laminates. Some of those can be maintained over the life of a bridge with periodic renewal of the wearing surface. Others can be replaced easily. Some membranes can be applied by state crews while others must be applied by external contractors. These options need to be investigated to create a toolkit of options for treating bridge decks.Ted Hopwood
10/1/2014October 2014White Paper on the Application of Permeable Pavement with Emphasis on Successful Design, Water Quality Benefits, and Identification of Knowledge and Data Gaps for Sustainable Transportationhttps://cptechcenter.org/ncc-projects/white-paper-on-the-application-of-permeable-pavement-with-emphasis-on-successful-design,-water-quality-benefits,-and-identification-of-knowledge-and-data-gaps-for-sustainable-transportation.--/Best practices; Hydraulics; Pavement performance; Permeability; Runoff; Sustainable transportation; Water qualityPermeable pavement presented in this paper is defined as a type of pavement that has ability to store stormwater until it infiltrates through the subgrade soil and can function as a conventional pavement to carry specific traffic load and speed. Hence, open graded friction course (OGFC) that is an overlay of open graded pavement installed over conventional pavements is not discussed in this paper. Depending on surface pavement, permeable pavements are generally grouped as porous asphalt (PA), pervious concrete (PC), and permeable interlocking concrete pavers (PICP). For permeable pavement to function well, regardless of the type of surface pavement, it is required to satisfy both the structural and hydrologic requirements. If designed and constructed well, then permeable pavement also can act as a best management practice and often viewed as an alternative low impact development option for urban areas.Masoud Kayhanian
9/1/2014September 2014Calibration and Implementation of the AASHTO Mechanistic Empirical Pavement Design Guide in Arizonahttps://cptechcenter.org/ncc-projects/calibration-and-implementation-of-the-aashto-mechanistic-empirical-pavement-design-guide-in-arizona/Bituminous overlays, Calibration, Composite pavements, Flexible pavements, Mathematical models, Mechanistic-empirical pavement design, Modulus of resilience, Rigid pavements, ValidationThis report documents efforts of the Arizona Department of Transportation (ADOT) to implement the America Association of State Highway and Transportation Officials (AASHTO) DARWin-ME pavement design guide in Arizona. The research team also prepared a practical stand-alone user's guide that provides guidance for obtaining inputs, conducting design, and establishing the recommended pavement design. Implementation focused on identifying the desired pavement design application of flexible hot-mix asphalt (HMA) pavements, composite pavements (thin asphalt rubber friction course over jointed plain concrete pavement [JPCP] and continuously reinforced concrete pavement [CRCP]), JPCP, and HMA overlays of flexible pavement; characterizing materials and subgrades; determining traffic loadings (conducted under Darter et al. 2010); collecting and assembling DARWin-ME input data from 180 Long Term Pavement Performance and pavement management system sections of flexible, rigid, composite, and rehabilitated pavements; calibrating the DARWin-ME distress and International Roughness Index (IRI) prediction models to Arizona conditions; and training ADOT staff. Several biased distress and IRI models were corrected through the local calibration of Arizona pavements. Several key inputs were more accurately defined and Arizona defaults provided (e.g., subgrade resilient modulus). The calibration process improved these models through verification, validation, and calibration with Arizona data. Overall, the inputs and calibrated models will provide more accurate, reliable, and cost?effective pavement designs than designs created with global calibrations.Michael I Darter, Leslie Titus-Glover, Harold Von Quintus, Biplab B Bhattacharya, Jagannath Mallela
7/1/2017July 2017Development of a Life-cycle Assessment Tool for Pavement Preservation and Maintenance on Flexible and Rigid Pavementhttps://cptechcenter.org/ncc-projects/development-of-a-life-cycle-assessment-tool-for-pavement-preservation-and-maintenance-on-flexible-and-rigid-pavement/Preservation, Life Cycle Assessment, Tool, Maintenance, Flexible Pavement, Rigid Pavement, Pavement Performance, Cost CycleA complete life-cycle assessment (LCA) methodology was developed to quantify sustainability impacts of preservation activities for asphalt and concrete surfaced pavements. The LCA models and methodology was implemented in a software tool to support making project-level decisions in between various preservation and rehabilitation activities. The key components of the development include the inventory analysis used in the LCA calculations, treatment lifetime models and decision trees for preservation treatment selection. A nationwide survey was conducted through questionnaires. Questionnaires were designed specifically to target collecting data to build lifetime models in addition to agency experiences and practices. Decision trees were developed to guide decision makers to select from various preservation and rehabilitation options for a given existing pavement condition and traffic information. Data for the LCA also included that available in the literature or other publicly and commercially available databases to determine the LCA impacts of different preservation and maintenance schedules. The LCA scope includes materials, construction, maintenance and rehabilitation, and use stages. The inventory analysis was performed on data applicable to all regions in the United States. A tool was developed with a user-friendly interface using pay items as the building block for the ease of future implementation. The tool was intended for the engineers in state and local agencies, practitioners in the industry, and contractors. A sustainability analysis is presented to compare individual treatments or a schedule of treatments.Qingwen Zhou, Egemen Okte, Sushobhan Sen, Hasan Ozer, Imad L. Al-Qadi, Jeffery R. Roesler, Karim Chatti
8/15/2019August 2019Field Implementation and Monitoring of an Ultra-High Performance Concrete Bridge Deck Overlayhttps://cptechcenter.org/ncc-projects/field-implementation-and-monitoring-of-an-ultra-high-performance-concrete-bridge-deck-overlay/Bridge decks, Evaluation and assessment, Overlays (Pavements), Rehabilitation (Maintenance), Service life, Ultra high performance concreteOverlays are placed on existing concrete bridge decks to increase cover for the deck reinforcing steel, improve rideability, and improve skid resistance. Previous research has demonstrated that ultra-high performance concrete (UHPC) has the potential to increase service lives of bridge deck overlays, and subsequently, the underlying concrete deck, because it has exceptional durability properties and contains silica fume that facilitates bond to substrate concretes. This research project will document, monitor, and assess the field implementation of a UHPC overlay produced with local materials on a bridge in Socorro, NM. This will be the first non-proprietary UHPC overlay constructed in the U.S. The research project consists of a comprehensive literature review to identify best practices for UHPC technologies and overlay construction methods. Short and long-term monitoring plans will then be developed for assessing the performance of the constructed UHPC overlay. Data collected during construction will include weather data, construction sequence, and other observations that might influence the quality of the completed project. After construction, the short and long-term monitoring plans that include mechanical, physical, and nondestructive testing, will be initiated, and the assessment of the initial measurements will be reported in the final research report.Brad Weldon, Craig Newtson
8/14/2019August 2019Engineered Geopolymer Composites (EGC) for Sustainable Transportation Infrastructurehttps://cptechcenter.org/ncc-projects/engineered-geopolymer-composites-(egc)-for-sustainable-transportation-infrastructure/Bond strength (Materials), Costs, Durability, Engineered materials, Fly ash, Geopolymer concrete, Mix design, Pavements, Repairing, Strain hardeningThe objective of this study is to develop novel Engineered Geopolymer Composites (EGCs) implementing locally available ingredients to produce a new generation of materials that are practical, cost-effective, and eco-friendly for repair and new construction of transportation infrastructure in the South-Central region. In order to achieve this objective, EGC mixtures will be designed with different types and proportions of locally available precursor materials (mainly locally available fly ash and metakaolin). EGCs fresh and hardened properties will be evaluated to identify key parameters ensuring EGC strain hardening response as well as optimum design of the composition balancing fresh and hardened properties. Furthermore, bonding properties of EGC with regular concrete will be assessed. Finally, a cost analysis for EGC implementation will be performed by comparing the cost of EGC materials to current materials utilized in the field.
8/14/2019August 2019One Mat Vs. Two Mats of Reinforcing Steel in 12 and 13 CRCPhttps://cptechcenter.org/ncc-projects/one-mat-vs.-two-mats-of-reinforcing-steel-in-12-and-13-crcp/Continuously reinforced concrete pavements, Distress, Pavement cracking, Transverse reinforcementThe distresses observed lately in thick CRCP sections in Texas are quite different from typical distress types that have long been recognized in CRCP – namely punchouts and spalling. The new distress type is characterized by segmentation of slabs at transverse cracks, generally under the wheel paths. Forensic investigations conducted to identify the cause(s) of those distresses indicate delamination of the slab at the depth of longitudinal steel. It appears that thicker slabs with longitudinal steel placed at mid-depth of the slab result in longer transverse crack spacing, which increases warping stresses. The increased warping stresses in concrete induce horizontal cracking at the steel depth, and wheel loading applications in this area cause segmentation of the upper half of concrete slabs, resulting in serious distresses. This project will investigate the mechanism of this distress type, and develop optimum steel designs. The investigation will consist of evaluating structural responses of CRCP through theoretical analyses as well as field experiments where various steel designs (different steel depths for one-mat and configurations for two-mat) are employed. The results of data analyses from both mechanistic analyses and field experiments will be used to develop optimum steel designs in CRCP.Moon Won
08/01/19August 2019Optimized Design Details for Continuously Reinforced Concrete Pavementshttps://cptechcenter.org/ncc-projects/optimized-design-details-for-continuously-reinforced-concrete-pavements/Concrete pavements, Continuously reinforced concrete pavements, Optimization, Pavement design, PavingCRC pavements have a long history of good performance in the United States and other countries when designed and constructed well. Many U.S. highway agencies consider CRC pavements their pavement of choice for implementing long-life pavement strategies that have lower life-cycle costs and require fewer lane closures for routine maintenance and repair/rehabilitation. Since the 1950s, CRCP design and construction practices have advanced considerably, resulting in a truly low-maintenance concrete pavement.Shiraz Tayabji, Mike Plei
12/18/2019December 2019Technology Transfer Concrete Consortium (FY20-FY24)https://cptechcenter.org/ncc-projects/technology-transfer-concrete-consortium-(fy20-fy24)/Concrete pavements, Cooperation, Research management, State departments of transportation, Technology transferThe goal of the Technology Transfer Concrete Consortium (TTCC) is to: (1) Identify needed research priorities by region; (2) Provide a forum for technology exchange between participants; (3) Develop and fund technology transfer materials; (4) Provide on-going communication of research needs faced by state agencies to the FHWA, industry, and CP Tech Center; and (5) Provide technical leadership for concrete related national initiatives to advance state-of-the-art construction and material practices. It is anticipated that this consortium would become the national forum for state involvement in the technical exchange needed for collaboration and new initiatives and provide tactical strategies and solutions to issues identified by the member states.
6/1/2019June 2019Alternative Cementitious Materials (ACMs) For Durable and Sustainable Transportation Infrastructureshttps://cptechcenter.org/ncc-projects/alternative-cementitious-materials-(acms)-for-durable-and-sustainable-transportation-infrastructures/Alternatives analysis, Binders, Cement, Durability, Frigid regions, Materials, Portland cement, Service lifeConcrete produced with Alternative Cementitious Materials (ACMs) often exhibits superior mechanical performances and lower carbon footprint compared to those produced with Ordinary Portland Cement (OPC). ACMs also allow utilizing high-volume of industrial by-products as the binding materials instead of OPC, thus offering an environment-friendly alternative of traditional concrete. However, the durability performances of ACMs can vary depending on the selection of the reaction route (i.e., strength gaining mechanism). As a result, any definite evidence on the service life performances and life cycle cost of these materials are still in infancy. To address these challenges, the research team will investigate the durability performances of ACM concrete in comparison to those of traditional OPC-concrete, specifically for typical cold-climatic regions. Two ACM systems will be evaluated in this project, including (i) alkali-activated binders and (ii) CO2 activated binders.Warda Ashraf
12/01/19December 2019Guidelines for Building Smooth Concrete Pavementshttps://cptechcenter.org/ncc-projects/guidelines-for-building-smooth-concrete-pavements/Concrete pavement, Smoothness, Specifications, Field trial, RTSReal-time smoothness (RTS) technology is arguably one of the most impactful technologies for concrete pavement construction quality control resulting from the Second Strategic Highway Research (SHRP2) Program. Contractors participating in equipment loans through the SHRP2 Solutions Implementation Assistance Program have quickly realized the benefits of RTS for improving smoothness for as-constructed concrete pavement in order to achieve smoothness specification requirements while maximizing incentives and minimizing disincentives and corrective actions.Peter Taylor
1/1/2019January 2019Development of Non-Proprietary UHPC Mix (University of Oklahoma)https://cptechcenter.org/ncc-projects/development-of-non-proprietary-uhpc-mix-(university-of-oklahoma)/Bridge construction, Bridges, Durability, Guidelines, Joints (Engineering), Local materials, Mix design, Reinforcing bars, Shear properties, Ultra high performance concreteDeterioration of bridges can often be related to poor performance of longitudinal connections or transverse deck joints, which can be more frequent when precast panels are used for accelerated bridge construction. Ultra-high performance concrete (UHPC) is a relatively recent advancement in cementitious composite materials with mechanical and durability properties far exceeding those of conventional concrete. It combines a high percentage of steel fibers with an optimized gradation of granular constituents, resulting in a compressive strength in excess of 22 ksi, a high post-cracking tensile strength, and exceptional durability. The short reinforcing bar development lengths and exceptional durability provided by UHPC lead to great potential for use in bridge deck joints, other applications for accelerated bridge construction, and as a repair material. The long-term benefits of using UHPC in a number of applications are evident, but commercially available proprietary mixture formulations are very expensive and mix design using local materials is much more complicated than for conventional concrete.Royce Floyd
1/1/2019January 2019Development of Non-Proprietary UHPC Mix (Iowa State University)https://cptechcenter.org/ncc-projects/development-of-non-proprietary-uhpc-mix-(iowa-state-university)/Cost effectiveness, Fibers, Laboratory tests, Local materials, Mix design, Ultra high performance concreteDespite superior strength and durability, the use of ultra-high performance concrete (UHPC) in conventional concrete applications has been limited mainly due to cost considerations. While the former efforts have made advances in the development of non-proprietary UHPC mixtures, the cost of the final product has still remained too high for an immediate implementation. A study completed by FHWA (2013) outlined promising advances made in the development of non-proprietary UHPC mixes with a material cost ranging from $355 to $500 per cubic yard, excluding the cost of fibers. Addition of steel fibers was reported to increase the total cost by up to $470 per cubic yard. In a very recent study completed at Iowa State University, it was found that the total material cost can be reduced to $450 per cubic yard if non-proprietary mixes with local materials are developed. The cost analysis showed that almost half of the total cost is to purchase steel fibers. As steel fibers are the main contributor to the unit cost of UHPC and they are also prone to chloride-induced corrosion, this project explores alternative fibers with optimal dosages for UHPC. This project develops and characterizes economic, non-proprietary UHPC mixes made with materials locally available. This will be achieved through a holistic set of laboratory experiments that will be primarily focused on the choice of fibers, which are known as the costliest ingredient of UHPC mixes.Behrouz Shafei
11/1/2015November 2015Optimized Joint Spacing for Concrete Overlays with and without Structural Fiber Reinforcementhttps://cptechcenter.org/ncc-projects/optimized-joint-spacing-for-concrete-overlays-with-and-without-structural-fiber-reinforcement/Concrete pavement overlay, Contraction joint activation, Contraction joint spacing, Fiber reinforcement, Overlay joint optimizationThe objective of this project was to determine the optimum joint spacing for thin concrete overlays based on different concrete overlay thicknesses, support systems, and concrete overlay types with and without structural macro-fibers. In thin concrete overlays, field observations have sometimes shown that not all contraction joints activate initially and, in some cases, do not activate until many years after construction. Contraction joints that do not activate may be considered an inefficient design that may lead to unnecessary maintenance efforts and costs. The optimum joint spacing design may need to be determined based on factors other than those that are currently considered.Jerod Gross, Dan King, Halil Ceylan, Yu-An Chen, Peter Taylor
4/30/2015April 2015Extended Life Concrete Bridge Decks Utilizing Improved Internal Curing to Reduce Crackinghttps://cptechcenter.org/ncc-projects/extended-life-concrete-bridge-decks-utilizing-improved-internal-curing-to-reduce-cracking/Bridge decks, Concrete bridges, Concrete curing, Cracking, Fine aggregates, Laboratory tests, Life cycle costing, Load tests, Mix design, Service life, Slag cementWith the ongoing concern about premature cracking of concrete bridge decks that reduces the service life of bridges and results in increased maintenance and replacement costs, this work aimed at assessing the benefits of using lightweight fine aggregate (LWFA) in concrete mixtures to assist the Ohio Department of Transportation (ODOT) in preparing a specification to increase the probability of achieving crack-free, long-lasting bridge decks. A laboratory testing program led to a recommended mix design for implementation on a bridge construction project in Ohio. The design included the use of 50% slag cement and LWFA for internal curing. Construction of two bridge decks involved a control using a conventional mix design and the other containing the recommended mixture. The decks were instrumented and load tested shortly after construction and inspected one year after placement. No differences in structural performance were noted, but there were far fewer cracks in the test deck compared to the control. A life-cycle cost analysis was also conducted and shown that the premium for the recommended mixture would be recovered in reduced maintenance over the life of the bridge.Xuhao Wang, Peter Taylore, Katelyn Freeseman, Payam Vosoughi
4/1/2016April 2016Automated Plate Load Testing on Concrete Pavement Overlays with Geotextile and Asphalt Interlayers: Poweshiek County Road V-18https://cptechcenter.org/ncc-projects/automated-plate-load-testing-on-concrete-pavement-overlays-with-geotextile-and-asphalt-interlayers:-poweshiek-county-road-v-18/AC interlayer, geotextile interlayer, interlayer test, PCC overlayAutomated plate load testing (APLT) was conducted on County Road V-18 in Poweshiek County, Iowa, to assess and compare performance of unbonded concrete overlay sections constructed in 2008–2009. The unbonded overlays on County Road V-18 were constructed in selected areas using an asphalt concrete (AC) interlayer or a non-woven geotextile fabric interlayer. Wiegand et al. (2010) documented the construction techniques and materials used to build the test sections (project TR-600). The results of the study documented here provide a new assessment of the in situ deformation and composite modulus of the test sections.David J. White and Peter Taylor
4/1/2019April 2019Development of Non-Proprietary Ultra-High Performance Concrete (UHPC) for Iowa Bridges TR-773https://cptechcenter.org/ncc-projects/development-of-non-proprietary-ultra-high-performance-concrete-(uhpc)-for-iowa-bridges-tr-773/Bridges, Cost effectiveness, Durability, Fibers, Laboratory tests, Literature reviews, Mix design, Optimization, Ultra high performance concreteThe main objectives of this project are to develop and characterize economic, non-proprietary UHPC mixes made with materials readily available in Iowa. These mixes are expected to be significantly less expensive than commercially available UHPC mixes, permitting to utilize the superior strength and durability of UHPC in more bridges in Iowa. To achieve this goal, a comprehensive review of published and unpublished literature will be conducted, followed by setting the performance criteria needed for various bridge components and exposure conditions. A special effort will be made to identify the materials that are available in Iowa and have the potential to replace the proprietary UHPC ingredients. Based on the information obtained from the literature review and the past experience of the proposing team, a number of non-proprietary mixes will be designed. A holistic set of laboratory tests will then be carried out to assess the performance of the developed UHPC mixes in both short and long term. The testing program will include the necessary experiments to ensure that the expected fresh, mechanical, transport, durability, and dimensional stability properties are achieved. Upon the completion of the laboratory tests, a cost analysis will be conducted to determine the most cost-effective, non-proprietary UHPC mixes for bridge applications. Noting that almost half of the total cost of a UHPC mix comes from steel fibers, the proposing team will explore the possibility of replacing them with other less expensive choices of fiber through an ABC UTC-sponsored project that will supplement the current project. This combined effort will be an important step forward to optimize and recommend the mixture proportion of non-proprietary UHPC mixes appropriate for a wide range of bridge applications in Iowa. To achieve the objectives of this project, five tasks are proposed. The tasks will be performed in very close communication with a Technical Advisory Committee (TAC) throughout the duration of the project. To this end, the research team plans to hold quarterly meetings with the TAC to update them on progress and to ensure that the research direction is as desired.Behrouz Shafei
2/1/2019February 2019Performance Evaluation of Very Early Strength Latex Modified Concrete TR-771 (Phase III of TR-690)https://cptechcenter.org/ncc-projects/performance-evaluation-of-very-early-strength-latex-modified-concrete-tr-771-(phase-iii-of-tr-690)/Bridge construction,  Bridges, Evaluation and assessment,  Latex modified concrete,  Life cycle costing,  Mechanical properties,  Overlays (Pavements),  Pavement performance,  Quality assurance,  Quality control,  RecommendationsThe overall goal of this proposed research is to explore the potential use of Very Early Strength Latex Modified Concrete (LMC-VE) in Iowa bridge overlays. This will be achieved through a study of the first Iowa LMC-VE overlay practice on the IA 15 over Black Cat Creek Bridge. The specific approaches to this defined goal include the following: (1) To document and identify the benefits and problems in construction of the LMC-VE overlay at the selected bridge. The documentation will include the information on the uses of materials, construction conditions and procedures, and quality assurance/quality control (QA/QC) methods and procedures. (2) To evaluate the key engineering properties (such as compressive and flexural strength, tensile adhesion bond strength, chloride penetration resistance, and fiction index) of LMC-VE using standard and accelerated test methods. (3) To monitor the field performance of the constructed LMC-VE overlay up to 5 years. (4) To conduct a life cycle cost analysis in a comparison of the LMC-VE overlay with a conventional rigid overlay. (5) To analyze the research results, understand LMC-VE performance, and provide insights and recommendations for future use of LMC-VE overlays for Iowa bridges.Kejin Wang, Brent Phares, Katelyn Freeseman
04/01/19April 2019Fiber-Reinforced Concrete for Pavement Overlays: Technical Overviewhttps://cptechcenter.org/ncc-projects/fiber-reinforced-concrete-for-pavement-overlays:-technical-overview/concrete overlays, fiber-reinforced concrete, macrofibersThis report summarizes the state of the art regarding different fiber types, test methods, structural design, and the construction modifications required to accommodate fiber-reinforced concrete (FRC) materials in concrete overlays. This document is a companion report to Overview of Fiber-Reinforced Concrete Bridge Decks, which summarizes the experience from existing bridge deck and bridge deck overlay construction projects that have employed FRC materials.Jeffery Roesler, Amanda Bordelon, Alexander Brand, Armen Amirkhanian
04/01/21April 2021Investigation on Pavement ME Design Reflective Cracking, Faulting, IRI Prediction Models, Concrete Overlays Design Tool, and Performance Threshold Levels for Iowa Pavement Systems https://cptechcenter.org/ncc-projects/investigation-on-pavement-me-design-reflective-cracking,-faulting,-iri-prediction-models,-concrete-overlays-design-tool,-and-performance-threshold-levels-for-iowa-pavement-systems/Mechanistic-empirical pavement design, Pavement management systems, Pavement performance, Reflection cracking The Mechanistic-Empirical Pavement Design Guide (MEPDG) and its accompanying software AASHTOWare Pavement ME Design (PMED) represent major improvements over their predecessors, particularly in their comprehensive coverage of the impact of design inputs on pavement performance. Since PMED’s release, numerous updates have been made to the software. Some of the most recent enhancements include the addition of Modern Era Retrospective Analysis for Research and Applications (MERRA) climate data (satellite-based data provided by NASA), a reflective cracking model for overlay performance prediction, and a tool to design bonded concrete overlays on asphalt (BCOA), renamed in PMED as short-jointed plain concrete pavement (SJPCP) over asphalt concrete (AC). A comprehensive evaluation of all the new PMED tools was performed and is presented in this study. The results demonstrate that these updates’ significant impact on the distresses predicted by the software compared to predictions using previous versions warrants recalibration. Evaluation of PMED’s nationally calibrated models was performed for flexible, rigid, and asphalt concrete over jointed plain concrete pavements for different representative geographical locations, ages, and traffic levels across Iowa. Locally calibrated models were developed for Iowa-specific conditions by determining an appropriate new set of calibration coefficients for use in the PMED software. During this process, multiple advanced optimization approaches were tested, and experiences and recommendations from the entire local calibration process are discussed. Additional analysis was performed to determine recommended layer thicknesses for varying reliability levels using the locally calibrated models. The overall findings from this study will serve as a useful reference and guide for implementing PMED for Iowa pavement design practices. Other states that plan to test and implement PMED for their state design practices will also benefit from this study’s complete description of the set of local calibration steps required by PMED. Brian Worrel, Halil Ceylan, Leela Sai Praveen Gopisetti, Sunghwan Kim, Bora Cetin, Orhan Kaya
7/1/2013July 2013Ultrasonic Imaging for Concrete Infrastructure Condition Assessment and Quality Assurancehttps://cptechcenter.org/ncc-projects/ultrasonic-imaging-for-concrete-infrastructure-condition-assessment-and-quality-assurance/Bridge decks, Concrete, Condition surveys, Detection and identification technologies, Deterioration, Field tests, Infrastructure, Laboratory tests, Quality assurance, Ultrasonic wavesThis report describes work on laboratory and field performance reviews of an ultrasonic shear wave imaging device called MIRA for application to plain and reinforced concrete infrastructure components. Potential applications investigated included bridge deck delamination detection, deck thickness profiles, and detection of internal steel bars and dowels. Based on the observed performance of the unit, three classification categories of applications were defined: field ready, potentially ready, and challenging. In general, the MIRA device is not well suited to provide full-coverage rapid scans over an entire structure. Rather MIRA is more suited for targeted inspection or failure analysis to determine general geometric and internal features of concrete elements because MIRA is able to be quickly deployed for spot inspections with little site preparation. A user’s manual was produced to assist in introducing new users to the proper operation and interpretation of the MIRA device.John S. Popovics, Jeffery R. Roesler, James Bittner, Armen N. Amirkhanian, Alexander S. Brand, Prakhar Gupta, and Katherine Flowers
9/15/2017September 2017Bridge Decks: Mitigation of Shrinkage Cracking - Phase IIIhttps://cptechcenter.org/ncc-projects/bridge-decks:-mitigation-of-shrinkage-cracking---phase-iii/Bridge decks, Cracking, Guidelines, Materials, ShrinkageThe goal of this study (i.e., Phase- III) is to develop ‘robust’ shrinkage mitigation strategies by combining knowledge of materials level testing with lab-scale structural testing, and develop guidelines for Illinois Department of Transportation (IDOT) for implementation of a holistic approach that lessens premature cracking in concrete bridge decks in Illinois. The workplan below primarily focuses on the materials part of the research. A separate workplan is being submitted by SLU on the structural part of the work. A joint effort will be made to combine the small-scale materials lab test data with large-scale structural test data in order to ultimately develop guideline for field application.Paramita Mondal
6/16/2019June 2019Review of Improved Subgrade and Stabilized Subbases to Evaluate Performance of Concretehttps://cptechcenter.org/ncc-projects/review-of-improved-subgrade-and-stabilized-subbases-to-evaluate-performance-of-concrete/Concrete pavements, Geotechnical engineering, Pavement design, Pavement performance, Recommendations, Specifications,  Subbase (Pavements),  Subgrade (Pavements),  ThicknessThe objective of this research is to provide IDOT with geotechnical solutions for highway and pavement applications that will advance current practice, and ensure that the pavements in the State of Illinois are constructed to the necessary levels of performance, economy and durability, without being overly conservative in thickness. The outcomes of this project will be to provide recommendations and draft specifications to update the standard specifications and manuals of IDOT regarding foundation issues that are currently pressing for IDOT.Erol Tutumluer
06/30/20June 2020Size and Shape Determination of the Rip Rap and Large Sized Aggregates Using Field Imaginghttps://cptechcenter.org/ncc-projects/size-and-shape-determination-of-the-rip-rap-and-large-sized-aggregates-using-field-imaging/Aggregate gradation, Aggregates, Field studies, Image analysis, Riprap, Shape Riprap rock and large-sized aggregates are extensively used in transportation, geotechnical, and hydraulic engineering applications. Traditional methods for assessing riprap categories based on particle weight may involve subjective visual inspection and time-consuming manual measurements. Aggregate imaging and segmentation techniques can efficiently characterize riprap particles for their size and morphological/shape properties to estimate particle weights. Particle size and morphological/shape characterization ensure the reliable and sustainable use of all aggregate skeleton materials at quarry production lines and construction sites. Aggregate imaging systems developed to date for size and shape characterization, however, have primarily focused on measurement of separated or non-overlapping aggregate particles. This research study presents an innovative approach for automated segmentation and morphological analyses of stockpile aggregate images based on deep-learning techniques. As a project outcome, a portable, deployable, and affordable field-imaging system is envisioned to estimate volumes of individual riprap rocks for field evaluation. A state-of-the-art object detection and segmentation framework is used to train an image-segmentation kernel from manually labeled 2D riprap images in order to facilitate automatic and user-independent segmentation of stockpile aggregate images. The segmentation results show good agreement with ground-truth validation, which entailed comparing the manual labeling to the automatically segmented images. A significant improvement to the efficiency of size and morphological analyses conducted on densely stacked and overlapping particle images is achieved. The algorithms are integrated into a software application with a user-friendly Graphical User Interface (GUI) for ease of operation. Based on the findings of this study, this stockpile aggregate image analysis program promises to become an efficient and innovative application for field-scale and in-place evaluations of aggregate materials. The innovative imaging-based system is envisioned to provide convenient, reliable, and sustainable solutions for the on-site quality assurance/quality control (QA/QC) tasks related to riprap rock and large-sized aggregate material characterization and classification. Erol Tutumluer
9/15/2019September 2019SPR-4419: Superabsorbent Polymers (SAP) for Internally Cured Concretehttps://cptechcenter.org/ncc-projects/spr-4419:-superabsorbent-polymers-(sap)-for-internally-cured-concrete/Absorbents, Bridge decks, Concrete, Concrete curing, Patching, PolymersThe goal of this research is to develop practical, cost-effective strategies to create internally cured concrete for INDOT bridge decks and full depth patching of pavements that do not require complicated processing steps to achieve the desired benefits, including improved hydration, reduced thermal expansion, and increased freeze-thaw resistance compared with conventional mixes.Kendra Erk, Jan Olek
09/01/19September 2019Practical Issues in Implementation of Mechanistic Empirical Design for Concrete Pavementshttps://cptechcenter.org/ncc-projects/practical-issues-in-implementation-of-mechanistic-empirical-design-for-concrete-pavements/Calibration,  Concrete pavements,  Mechanistic-empirical pavement design, Pavement distress, Pavement joints, Slabs,  Structural models,  Unreinforced concreteThis study was undertaken to locally calibrate and implement the models for a mechanistic-empirical design guide (MEPDG) for jointed plain concrete pavement (JPCP) sections. Twenty-two newly constructed JPCP projects were selected to calibrate the rigid pavement models—17 for calibration and 5 for validation. The traditional split sampling method was followed in calibration. MEPDG-predicted distress of road segments was compared with the measured distress. Statistical analysis was performed using the Microsoft Excel statistical toolbox. The JPCP transverse joint faulting model was calibrated using sensitivity analysis and iterative runs of the MEPDG software to determine optimal coefficients that minimized the bias. The International Roughness Index (IRI) model was calibrated using the generalized reduced gradient nonlinear optimization technique in Microsoft Excel Solver. The transverse slab cracking model could not be calibrated due to lack of measured cracking data. Eleven prospective and two in-service JPCP sections with varying design traffic levels were reanalyzed using traditional empirical and new MEPDG design methods. The results showed that the traditional empirical design method yielded higher slab thickness than the MEPDG method for projects with high traffic levels. However, thinner slab thicknesses were obtained by the traditional empirical design method for projects with low to medium traffic.Shuvo Islam, Abu Sufian, Mustaque Hossain, Nat Valasquez Jr.
07/01/2019July 2019Mechanistic-Based Parametric Model for Predicting Rolling Resistance of Concrete Pavementshttps://cptechcenter.org/ncc-projects/mechanistic-based-parametric-model-for-predicting-rolling-resistance-of-concrete-pavements/Concrete pavements, Deformation, Dissipation,  Mathematical models,  Mathematical prediction, Rigid pavements,  Rolling resistance, ViscoelasticityThe structural rolling resistance (SRR) is the component of rolling resistance that occurs because of the viscoelastic deformation of the pavement structure. In this paper, a simple model to calculate the energy dissipation as a result of the SRR on rigid pavements is developed for use in applications such as life cycle cost analysis and life cycle assessment. First, the energy dissipated by different vehicles was calculated on 12 concrete pavement sections using a fully mechanistic approach. Using the program DYNASLAB to simulate the vehicles moving along the pavement sections, the energy dissipation was calculated as the work done by the vehicle to overcome the slope seen by the wheels because of the pavement deformation. The results were then used to develop a simple and rapid-to-use model to predict the energy dissipation on any jointed concrete pavement. The model consists of a simple predictive function that can provide the value of the SRR energy dissipation given the mechanical properties of the pavement section (slab thickness and stiffness, modulus of subgrade reaction, subgrade damping coefficient, pavement geometry, and load transfer efficiency) and the loading conditions (speed and loads). The model was based on a sensitivity analysis that was used to select the optimal set of structural and environmental factors.Danilo Balzarini, Karim Chatti, Imen Zaabar, Ali A Butt, John T Harvey
9/3/2019September 2019Research for AASHTO Standing Committee on Highways. Update of the 2012 AASHTO Guide Specification for Design of Bonded FRP Systems for Repairhttps://cptechcenter.org/ncc-projects/research-for-aashto-standing-committee-on-highways.-update-of-the-2012-aashto-guide-specification-for-design-of-bonded-frp-systems-for-repair/Bond strength (Materials), Concrete bridges, Fiber reinforced polymers, Repairing, SpecificationsBonded Fiber-Reinforced Polymer (FRP) systems have proven to be an economical means for the repair and strengthening of concrete bridge elements in many projects. The first edition of the AASHTO Guide Specifications for Design of Bonded FRP Systems for Repair and Strengthening of Concrete Bridge Elements, published in 2012, provides design tools for bridge elements subjected to flexure, shear and torsion, and combined axial force and flexure. However, many projects have been constructed and changes in the state of practice have occurred since the publication of these guide specifications. Also, during this period, substantial research on the different aspects of bonded FRP system applications has been performed. In addition, the current guide specifications are limited in scope (e.g., do not explicitly cover flanged sections, prestressed concrete elements, and FRP anchoring design). Because of these changes and limitations, there is a need for updating the guide specifications to recognize these issues and provide updated information and guidance on all aspects bonded FRP systems for repair and strengthening, including topics such as FRP near surface mounted applications, anchorage detailing, material specifications, and test requirements. Such guide specifications will help highway agencies address relevant issues and improve the use of FRP systems for repair and strengthening applications. The objective of this research is to update the 2012 AASHTO Guide Specifications for Design of Bonded FRP Systems for Repair and Strengthening of Concrete Bridge Elements.Issam Harik
3/19/2019March 2019Recommendations for Revision of AASHTO M 295 Standard Specification to Include Marginal and Unconventional Source Coal Fly Asheshttps://cptechcenter.org/ncc-projects/recommendations-for-revision-of-aashto-m-295-standard-specification-to-include-marginal-and-unconventional-source-coal-fly-ashes/Cement, Concrete, Evaluation and assessment, Fly ash, Highways, Pozzolan, Recommendations, StandardsFly ash is the most common supplementary cementitious material used to help improve the durability and sustainability of concrete and mitigate alkali-silica reactivity (ASR). While the demand for fly ash for use in concrete remains steady, the supply of high quality fly ash has been dwindling or, at least, becoming unpredictable. This is partly due to electric power plants changing their fuel sources (e.g., from coal to natural gas) and partly because of tighter environmental and air pollution regulations that have resulted in increased carbon, calcium, sulfur, alkali, and ammonia contents of the fly ash, which adversely affect its quality for use in concrete. In recent years, there has been a growing concern among concrete users and producers about the quality and the quantity of fly ash presently available. In a recent American Association of State and Highway Transportation Officials (AASHTO) survey of the state departments of transportation, respondents noted significant issues with the supply of coal fly ash. This supply and demand imbalance for quality fly ash has already resulted in regional and seasonal shortages, which is expected to further exacerbate with time. Given this restriction on supply, coal fly ash that was once deemed marginal is now being used in concrete. Marginal fly ash is defined as the fly ash that is of lower quality [i.e., with high loss-on-ignition (LOI), fineness, moisture content, etc.] or otherwise unusable in concrete. To address the shortage, even unconventional sources of fly ash are now being considered, i.e., primarily the ash disposed of in landfills or impoundments. To help meet the growing need for fly ash while maintaining the quality and performance of concrete, it becomes imperative for the concrete industry and the transportation agencies to look for and evaluate marginal and unconventional source fly ashes. To that end, it is also imperative that fly ash specifications measure properties that affect performance and not reject materials that, although suitable for use in concrete, just do not come up to the historical specifications adopted when high quality fly ash was plentiful.
11/2/2015November 2015Entrained Air Void System for Durable Highway Concretehttps://cptechcenter.org/ncc-projects/entrained-air-void-system-for-durable-highway-concrete/Admixtures, Air entrainment, Air voids, Concrete, Freeze thaw durability, Laboratory tests, Test proceduresLaboratory testing and long-term field experience have shown that highway concrete must be properly air-entrained if it is to resist the action of freezing and thawing, particularly in wet climates. Experience has also shown that the effectiveness of air entrainment in providing resistance to freezing and thawing depends on the characteristics of the air void system. These characteristics are influenced by the materials used in producing concrete (e.g., cement type and composition, supplementary cementitious materials, air-entraining and other admixtures, and aggregate size); the practices for proportioning, mixing, and placing concrete; and field conditions. However in some situations, air entrainment has shown adverse effects on other concrete properties (e.g., strength). Laboratory methods are currently available for characterizing the air void system in hardened concrete and for evaluating the freeze-thaw resistance of concrete. However, the parameters associated with this characterization and the results of these laboratory tests do not always reflect the observed field performance nor do they consider the possible effects on other concrete properties. There is a need to identify the characteristics of the air void system that relate to field performance and develop improved test methods for evaluating the freeze-thaw resistance of highway concrete. Ideally, these methods would evaluate the concrete mixture immediately before placement to allow adjustment of mixture if necessary. This information will help highway agencies prepare specifications for concrete procurement that will provide the air-void characteristics and freeze-thaw resistance needed for enhanced durability and thus ensure longevity of highway structures and pavements. The objectives of this research are to (1) identify the characteristics of the entrained air void system required for freeze-thaw durability of highway concrete, (2) identify/develop new or modified test methods for measuring these characteristics, and (3) identify/develop new or modified test methods for evaluating freeze-thaw durability.Peter Taylor
10/1/2017October 2017Surface Resistivity Testing for Quality Control of Concrete Mixtureshttps://cptechcenter.org/ncc-projects/surface-resistivity-testing-for-quality-control-of-concrete-mixtures/Admixtures, Durability, Electrical resistivity, Methodology, Mix design, Quality assurance, Quality control, Water cement ratioThe purpose of this study is to investigate the potential of resistivity testing in assessing key mixture design parameters critical for durability performance of concrete mixtures. The methodology proposed will enable the development of a method based on resistivity criteria to identify the water-to-cement ratio of a given mixture whether the mixture contains a certain type of supplementary cementitious material. The objectives of the experimental study are to perform an experimental parametric investigation to determine the time-resistivity behavior of typical concrete mixtures used in pavement and infrastructure construction and determining the efficacy of resistivity testing in differentiating key mixture components. It was found that resistivity testing is sensitive to water-to-cement ratio, with some exceptions, and sensitive to supplementary cementitious replacement. The preliminary results will aid in the development of a new quality control and assurance criteria for concrete mixture approval in addition to currently used test methods and specifications.Hartell, Julie Ann; Shults, Cody
7/1/2019July 2019Reclaimed Stabilized Base - Stabilizing Agent Selection & Designhttps://cptechcenter.org/ncc-projects/reclaimed-stabilized-base-stabilizing-agent-selection-&-design/Cold weather, Freeze thaw durability,  Stabilizers, Stiffness,  Subbase (Pavements),  Subbase materialsReclaimed stabilized base (RSB) is a common technique utilized to rehabilitate roadways (e.g. NCHRP 144 Report, 2009; NCHRP 421 report, 2011). RSB involves reclaiming the base material and adding a stabilizing agent (e.g. cement, lime, calcium chloride, emulsion, foamed asphalt) to increase the strength and durability of the subbase structure. In this project, the research team plans to investigate the suitability of the various stabilizing agents for common subbase materials encountered in Vermont roadways and develop a process for VTrans to determine the applicability of RSB for a project, and the appropriate types and percentages of stabilizing agents. The team plans to investigate the performance of the stabilized sub-base materials in winter conditions, including ice lens formation and stiffness as well as long-term (multiple-year equivalents) freeze-thaw implication for durability through accelerated cold room testing. The outcomes of this research will assist VTrans in the scoping phase of the projects to determine applicability of RSB, and in the design and construction phases with guidance on appropriate stabilizing agents, and installation parameters, respectively.
3/15/2018March 2018Development of Geopolymers Based Cement and soil stabilizers for Transportation Infrastructurehttps://cptechcenter.org/ncc-projects/development-of-geopolymers-based-cement-and-soil-stabilizers-for-transportation-infrastructure/Durability, Geopolymer concrete, Infrastructure, Life cycle analysis, Pavement design, Soil stabilization, Waste productsIn recent years, geopolymer cement (GPC) have received much attention as an alternative to Ordinary Portland Cement (OPC) for soil stabilization, pavements, bridges, and other transportation structures, because they show good mechanical properties when compared to OPCs. More importantly, GPC provides sustainable and environmentally friendly alternative to OPCs as GPC can be processed at room temperatures from aqueous solutions of waste materials (e.g. fly ash) or abounded natural sources (e.g. clay) and thus reduce significant CO2 production associated with the processing of OPC. Although significant progress has been achieved over the last couple of decades on developing GPCs with desired properties, their durability in real service conditions, especially when they are exposed to significant water uptake during flooding or extensive rainfalls, is still not well understood. Hence, this project aims to investigate the long-term durability of GPC concrete and stabilized base and subgrade materials for transportation infrastructure. Specifically, the objective of this study is to develop an innovative, sustainable, eco-friendly and durable GPC for transportation infrastructure in Region 6, more specifically for GPC concrete structures (pavements, bridges, etc.) and stabilization base and subgrade foundation support for pavements, using natural and waste materials that abound in the region.Ibrahim Karaman
6/21/2013June 2013Concrete Strength Required to Open to Traffichttps://cptechcenter.org/ncc-projects/concrete-strength-required-to-open-to-traffic/ Compressive strength, Concrete curing, Concrete pavements, Field tests, Laboratory tests, Load tests, Nondestructive tests, Pavement design, Pavement distress, RecommendationsDevelop innovative mechanistic-based procedures for monitoring concrete early age development and evaluate the effect of early traffic opening on long-term damage accumulation. The procedure will utilize recent developments in nondestructive testing to optimize traffic opening timing without jeopardizing pavement longevity.Lev Khazonovich, University of Minnesota
7/31/2019July 2019Detection of Flaws in Asphalt Overlaid Concrete Decks Using Ultrasonic Guided Waveshttps://cptechcenter.org/ncc-projects/detection-of-flaws-in-asphalt-overlaid-concrete-decks-using-ultrasonic-guided-waves/Bridge decks, Inspection equipmentThe research proposed here builds on the achievements of a previous NOOT project. The novel, nondestructive ultrasonic guided wave leakage (UGWL) based testing method we developed recently promises to be able to detect the onset of corrosion and delamination in reinforced concrete bridge decks earlier than any other nondestructive testing (NDT) method (Garcia, Erdogmus, et al. 2017 and 2019); however, the effects of asphalt overlay on the method's effectiveness remains unclear. With this project, we aim to investigate the effect of asphalt overlays on the feasibility of the recently developed UGWL method. In this section, the background and the motivation for the proposed work are summarized. Reinforced concrete bridge decks are highly susceptible to deterioration, mainly due to corrosion of the rebars and the subsequent propagation of issues, such as delamination, cracking, and spalling. According to the Federal Highway Administration (FHWA 2014), 145,890 out of the 610,749 highway bridges (24%) in the U.S. are structurally deficient. Yunovich et al. (2001) state that corrosion and delamination problems account for approximately 40% of all bridge deck repair costs; and Arndt et al. (2011) identify the highway bridge corrosion related repair costs to be around $8.3 billion, with $2 billion of this just for the repair of bridge decks.Unviersity of Nebraska, Lincoln
05/01/17May 2017Performance of Bridge Deck Overlays in Virginia: Phase I: State of Overlayshttps://cptechcenter.org/ncc-projects/performance-of-bridge-deck-overlays-in-virginia:-phase-i:-state-of-overlays/Bridge decks, Deterioration, Overlays (Pavements), Service life, State of the practiceMaintaining the existing transportation infrastructure is a major concern of the Virginia Department of Transportation (VDOT). The increased user travel costs, safety concerns, and financial burdens involved in replacing deteriorating decks are reasons for finding appropriate rehabilitation actions that can safely extend the service life of structures. Virginia has been a leader in employing overlays as a rehabilitation method for bridge decks. VDOT’s Manual of the Structure and Bridge Division contains guidance for the decision-making process related to maintenance and repair of structures. Yet there is a need to update the guidelines based on contemporary experience and the knowledge gained through technological advances. This report presents and discusses the preliminary findings of Phase I of a multi-phase study to determine the performance of bridge deck overlays in Virginia. Phase I focused on obtaining information regarding the experiences of VDOT’s nine districts with regard to their use of different kinds of overlays and the factors that influence which overlays are used. In addition, VDOT’s bridge inventory was analyzed to gain an understanding of the types of overlay systems used in Virginia.Soundar S.G. Balakumaran, Ph.D., P.E., and Richard E. Weyers, Ph.D., P.E
10/5/2017October 2017Evaluation of Penetrating Sealers Applied to Saw Cut Faces in Concrete Pavement Jointshttps://cptechcenter.org/ncc-projects/evaluation-of-penetrating-sealers-applied-to-saw-cut-faces-in-concrete-pavement-joints/Concrete pavements, Durability, Field studies, High performance concrete, Pavement joints, Sealing compounds, SpecificationsFor the last six years, the Wisconsin Department of Transportation (WisDOT) as part of the high performance concrete (HPC) pavement standard special provision has specified the use of a penetrating concrete sealer be applied to the saw cut faces in the joints. The HPC pavements on the Interstate 94 North-South corridor and the Interstate 41 corridor from Oshkosh to Green Bay have received this joint treatment. The specification requires the use of a silane or siloxane-based concrete penetrating sealer to be applied as soon as possible after the sawing operation is complete. To date, a variety of different products have been used, a number of different application methods have been employed, and the rates of application have been variable. In addition, the construction process and the construction inspection have not been uniform or consistent statewide. Therefore, there is no assurance that WisDOT is accomplishing the goal of distress free joints and longer life of the pavement. Finally, there has been no assessment by WisDOT on whether there are benefits and cost effectiveness to doing this work.Danny Xiao
09/01/19September 2019Impact of Joint Spacing on Bonded Concrete Overlay of Existing Asphalt Pavement in the AASHTOWare Pavement ME Design Softwarehttps://cptechcenter.org/ncc-projects/impact-of-joint-spacing-on-bonded-concrete-overlay-of-existing-asphalt-pavement-in-the-aashtoware-pavement-me-design-software/Asphalt pavements, Bonding, Concrete overlays, Mechanistic-empirical pavement design, Pavement cracking, Pavement joints, Pavement performance, SpacingThis paper describes the impact of joint spacing or panel size on the performance and relative cost of short jointed bonded concrete overlay of asphalt (SJPCP) pavement using the AASHTO Pavement ME Design procedure. Joint spacing, or panel dimension, is a critical design issue that greatly affects both performance and cost of the SJPCP as well as conventional jointed plain concrete pavement (JPCP) overlays. In fact, pavement performance is more dictated by the panel size than thickness.Biplab Bhattacharya, Alex Gotif, Michael Darter, Lev Khazanovich
11/25/2019November 2019Synthesis of Information Related to Airport Practices, Topic S09-09. Automated Pavement Condition Survey Practices at Airportshttps://cptechcenter.org/ncc-projects/synthesis-of-information-related-to-airport-practices-topic-s09-09-automated-pavement-condition-survey-practices-at-airports/Airport runways, Airports, Automatic data collection systems,  Condition surveys, Literature reviews, Pavement management systems, State of the practicePavement condition data is a critical component of all pavement management systems. The accuracy and validity of pavement condition data is the basis for many activities conducted by airports and local agencies. Pavement condition data is used, for example, to support asset management, assess existing and future pavement condition, establish budget needs and evaluate budget impacts, and select projects for pavement maintenance and rehabilitation. Many federal transportation bills (National Performance Management Measures; Assessing Pavement Condition for the National Highway Performance Program and Bridge Condition for the National Highway Performance Program) are performance-based. As such, agencies are increasingly required to report validated pavement conditions when requesting funding. Pavement condition reporting in support of federal funding requests includes existing project data on rut depth, the International Roughness Index (IRI) and percent cracking for flexible pavements and faulting for jointed concrete pavements, and IRI and percent cracking for continuously reinforced concrete pavements. ACRP Research Report 203, Collecting, Applying, and Maintaining Pavement Condition Data at Airports, was published in 2019. 
10/01/2019October 2019Quality Testing of Wisconsin Aggregateshttps://cptechcenter.org/ncc-projects/quality-testing-of-wisconsin-aggregates/Aggregate tests, Aggregates, Freeze thaw durability, Geotechnical engineering, Quality controlAt a minimum, WisDOT requires sodium sulfate soundness testing (AASHTO T104) and Los Angeles wear (AASHTO T96) aggregate quality testing be completed once every three years for quarried aggregate sources and once every five years for pit aggregate sources. Aggregate sources located in the Sinnippee geological group, generally in the southwest part of Wisconsin, require an additional freeze-thaw test (AASHTO T103) on a three-year or five-year testing cycle. An internal audit of WisDOT specifications concluded that the frequency of testing for quality is lacking relative to surrounding states. Reduced testing frequencies is due, in part, to the higher level of aggregate quality available to paving contractors in Wisconsin. Despite the inventory of high-quality construction aggregates, localized pavement performance issues have raised concerns about the effectiveness of the current quality testing program. Recent changes to the standard specifications have partially addressed concerns regarding the minimal quality testing frequencies, but there is a need to revisit quality thresholds and accuracy of current testing methods to represent aggregate durability. Hani Titi
01/01/2020January 2020Developing Anti-Icing Airfield Runways Using Surface Embedded Heat Wires and Renewable Energyhttps://cptechcenter.org/ncc-projects/developing-anti-icing-airfield-runways-using-surface-embedded-heat-wires-and-renewable-energy/airport runways, anti-icing, electric wire, heating systems, renewable energy sources, snow and ice controlAirfield runway safety is significantly affected by winter snow, ice, and slush conditions. These wet wintry conditions impact aircraft control and stopping distances. Airport operators use deicing chemicals and plowing to maintain safe runways during wet wintry conditions. However, snow removal is costly. This article presents an alternative approach to applying deicing chemicals and plowing. The approach discusses using a heated pavement system (HPS) with surface embedded wire. Nichrome heating wire is embedded at the slab surface level and energized by an outside source to heat the pavement through Joule heating. Renewable energy generated through a photovoltaic system is used to energize the wires within the concrete slab. To reduce energy demand, the system is designed as an anti-icing system in contrast to a deicing system. Consequently, energy is continually supplied to the system to maintain an above freezing pavement surface temperature independent of ambient weather conditions.An anti-icing runway slab was developed by supplying DC energy from a photovoltaic energy system to experimental concrete slabs with surface embedded heat wire. Experiments were conducted supplying energy to test panels and analyzing pavement surface temperature changes. Energy usage is controlled in the proposed system using control relays. The control relays allow current flow to only surface embedded wires in pavement sections that require a pavement surface temperature increase. This article identifies the challenges and benefits of using surface embedded heat wires with a photovoltaic system to develop an anti-icing pavement system. The approach discussed in this article proposes methodology to develop an anti-icing airfield runway pavement system that relies on a sustainable energy source, solar energy, as it’s energy source. Solar energy is used to recharge a storage energy bank for energizing the proposed system.Heymsfield, Ernie; Daniels, Joseph W; Saunders, Robert F; Kuss, Mark L
08/01/2019August 2019Development of Improved Guidelines and Designs for Thin BCOA: Summary, Conclusions, and Recommendationshttps://cptechcenter.org/ncc-projects/development-of-improved-guidelines-and-designs-for-thin-bcoa-summary-conclusions-and-recommendations/concrete overlays, concrete tests, cracking of concrete pavements, guidelines, laboratory tests, load transfer, paving, rigid pavements, thermal expansion, whitetoppingThis report summarizes the investigations undertaken by the University of California Pavement Research Center between 2014 and 2017 to develop recommendations and guidance on the use of thin bonded concrete overlay of asphalt (BCOA) as a rehabilitation alternative for California based on the adoption of, and improvements to, the technology developed in other US states. The main tasks of the project included: 1) laboratory testing of four rapid-strength concrete mixes and a number of concrete-asphalt interfaces, 2) evaluation of the construction of a full-scale test track, 3) monitoring of the structural and hygrothermal responses of six thin BCOA sections to the ambient environment, 4) accelerated pavement testing with the Heavy Vehicle Simulator (HVS) on eleven thin BCOA sections, 5) finite element method modeling, and 6) development of a set of recommendations for the design and construction of thin BCOA pilot projects in California. Based on this testing and analysis, it was possible to obtain a better understanding of the mechanics of the structure of thin BCOA and of the rolesof the different factors that determine thin BCOA performance. Overall, the performance of the thin BCOA sections in the HVS testing far exceeded expectations. The 11 sections resisted the predefined HVS loading without cracking. In five of the sections, that loading was equivalent to 6 million equivalent single axle loads (ESALs) and included load levels more than twice the legal limit in California, channelized traffic at the edge of the slabs, and a continuous water supply that simulated flooded conditions.The main conclusion from this research project is that a well-designed, well-built 6×6 thin bonded concrete overlay section placed on top of an asphalt base that is in fair to good condition can potentially provide 20 years of good serviceability on most of California’s non-interstate roadways. Eight individual reports prepared for the project provide a complete description of the work carried out, and include detailed conclusions about each phase. This report includes a summary of those conclusions and a set of recommendations for the design of thin BCOA that considers California traffic, climate and materials conditions,and construction work zone practices.Mateos, Angel; Harvey, John; Paniagua, Fabian; Paniagua, Julio; Wu, Rongzong
12/01/2019December 2019Application of Permeable Pavements in Highways for Stormwater Runoff Management and Pollution Prevention: California Research Experienceshttps://cptechcenter.org/ncc-projects/application-of-permeable-pavements-in-highways-for-stormwater-runoff-management-and-pollution-prevention-california-research-experiences/hydraulic properties, porous pavements, research, runoff, water quality managementIn the future, permeable pavements including the full depth permeable pavement (FDPP) will be part of an integrated sustainable transportation program. When designed properly, FDPP can be used as an alternative best management practice (BMP) for stormwater runoff management. From a practical point of view, FDPP must maintain specific characteristics throughout the life of the pavements: (1) have adequate subgrade reservoir capacity to capture runoff volume, (2) surface pavement remain highly permeable and unclogged, (3) allowing minimum permeability of subgrade soil to infiltrate the captured runoff, and (4) assuring no adverse impact on underground water. During the past ten years the University of California Pavement Research Center (UCPRC) conducted numerous research studies to address some of the above critical questions related to the application of permeable pavement with respect to the highway stormwater runoff management. The focus of this paper is to discuss and summarize the major findings of these collective studies related to: (1) hydraulic performance evaluation of permeable pavement, (2) permeability measurement of porous asphalt and pervious concrete paved surfaces, (3) clogging evaluation of permeable pavement surfaces, and (4) water quality and pollution control issues.Kayhanian, Masoud; Li, Hui; Harvey, John T; Liang, Xiao
02/01/2022February 2022Road Salt Impact Assessmenthttps://cptechcenter.org/ncc-projects/road-salt-impact-assessment/Deicing chemicals, Environmental impacts, Financing, Highway safety, Impacts, Level of service, Water wells, Weather and climate, Winter maintenanceThe overall goal of this project is to inform public policy in Maine regarding winter road maintenance. The project will consider state and municipal funding, levels of service, environmental impacts associated with the use of road salt and other anti-icing agents, the impact of anti-icing agents on wells used for drinking water along roads maintained by Maine Department of Transportation, safety to drivers and how changes in weather may impact anti-icing activities.University of Maine
10/07/2022October 2022Investigating Thermal Imaging Technologies and Unmanned Aerial Vehicles to Improve Bridge Inspectionshttps://cptechcenter.org/ncc-projects/investigating-thermal-imaging-technologies-and-unmanned-aerial-vehicles-to-improve-bridge-inspections/Bridges, Delamination, Drones, Infrared imagery, Inspection, Sensors, Thermal imageryBridge inspection is central to any transportation facilities maintenance program. A particular concern with bridge conditions is concrete delamination on the underside of bridge decks, especially on overpass bridges and on bridges that see pedestrian or boat traffic underneath. Current methods for inspecting overpass bridge decks include visual observations from the roadway underneath by maintenance personnel. Areas identified that may be prone to loosen and fall are then chipped off, before the concrete fails and lands on passing traffic. Sometimes the visual observations can miss deteriorated areas creating a potential safety hazard. A more robust method to determine these concrete delaminated areas will both increase safety and allow better use of limited staff and resources. Unmanned aerial vehicles (UAVs), or more popularly, “drones” are emerging as a practical and inexpensive alternative to traditional manual inspections. Although there is a significant push from FHWA through State DOT’s to explore effective use of UAVs, it has so far only been tested in a few states. Infrared thermal imaging (IR) is being successfully used to determine concrete delaminated areas on bridges. The FHWA Turner-Fairbanks Research Center is successfully using handheld IR on the top side of bridge decks. Iowa DOT has had success with high temperature hand held IR cameras on the underside of bridge decks. Despite some preliminary successes, several key gaps exist. First, despite a plethora of research going into different UAV-mounted imaging technologies and AI-based analysis of data, field studies in which the UAV condition assessment has been validated to actual bridge condition are limited. Second, UAV-based inspections of bridge undersides have been limited due to difficulties in maneuvering the UAV beneath the structure. This latter problem can be particularly acute in cases where deterioration leading to falling debris creates a hazard below the bridge. Finally, given the wide range of imaging technologies that can be applied to UAV-mounted systems (e.g. optical, infrared, lidar, GPR, etc.), which ones are best suited to identifying the types of deterioration likely to occur in different structures. The overall research objective is to focus on developing UAV-based inspection and analysis protocols using Infrared thermal imaging to determine concrete delaminations, with emphasis on the underside of bridge decks. In addition, other sensor technologies will be investigated should the IR technology not provide acceptable data and results.
03/01/20March 2020Local Recalibration of JPCP Performance Models and Pavement-ME Implementation Challenges in Michiganhttps://cptechcenter.org/ncc-projects/local-recalibration-of-jpcp-performance-models-and-pavement-me-implementation-challenges-in-michigan/Calibration, Computer models, Concrete pavements, Mechanistic-empirical pavement design, Pavement performance, Rigid pavements, Transverse crackingThe AASHTOWare Pavement Mechanistic-Empirical (ME) Design version 2.0 performance models were locally calibrated in 2014. Subsequently, the software was updated to versions 2.2 (2015) and 2.3 (2016) since the last calibration effort in Michigan. In the newer versions, several bugs were fixed, and some of the performance models were modified. As a result, concrete pavement designs were impacted. Thus, there is an urgent need to verify the performance predictions for rigid pavements in the State of Michigan for the Pavement-ME versions 2.2 and 2.3. Performance model predictions for rigid pavement between different versions were compared in order to highlight the changes in models. Also, this paper compares observed and predicted performance for testing the need for recalibration. The results show that performance models for rigid pavements [transverse cracking and international roughness index (IRI)] have changed since the Pavement-ME version 2.0. Recalibration is warranted because of model changes and additional time series availability. The recalibration of transverse cracking and IRI model reduced the standard error of estimate (SEE) and bias for both the models. Several challenges in the implementation of the Pavement-ME after recalibration were encountered. This paper documents the lessons learned while addressing these issues. For cumulative damage lower than 0.1, the predicted cracking levels are negligible. The local calibration model coefficients can be further improved by considering the project-specific permanent curl value. A model was developed to predict the permanent curl value for a location based on the site-specific climate and design properties.Haider, Syed Waqar; Musunuru, Gopikrishna; Buch, Neeraj; Brink, Wouter C
11/01/19November 2019New Procedure to Evaluate the Post-Crack Behavior of Fiber-Reinforced Concretehttps://cptechcenter.org/ncc-projects/new-procedure-to-evaluate-the-post-crack-behavior-of-fiber-reinforced-concrete/Cracking of concrete pavements, Fiber reinforced concrete, Methodology, Overlays (Pavements), Pavement performance, Residual strengthThis study attempted to identify the challenges in testing and characterization of the post-crack behavior of structural fiber-reinforced concrete (FRC) for use in pavements. The benefits and challenges associated with three different FRC testing methods, ASTM C1550, C1399, and C1609 were discussed and compared. Two new parameters, post-crack toughness, and post-crack performance (PCP) index were proposed to characterize the post-crack behavior of FRC. These parameters are a function of the fibers’ contribution and are minimally influenced by the properties of the non-fiber ingredients of concrete such as aggregates, cement, and water. A laboratory study conducted on 10 different types of FRCs validated the applicability of the two proposed new parameters. Transportation agencies can use the PCP index to shortlist effective fibers and post-crack toughness to determine fiber dosage. The study found that fibers with irregular cross-section or geometry and high lateral stiffness provide a high post-crack contribution.Bryce Hansen, Manik Burman
11/01/19November 2019A Framework Based on Engineering Performance and Sustainability to Assess the Use of New and Recycled Materials in Pavementshttps://cptechcenter.org/ncc-projects/a-framework-based-on-engineering-performance-and-sustainability-to-assess-the-use-of-new-and-recycled-materials-in-pavements/Pavement performance, Recycled materials, Structural engineering, Sustainable developmentGrowing need for increased use of recycled and new materials in road construction has emerged due to the continuous depletion of natural resources and increased impact of the current state of practice on the environment. Sustainable construction practices have been favoured by Federal and State Departments of Transportation as well as the industry. However, the impacts of using new and recycled materials in pavements, particularly on long-term pavement durability and performance, are often unknown. A comprehensive procedure for evaluating these “proposed materials” in terms of engineering performance and sustainability is very significant for making appropriate decisions on whether to use them for road construction. The research is performed based on whether the material is proposed to be used in asphalt, concrete, or in unbound layers. An analysis framework and, a software (called NewPave) was developed to help the Michigan Department of Transportation (MDOT) identify the impacts of new and recycled materials on pavement performance and the environment. The analysis framework included two basic components; (i) engineering performance, and (ii) sustainability. Engineering performance evaluation included several options for each material type to be used in different pavement layers. The sustainability analysis included three basic components; environmental, economic and social analyses. Finally, the scores obtained from the engineering evaluation are combined with those based on sustainability to obtain an overall score. The overall score can be used to accept/reject the trial use of the new and recycled materials in MDOT administered roads. While the framework presented herein was developed for MDOT, it can easily be adapted by other DOTs.Varma, Sudhir; Jamrah, Anas; Kutay, M Emin; Korkmaz, Kasim A; Haider, Syed W; Buch, Neeraj
04/30/21April 2021Solutions to Mitigate Dowel/Tie-Bar Propagated Cracking – Phase 1https://cptechcenter.org/ncc-projects/solutions-to-mitigate-dowel-tie-bar-propagated-cracking-phase-1/Concrete pavements, Delamination, Dowel, Dowels (Fasteners), Tie barsThe goal of this project is to identify the cause(s) and contributing factors of concrete pavement longitudinal and delamination cracking caused by dowel and/or tie-bars. This will be accomplished by reviewing existing literature and developing case studies of projects in NRRA member states exhibiting dowel and/or tie-bar related distresses. Based on the case studies, contractors will be responsible for proposing analytical and/or laboratory experiments that will enable the development of solutions that mitigate longitudinal and/or delamination cracking caused by dowel bar and/or tie-bar stresses.Shreenath Rao, Applied Research Associates
05/31/20May 2020Field Implementation of Compacted Concrete Pavementhttps://cptechcenter.org/ncc-projects/field-implementation-of-compacted-concrete-pavement/Compressive strength, Durability, Field tests, Flexural strength, Mechanical properties, Roller compacted concrete pavements, Shrinkage, Surface course (Pavements)The main objective of this research is to investigate the performance of Compacted Concrete Pavement (CCP) with special design features of surface texture that can reduce construction cost and secure safe and durable surface texture. This research was part of a larger project undertaken by the City of Mexico, Missouri in collaboration with Missouri Department of Transportation (MoDOT). The CCP mixture was evaluated for key fresh properties (unit weight, air content, and Vebe consistency), mechanical properties (compressive strength, flexural strength, and modulus of elasticity), drying shrinkage, and durability (air-void system, freeze thaw resistance, scaling resistance, bulk and surface resistivity). The results of this project aimed to add value to the current state of practice related to the use of CCP, synthesize current technical knowledge, study the potential problems associated with the use of CCP in pavement construction in Missouri, and propose guidelines for best practice related to CCP construction. Test results indicate the reliability of mechanical properties for the investigated CCP material. The compressive and flexural strengths and elastic modulus of the investigated concrete were approximately 4970 psi, 410 psi, and 4120 ksi for cast-in-field samples and 4470 psi, 450 psi, 3550 ksi for core samples, respectively. The drying shrinkage was limited to 60 με after 70 d of testing, indicating low drying shrinkage. The durability tests showed that the CCP mixture can be classified as a mixture with moderate chloride ion permeability and acceptable resistance to de-icing salt scaling. However, the non-air entrained CCP showed poor resistance to freezing and thawing.Kamal H. Khayat, Nima Farzadnia
03/31/23March 2023Evaluation of Thin Polymer Overlays for Bridge Deckshttps://cptechcenter.org/ncc-projects/evaluation-of-thin-polymer-overlays-for-bridge-decks/Bridge decks, Composite materials, Maintenance practices, Overlays (Pavements)Thin composite polymer overlays are a cost-effective method for extending the service life and serviceability of concrete bridge decks by filling concrete cracks and increasing skid resistance. The overlay is a thin (1/4 to 1/2 inch) layer of polymer that seals existing cracks and is embedded with aggregate for wear and skid resistance. The Montana Department of Transportation (MDT) has recently observed varying performance of two different polymer overlay systems applied to four different bridge decks across the state. This research proposes to assess the performance of thin polymer overlays on concrete bridge decks in Montana. The project includes a literature review, a review of the polymer systems on MDT’s qualified product list and recent skid resistance data for two of these materials. The project also includes the implementation of an expanded and focused field investigation to measure skid resistance and durability of selected polymer systems. The anticipated product of this research will be an updated process for selecting and utilizing thin polymer overlays to increase the service life of bridge decks in Montana.Paul Krauss
06/03/20June 2020Feasibility of Non-Proprietary Ultra-High Performance Concrete (UHPC) for Use in Highway Bridges in Montana: Implementationhttps://cptechcenter.org/ncc-projects/feasibility-of-non-proprietary-ultra-high-performance-concrete-uhpc-for-use-in-highway-bridges-in-montana-implementation/Admixtures, Bridge construction, Bridges, Building materials, Concrete bridges, High performance concrete, Highway bridges, Materials tests, Ultra high performance concrete (UHPC)Ultra-high performance concrete (UHPC) has mechanical and durability properties that far exceed those of conventional concrete. However, using UHPC in conventional concrete applications has been cost prohibitive, with commercially available/proprietary mixes costing approximately 30 times more than conventional concrete. Previous research conducted at Montana State University (MSU) has focused on the development and evaluation of non-proprietary UHPC mixes made with materials readily available in Montana. These mixes are significantly less expensive than commercially available UHPC mixes, thus opening the door for their use in construction projects in the state. The focus of the proposed project is on taking this material beyond the laboratory, and successfully use it on a bridge project in Montana, specifically for field cast joints. This project is a required step to fully understand and capitalize on the benefits of using UHPC for this application and increase the performance, durability, and efficiency of Montana bridges.
07/31/21July 2021Fiber Reinforcement for Latex-Modified Concrete Overlayshttps://cptechcenter.org/ncc-projects/fiber-reinforcement-for-latex-modified-concrete-overlays/Bridge decks, Concrete overlays, Cracking, Fiber reinforced concrete (FRC), Latex modified concrete, Rehabilitation (Maintenance), ShrinkageA large number of bridge deck rehabilitations are performed each year in North Carolina. Latex Modified Concrete (LMC) and LMC–Very Early Strength (LMC-VES) are frequently used in these rehabilitations because these materials provide reasonable installed performance and allow for a rapid return to service. Over the last 5 years, the North Carolina Department of Transportation (NCDOT) has completed an average of about 25 overlays per year using LMC or LMC-VES materials. The vast majority of these projects are highly successful. However, despite comprehensive NCDOT guidelines and specifications (such as PSP003 and PSP004), substantial cracking is sometimes observed in these overlays shortly after installation. Prior research funded by NCDOT has indicated that if placement and curing follows proper construction procedures, then the primary causes of cracking (such as shrinkage and plastic shrinkage) in LMC and LMC-VES materials are unlikely to develop. However, other secondary mechanisms can potentially cause cracking, including vibration of the structure during casting and curing, temperature changes during casting, and slight differential settlement/deflection of supporting decks as overlay placement progresses across a bridge. Gregory Lucier, Mohammad Pour-Ghaz
03/01/17March 2017Control of Concrete Cracking in Bridgeshttps://cptechcenter.org/ncc-projects/control-of-concrete-cracking-in-bridges/Bridge substructures, Bridge superstructures, Concrete bridges, CrackingThe primary objectives of this synthesis are to provide a compilation and discussion of methods used to control concrete cracking in bridge superstructures and substructures and to present information on the influence of cracking on long-term durability. Superstructure components discussed in this synthesis include full-depth, cast-in-place concrete decks; partial-depth, precast concrete panels with a cast-in-place topping; full-depth, precast concrete deck panels; and prestressed and nonprestressed concrete beams. Information for concrete decks on both steel and concrete beams is included. Substructure components include pier caps, columns, abutments, and pile caps.Henry G Russell
11/12/17November 2017Performance-Related Specifications for Pavement Preservation Treatmentshttps://cptechcenter.org/ncc-projects/performance-related-specifications-for-pavement-preservation-treatments/Flexible pavements, Guidelines, Pavement maintenance, Performance based specifications, Rigid pavementsThis report (1) presents guidelines for use in preparing performance-related specifications (PRS) for pavement preservation treatments and, if desired, determining pay adjustment factors and (2) illustrates the applicability of these guidelines for selected preservation treatments for flexible and rigid pavements. The guidelines follow a systematic process that considers acceptance quality characteristics and performance measures for preservation treatments. The information contained in the report will be of immediate interest to state materials and maintenance engineers and others involved with the specification and quality aspects of pavement preservation treatments.Karim Chatti
03/05/22March 2022Guide for Implementing Performance Specificationshttps://cptechcenter.org/ncc-projects/guide-for-implementing-performance-specifications/Asphalt mixtures, Concrete, Guidelines, Impacts, Implementation, Performance measurement, Quality assurance (QA), Specifications, Test proceduresMany state departments of transportation (DOTs) are implementing performance specifications for asphalt pavements and portland/alternative cement concrete. This is being done to improve long-term durability, encourage contractor innovation, better align design requirements with construction, and introduce rational pay adjustments tied to predicted project life. Ongoing initiatives such as Performance Engineered Concrete Mixes for portland/alternative cement concrete and Balanced Mix Designs for asphalt pavements lend themselves to a performance specification approach by introducing higher level test methods more directly related to material performance. Introduction of these test methods and mix design criteria will have a major impact on existing quality assurance (QA) programs. Agencies will need to make informed decisions regarding applicability of new tests to process control, quality control, and acceptance. Lot and sublot sizes may need to be adjusted to account for test time and complexity. Quantity of material obtained for testing may need to be increased. Technician training and certification programs will need to be addressed, as will laboratory qualification and accreditation programs. Independent Assurance (IA) procedures will need to be developed and the impact on dispute resolution programs assessed. Precision and bias of the newer test methods will need to be determined, along with appropriate specification limits for various quality characteristics. New approaches to pay adjustments will need to be developed.Shreenath Rao
12/31/22December 2022Manual for Incorporating Nondestructive Testing (NDT) in Quality Assurance of Highway Pavement Constructionhttps://cptechcenter.org/ncc-projects/manual-for-incorporating-nondestructive-testing-ndt-in-quality-assurance-of-highway-pavement-construction/Asphalt based materials, Concrete, Handbooks, Implementation, Nondestructive tests (NDT), Paving, Quality assurance (QA), Quality control, Road construction, State departments of transportation, State of the practiceState departments of transportation (DOTs), as part of their routine practice, employ quality assurance (QA) procedures based on certifications, inspections, sampling, and testing in their acceptance process for highway pavement construction. The QA requirements are generally in accordance with the federal regulations for construction QA procedures (23 CFR, Part 637B) as well as the recommendations of the Federal Highway Administration (FHWA) and the American Association of State Highway and Transportation Officials (AASHTO) for QA programs. However, one thing generally absent from these programs or plans is the utilization of nondestructive testing (NDT) methods in the QA process. Several studies in recent years have identified the potential advantages of incorporating NDT methods into the QA process for highway pavement construction. These NDT methods are considered to provide an “added value” in the QA process since they potentially allow for (1) quickly assessing product uniformity in real-time as construction progresses; (2) identifying potential defects during construction to allow for timely corrective actions; (3) more frequent inspecting, testing, and replicating without the damaging effects of coring and other destructive testing; and (4) minimizing testing and inspection costs, while improving construction quality. For example, for concrete, the NDT methods can evaluate concrete properties, uniformity, honeycombing, segregation, and cover depth as well as detect reinforcement and dowel bar location and characteristics. Similarly, for asphalt mixtures, the NDT methods can assess properties and conditions such as density, stiffness, thickness, and thermal uniformity. However, despite their high potential and usefulness, the transition of NDT methods from research and forensic investigation to DOTs’ QA process has been rather limited. This is because of the relative complexity of some NDT technologies, inadequate training of QA technicians and inspectors in their use, reluctance to adopt a new technology, and a lack of guidance on how to incorporate the NDT technologies into the overall QA program. The objective of this research is to develop a guidance manual to assist state DOTs in selecting and incorporating NDT methods into their QA programs for highway pavement construction.Harold Von Quintos
05/19/20May 20203D Modeling Guide for Construction Inspectionhttps://cptechcenter.org/ncc-projects/3d-modeling-guide-for-construction-inspection/Building information models (BIM), Construction projects, Inspection, State departments of transportation, Three dimensional displaysVarious advanced technologies have been adopted in the transportation industry to improve the accuracy and efficiency in design and construction, including global positioning system (GPS), LiDAR, and 3D/4D modeling. Transportation design and construction processes have been gradually improved with the emergence of these technologies. Many state DOTs and their contractors and consultants have been using 3D models for various applications in project planning, design and construction phases. The design and survey communities are advancing 3D/4D modeling and design (also referred to as Building Information Modeling (BIM) for infrastructure). The specific goals vary by state; however, the common goal is to eliminate 2D plan sets and make the 3D model the design of record. Construction contractors have been utilizing 3D models to increase their efficiencies utilizing Automated Machine Guidance (AMG) and developing BIMs for applications such as bridge beam erection plans and crane optimization. However, field Inspection staff have very limited exposure to this technology, and inspection processes and procedures using 3D/4D BIM have yet to be developed on a national level. Some states who are piloting 3D modeling generally have 2D plans still available. Eventually 2D plans will be eliminated as a deliverable so guidance and training for field inspectors is needed. Design models contain more data than is represented by 2D plan sheets. Conveying the model to field engineers and inspectors presents an opportunity to leverage this data in the inspection process. However, there is little research into how the exposure to this data, when combined with new technology, can make inspection more efficient or more complete. The objective of this research is to identify technologies used by DOTs, inspectors in the vertical construction sector (i.e. BIM), or other technologies available that allow element location and dimension information from the model to be viewed, modified, or otherwise consumed by inspection staff. The research should identify the pros and cons of each and explore opportunities for inspectors to use data from the model rather than snapshots of the design plans. Managers, engineers, and field inspection staff from Departments of Transportation will benefit from this research, as it will identify potential technologies that may be used by field staff inspection staff, to leverage advancing technologies being used by designers and contractors.
05/01/20May 2020Agency Inspection and Monitoring of Quality Control Plans for Use in Administering Quality Assurance Specificationshttps://cptechcenter.org/ncc-projects/agency-inspection-and-monitoring-of-quality-control-plans-for-use-in-administering-quality-assurance-specifications/Construction projects, Contractors, Inspection, Literature reviews, Quality assurance (QA), Quality control (QC), State departments of transportation, SurveysModern quality assurance (QA) specifications promoted by the Federal Highway Administration (FHWA) recognize the state departments of transportation’s (DOT’s) responsibility for monitoring the contractor’s quality control (QC) activities, conducting agency inspection, and conducting acceptance sampling and testing. Research and training focused on acceptance sampling and testing is currently available, and national, regional, and state certification programs have been developed to support this effort. Research and training on monitoring the contractor’s QA/QC and appropriate methods of DOT inspection are more limited. QA/QC plans are usually written by contractors and approved by DOTs, based on DOT requirements and specifications. Well-developed, proactive QA/QC plans should be used to solve problems, but often they are boilerplate or are developed only to be used to meet agency QA/QC specification requirements. Based on the historical quality of QA/QC plans submitted, some DOTs have even stopped requiring QA/QC plans to be submitted. Research has confirmed the importance of QA/QC and inspection in transportation projects, and further research is needed in the areas of contractor QA/QC, including adequate level of inspection. The objective of this synthesis is to document the various QA/QC plans and manuals used by DOTs and how QA/QC plans are reviewed and inspected to achieve project specifications. Information gathered includes (but is not limited to): QA/QC plans and manuals used by DOTs; input of DOTs into QA/QC plans; requirements of contractors regarding QA/QC plans; DOT compliance review and inspection of QA/QC plans; DOT monitoring of contractor implementation of QA/QC plans; and incentives that DOTs are using to achieve effective QA/QC. Information will be collected through literature review, a survey of DOTs, and follow-up interviews with selected agencies for the development of case examples. Information gaps and suggestions for research to address those gaps will be identified.
05/20/20May 2020Develop a Guidebook for the Use of Non-Chemical Methods for Removing Snow and Ice from Roadwayshttps://cptechcenter.org/ncc-projects/develop-a-guidebook-for-the-use-of-non-chemical-methods-for-removing-snow-and-ice-from-roadways/Handbooks, Literature reviews, Maintenance equipment, Snow and ice control, State of the practice, Winter maintenanceThe FHWA compiled statistics that showed that during the 10-year period 2005-2014 approximately 321,000 vehicle crashes per year were attributed to icy or snow-covered roads. These same statistics showed 5,650 fatalities per year were attributed to adverse weather. This is approximately 10 times more fatalities than all the other adverse weather fatalities tracked by the National Weather Service. While participation fluctuates from year to year, 44 state DOTs and one Canadian Province rely on AASHTO’s SICOP Technical Service Program, the Clear Roads, and/or Aurora Pooled Fund Studies to help them fulfill their winter maintenance mission. This clearly demonstrates the impact winter weather has on the transportation network across North America. Road maintenance agencies employ a variety of strategies to maintain safe, passable roadways during wintertime weather events. In general, these strategies can be categorized into those that rely on the use of chemicals (primarily sodium chloride --salt) and non-chemical-based strategies utilizing mechanical means (e.g., brooming, plowing, scraping, or mechanical ice breaking). The reliance on deicing chemicals alone has presented issues for agencies as some salt supplies are becoming irregular with some agencies not able to secure sufficient quantities and the resulting increases in salt prices adversely affecting state wintertime budgets.
05/19/20May 2020Rumble and Mumble Strip Preservation Treatment Optionshttps://cptechcenter.org/ncc-projects/rumble-and-mumble-strip-preservation-treatment-options/Overlays (Pavements), Pavement maintenance, Road markings, Rumble strips, Sealing compounds, ThicknessCenterline and shoulder rumble and mumble strips have long served as a safety treatment tool to alert motorists to realign their vehicles to the driving lane. As part of the 2018 Midwest and Southeast Pavement Preservation Research Survey, rumble strip preservation was identified a research need. Many rumble and rumble strips are installed as part of contract overlay projects where pavement thicknesses can be as thin as 1 inch. Rumbles are then ground into the new overlay effectively reducing the thickness in the grounded areas to ½” or less. In addition as a result the ground pavement area making up the rumble strip generally displays premature deterioration and requires ongoing maintenance to keep the roadway free of pot holes. The purpose of this research is five fold: (1) Threshold for minimum thickness of pavement or pavement overlay for rumble and mumble strips to be milled; (2) Threshold for the age of pavement or pavement overlay for rumble and mumble strips to be milled; (3) Effects of preservation strategies on pavement markings that are maintained or preserved on rumble and mumble strips; (4) Effects of sealers, rejuvenators and other preservation strategies on the performance of rumble and mumble strips; and (5) Strategies to maintain and preserve rumble and mumble strips to meet the design life of the pavement or pavement overlay. Much of the research done on the topic references the performance of rumble strips on how they perform their function in keeping motorists in their driving lane. More research is needed to determine the effects of rumble strips on older pavements and thin lift pavement overlays and offer solutions to owner agencies on how to maintain and preserve them for the life of the pavement. The objective of this research is to develop a guide to maintain and preserve rumble and mumble strips that last as long as the main line pavement where they were installed.
07/01/19July 2019Evaluation of Material Input Levels on Design of Unbonded Concrete Overlay Using Pavement Mechanistic-Empirical Designhttps://cptechcenter.org/ncc-projects/evaluation-of-material-input-levels-on-design-of-unbonded-concrete-overlay-using-pavement-mechanistic-empirical-design/Compressive strength, Concrete overlays, Mechanical properties, Mechanistic-empirical pavement design, Pavement performance, Stiffness, Strength of materials, Transverse crackingUnbonded concrete overlay (UBCO) is the most widely used rehabilitation option being used as compared to other types of overlays based on its long-term performance, minimal pre-overlay repairs, and relatively easier construction. The implementation of latest pavement performance prediction tools such as the Pavement ME Design [previously called AASHTOware Pavement Mechanistic Empirical (ME) Design guide or MEPDG] has provided the opportunity for designing and performance analysis of UBCOs. The levels of design inputs, for concrete mechanical properties, range from time series data (time series means tested data from 7 to 90 days) of elastic modulus (Ec) and modulus of rupture (MOR) to 28-day compressive strength. This study focuses on evaluating the impact of design input levels for concrete strength and stiffness properties on performance predictions of UBCO using Pavement ME Design. Previous studies have shown that concrete strength properties including compressive strength, Ec, and MOR have significant effects on UBCO performance. The effects of these input levels on predicted faulting and transverse cracking are evaluated for three different paving mixes. The results show that the combination of measured 28-day MOR and Ec yielded predicted distresses that were consistently in close agreement with the predictions using time series data. It became evident that accurate 28-day MOR and Ec values can be used as a less challenging and less expensive alternative to the time series characterization of concrete mechanical properties for UBCO design and performance evaluation.Gauhar Sabih, Rafiqul Tarefdar
05/31/22May 2022Rapid Concrete Bridge Repair Survey and Patch Material Evaluationhttps://cptechcenter.org/ncc-projects/rapid-concrete-bridge-repair-survey-and-patch-material-evaluation/Concrete bridges, Evaluation and assessment, Heat of hydration, Patching, Portland cement concrete, Repairing, Setting (Concrete), SurveysTracking the heat of hydration (HoH) of Portland cement concrete has become a widely used and viable technique to characterize cement mixtures hydration behavior for cement producers, practicing engineers, and contractors (ASTM C1679). The Nebraska Department of Transportation (NDOT) is interested in gaining background knowledge on the HoH generated from local cements at different ambient temperatures. This information will be primarily beneficial for troubleshooting field concrete setting issues thereby improving support for Portland cement concrete contractors and ultimately improving project quality. Isothermal calorimetry (IC) has become the method of choice for characterizing cement set and hydration behavior due to its reliability and relatively easy data collection.Marc Maguire, Jiong Hu
05/23/22May 2022UHPC Thin Bonded Overlay on Deteriorated Bridge Deckshttps://cptechcenter.org/ncc-projects/uhpc-thin-bonded-overlay-on-deteriorated-bridge-decks/Bridge decks, Bridge design, Bridge engineering, Ultra high performance concrete (UHPC)Previous research has demonstrated that ultra-high performance concrete (UHPC) has the potential to increase service lives of bridge deck overlays and subsequently, the underlying concrete deck, because it has exceptional durability properties and contains silica fume that facilitates bond to substrate concretes. This research project will document, monitor, and assess the field implementation of a UHPC overlay produced with local materials on a bridge in Socorro, NM. This will be the first non-proprietary UHPC overlay constructed in the United States. The research project consists of a comprehensive literature review to identify best practices for UHPC technologies and overlay construction methods. Short and long-term monitoring plans will be developed for assessing the performance of the constructed UHPC overlay. After construction, the short and long-term monitoring plans that will include mechanical, physical, and nondestructive testing shall be initiated and the assessment of the initial measurements shall be reported in the final research report.Brad Weldon, David Jauregui, Craig Newtson
06/04/19June 2019Artificial Neural Networks for Predicting the Response of Unbonded Concrete Overlays in a Faulting Prediction Modelhttps://cptechcenter.org/ncc-projects/artificial-neural-networks-for-predicting-the-response-of-unbonded-concrete-overlays-in-a-faulting-prediction-model/Composite pavements, Concrete overlays, Concrete pavements, Fault location, Neural networks, Pavement distress, Structural analysis, Transverse jointsTransverse joint faulting is a common distress in unbonded concrete overlays (UBOLs). However, the current faulting model in Pavement mechanistic-empirical (ME) is not suitable for accurately predicting the response of UBOLs. Therefore, to develop a more accurate faulting prediction model for UBOLs, the first step was to develop a predictive model that would be able to predict the response (deflections) of these structures. To account for the conditions unique to UBOLs, a computational model was developed using the pavement-specific finite element program ISLAB, to predict the response of these structures. The model was validated using falling weight deflectometer (FWD) data from existing field sections at the Minnesota Road Research Facility (MnROAD) as well as sections in Michigan. A factorial design was performed using ISLAB to efficiently populate a database of fictitious UBOLs and their responses.John DeSantis, Julie Vandenbossche, Steven Sachs
03/30/20March 2020Time-Lapse Infrared Thermography Applied to Concrete Bridge Deck Inspection Surveyshttps://cptechcenter.org/ncc-projects/time-lapse-infrared-thermography-applied-to-concrete-bridge-deck-inspection-surveys/Bridge decks, Concrete bridges, Condition surveys, Data analysis, Data collection, Delamination, Infrared analysis, Inspection, Overlays (Pavements), ThermographsThe Federal Highway Administration mandates that all [bridge] structures in its inventory are to be inspected every two years. Consequently, deck surveys are conducted to identify unseen damage within them. A significant number of bridges in Virginia have concrete decks with an overlay. Methods commonly deployed on these decks, are limited in the quantitative results they can provide. To overcome these limitations, an improved method of applying infrared thermography using time-lapse technology is introduced. Following a simulated parametric study, a time-lapse infrared thermography data collection system was acquired along with a basic program to analyze the data qualitatively. A novel physics-based program was also developed to analyze the data quantitatively. The system is ready to be deployed on most bridges, offering a full-field non-contact survey of the entire deck with minimal impact to traffic flow. However, it is recommended that the quantitative program undergo additional testing prior to production level deployment.Steven B. Chase and Chad M. Anderson
01/01/20January 2020Nondestructive Corrosion Evaluation of Reinforced Concrete Bridge Decks with Overlays: An Experimental Studyhttps://cptechcenter.org/ncc-projects/nondestructive-corrosion-evaluation-of-reinforced-concrete-bridge-decks-with-overlays-an-experimental-study/Bridge decks, Concrete, Corrosion, Nondestructive tests (NDT), Overlays (Pavements), Reinforcement (Engineering)Concrete corrosion induced by deicing agents can decrease the durability of concrete bridge decks by causing cross-sectional loss of reinforcement, concrete delamination, and spalling owing to the expansion of corroded reinforcement. The installation of overlays can extend the service life of the deteriorated decks. However, overlays present challenges in the evaluation of the corrosion condition of the underlying decks. This laboratory study employed three nondestructive testing (NDT) methods to assess the effects of seven types of overlays on corrosion evaluation for concrete bridge decks. The NDT methods were electrical resistivity (ER), ground-penetrating radar (GPR), and half-cell potential (HCP). The ER method could not evaluate the corrosive environment in the concrete decks through the overlays. The GPR method could detect the corrosive environment through four of the seven overlays. The HCP method could detect the decrease of electrical potential over the actively corroded reinforcement for all seven specimens; however, only two of the seven specimens could be identified as having active corrosion per ASTM C876-15, Standard Test Method for Corrosion Potentials of Uncoated Reinforcing Steel in Concrete. Overlay debonding did not affect GPR and HCP testing results in this study.Dewei Meng, Shibin Lin, and Hoda Azari
05/01/20May 2020Field Performance of Low-Cracking Concretes for the Closure Pours and Overlays of Bridge Deckshttps://cptechcenter.org/ncc-projects/field-performance-of-low-cracking-concretes-for-the-closure-pours-and-overlays-of-bridge-decks/Bridge decks, Compressive strength, Concrete overlays, Fiber reinforced concrete (FRC), Field tests, Lightweight aggregates, Polypropylene, Silica fume, Steel fibersJoints, wide cracks, and poor quality concretes facilitate the intrusion of chlorides, causing corrosion in bridge decks and substructures that limit the service lives. Distress in deck concretes can adversely affect ride quality and structural integrity. The objective of this study was to eliminate the joints in existing bridges and to improve the surface conditions of the decks by overlays. Two parallel bridges in Virginia were selected for study. The performance of the closure pours and overlays was observed for 4–5?years. Joints were replaced with closure pours (also known as link slabs) consisting of fiber-reinforced concretes resistant to wide cracking and intrusion of solutions. Polyvinyl alcohol, polypropylene, and steel fibers were used in the closure pours; a compressive strength of 3,000?psi (pounds per square inch) at 24?h was sought. In the overlays, silica fume concrete alone and with shrinkage reducing admixture, lightweight coarse aggregate, and lightweight fine aggregate was investigated for crack control and low permeability, and compared with the control of latex-modified concrete with rapid set cement. A compressive strength of 3,000?psi at 3?days was sought. Test results and surveys showed that satisfactory strengths and permeability were achieved; the closure pours containing steel and polyvinyl alcohol fibers had tight cracks (most less than 0.1?mm with a few up to 0.2?mm). All overlays were performing well except for one section placed in adverse weather conditions and exposed to a truck fire. There were a few areas patched where poor surface preparation had led to delamination.Ozyildirim, H. Celik; Nair, Harikrishnan; and Sharifi, Mary
08/31/24August 2024Concrete Mix Designs for Partial-Depth Link Slabs and Deck Extensionhttps://cptechcenter.org/ncc-projects/concrete-mix-designs-for-partial-depth-link-slabs-and-deck-extensionAdmixtures, Bridge construction, Bridge decks, Concrete bridges, Joints (Engineering), Mix designOne of the main factors affecting the durability of bridge structures is the presence of joints in the deck. The inability of current joint systems to provide reliable, long-term, leak-proof performance leads to the infiltration of harmful solutions and to rapid deterioration of the ends of beams, bearings, and substructures, which require major maintenance efforts. To address this issue, the idea of using full-depth link slabs to eliminate existing deck joints has been investigated. This joint type is expected to extend the service life of conventional bridges. However, these full-depth link slabs are often times not feasible on high-traffic bridges because of the length of time for construction. However, partial-depth link slabs are a possible alternate solution because they offer the advantages of shorter construction durations, thus minimizing traffic interruptions, and lower construction costs compared to full-depth link slabs. Regardless, link slabs require concrete with high early strength, flexibility, and durability for rapid installation and longevity. In this study, concrete mixtures including fibers for flexibility and high tensile strength will be investigated and used in partial-depth link slabs. The performance of the link slabs will be monitored for a period of at least one year.Celik Ozyildirim, Bernie Kassner, Mary Sharifi
10/31/21October 2021A New Method of Determining Payment for In-Place Concrete with Double-Bounded Compressive Strength Pay Factorshttps://cptechcenter.org/ncc-projects/a-new-method-of-determining-payment-for-in-place-concrete-with-double-bounded-compressive-strength-pay-factors/Cast in place concrete, Compressive strength, Construction projects, Incentives, Methodology, Payment, SimulationThe Vermont Agency of Transportation (VTrans) currently uses a lower acceptance limit on 28-day concrete compressive strength (CCS) of 4,000 psi for acceptance of in-place concrete in its construction projects. Over time, to mitigate risk, the concrete industry’s response has led to increasingly higher average 28-day CCS, which is believed to be associated with increased brittleness and excessive early cracking. UVM researchers worked with VTrans’ Materials Testing & Certification Lab to develop a set of initial pay factors for a new double-bounded system with an upper limit as well. The scenario-based heuristic approach balances Agency risk with industry risk in the use of payment incentives and disincentives. Several likely scenarios for an initial industry response to new pay factors were simulated. The success of that research effort, and ensuing meetings with leading industry representatives, led VTrans to the decision to implement this double-bounded approach, tentatively beginning in the Spring of 2020. Pay factors are typically enforced for payment using the percent-within-limits (PWL) approach, but a drawback of the traditional PWL approach is its implicit assumption that the distribution of CCS is Gaussian so that z-scores can be used for assessment of payment, and that payment for strengths exceeding the target mean equal those falling short of the target mean by the same amount. Although this approach works well when a single lower acceptance boundary exists, it will not be likely to work when an upper and lower acceptance boundary are used, since pay factors are not likely to be identical above and below the target value. Additionally, the research team’s review of the literature and historical data in Vermont suggests that the distribution of resulting industry-wide CCS is not likely to be best-fit to a Gaussian probability distribution function (PDF) once the double-bounded system is implemented. The goal of this project is to develop a new method of enforcing pay factors for payment of in-place CCS that does not rely on the Gaussian distribution and allows for the use of an asymmetrical set of pay factors.James Sullivan, David Novak, Eric Hernandez
10/31/19October 2019Calibrating the Iowa Pore Index with Mercury Intrusion Porosimetry and Petrography—Phase IIhttps://cptechcenter.org/ncc-projects/calibrating-the-iowa-pore-index-with-mercury-intrusion-porosimetry-and-petrography-phase-ii/Coarse aggregates, Concrete, pore index, pore struture, Portland cement concreteCoarse aggregate, depending on intended usage, constitutes roughly 20–45% of portland cement concrete as well as being a major component in the construction of granular surface roads and shoulders for paved roads. However, coarse aggregate quality greatly varies among sources based on its petrophysical properties. Therefore, it is important to understand how these properties emerge from the depositional and diagenetic history of a deposit in order to accurately predict pavement durability, which can be negatively impacted by oscillating freeze/thaw cycles. To derive more information about a coarse aggregate’s pore system, this study used a “third generation” Iowa Pore Index (IPI) device capable of measuring the volume of intruded water at various time intervals ranging from 0.1–2.0 seconds, as well as measuring intrusion at variable pressures up to 70 psi (480 kPa). Using this new device, 21 carbonate samples (10 dolostones and 11 limestones) were compared to “traditional” IPI measurements. The new method gave slightly higher primary loads.Joseph F. Orso IV , Fransciszek Hasiuk
01/19/22January 2022Developing Design Specifications to Ensure Long-Life Skid-Resistant Concrete Pavementshttps://cptechcenter.org/ncc-projects/developing-design-specifications-to-ensure-long-life-skid-resistant-concrete-pavements/Concrete, Design, Skid resistance, SpecificationsWith the goal of developing design specifications for durable skid-resistant concrete pavements, this project explores concrete mixture design factors that most significantly impact the retention of skid resistance in concrete pavements. Specifically, the objectives are twofold: 1. To determine how aggregate composition and properties, aggregate blending, aggregate gradation, concrete mixture proportions and properties (e.g., compressive strength), and concrete curing impact the long-term polishing resistant (PR) of concrete pavements; 2. To develop specification limits for the above-mentioned parameters to produce a long term polish-resistant concrete wearing surface while complying with specifications for performance engineered concrete pavements with optimized aggregate gradation.
12/31/20December 2020Effects of High Early Strength Concrete Thermal Contraction, Shrinkage, and Creep on Pavement Performancehttps://cptechcenter.org/ncc-projects/effects-of-high-early-strength-concrete-thermal-contraction-shrinkage-and-creep-on-pavement-performance/Concrete overlays, Contraction (Thermodynamics), Creep, High early strength cement, Laboratory tests, Mix design, Pavement cracking, Pavement performance, Rehabilitation (Maintenance), Shrinkage, Tensile strength, Test tracksThis research is focused on the development of recommendations and guidance on the use of thin bonded concrete overlay of asphalt (BCOA) as a rehabilitation alternative for California based on the adoption of, and improvements to, the technology developed in other US states. The main tasks of this research include: (1) laboratory testing of four rapid-strength concrete mixes and a number of concrete-asphalt interfaces, (2) evaluation of the construction of a full-scale test track, (3) monitoring of the structural and hygrothermal responses of thin BCOA sections to the ambient environment, (4) accelerated pavement testing with the Heavy Vehicle Simulator (HVS) on eleven thin BCOA sections, (5) characterization of CTE variability under different humidity conditions, (6) understanding of tensile creep in concrete slabs, (7) characterization of micro-cracking in different high-early strength concrete mixes. Based on this testing and analysis, it was possible to obtain a better understanding of the mechanics of the structure of thin BCOA and of the roles of the different factors that determine thin BCOA performance.Julio Paniagua
01/01/20January 2020Influence of Casting Conditions on Durability and Structural Performance of HPC-AR: Changes in Workability and Air-Void System of Concrete due to Pumpinghttps://cptechcenter.org/ncc-projects/influence-of-casting-conditions-on-durability-and-structural-performance-of-hpc-ar-changes-in-workability-and-air-void-system-of-concrete-due-to-pumping/Air voids, Bridge decks, Casting, Concrete pavements, Durability, Pumped concrete, Self compacting concrete (SCC), WorkabilityThis report summarizes the research performed on the influence of pumping operations on the changes in workability, rheology, air content, air-void system, freeze-thaw and scaling resistance of self-consolidating concrete (SCC). This project is a collaboration between the RE-CAST Tier-1 UTC the ACI Foundation, the Kansas State University (through funding from the Kansas DOT), EllisDon and CBM St-Marys. A portion of the results are summarized in the K-DOT report based on a research project on the effect of pumping on properties of low-slump concrete mixtures for bridge decks, as well as a paper in Materials and Structures. This report discusses the continuation of the research work, as some dramatic results were observed especially for SCC. When pumping concrete, a portion of the material is subjected to very high shear rates, and the lower the yield stress, the larger the concrete volume in the pipe which is exposed to shear. Shearing can cause substantial changes in rheology and workability, while a combination of pressure and shearing can induce major changes in the air-void system. Figure 1 shows the change in spacing factor, which is the difference between the spacing factor of the pumped and non-pumped concrete, due to the pumping process. These results were obtained in an experimental campaign with EllisDon and CBM-St-Marys in Toronto, ON, Canada in May 2015. No major changes were imposed on the different SCC mix designs, apart from the workability level. Figure 1 shows that the spacing factor increases more with a faster flow rate, due to the increase in applied pressure and in shearing. The use of a reducer (triangles), also increases the change in spacing factor, due to the same reasons. It should also be mentioned that one of the tests when using a reducer caused segregation of the SCC. However, the most striking results are the magnitude of those changes: the spacing factor increased with values between 250 and 550 μm, significantly above the acceptable limits. Normal concrete shows changes up to 100-150 μm, making SCC more sensitive. This is why further investigation on SCC is necessary.Dimitri Feys, Kyle Riding, Daniel Galvez Moreno, Alexis Salinas, Alexandra Wehar
01/01/20January 2020Investigation on Thixotropy of Vibration-Free Concrete Mixtures Intended for Rapid Pavement Construction (Volume II)https://cptechcenter.org/ncc-projects/volume-ii-investigation-on-thixotropy-of-vibration-free-concrete-mixtures-intended-for-rapid-pavement-construction/Admixtures, Concrete pavements, Paving, ThixotropyThis report discusses the advances and setbacks encountered when attempting to develop a vibration-free, self- consolidating concrete for slipform applications. Such concrete would have significant advantages compared to conventional slipforming, as vibration would not be necessary. All negative aspects of incorrect vibration, such as inadequate air content (too much entrapped air or insufficient entrained air), and segregation, which on its turn could lead to inferior freeze-thaw and scaling resistance or cracking, would be avoided [1] [2] [3] [4]. Based on previous work [5] [6], further referenced in the literature review, the research team wanted to attain a higher slump flow (> 550 mm) to ensure full self-consolidation, while also showing substantial thixotropy to develop the necessary shape stability. Current techniques in the development of 3D printing, which require similar properties of the construction material, use different chemical admixtures added at specific times when necessary. As an example, some mixtures are heavily retarded, and a large amount of accelerator is added just before the material passes through the nozzle [7] [8]. Although this technique would be certainly applicable for slipforming, it is questionable whether this can be executed on a large scale such as slipforming. Any mistakes in timing or dosage of the admixtures, or inadequate incorporation or distribution of the admixtures in the concrete would result in disastrous increases in cost as the concrete would remain too fluid or harden too soon, dependent on the error. As such, the team has chosen to pursue an approach in which intervening on the jobsite would be kept to a minimum in order to avoid those errors. In this report, a literature review is made on previous work on this topic, as well as a revision of how constituent materials influence thixotropy. Some basic concepts from physics and chemistry are also highlighted as they are applicable to this work. The material properties, mix designs and testing protocols are described in section 3, while the results for cement paste and concrete are discussed in sections 4 and 5, respectively. Section 6 concludes this report.Dimitri Feys, Piyush Rajendra Lunkad
01/01/20January 2020Development of Rapid Pavement Repair Materialshttps://cptechcenter.org/ncc-projects/development-of-rapid-pavement-repair-materials/Bond strength (Materials), Concrete pavements, Curing agents, Lightweight aggregates, Paving materials, Recycled materials, RepairingBeing that pavement repair and construction represents a significant percentage of federal and state funding, new materials are being investigated to reduce cost and generate a more resilient material. The goal of the project is to develop cost-effective, high performance concrete materials for rapid pavement repair minimizing environmental impact. Experimental study was conducted to investigate sustainable concrete with recycled concrete aggregate (RCA), lightweight aggregate (LWA), and other materials to be used in rapid full-depth repair. To minimize cracking at early age, internal curing (IC) was adapted with RCA and LWA. RCA and LWA is a viable and practical way of producing rapid repair concrete with less drying shrinkage. 10% replacement of silica fume was found to improve performance as necessary as introducing pre-soaked aggregates increases moisture affecting hydration of concrete specimen and decrease drying shrinkage. Further investigation on the materials and techniques together by conducting test trials consisting of fully and partially adding wet and nonwet RCA and LWA, is studied to satisfy the sustainable aspect of the research as a viable method for today’s standards. The Vibration-free concrete (VFC) mixtures provided by Dr. Feys in Missouri University S&T were modified to study the applicability in rapid pavement repair. The modified mixtures were used to study the effects of four different curing conditions (ambient, heat blanket, heat fan, and oven) and the results are presented. The study shows that heating can expedite the strength gain in early age, and oven curing was the best among the curing conditions. The blanket with higher hearing capacity is further studied since it is considered as the practical application in rapid pavement repair in the field. The bond strength between old concrete and VFC modified concrete shows pretty promising results to apply in the bonded concrete overlay, though more extensive measurement of bond strength should be followed. The elastic modulus of VFC modified concrete was measured at early age and the value was smaller than typical elastic modulus of concrete.Alex Hak-Chul Shin, Denita Walker
01/01/20January 2020High-Volume Recycled Materials for Sustainable Pavement Construction (Volume III)https://cptechcenter.org/ncc-projects/volume-iii-high-volume-recycled-materials-for-sustainable-pavement-construction/Fly ash, Greenhouse gases, Rigid pavements, Slag, Sustainable developmentConcrete production uses a considerable amount of non-renewable natural resources and generates a significant amount of greenhouse gases. To obtain a more sustainable solution requires examining the two main components of concrete – aggregates and cement. Recycling concrete as aggregate for new concrete reduces construction waste, diverts material from already over-burdened landfills, and lowers demand for virgin aggregate. Using supplementary cementitious materials – such as fly ash, blast furnace slag, and glass powder – also diverts material from landfills and reduces the carbon footprint of concrete. The Federal Highway Administration (FHWA) estimates that two billion tons of new aggregate are produced each year in the U.S. Aggregate demand is anticipated to increase to two and a half billion tons per year by 2020. With such a high demand for new aggregates, concern arises about the depletion of current sources of natural aggregates and the availability of new sources. Similarly, construction waste produced in the U.S. is expected to continue increasing. From building demolition alone, the annual production of construction waste is estimated to be 123 million tons, with concrete accounting for up to two-thirds of the total weight. Currently, this waste is most commonly disposed of in landfills. To address both the increasing demand for new aggregates and the increasing production of waste, many states have begun to recognize that more sustainable solutions exist in recycling waste concrete for use as aggregate in new concrete – recycled concrete aggregate (RCA). RCA helps address the question of how to sustain modern construction demands for aggregates and reduce the amount of waste entering already overburdened landfills. Many states have begun to implement RCA in new construction. For instance, 41 states have recognized the many uses of RCA as a raw material for riprap, soil stabilization, pipe bedding, and even landscape materials. Of these, 38 states have gone a step further in taking the additional step of integrating RCA into roadway systems for use as aggregate base course material.Jeffery S. Volz, Julie Ann Hartell, Lexis Allen, Jonathan Drury, Rex McLauchlin, Mohammad Zare Banadkoki
12/31/20December 2020Service Life Design Guidance For UHPC Link Slabshttps://cptechcenter.org/ncc-projects/service-life-design-guidance-for-uhpc-link-slabs/Bridge decks, Bridge design, Retrofitting, Service life, Ultra high performance concrete (UHPC)Design for service life rather than just for strength against potential overload and fatigue failure is becoming a more common consideration for bridges. One aspect of design, and often bridge retrofit, with potential for a large impact is minimizing the number of transverse deck joints. Bridge deterioration can often be traced to poor performance of these deck joints due to failure of the joint seal allowing chloride laden water onto bridge girder ends, bearings, and substructure elements. Using link slabs over the piers allows for eliminating some interior joints and moving expansion joints to the end of the bridge while still maintaining typical bridge behavior. Link slabs allow the simply supported behavior expected for many bridges, yet still transmit deformations and forces to expansion joints and reduce potential penetrations in the bridge deck. Advanced materials, such as ultra-high performance concrete (UHPC) can simplify link slab details and substantially improve their durability. UHPC link slabs are specifically relevant to accelerating bridge retrofit in that the short required debonded lengths can significantly reduce the required amount of demolition and the overall time required for the project. Debonded lengths for UHPC link slabs can be as small as 16 in. compared to several feet for conventional construction. While the concrete in the immediate area of the joint may be deteriorated and can be removed quickly, concrete further from the joint will often be sound and take substantial time and labor to remove. The hairline distributed cracks that form in a UHPC link slab limit pathways for water to penetrate to the bridge girders and substructure, and UHPC itself is inherently more durable than conventional concrete due to its very low permeability.Royce Floyd, Jeffery Volz, Musharraf Zaman
01/31/22January 2022Extending the Service Life of Rigid Pavement Joints with Self-Healing Sealantshttps://cptechcenter.org/ncc-projects/extending-the-service-life-of-rigid-pavement-joints-with-self-healing-sealants/Rigid pavements, Sealing (Technology), Service life, Structural analysisIn the work proposed here, we will synthesize and characterize a range of CAN materials as potential sealants. Specifically, we will use materials that cure as a two-part epoxy resin that are subsequently capable of undergoing an exchange mechanism between polymer strands within the molecular structure of the materials. This type of rearrangement mechanism does not influence the mechanical properties, such as the Young’s modulus, enabling the material to maintain its structural integrity (i.e., ability to stand up to vehicular loading); however, thermal cycling over time promotes the material to heal cracks and other material defects4 . The starting materials are readily scaled to large applications and can even be bio-sourced to enhance the sustainability of these polymers. Within this chemistry, we will incorporate silicon-based structures to impart flexibility and water resistance. Finally, we will incorporate adhesion promoting silane agents within the monomer formulation for strong concrete-sealant adhesion. Taken together, this material is hypothesized to have excellent mechanical properties with an enhanced service lifetime.
02/01/19February 2019Strategies for Concrete Pavement Preservationhttps://cptechcenter.org/ncc-projects/strategies-for-concrete-pavement-preservation/Concrete, Concrete pavements, Economic analysis, Overlays (Pavements), Pavement design, Pavement maintenance, Rehabilitation (Maintenance)The use of the term “preservation” for concrete pavements is somewhat of a misnomer in that many preservation treatments are actually stop-gap measures used to address visible signs of deterioration in the existing pavement. The treatments address the symptoms of the problem but may not directly address the underlying causes of the distress, which can progress until requiring even more significant rehabilitation, or perhaps even reconstruction. This report redefines the term concrete pavement preservation as “preserving the existing concrete pavement structure to extend its service life for as long as possible, by arresting, greatly diminishing, or avoiding the pavement deterioration process.” This can be achieved through three fundamental approaches: (a) designing and constructing pavements that remain structurally adequate and relatively distress-free throughout their service lives (i.e., using long-life concrete pavement), (b) using asphalt or concrete overlays as preservation treatments to maintain the functional performance of the pavement, and (c) maintaining the serviceability of the pavement using concrete pavement restoration (CPR) treatments. This report reviews the primary factors affecting concrete pavement performance and strategies for concrete pavement preservation. A state-of-the-practice review on the approaches for evaluating the condition of concrete pavements that will help in developing long-term concrete pavement preservation strategies and the engineering economic analysis techniques that can be employed to evaluate the cost-effectiveness of various preservation strategies is also included.Tom Van Dam, Kurt Smith, Mark Snyder, Prashant Ram, Nicole Dufalla
04/29/22April 2022Experimental and Numerical Investigation of Recycled Fiber Reinforced Concrete for Green Bus Padshttps://cptechcenter.org/ncc-projects/experimental-and-numerical-investigation-of-recycled-fiber-reinforced-concrete-for-green-bus-pads/Concrete, Construction, Design, Pavement crackingState transit administrations across the Mid-Atlantic states operate independent or connected transit systems within cities or within several states. Our particular interest is developing new methodologies to help the Maryland Transit Administration (MTA) in its operation of a comprehensive transit system throughout the Baltimore-Washington Metropolitan area, one that has a daily and annual ridership of > 380,000 and 110 million people, respectively. The MTA operates 80 bus lines with over 840 buses serving Baltimore’s public transportation needs, along with the Light Rail, Metro subway, and MARC train. Since nearly half the population of Baltimore residents lack access to a car, the MTA is an important part of the regional transit system. Subsequently, maintaining a durable infrastructure to support the bus transit system and mobility of Baltimore residents is critical. One of the most common issues observed in the Baltimore City bus transit system is the crumbling of bus pads, where the buses stop to pick up riders. Bus pads are highly durable areas of the city roadways at bus stops, typically made of concrete, which is used to address the issue of asphalt distortion at bus stops. This issue is more problematic at high-volume stops where idling buses further heat the roadway surface, as well as near-side stops in mixed-traffic lanes where trucks may be adding to wear and tear. Cracks and damage in concrete pavement occur as a result of shrinkage, settlement, uplift, and excessive weight on the slab. Therefore, there is a continuous need to investigate the cause of the cracking of bus pads and develop a more sustainable design and monitoring approach so that bus pads are not replaced as often, reducing costs and disruptions to service.Kadir Aslan
08/31/20August 2020Testing Methods to Assess the Durability of Concrete Permeability-Reducing Admixtureshttps://cptechcenter.org/ncc-projects/testing-methods-to-assess-the-durability-of-concrete-permeability-reducing-admixtures/Admixtures, Concrete, Cracking, Durability tests, Literature reviews, Permeability, Test proceduresThe objectives of this project are to perform a thorough literature review to determine if there are existing test methods that can quantify the performance of chemical PRAs, and if so, what acceptance limits should be used. If the researchers do not find suitable existing test methods, they will provide recommendations for the development and evaluation of new test methods. Candidate test methods will be evaluated based on their ability to measure the performance of uncracked concrete, concrete with autogenously healed cracks, admixed materials, and surface-applied materials. Preference will be given for test methods that can be performed in a short time period (~28 days), are low-cost, and quantify fundamental transport properties.Kyle Riding
04/01/19April 2019Fiber-Reinforced Concrete Pavement Overlays: Tech Briefhttps://cptechcenter.org/ncc-projects/tech-brief-fiber-reinforced-concrete-pavement-overlays/Concrete pavements, Fiber reinforced concrete (FRC), Fibers, Overlays (Pavements)The objective of this tech brief is to provide pavement engineers with the information necessary to use fiberreinforced concrete (FRC) for concrete overlays. This tech brief explains how to determine the appropriate fiber reinforcement performance values to specify and implement in the structural design calculations for bonded and unbonded concrete overlay projects. A spreadsheet tool called the Residual Strength Estimator was developed to help pavement engineers use FRC in concrete pavement applications. The tool provides an estimate of the FRC performance value to specify for a project as well as the effective flexural strength to input into the mechanisticempirical (M-E) concrete pavement design software.Jeffery Roesler, Amanda Bordelon, Alexander Brand, Armen Amirkhanian
07/31/25July 2025Performance Evaluation of Polyester Polymer Concrete Overlays Continuation Proposal—Phase II (TR-772)https://cptechcenter.org/ncc-projects/performance-evaluation-of-polyester-polymer-concrete-overlays-continuation-proposal-phase-ii-tr-772/Bridge decks, Case studies, Evaluation and assessment, Guidelines, Overlays (Pavements), Pavement performance, Polymer concreteThe main objective of this study is to evaluate the performance of Polyester Polymer Concrete (PPC) overlays to be applied on two older bridge decks in Iowa and develop guidelines for Iowa DOT that can aid in the implementation, design, and construction of PPC overlays based on challenges and successes observed in the two case studies. This project will aid in future bridge deck overlay decision making and provide design, construction, and quality assurance/quality control (QA/QC) guidance for future practice.Mohamed ElBatanouny
04/15/19April 2019Investigation into Shrinkage of High-Performance Concrete Used for Iowa Bridge Decks and Overlays – Phase II Shrinkage Control and Field Investigationhttps://cptechcenter.org/ncc-projects/investigation-into-shrinkage-of-high-performance-concrete-used-for-iowa-bridge-decks-and-overlays-phase-ii-shrinkage-control-and-field-investigation/Bridge decks, Cement, Concrete overlays, Field tests, High performance concrete (HPC), Laboratory tests, ShrinkageThis Phase II research project on the shrinkage behavior of high-performance concrete (HPC) used in Iowa bridge decks and overlays evaluated several concrete mixes, building off or modifying mixes developed in Phase I. Based on shrinkage behavior and mechanical properties, the mixes studied in Phase I were characterized as having either high, medium, or low cracking potential. In the Phase II study, three concrete mixes (Mixes 6, 8, and 2, characterized in Phase I as having high, medium, and low cracking potential, respectively) were selected for further investigation. The selected mixes were modified using three shrinkage control technologies: shrinkage-reducing admixtures (SRAs), cementitious materials (CM), and internal curing (IC) agents, respectively. The modification methods were first studied in a laboratory until the optimal shrinkage behavior of each concrete mix was achieved. Two pairs of the tested concrete mixes (Mixes 6 and 8 with and without modification) were then used in a field investigation on the US 20 over I-35 dual bridge. The mixes were placed side by side for the bridge overlays, which were monitored for about one year with strain gages, temperature and moisture sensors, and regular visual examinations. The laboratory investigation confirmed positive effects for the concrete shrinkage control technologies used. The laboratory test results also provided specific details for the concrete mix modifications, ensuring optimal concrete performance and shrinkage control.Kejin Wang, Yifeng Ling, Gilson Lomboy, Sri Sritharan
05/15/21May 2021Aggregate Subgrade Improvements Using Quarry By-Products: A Field Investigationhttps://cptechcenter.org/ncc-projects/aggregate-subgrade-improvements-using-quarry-by-products-a-field-investigation/Aggregates, Field studies, Improvements, Pavement maintenance, Subgrade (Pavements), Traffic loads, Waste products (Materials)The purpose of this project is to investigate the constructability, longevity, and overall field performance of aggregate subgrade improvements with quarry by-products subjected to real traffic loads and environmental conditions and incorporate the successful subgrade improvements with QBA into Illinois Department of Transportation’s standard practices for pavement construction and rehabilitation.Erol Tutumluer
01/14/22January 2022Development of In-Situ Sensing Method for Monitoring of Water-to-Cement (W/C) Values and the Effectiveness of Curing of Concretehttps://cptechcenter.org/ncc-projects/development-of-in-situ-sensing-method-for-monitoring-of-watercement-w-c-values-and-the-effectiveness-of-curing-of-concrete/Concrete curing, Monitoring, Water cement ratioWater-to-cement (w/c) ratio affects many concrete properties, including strength, porosity, durability, and constructability. However, w/c ratio of any given mixture can be altered during the manufacturing, transportation, and placement of concrete. This proposal aims to develop a sensing method that will enable accurate, in-situ determination of w/c ratio of freshly placed concrete and monitoring of concrete curing conditions. The successful completion of this program will result in significant cost savings to INDOT and taxpayers.Na Lu, Jan Olek
04/01/20April 2020Evaluating Laboratory Tests for Use in Specifications for Unbound Base Course Materialshttps://cptechcenter.org/ncc-projects/evaluating-laboratory-tests-for-use-in-specifications-for-unbound-base-course-materials/Base course (Pavements), Granular materials, Laboratory tests, Load tests, Repeated loads, Traffic loads, Triaxial shear testsA key requirement for performance-based specification for pavement materials is the selection of laboratory tests that can predict their response under conditions similar to those encountered in the field. This paper presents the results of a study that was conducted to evaluate the capability of different laboratory tests to predict the behavior of unbound granular base course materials under cyclic traffic loading. To achieve this objective, a laboratory testing program was conducted on three types of unbound granular base course materials, namely limestone, sandstone, and granite. The laboratory testing program included conducting a static triaxial test as well as three types of repeated load triaxial (RLT) tests on the materials considered at their optimum field compaction conditions. The three types of RLT tests considered included: resilient modulus, single-stage, and multistage RLT tests. The results of the static triaxial tests showed that the considered materials had similar shear strength properties. However, the RLT test results showed a distinct behavior between those materials, such that the limestone and sandstone exhibited the highest and lowest resilient modulus values, respectively, in the resilient modulus test. In addition, the granite and sandstone accumulated the highest and lowest permanent strain, respectively, in both single-stage and multistage RLT tests. The multistage showed that the granite and limestone experienced the unstable collapse behavior at higher cyclic deviatoric stress than sandstone. In addition, the results demonstrated that the resilient strain behavior was distinct from that of the permanent strain, which indicates that the resilient modulus test cannot be solely used to evaluate the performance of base course materials under cyclic traffic loading. Finally, this study demonstrated that the multistage RLT test provides an important tool to characterize the long-term behavior of a base course material at varying stress conditions. Therefore, it is recommended to use this test in future performance-based specification.Nazzal, Munir D; Mohammad, Louay N; Austin, Aaron
01/01/19January 2019Best Practices for Placing Concrete Overlays on Prestressed Slab Bridgeshttps://cptechcenter.org/ncc-projects/best-practices-for-placing-concrete-overlays-on-prestressed-slab-bridges/Best practices, Bond strength (Materials), Bridge decks, Concrete overlays, Laboratory tests, Precast concrete, Prestressed concrete bridges, Shear strength, Slabs, Tensile strengthThe objective of this research was to identify alternatives to the Maryland Department of Transportation State Highway Administration’s (MDOT SHA's) procedure of placing cast-in-place concrete overlays on prestressed bridge decks. The current practice involves the application of a cement-sand slurry mix over the bridge deck prior to placement of overlay concrete. The reinforcement cage for the overlay is removed from its position to facilitate uniform, consistent application of slurry mix over the bridge deck and then subsequently placed back in position. Overlay concrete is then poured to finish the procedure. The current process is time sensitive as it requires that the slurry mix at the deck-overlay interface is in a non-set condition and is still consistent when the overlay concrete is being poured. To evaluate alternatives to this process, this research tested the shear bond and tensile bond strengths by two different test setups: Double-L test and Split-Prism test, respectively. Seven different cases including the reference test case that uses slurry mix were designed for both test setups and the results compared to suggest recommendations for laying concrete overlays in future projects. Of the six cases other than the reference case with slurry mix, four cases simply had different groove configurations running on the underlying substrate. The other two cases involved use of a commercial bonding agent and anchors used as shear studs. Use of materials, mix design specifications, and curing regimes, were in accordance with current MDOT SHA specifications and industry practices. The results of the research on the prestressed slab panels with pre-existing grooves over which the overlay concrete could be directly poured without the need for a slurry or other bonding agents, were very positive.A.M. Amde, S. Sharma, K. Singaraju and S. Essien
04/01/20April 2020Optimizing Field Data Collection & Developing Advanced GPR Processing Moduleshttps://cptechcenter.org/ncc-projects/optimizing-field-data-collection-developing-advanced-gpr-processing-modules/Bituminous overlays, Bridge decks, Condition surveys, Data collection, Delamination, Ground penetrating radarOver the past several years Maryland Department of Transportation State Highway Administration (MDOT SHA) developed a Ground Penetration Radar (GPR) data collection plan for bridge decks. GPR data was collected and analyzed to monitor several hundred bridge decks. MDOT SHA worked with the Maryland Environmental Services (MES) and the University of Maryland (UMD) to develop new analysis modules for concrete delamination and HMA overlay condition and evaluate the feasibility of higher-speed protocols for SF-GPR data collection. A bridge deck condition assessment model (BDCAM) was developed to estimate the deck condition and condition state. Deck condition is defined based on a fuzzy model of the various levels of defect and deterioration of the deck. The UMD study concluded that the BDCAM model estimates agree with the NBI values for 90.9% of the 219 bridge decks analyzed within two levels of the condition scale. The comparison of BDCAM analysis with state inspection deck reports for eight bridges provided consistent conclusions for seven out of the eight cases, all in the “fair” category. The study also concluded that it is possible to increase the GPR data acquisition speed from 10 mph to 13 mph on driving lanes with low surface roughness (IRI less than 100).Dimitrios G. Goulias
01/01/20January 2020Enhancing Performance of Fiber-Reinforced Concrete for Construction and Repairhttps://cptechcenter.org/ncc-projects/enhancing-performance-of-fiber-reinforced-concrete-for-construction-and-repair/Bridge decks, Concrete bridges, Concrete pavements, Fiber reinforced concrete (FRC), Reinforcement (Engineering), RepairingThe overarching purpose of this research is development of knowledge and a novel technique to enhance properties of Eco-Bridge-Crete, fiber-reinforced self-consolidating concrete (FR-SCC) and fiber-reinforced super-workable concrete (FR-SWC) for higher crack resistance and improved flexural properties in construction and repair by taking advantage of hybrid fibers, chemical admixtures (shrinkage reducing agents (SRA) and expansive agents (EA)) and lightweight sand (LWS). A binary or ternary system of EA, SRA and LWS with selected fibers will be optimized to enhance shrinkage cracking resistance, mechanical properties and durability of the targeted mixtures. The incorporation of fibers with EA, SRA and LWS can increase the flexural properties and help to replace a portion of steel reinforcement bars in flexural members or reduce thickness of repair overlays without compromising flexural strength/toughness and crack resistance. The selected mixtures will be used in large-scale members to assess their structural performance in construction and repair.Kamal Khayat
12/01/20December 2020Mechanical Properties of Pressure-Moulded Fibre-Reinforced Pervious Concrete Pavement Brickhttps://cptechcenter.org/ncc-projects/mechanical-properties-of-pressure-moulded-fibre-reinforced-pervious-concrete-pavement-brick/Composite materials, Compressive strength, Concrete pavements, fiber reinforced concrete, Mechanical properties, Permeability, Porosity, Tensile strengthUtilising pervious concrete (PC) increases the environmental, economic, and social benefits. This study aims to investigate the mechanical performance of PC paving bricks using smaller single-sized coarse aggregates with different types of fibres: Kevlar, Polyvinyl Alcohol (PVA), and Ultra-High Molecular Weight Polyethylene (UHMWPE) fibres. Four PC mixes were designed using a modified ACI method and paving bricks formed using a pressure compaction method of 2 MPa and air-curing for 28 days. Results showed that the use of smaller coarse aggregate results in reduced porosity. However, the addition of fibres at a volume fraction of 0.3% lead to approximately 47%, 21.5%, and 18.8% decrease in 28-days compressive strength, and 26%, 7.3%, and 17.6% reduction in tensile splitting strength for specimens containing Kevlar, PVA, and UHMWPE fibres, respectively. When compared with the control group, an optimum 9.5% increase in the flexural strength shows the effectiveness of the fibre addition. The permeability values range between 0.15  cm/s to 0.39  cm/s, which is proportional to the porosity of the material and satisfactory according to ACI standards. Combining the pressure compaction method and the addition of fibres adversely affects the compressive and splitting tensile strength, while increasing the flexural strength slightly. An alternative forming/moulding method that can fully utilise the addition of fibres is worth further investigation. Bukola Oni, Jun Xia, Mengdi Liu
12/10/19December 2019Utilization of Recycled Concrete Aggregates for Light-Stabilization of Clay Soilshttps://cptechcenter.org/ncc-projects/utilization-of-recycled-concrete-aggregates-for-light-stabilization-of-clay-soils/Clay soils, Compressive strength, Concrete aggregates, Recycled materials, Shear strength, Soil stabilizationDue to the abundance of urban building constructions and renewals in developing and developed countries, there is a continuous increase in the amount of construction and demolition (C&D) wastes that is landfilled. Recycling and reuse of construction and demolition materials, in applications such as in pavement constructions and non-structural building elements, results in preserving natural resources and reducing environmental pollution. This experimental study evaluates the viability of using recycled concrete aggregates (RCA) for improving the shear/compressive strengths and deformation properties of clay soils. A comprehensive series of compaction, uniaxial compression, and direct shear tests were performed on carefully proportioned mixtures of RCA and a clay soil. Test results and observations indicate that the introduction of RCA to clay soils results in lower dry density and higher unconfined compressive strength (UCS), which increases with moist curing. Clay soils mixed with RCA have higher tendencies for dilative behavior (during shear) and enhanced shear strengths compared to the parent clay soil. Mixing RCA with clay soils results in stronger, stiffer, and less compressible blends that are particularly suitable for construction purposes such as sub-base/subgrade of road pavements. Marzieh Kianimehr, Piltan Tabatabaie Shourijeh, Seyed Mohammad Mohammad Binesh, Alireza Mohammadinia, Arul Arulrajah
12/01/19December 2019Experimental Evaluation of the High-Grade Properties of Recycled Concrete Aggregates and their Application in Concrete Road Pavement Constructionhttps://cptechcenter.org/ncc-projects/experimental-evaluation-of-the-high-grade-properties-of-recycled-concrete-aggregates-and-their-application-in-concrete-road-pavement-construction/Case studies, Coarse aggregates, Concrete aggregates, Concrete pavements, Freeze thaw durability, Mechanical properties, Paving, Recycled materialsIn Flanders, up to 20% of the coarse natural aggregates in concrete mixtures for certain applications in road pavement construction may be replaced by high-grade recycled concrete aggregates (RCA). The RCA and resulting recycled aggregate concrete (RAC) have to comply with the high-grade criteria specified in the Flemish ‘Standard Tender Specifications 250 version 3.1’ and require extensive and time-consuming testing procedures, leading to reluctance in effectively prescribing and using recycled aggregates. The objective of this case study is therefore to draw up practical recommendations for the rapid identification of high-grade RCA. RCA from different sources are investigated and subsequently used in two concrete road pavement construction applications, namely linear elements and applications within the Flemish concrete construction class ‘BF’ (i.e. cycle paths, footpaths and agricultural roads). The experimental results indicate that the aggregate density along with the water content appear to be good predictors for the resistance to abrasion (i.e., the Los Angeles coefficient). The aggregate experiments also show that, in order to fulfill the aforementioned tender specifications criteria, it is important to demolish and store the source material in such a way that no contamination with non-concrete materials (such as ceramics) takes place, maintaining a high specific density. The experiments on RAC, on the other hand, show that an aggregate replacement rate of up to 40% of the coarse fraction has no detrimental effect on the mechanical and durability performance. When comparing the results of both aggregate and concrete experiments, they show that freeze-thaw resistance of the concrete aggregates has slight to no impact on the freeze-thaw resistance of the concrete. S. Kox, J. Vanroelen, H. de Krem, B. Vandoren
December 2019Mechanical Performance of Concrete Made of Steel Fibers from Tire Wastehttps://cptechcenter.org/ncc-projects/mechanical-performance-of-concrete-made-of-steel-fibers-from-tire-waste/Concrete, Mechanical properties, Recycled materials, Steel fibers, Tires, Waste products (Materials)Currently, the disposal of used tires is a worldwide challenge, due to their non-degradability. Therefore, recycling has become a potential solution for managing such waste. During recycling, materials such as rubber and steel are recovered from the used tires. The use of steel fibres, recovered from tire waste, as a raw material to reinforce concrete is an environmentally friendly and economically viable solution to manage the end-products of tire recycling. Few studies have been carried out to study the behaviour of fibre-reinforced concrete made using steel fibres recovered from tire waste. However, it has been found that there is the potential to reuse steel fibres recovered from tire waste (RF) as an alternative building material to manufactured steel fibres (SF). Nevertheless, more research is needed to verify that the structural performance of recycled fibre reinforced concrete (RFRC) is similar to that of manufactured fibre reinforced concrete (SFRC). Therefore, this study focuses on the laboratory testing of the mechanical properties of RFRC and compares them with those of SFRC. Moreover, the flexural performance of reinforced concrete beams cast with RF and SF have been tested to compare their performance. S M Samindi M K Samarakoon, Pål Ruben, Jørgen Wie Pedersen, Luis Evangelista
12/01/19December 2019The Effect of Using Low Fines Content Sand on the Fresh and Hardened Properties of Roller-Compacted Concrete Pavementhttps://cptechcenter.org/ncc-projects/the-effect-of-using-low-fines-content-sand-on-the-fresh-and-hardened-properties-of-roller-compacted-concrete-pavement/Coarse aggregates, Fine aggregates, Mechanical properties, Porosity, Roller compacted concrete pavements, sand, Tensile strengthAggregate gradation is one of the most important property that influence the behaviour of roller-compacted concrete pavement (RCCP). There are some limitations for gradation of coarse and fine aggregates from the standards. Based on the ACI 211.3R, the content of sand size less than 75 micrometres should be between 2% to 8% of the total aggregates. To study the effectiveness of using a nonstandard sand (a sand with a gradation out of the specified restrictions) on the properties of RCCP, three types of sand with a difference in very fine particles content were used. The sands used are: 1) standard sand, 2) modified sands containing about 6% limestone powder, and 3) a low fines content sand containing <1% very fine particles. Two types of RCCP containing 12% and 15% cement were used as control mix. The results show that using low fines content sand or limestone modified sand instead of standard sand in RCCP increased Vebe time. The use of low fines content sand in RCCP did not have significant effect on the compressive, splitting tensile and flexural tensile strengths. However, the use of limestone modified sand in the RCCP significantly reduced the mechanical properties. RCCP was made of low fines content sand had more porosity than RCCP with standard sand. It can be concluded from test results that sand with lack in very fine particles can be used in RCCP. Mohammad Hashemi, Payam Shafigh, Mehdi Abbasi, Iman Asadi
03/10/20March 2020Alternative Materials for Wearing Course of Concrete Pavements: A Critical Reviewhttps://cptechcenter.org/ncc-projects/alternative-materials-for-wearing-course-of-concrete-pavements-a-critical-review/Admixtures, Concrete pavements, fiber reinforced concrete, Fly ash, Mechanical properties, Silica fume, wearing course (pavements)The existing worldwide road length of concrete pavements is significant. Furthermore, concrete pavements have a number of specific applications, even though they are second to asphalt pavements in terms of current popularity. Besides, asphalt is a rapidly depleting resource, which might mean that concrete is the chief material for the future. However, concrete pavements have their drawbacks, such as high construction cost, low tensile strength, and significant contribution to global carbon-dioxide emissions. The present study aims to address these drawbacks by reviewing the prominent alternative materials that may be utilized to replace cement and/or aggregates in concrete. The potential of alternatives such as coal ash, silica fume, nano-silica, fly ash, slag, and recycled concrete aggregate is investigated. In addition, the effects of adding fibers (as both fiber-reinforced concrete and engineered cementitious composite) to concrete pavements are discussed. This review will also help pavement engineers and researchers to ascertain which combination of materials to use so that mechanical properties better than conventional concrete are achieved. The specific advantages and disadvantages due to various combinations of materials, in several types of concrete pavements such as conventional concrete, roller-compacted concrete, and self-compacting concrete are discussed in detail. Shreyas Pranav, Shubham Aggarwal, Enh-Hua Yang, Ashoke Kumar Sarkar, Ajit Pratap Singh, Mukund Lahoti
04/20/20April 2020Using Post-Cracking Strength to Determine Flexural Capacity of Ultra-Thin Whitetopping (UTW) Pavementshttps://cptechcenter.org/ncc-projects/using-post-cracking-strength-to-determine-flexural-capacity-of-ultra-thin-whitetopping-utw-pavements/Composite pavements, fiber reinforced concrete, Flexural strength, Polymer fibers, Polypropylene, WhitetoppingUtilizing fibrillated polypropylene fibers (FPP) in ultra-thin whitetopping (UTW) has become increasingly popular to improve the flexural capacity of concrete slabs. The calculated flexural strength (i.e., modulus of rupture [MOR]) depends on the elastic formula of ASTM C78 does not illustrate the fiber’s benefits. Therefore, the concept of effective modulus of rupture (MOReff.) that is determined from the equivalent flexural strength ratio has been used to quantify the added flexural capacity of fibers on unreinforced concrete. The purpose of this study is to investigate the benefits of testing the FRC/asphalt composite beam on the flexural capacity of UTW. Three main parameters have been taken into consideration: FPP content, pavement thickness, and failure mode. Furthermore, comparison was made to verify the effectiveness of composite beams for flexural capacity. Six different cases of concrete beams and ten cases of FRC/asphalt composite beams were performed. The results of the composite beam showed that the flexural capacity was higher than the capacity of the concrete layer. In addition, using FPP in the composite beams improved the MOReff. The results also revealed that testing UTW under noncommon failure modes did not reflect the real flexural capacity of UTW. The required UTW thickness depends on the proposed flexural capacity of the composite beam being less than the required thickness that is calculated depends on the concrete beam. Nakin Suksawang, Ahmed Alsabbagh, Alaa Shaban, Salam Wtaife
02/28/20February 2020Utilisation of Recycled Concrete Aggregates for Sustainable Highway Pavement Applications: A Reviewhttps://cptechcenter.org/ncc-projects/utilisation-of-recycled-concrete-aggregates-for-sustainable-highway-pavement-applications-a-review/Concrete aggregates, Life cycle analysis, Paving materials, Recycled materials, Sustainable developmentHighway pavements are very expensive infrastructures that consume very high amounts of natural resources. Utilisation of recycled concrete aggregates (RCA) for highway pavement construction can bring a number of benefits towards environmental, economic, and societal sustainability. This would reduce the carbon footprint of the construction industry, result in natural resource conservation, reduction in harmful emissions, and minimisation of cost of pavement construction. This paper reviews available literatures on the use of RCA for highway pavements. Both flexible and rigid pavements were covered. The studies revealed that RCA can be applied in all pavement layers; subgrade, capping, subbase, roadbase, and surfacing. The physical and mechanical properties of the RCA and how they affect its performance were studied and compared with those of natural aggregates (NA). Available techniques for improving the performance of RCA in concrete and asphalt mixes were also discussed. The benefits and sustainability gains of RCA utilisation were summarised from available life-cycle assessments conducted in the literatures. RCA has been considered as a feasible sustainable alternative to NA in highway pavement applications, but there still exists a large disparity in the recommendations of the replacement levels for asphalt mixes. To ensure that the pavements are sustainable without compromising their quality and functionality, the utilisation of RCA should be encouraged after further indebt studies that would lead to a more consensus standard specifications and guidelines.Chidozie Maduabuchukwu Nwakaire, Soon Poh Yap, Chiu Chuen Onn, Choon Wah Yuen, Hussein Adebayo Ibrahim
02/10/20February 2020Performance Assessments of Open-Graded Cement-Stabilized Macadam Containing Recycled Aggregatehttps://cptechcenter.org/ncc-projects/performance-assessments-of-open-graded-cement-stabilized-macadam-containing-recycled-aggregate/Cement, macadam, Open graded aggregates, Performance tests, Recycled materials, Stabilized materials, WastesIncreased awareness of sustainability has called for increasing use of construction waste in civil infrastructures. However, the incorporation of construction waste should be well examined without compromising the performance. There are few studies focusing on applying construction waste in pervious concrete. This study was aimed at exploring the feasibility of reusing recycled aggregate from construction waste for open-graded cement stabilized macadam (OGCSM) and evaluating its performance. Various replacement ratios of recycled aggregate ranging from 0% to 100% were designed and studied in the OGCSM. The performance of OGCSM containing recycled aggregate are comprehensively evaluated. Specifically unconfined compressive strength (UCS) test, indirect tensile strength (ITS) test, compression resilience modulus test, dry shrinkage test, frost resistance test, and permeability test were conducted. As the results showed, the UCS, ITS, and compression resilience modulus of OGCSM decreased with the increase of replacement ratios of recycled aggregate. Dry shrinkage performance also declined with the increase of recycled aggregate content while permeability performance increased with the increase of recycled aggregate content. The UCS after freeze-thaw cycles declined with the increase of recycled aggregate content and cycles. However, there was no significant correlation between residue strength rate and recycled aggregate content. When the replacement ratio was 30%, the residue strength rate was maximum. Although the performance of OGCSM declined with the increase of recycled aggregate content, it could be potentially used in the base of the highway when the performance of OGCSM containing appropriate amount of recycled aggregate met the requirement of base layer of pavements. Kezhen Yan, Guokai Li, Lingyun You, Yubo Zhou, Shenghua Wu
01/20/20January 2020 Advanced Reinforced Concrete Pavement: Concept and Designhttps://cptechcenter.org/ncc-projects/advanced-reinforced-concrete-pavement-concept-and-design/Continuously reinforced concrete pavements (CRC pavements), Costs, Cracking, Pavement design, Reinforcing bars, Rigid pavementsA state-of-the-art rigid pavement structure called the advanced reinforced concrete pavement (ARCP) was developed to overcome major shortcomings of the continuously reinforced concrete pavement (CRCP), which were the high construction cost because of a huge amount of steel bars and the performance reduction caused by undesirable crack patterns. The steel design method of ARCP was developed to eliminate unnecessary steel bars in CRCP, and the crack induction strategies of ARCP were accomplished to provide even better pavement performance. The numerical analyses, laboratory experiments, and field experiments were conducted to confirm the concept of ARCP, to find the most appropriate design of ARCP, and to validate ARCP finally. Details of the efforts to develop ARCP are comprehensively presented. Seong-Min Kim, Young Kyo Cho, Jun Ho Lee
01/25/21January 2021Mechanical and Durability Properties of Fiber Reinforced Concrete Overlay: Experimental Results and Numerical Simulationhttps://cptechcenter.org/ncc-projects/mechanical-and-durability-properties-of-fiber-reinforced-concrete-overlay-experimental-results-and-numerical-simulation/Concrete overlays, Durability, fiber reinforced concrete, Finite element method, Mechanical properties, Simulation, Steel fibers, Synthetic fibersNowadays, fiber reinforced concrete (FRC) overlays are used for repairing and reinforcing pavements. In this research, some experimental tests performed to investigate the effects of steel and synthetic fibers on the performance of the concrete overlay. The synthetic fiber in this study is based on Modified Synthetic Polypropylene (MSP) Fiber. Plain and FRC specimens underwent flexural and compressive strength, and durability tests. The results show that the use of MSP in concrete overlays increases compressive and flexural strength, residual strength, ductility, and energy absorption, and reduces the resistance of concrete against freezing and thawing cycles. Using similar addition volume, steel fiber reinforced concrete (SFRC) has better flexural performance and lower compressive strength and workability than modified synthetic polypropylene fiber reinforced concrete (MSPFRC). To determine the thickness of the bonded concrete overlay (t), the Portland Cement Association (PCA) design criteria were used. In this study, these criteria simulated using finite element (FE). The results showed that the use of MSP in concrete overlays could reduce the thickness of bonded concrete overlay up to 15%. Mahmoud Hasani, Fereidoon Moghadas Nejad, Jafar Sobhani, Mahdi Chini
12/30/20December 2020Evaluation of Novel Jointless Engineered Cementitious Composite Ultra-thin Whitetopping (ECC-UTW) Overlayhttps://cptechcenter.org/ncc-projects/evaluation-of-novel-jointless-engineered-cementitious-composite-ultra-thin-whitetopping-ecc-utw-overlay/Cement, Composite materials, Evaluation, Overlays (Pavements), WhitetoppingThe objective of this study was to evaluate the construction, material characterization, initial structural assessment, and cost of a novel jointless engineered cementitious composite ultra-thin whitetopping (ECC-UTW) overlay. After construction, early-age cracks (from less than 0.25 mm to up to 2.54 mm width) were observed in the 101.6 mm (4 in.) jointless ECC-UTW section; yet, the majority of the cracks coincided with areas where fiber clumps were observed during construction and places of heavy instrumentation. On the other hand, no cracks were observed in the 63.5 mm (2.5 in.) jointless ECC-UTW at early ages; yet, when winter arrived, micro-cracks (<0.25 mm in width) developed. These micro-cracks were attributed to the normal functioning of the ductile pseudo strain-hardening (PSH) mechanism of ECC materials. Falling weight deflectometer (FWD) evaluation conducted before and after the construction of the UTWs showed a significant reduction in pavement deflection after construction. This deflection reduction was much more substantial for thicker 101.6 mm UTWs; yet, no major difference in deflection reduction was found between the 101.6 mm ECC and the 101.6 mm regular concrete UTW sections. The 28-day compressive and flexural strength of ECC evaluated from field specimens underperformed that of previous studies by 9.6% and 14.8%, respectively; however, deflection capacity slightly outperformed that of previous studies by 4.1%. The flexural performance of the ECC material was vastly superior to that of regular concrete exceeding the flexural strength by 92%. All specimens evaluated in uniaxial tension exhibited a PSH behavior after first-cracking; however, the tensile strength and tensile ductility values obtained underperformed expected values for ECC M3-15% and exhibited substantial variability. Uniaxial tensile test results from field specimens were deemed unreliable. Cost analysis results showed that a cost reduction of 14.8% per lane kilometer is expected by implementing the proposed jointless ECC-UTW system compared to that of the regular jointed concrete UTW. The greatest construction cost savings for utilizing ECC originates from its potential jointless attribute and its reduced thickness. Ricardo Hungria, Gabriel Arce, Marwa Hassan, Michele Anderson, Moinul Mahdi, Tyson Rupnow, Susan Bogus
11/20/20November 2020Influence of Dually Mixing with Latex Powder and Polypropylene Fiber on Toughness and Shrinkage Performance of Overlay Repair Mortarhttps://cptechcenter.org/ncc-projects/influence-of-dually-mixing-with-latex-powder-and-polypropylene-fiber-on-toughness-and-shrinkage-performance-of-overlay-repair-mortar/Fibers, latex, Overlays (Pavements), patching mortar, Polymer fibers, Polypropylene, Shrinkage, toughnessThe influence of dually mixing of polymer latex powder and polypropylene fiber on the toughness and the shrinkage of the overlay repair mortar (ORM) was investigated. To this end, the L9(34) orthogonal test scheme was designed to evaluate the strength, the ratio of flexural strength to compressive strength (RFSCS), and shrinkage ratio of the mortar at different ages and to optimize the mix parameters of ORM with minimum shrinkage, high toughness, and strength. Fitting and regression analysis were conducted to establish the shrinkage model of ORM, and the significance was assessed by a run test. The results indicate that the latex powder and the polypropylene fiber can significantly improve the toughness, but weaken the strength of the mortar to some extent. The exponential relation between the shrinkage ratio and time is significant at a significance level of α = 0.01. The comprehensive performance of the mortar of prioritizing the volume stability is optimal when the amount of polymer is 2.5%, length of the fiber is 9 mm, amount of the fiber is 0.2%, and content of silica fume is 2.5%. Moreover, it is suitable to be used as an overlay repair material for concrete pavements. Jiansen Yang, Rui Wang, Yuanyuan Zhang
01/25/21January 2021Fracture and Mechanical Performance of Two-Lift Concrete Pavements Made of Roller Compacted Concrete and Polypropylene Fibershttps://cptechcenter.org/ncc-projects/fracture-and-mechanical-performance-of-two-lift-concrete-pavements-made-of-roller-compacted-concrete-and-polypropylene-fibers/Concrete pavements, Flexural strength, fracture properties, Mechanical properties, Polymer fibers, Polypropylene, Roller compacted concreteThe present study has examined the two-lift concrete pavement (2LCP) fracture and mechanical behavior by casting the Roller Compacted Concrete (RCC) as the bottom lift and the conventional or fibrous portland cement concrete (PCC, FPCC) as the top lift. To this end, the three-point bending test was carried out on notched beams by considering different thicknesses for both layers. Results showed that fibers had no positive effects on the compressive and flexural strength, but improved the post cracking behavior considerably. Compared to full-depth RCC/PCC, 2LCP specimens had similar flexural strengths, but an increase in the FPCC top-layer thickness increased the fracture energy noticeably. Mohsen Ahmadi, Gholam Ali Shafabakhsh, Abolfazl Hassani
01/25/21January 2021Feasibility of Low Fiber Content PVA-ECC for Jointless Pavement Applicationhttps://cptechcenter.org/ncc-projects/feasibility-of-low-fiber-content-pva-ecc-for-jointless-pavement-application/Cement, Composite materials, Concrete pavements, continuous structures, fiber reinforced concrete, Finite element methodThe objectives of this study were to: (1) develop and evaluate the properties of low fiber content engineered cementitious composites (ECC) incorporating readily available ingredients (i.e., non-oil-coated PVA fiber, fine river sand, and Class F fly ash); and (2) evaluate the response of a low fiber content ECC material in pavement applications based on finite element analysis (FEA). Experimental results showed that reducing fiber content produced a decrease in the tensile strength and tensile ductility of ECC, which translated into a reduction of the flexural strength and deflection capacity of the composites; however, the compressive strength increased. Furthermore, increments in fly ash content caused an increase in the ductility of the composites; yet, the strengths (i.e., compressive, tensile, and flexural) were negatively affected. The modified restrained cracking potential parameter (Pm) calculated for all ECC materials was highly negative suggesting the possibility of jointless pavement functionality. A low fiber content PVA-ECC material, M3-1.5%, was successfully developed and evaluated for pavement applications utilizing flexural fatigue testing and FEA. Flexural fatigue performance of M3-1.5% underperformed regular ECC; yet, substantially outperformed regular concrete. Furthermore, FEA results showed that the critical tensile stresses developed at the bottom of the low fiber content ECC pavements can be substantially reduced compared to those generated on regular concrete pavements due to its plastic deformation capability. In turn, this could mitigate the brittle failure of rigid pavements and allow for substantial thickness reduction. Gabriel A. Arce, Hassan Noorvand, Marwa M. Hassan, Tyson Rupnow, Nirmal Dhakal
12/10/20December 2020Temperature Variation and Stresses in Unreinforced Concrete Pavement Containing RAPhttps://cptechcenter.org/ncc-projects/temperature-variation-and-stresses-in-unreinforced-concrete-pavement-containing-rap/Admixtures, Concrete pavements, Reclaimed asphalt pavements, Temperature, thermal stressesTemperature profile and corresponding stresses in concrete pavement were investigated on prototype scale. Four prototypes were considered, conventional and 25%, 50%, and 75% of fine-reclaimed asphalt pavement (RAP) inclusive concrete mixes. The observed temperature profile during 270 days was nonlinear with higher degree of nonlinearity for conventional mixes. The profile could be represented in quadratic form, which annuls the assumption of linear temperature variation in numerous design methodologies. The total temperature stresses were lower for RAP inclusive prototypes. Stresses with linear temperature profile assumption over or under-estimated and failed to identify the nature of the stress due to actual temperature profile. Sarah Mariam Abraham, G D R N Ransinchung
12/01/20December 2020Concrete Roadway Crack Segmentation Using Encoder-Decoder Networks with Range Imageshttps://cptechcenter.org/ncc-projects/concrete-roadway-crack-segmentation-using-encoder-decoder-networks-with-range-images/Concrete pavements, Cracking, image coding, networks, Neural networks, pavement grooving, RoadsRecently, researchers have utilized DCNN for pixel-wise crack classification through semantic segmentation. Nevertheless, some issues in current DCNN-based roadway crack segmentation are yet to be fully addressed. For example, image pre-processing techniques are often required to eliminate the surface variations in range images, which may bring uncertainties due to subjective parameter selection; besides, disturbances from many non-crack patterns such as pavement grooves can deteriorate the crack segmentation performance, which remains a challenge for current DCNN-based methodologies. This paper proposes a methodology based on encoder-decoder networks to achieve pixel-wise crack classification performance on laser-scanned range images, under the disturbance of surface variations and grooved patterns in concrete pavements. The raw range data is directly applied in this methodology without any pre-processing. A comparative study is performed to determine the optimal architecture layout among 12 proposed candidates. Meanwhile, the influence of residual connections on DCNN performance is investigated and demonstrated. Shanglian Zhou, Wei Song
01/10/21January 2021Hardened State Behaviour of Self-Compacting Concrete Pavement Mixes Containing Alternative Aggregates and Secondary Bindershttps://cptechcenter.org/ncc-projects/hardened-state-behaviour-of-self-compacting-concrete-pavement-mixes-containing-alternative-aggregates-and-secondary-binders/Admixtures, Binders, Concrete aggregates, Concrete pavements, Mechanical properties, Nondestructive tests (NDT), Recycled materials, self compacting concreteHardened state behaviour of two grades (normal- and medium-strength) of self-compacting concrete (SCC) pavement mixes containing varying proportions of recycled concrete aggregates (RCAs) as an alternative aggregate is reported in this paper. These two SCC grades were designed by varying the proportions of fly ash, silica fume, and metakaolin in binary and ternary blends of portland cement. The suitability of these mixes were evaluated for continuously reinforced concrete pavements (CRCP) application considering various performance as well as the quality control parameters. The results (both experimental and analytical) depicted that inclusion of RCA in saturated-surface-dry (SSD) moisture state would not have any negative effect on fresh and hardened state behaviour of the SCC-CRCP mixes. Although the cement content in some of the mixes were higher than the recommended limit, all the mixes could meet the minimum stipulated flexural strength criterion of 4.5 MPa at 28 days of curing for CRCP. However, to maximize the benefit (utilizing fewer natural resources and more recycled materials) without compromising with the engineering properties, high-volume fly ash based (50%) normal-grade SCC containing 100% RCAs is recommended. Ran Bir Singh, Solomon Debbarma, Navanit Kumar, Surender Singh
12/01/20December 2020Dual-Crystallization Waterproofing Technology for Topical Treatment of Concretehttps://cptechcenter.org/ncc-projects/dual-crystallization-waterproofing-technology-for-topical-treatment-of-concrete/Building materials, Concrete, Concrete pavements, crystallization, Durability, Pavement maintenance, Properties of materials, WaterproofingConcrete structures and pavements are subjected to various durability problems associated with moisture penetration through the pores and the capillary networks. Published data on waterproofing has provided conflicting and inaccurate information on crystalline-based technologies. Chem-Crete Pavix DCE is a patented, dual-crystalline waterproofing technology with performance characteristics, which are materially distinct from other crystalline-based technologies. It combines hygroscopic crystallization, hydrophilic crystallization, and hydrophobic characteristics. This publication presents the results of experimental research work on the significant characteristics of the dual-crystallization waterproofing technology as a treatment for existing or fully cured concrete. A program of laboratory testing has been completed in compliance with applicable ASTM and AASHTO standards using common concrete design mixes, in addition to cored specimens obtained from existing concrete pavements. The investigated experimental parameters included pore size, density, permeability, water absorption, resistance to cycles of freezing and thawing, chloride ion penetration, and mechanical properties of the surface, including pull-off strength, abrasion resistance and the coefficient of friction. Treated concrete has been found to have higher density, less voids, less surface area, and lower permeability than untreated specimens. These characteristics yielded significant reduction in water absorption, significant increase in resistance to damage from freezing and thawing and to biological attack, and significant reduction in chloride ion penetration, without negative impacts on mechanical properties. Radi Al-Rashad, Maher Jabari
11/30/20November 2020Flexural Behavior of Glass Fiber-Reinforced Recycled Aggregate Concrete and Its Impact on the Cost and Carbon Footprint of Concrete Pavementhttps://cptechcenter.org/ncc-projects/flexural-behavior-of-glass-fiber-reinforced-recycled-aggregate-concrete-and-its-impact-on-the-cost-and-carbon-footprint-of-concrete-pavement/Concrete aggregates, Concrete pavements, Costs, Flexural strength, glass fiber reinforced concrete, Greenhouse gasesIn this study, an effort is presented towards the appraisal of the economic and environmental performance of concrete pavement with the glass fiber (GF) reinforced concrete with and without concrete waste aggregates (CWA). The performance of pavement with plain and fiber-reinforced concretes was compared based on the results of economic and environmental analysis. Firstly, this study evaluated the important mechanical properties (flexural strength, elastic modulus, and residual strength) of the concrete mixes incorporating different quantities of CWA (as 0%, 30%, 50%, and 100% replacement of natural coarse aggregate) and GF (as 0%, 0.25%, 0.5%, and 1% volume fraction). Then, the mechanical properties were used to design the thickness of jointed plain concrete pavement (JPCP) for different concrete mixes under similar design loading conditions. Finally, using the cost and carbon emissions of each mix per cubic meter, the cost of pavement (CP) and carbon emissions of pavement (EP) per square meter were evaluated. The results of flexural testing revealed that CWA concretes with a small percentage of GF (i.e., 0.25%) can yield better flexural strength, toughness, and residual strength than conventional plain concrete. CP and EP analysis showed the remarkable economic and environmental benefits of fiber-reinforced concrete application in JPCP. At any level of CWA, 0.25% GF addition into concrete yielded concrete pavement with a 20% lower cost and carbon-footprint than that produced with the conventional plain concrete. The CWA level can be maximized into concrete pavement with the GF addition, otherwise plain CWA concrete yields cost and carbon footprint similar to that of the conventional concrete. Babar Ali, Liaqat Ali Qureshi, Sibghat Ullah Khan
11/30/20November 2020Microstructural Study and Surface Properties of Concrete Pavements Containing Nanoparticleshttps://cptechcenter.org/ncc-projects/microstructural-study-and-surface-properties-of-concrete-pavements-containing-nanoparticles/Abrasion resistance, Concrete pavements, Microstructure, Nanostructured materials, Skid resistance, Surface course (Pavements), surface dynamicsThis investigation focused on the effect of nanoparticles on microstructural surface characteristics, abrasion, and skid resistance of concrete pavements. Firstly, the percentage of optimal replacement of nanoparticles was determined. In the second part, the nano-modified concrete similar to mortars in terms of water-to-cement and sand-to-cement ratio were made to study the abrasion resistance and British pendulum number (BPN) as skid resistance property. Mercury intrusion porosimetry (MIP), X-ray diffraction (XRD), scanning electron microscopy (SEM), and atomic force microscopy (AFM) were applied to accurately evaluate the microstructural properties. Concerning concrete containing different nanoparticles, nano-montmorillonite yielded the most considerable improvement in abrasion resistance (about 23%). By examining the MIP results, a good correlation was observed between the volume of the large pores plus the average pore size and the volume reduction in the abrasion test. By comparing the effect of nanoparticles on improving the skid resistance under wet and dry conditions, it was found that the samples containing nanoparticles in dry conditions generated more significant improvements (about 20%) compared with the wet conditions (about 7%). The results of the AFM test revealed that improvement in samples containing nanoparticles was because of increased surface roughness and enhanced surface adhesion due to Van Der Waals forces. Parviz Ghoddousi, Maziar Zareechian, Ali Akbar Shirzadi Javid, Asghar Habibnejad Korayem
12/10/20December 2020Deep Learning Models for Bridge Deck Evaluation Using Impact Echohttps://cptechcenter.org/ncc-projects/deep-learning-models-for-bridge-deck-evaluation-using-impact-echo/acoustic emission tests, Bridge decks, Concrete bridges, machine learning, Neural networks, Nondestructive tests (NDT)Impact echo (IE) is a common nondestructive evaluation (NDE) method to detect subsurface defects in concrete bridge decks. The conventional approach for analyzing the IE data requires user expertise to define analysis parameters that could hinder broad field implementation. In this paper, the feasibility of using deep learning models (DLMs) for autonomous subsurface defect detection in bridge decks using IE has been investigated. A set of eight laboratory-made reinforced concrete bridge specimens with artificial defects were constructed at the Federal Highway Administration Advanced Sensing Technology NDE laboratory. A total number of 2016 of IE data was collected from these specimens. A one-dimensional (1D) convolutional neural network (CNN), and a 1D recurrent neural network using bidirectional long-short term memory units, were developed and applied on the IE data. In addition, two-dimensional (2D) world renowned CNNs were applied on the 2D representatives of the IE data, i.e., spectrograms. The proposed 1D CNN was the most accurate model achieving an overall accuracy of 0.88 by classifying 0.70 of the defects and 0.95 of the sound regions correctly. The proposed 1DCNN was superior to previous machine learning models that were previously used for IE classification. The results of this study showed the feasibility and the potentials of the DLMs for subsurface defect detection. Sattar Dorafshan, Hoda Azari
11/10/20November 2020Review of Ultra-High Performance Concrete and Its Application in Bridge Engineeringhttps://cptechcenter.org/ncc-projects/review-of-ultra-high-performance-concrete-and-its-application-in-bridge-engineering/Bridge decks, Bridge engineering, bridge piers, Durability, Girders, Mechanical properties, Strength of materials, ultra high performance concreteDue to the superior mechanical properties and durability, the ultra-high performance concrete (UHPC) has been widely used for the design of various types of structures, while research on its performance has been rapidly growing in the last five years. While the application of UHPC in bridge engineering is limited due to its higher cost, relatively little is known about the mechanical behavior of UHPC in different bridge components. In order to inform future research needs, this paper provides a comprehensive review of the properties of UHPC and its application in bridge engineering. Applications in various bridge components, such as the piers, girders, decks, and link slabs used for jointless bridges have been summarized. This review also discusses future research on optimized UHPC mix designs considering economic cost and its applications in both jointed and jointless bridges. Junqing Xue, Bruno Briseghella, Fuyun Huang, Camillo Nuti, Habib Tabatabai, Baochun Chen
12/01/19December 2019Experimental Study on the Effect of Hot Climate on the Performance of Roller-Compacted Concrete Pavementhttps://cptechcenter.org/ncc-projects/experimental-study-on-the-effect-of-hot-climate-on-the-performance-of-roller-compacted-concrete-pavement/Absorption, capillary water, Climate, Compressive strength, hot weather, Hydration, Mechanical properties, Roller compacted concrete pavements, Tensile strengthThe aim of this paper is to investigate the effect of hot climate on the performance of roller-compacted concrete which is used for pavement. Mixes were placed in different environments in order to simulate the local climate conditions. Large-scale test has been carried out to assess the mechanical strength development in function of curing mode, temperature treatment and silica fume addition. Compressive strength, splitting tensile strength, shrinkage, and capillary absorption of water were evaluated according to the program tests. The main results showed that an increase in temperature (over 40°) affects negatively the physical and mechanical properties due to malformation of hydration products, while cure methods showed a higher efficiency of the improvement in such properties. However, it should be noted that the wet cure method gave the best results as it provides appropriate and effective conditions to the hydration process. Regarding the effect of silica fume addition, even an improvement in the compressive strength was confirmed; however, it has a negative impact on the shrinkage. Moussa Deghfel, Abdelaziz Meddah, Miloud Beddar, Mohamed Aziz Chikouche
February 2020Thermo-Mechanical Properties of Alkali-Activated Slag–Red Mud Concretehttps://cptechcenter.org/ncc-projects/thermo-mechanical-properties-of-alkali-activated-slag-red-mud-concrete/Alkali aggregate reactions, bauxite, Concrete pavements, Drying, Mechanical properties, Shrinkage, Slag, specific heat, thermal conductivity, waste managementThis study conducts an experimental programme to investigate the possibility of utilising a binary combination of red mud (RM) and slag in the form of alkali-activated slag-RM (AASR) as a useful material for application in jointed plain concrete pavement (JPCP). Slag was replaced with RM at levels of 10%, 20%, 30%, and 40% by weight, and the mechanical, thermal, and dimensional stability properties of the mixtures were measured at various ages. The results show that mechanical strength was reduced with increasing RM. Samples of AASR concrete with 30% RM had the best thermal properties with increases in thermal conductivity and specific heat of 9% and 5%, respectively, over those of neat alkali-activated slag (AAS) concrete. The drying shrinkage of AASR is high and samples with 30% RM had the highest drying shrinkage values of 1.90 and 3.95 times those of neat AAS and ordinary portland cement (OPC) concretes, respectively. A. Bayat, A. Hassani, O. Azami
09/01/19September 2019Performance of Bridge Deck Overlays in Virginia: Phase II: Service Life Performancehttps://cptechcenter.org/ncc-projects/performance-of-bridge-deck-overlays-in-virginia-phase-ii-service-life-performance/Bridge decks, Concrete overlays, Data collection, Durability, Epoxides, Latex modified concrete, Multiple regression analysis, Rehabilitation (Maintenance), Service lifeOverlaying bridge decks has remained one of the best rehabilitation methods to extend their service life, and the Virginia Department of Transportation (VDOT) has been a leader in the use of bridge deck overlays. Although VDOT has extensive experience in overlays, the long-term performance of overlays has not been entirely understood. One of the biggest challenges for studying the performance of overlays is that only minimal information is available in bridge inventory and inspection records. This limits any scientific assessment of this system. Therefore, the purpose of this study was to provide a strong framework for the understanding of the long-term performance of overlays and the factors affecting them. This Phase II report reports on an extensive data collection process that led to the development of a robust database of 133 overlaid bridge decks after verification of historical inspection reports, verification of as-built plans and communication with VDOT district bridge engineers. This helped in developing a model for understanding the amount of time it takes for bridge decks to require the first major rehabilitation and the major factors influencing the durability. A database of information about overlays that were replaced at the end of their functional service life was compiled. This helped develop a multiple regression model for understanding the factors that affected the durability of overlays. Survival analyses were conducted to estimate the service life of overlays and corresponding risk. As a preventive method, epoxy concrete (EC) overlays were predicted to serve an average of 20.9 years, with 18 to 22 years at a 95 percent confidence level. As a rehabilitative method, rigid concrete overlays were predicted to serve an average of 25.9 years, with 21 to 32 years at a 95 percent confidence level. The recent trend of preferred overlay types has been identified as EC and very-early-strength latex-modified concrete (VELMC) overlays. EC overlays have proven to be one of the better performing overlays through extensive VDOT experience. VELMC overlays are an improvement upon latex-modified concrete overlays by vastly reducing the time of construction and thus become more suitable for decreased construction time, reduced traffic disruption, and lessened worker exposure to the field environment. An important discovery was the identification of the influence of the degree of deck damage prior to overlaying on the service life of overlays. Preventive EC overlays should be used in a preventive sense, as the name suggests. If preventive EC overlays are installed on bridge decks with spalls, patches, or delaminations, irrespective of the amount of damage, an increased rate of deterioration in the overlays is likely to follow. The future performance of rehabilitative overlays such as latex-modified concrete, silica fume, and VELMC overlays will not be influenced by the presence of bridge deck damage prior to overlaying. This might be because of the removal of deteriorated concrete before these rigid overlays are constructed. This emphasizes the importance of proper removal of poor quality concrete from bridge decks before overlaying during rehabilitation. Soundar S.G. Balakumaran, Ph.D., P.E., and Richard E. Weyers, Ph.D., P.E
12/31/23December 2023Fiber-Reinforced Concrete Overlays for Bridge Structureshttps://cptechcenter.org/ncc-projects/fiber-reinforced-concrete-overlays-for-bridge-structures/Bridge decks, Corrosion, Cracking, Fiber reinforced concrete (FRC), Overlays (Pavements), Permeability, Ride quality, ThicknessRigid overlays measuring 1.5 to 2 inches are placed on bridge decks to improve the ride quality and lower the permeability of the concrete over the reinforcement. Low permeability concretes resist the penetration of water and harmful solutions into concrete. On the other hand, cracks in concrete can facilitate the intrusion of solutions. Chloride solutions induce corrosion of reinforcement, which is the leading distress in bridge decks. Corrosion products cause cracking and spalling of the concrete above the reinforcement and in later stages can cause failure of the reinforcing bars. Rigid overlays are prone to cracking if proper placement and curing procedures are not followed. Cracks in decks can reflect through the overlays. Rigid low-permeability overlays with synthetic or steel fibers can be placed on bridge decks that will control cracking and resist intrusion of solutions into concrete. These fiber reinforced concretes can enable overlay thicknesses less than 1 inch. Lower thickness can reduce dead load, reduce materials cost, and contribute to sustainability. Celik Ozyildirim, Mary Sharifi
10/31/23October 2023Mass Concrete Mixtures Optimized For Temperature Control and Workabilityhttps://cptechcenter.org/ncc-projects/mass-concrete-mixtures-optimized-for-temperature-control-and-workability/High strength concrete, Mass concrete, Optimization, temperature control (structures), thermal stresses, Virginia Department of Transportation, WorkabilityMass concrete elements are usually heavily reinforced and subject to large thermal change as the concrete cures. The definition of mass concrete is generally based on the minimum dimension of the element, but is more complicated because of the many factors involved. High heat retention in mass concrete causes differential and high temperatures that can result in detrimental cracks. In some applications of mass concrete, high strengths or early strengths are needed, requiring increases in cementitious material contents beyond the usual low amount of cementitious materials needed in mass concrete to keep the temperature from rising too high during cement hydration. Typically, concretes with regular consistency measured by slump test are used in mass concrete elements. However, congestion of the reinforcement in the element combined typically with geometric and placement constraints require concretes with high flow rates, as in self-consolidating concrete (SCC). Such concretes generally have high cementitious material contents for flowability and stability. There is a conflict in the amount of cementitious materials between mass concrete which requires low cementitious contents to control temperature rise and the use of high cementitious contents for early or high strengths and high workability. The cementitious material contents include supplementary cementitious materials, fly ash, and slag cement, for durability and to reduce portland cement contents for temperature control. The objective of this study is to investigate and optimize mass concrete mixtures with regards to temperature control and high workability. Also, the definition of mass concrete will be refined in ways that are helpful to Virginia Department of Transportation (VDOT) in taking precautions to avoid problems that can arise during placement and curing. Celik Ozyildirim, Shabbir Hossain, Mary Sharifi
08/31/23August 2023Use of Sand Lightweight Concrete and All Lightweight Concrete to Improve Propertieshttps://cptechcenter.org/ncc-projects/use-of-sand-lightweight-concrete-and-all-lightweight-concrete-to-improve-properties/Bridge construction, Cracking, Density, Fibers, lightweight concrete, Mix design, Modulus of elasticity, Optimization, sand, Shrinkage, Thermal expansionLightweight concrete (LWC) mixtures are made with lightweight coarse aggregate and normal weight sand — herein referred to as Sand LWC — or have both coarse and fine aggregate that are lightweight, herein referred to as All LWC. Using these lightweight aggregates as ingredients for concrete can enable a variation in the design density for structural elements varying between a practical maximum of about 105 lb/ft3 for All LWC and a maximum of 120 lb/ft3 for Sand LWC, which will be investigated in this study to determine the optimum proportions. The reduced density compared to normal weight aggregates enables a reduction in dead weight enabling longer spans, more slender columns, and fewer piers in structures, or larger precast elements for accelerated bridge construction (ABC). Either type of LWC also has reduced cracking potential because of internal curing, lower elastic modulus, and lower thermal coefficient of expansion. These benefits enable improved curing, and minimize shrinkage and thermal stresses resulting in less cracking and improved durability. This study will also investigate fibers in LWC to further control cracking. LWC can be used in patch repairs, piers, footings, decks, overlays, and other elements where reducing weight or avoiding cracking is desirable. The purpose of this study is to optimize mixture proportions for Sand LWC and All LWC to enable consistent low density, good workability, and reduced cracking potential. Tests will be conducted to determine the density, modulus of elasticity, coefficient of thermal expansion, shrinkage, and the curing efficiency. Celik Ozyildirim, Harikrishnan Nair, Mary Sharifi
09/30/22September 2022Repair or Strengthening of Bridge Decks with Partial-Depth Precast Deck Panelshttps://cptechcenter.org/ncc-projects/repair-or-strengthening-of-bridge-decks-with-partial-depth-precast-deck-panels/Bridge decks, DelaminationThis research will provide methods to economically repair or strengthen structurally delaminated decks built using partial-depth precast concrete deck panels with minimal interruption of traffic. The primary objective of this UDOT research project is to develop and recommend a strengthening and repair method to re-laminate the precast concrete panel and cast-in-place (CIP) deck, ensure composite behavior through mechanical connections, or strengthen the panel such that bridge deck delamination does not pose a safety risk. Secondary objectives of this research project are to provide guidelines for repair/strengthening methods and develop a set of draft working drawings and draft specifications. David Stevens, Chris Pantelides
02/28/23February 2023Investigation and Assessment of Effective Patching Materials for Concrete Bridge Deckshttps://cptechcenter.org/ncc-projects/investigation-and-assessment-of-effective-patching-materials-for-concrete-bridge-decks/Bridge decks, PatchingPatching of deteriorated portions of concrete bridge decks is an important repair activity that has to be conducted in a timely manner to maintain the serviceability and extend the longevity of these vital links in our transportation infrastructure. Currently, the South Carolina Department of Transportation (SCDOT) specifies the use of ready-mix concrete (plant-produced) for bridge-deck patching. Alternative rapid set patching materials that are amenable to on-site batching and mixing with excellent bond characteristics and accelerated cure rates are desirable. The objectives of the research are to: (1) develop of a curated set of alternate repair materials; (2) develop a process of rapid investigation techniques through non-destructive testing to identify the cause and extent of deterioration in the bridge deck; and (3) develop guidelines, based on the above, to appropriately select suitable repair methods and materials. Prasada Rangaraju
12/31/23December 2023Alternative High Early Strength Concrete (HESC) Structural Overlayshttps://cptechcenter.org/ncc-projects/alternative-high-early-strength-concrete-hesc-structural-overlays/Bridge decks, High early strength cement, High strength concrete, Overlays (Pavements), SpecificationsThe objective of this research project is to identify the obstacles or impediments to successfully and reliably using high early strength concrete (HESC) for structural bridge deck overlays on Oregon bridges and to develop the standards, specifications, processes, and practices necessary to using them on Oregon Department of Transportation (ODOT) bridges. Matthew Mabey, Jason Ideker
12/01/22December 2022Analysis of Mitigating Concrete Cracks with Bacteriahttps://cptechcenter.org/ncc-projects/analysis-of-mitigating-concrete-cracks-with-bacteria/bacteria, calcites, Concrete bridges, Cost effectiveness, Costs, Cracking of concrete pavements, Feasibility analysis, Freeze thaw durability, Maintenance, Mix design, Service life, Strength of materials Incorporating bacteria into concrete has been proposed as a method of mitigating the negative impacts of concrete cracking, and may also lead to increased strength and durability through calcium carbonate precipitation and porosity reductions by the bacteria. This study aimed to increase understanding of the use of microorganisms in concrete by investigating: performance of axenic and environmentally-derived bacteria cultures to increase resiliency of bacteria for use in upscaled use in concrete systems; effects of curing method and exposure to hot and cold temperatures and salts; and performance of bacteria in a pilot scale pavement application. In this work, B. subtilis was used as an axenic strain and a non-axenic bacterial system was produced from Columbus, Ohio soil. The effects of pH, growth time, incubation temperature, and nutrient solution concentration were compared with their effectiveness in generating dense bacterial cultures capable of biomineralization. Changes in compressive strength, electrical resistivity, sorptivity, and drying shrinkage in paste, mortar, and concrete samples incorporating bacteria were compared to controls. Varying curing regimes (ponding of the samples and daily spraying) were evaluated for their ability to induce biomineralization and crack healing. The effect of environmental factors including cold and hot weather temperatures, and exposure to deicing salt solution were evaluated. Numbers of living bacterial cells were tracked across all samples to link numbers of cells with changes in performance. The results demonstrate that bacteria are capable of healing cracks <0.3mm in width, and non-axenic bacterial cultures can be used to promote biomineralization and crack healing. Existing concrete mixture designs using portland cement and fly ash can be used with bacterial solutions. Calcium sulfoaluminate (CSA) cement can also be used, and provided a better environment for preserving living bacterial cells within the paste over time. CSA showed slightly better improvements to microstructure and crack healing over time compared to OPC mixtures. A lightweight aggregate must be incorporated into mortar and concrete mixtures, replacing a portion (~10%) of the fine aggregate, in order to protect the bacteria during the initial mixing process. Nutrient solution provided to the bacteria to induce biomineralization and heal cracks should be applied through spraying in order to generate the best crack healing potential. Exposure to hot and cold temperatures and salt solutions resulted in bacterial cell death and reduced the crack healing potential of the bacteria. Finally, simple life-cycle evaluations indicated only minor improvements in service life, although the evaluation method used could not account for cracking healing effects. Production and use of bacteria approximately doubled the cost of concrete during the initial construction period. Lisa Burris, Natalie Hull, Zeynep Basaran Bundur, Cansu Acarturk, Judith Straathof, Yijing Liu, Ilgin Sandalci
02/01/22February 2022Durability of Concrete Produced with an Alternative Supplementary Cementitious Materialhttps://cptechcenter.org/ncc-projects/durability-of-concrete-produced-with-an-alternative-supplementary-cementitious-material/Alkali silica reactions, Cement, Concrete, Durability, Fly ash, Literature reviews, Mix design, PozzolanNew Mexico contains several aggregate sources that are extremely susceptible to alkali-silica reaction (ASR). To mediate ASR, the New Mexico Department of Transportation (NMDOT) requires a minimum of 20% class F fly ash (by mass of cement) in nearly all concrete produced for their projects. However, class F fly ash has become difficult for concrete producers to procure, and future availability is uncertain. Consequently, NMDOT is considering adopting alternative supplementary cementitious materials (SCMs) that could be used in place of class F fly ash. The purpose of this research project is to assess one of the alternative SCMs being considered for potential acceptance by NMDOT. The SCM to be studied is a natural pozzolan mined from a pumicite deposit near Espanola, NM. Natural pozzolans are a class of siliceous or siliceous and aluminous materials that possess little or no cementitious value by themselves, but can react chemically with calcium hydroxide and water at ordinary temperatures to form compounds possessing cementitious properties that can improve concrete strength and durability. NMDOT has little data for mixture proportions and durability properties of concrete produced with this material, so they are not able to confidently accept the material for use in concrete produced for NMDOT projects, even if class F fly ash is not available. This research project consists of a comprehensive literature review to identify the most important properties and characteristics of SCMs, and especially natural pozzolans, in terms of their influence on concrete durability. For the experimental work to be conducted in this study, a suite of concrete mixtures, similar to currently accepted NMDOT mixtures, will be proportioned using the natural pozzolan to replace different percentages of fly ash. Concrete produced from these mixtures will be tested for slump, air content, compressive strength, and flexural strength to ensure that the mixtures provide adequate workability and strength. Then, the durability of the concrete mixtures will be tested by assessing their chloride permeability, resistance to freezing and thawing, susceptibility to ASR, and their shrinkage characteristics. Results from mixtures containing the natural pozzolan will be compared to control mixtures produced using NMDOT concrete mixtures containing only class F fly ash. The implementation phase of the project includes documenting and disseminating the results of the research. Dissemination of the results will include the final report for the project, publication of journal papers, publication of conference papers, and presentations at conferences. The New Mexico State University (NMSU) research team is led by the PI, Professor Craig Newtson, who has over 20 years of concrete related research experience on projects totaling more than $2,300,000 in funding. The team also includes Associate Professor Brad Weldon as a Co-PI. Dr. Weldon has supervised more than $1,300,000 in funded research projects and has received national recognition for his research. Craig Newtson
12/31/21December 2021Zero Speed Profiler Assessment for Pavement Smoothness and Continuous Pavement Texture Measurementshttps://cptechcenter.org/ncc-projects/zero-speed-profiler-assessment-for-pavement-smoothness-and-continuous-pavement-texture-measurements/Continuously reinforced concrete pavements (CRC pavements), Highway bridges, Pavement distress, Pavement maintenance, Preservation, Rehabilitation (Maintenance), Skid resistance, Smoothness, Specifications, speed, State of the art, Texture, Urban highwaysThe primary goal of this proposal is to evaluate a state of the art technology in roadway profiling called Zero Speed Profiling. Conceptually developed under NCHRP Project 10-93, “Measuring, Characterizing, and Reporting Pavement Roughness of Low-Speed and Urban Roads,” this research study will evaluate the methodologies and concepts proposed in NCHRP 10-93 on New Jersey pavements and bridges. It is anticipated that with successful implementation, the Zero Speed Profiler will provide a better assessment of the current pavement profile when compared to the High Speed Profiler. A more realistic and comprehensive pavement surface assessment will result in better decisions regarding how to preserve or rehabilitate the pavement. The first implementation task to be proposed will be presentations of research findings to the NJDOT, NJ State asphalt industry and federal agency members (FAA and FHWA). The second Implementation task proposed will be a workshop consisting of how the Zero Speed Profiler and its respective capabilities can be beneficial to local, state, and federal agencies required to monitor highways. Lastly, based on the availability of the interested agencies, it will be recommended that the technologies be introduced through pilot projects to create a real-world scenario where the Zero Speed Profiler can be utilized and the proposed specification be evaluated thoroughly prior to full implementation. Sue Gresavage, Patrick Szary, Michael Boxer, John Hencken
02/25/20February 2020Examination of a Geocomposite Joint Drainhttps://cptechcenter.org/ncc-projects/examination-of-a-geocomposite-joint-drain/Composite materials, Drainage, Joints (Engineering), Loads, Pavement design, Pavement performanceInadequate subsurface drainage tremendously impacts pavement performance. Pavement foundation models in various degrees of superposition and complexity including the Winkler foundation model idealized as a dense liquid, the two-parameter Vlaslov model and the three-parameter Kerr foundation model are indispensable idealizations in the mechanistic-empirical design processes. These design idealizations of foundation types are confounded by undrained or poorly drained subsurface conditions of erodible base and subgrade materials associated cracking, faulting, and accelerated degradation of surface ride quality. In concrete pavements, in particular inadequately drained bases have caused surface joint-spalling, mid-depth joint-cavitation-induced-scouring, and bottom trapezoidal-erosion of the concrete. In addressing this challenge, research examined characteristics of a geocomposite joint drain (GJD) as a subsurface drainage material. This research showed that the numerous benefits of geocomposite joint drain are not limited to lateral stability under load, lateral transmissivity as well as ease of construction and reduction in overall pavement structural thickness. Bernard Igbafen Izevbekhai
02/25/20February 2020Effect of Geogrid Stabilization on Performance of Granular Base Course over Weak Subgradehttps://cptechcenter.org/ncc-projects/effect-of-geogrid-stabilization-on-performance-of-granular-base-course-over-weak-subgrade/Base course (Pavements), Deformation, deformation curve, Geogrids, Geosynthetics, Granular materials, Pavement design, Pavement performance, Subgrade (Pavements)For years, geosynthetics have been placed at the interface between the granular base course and the weak subgrade of pavement sections to provide stabilization. Geosynthetics may provide physical stabilization (i.e., separation), mechanical stabilization (lateral restraint), and reinforcement (tensioned membrane effect). For pavement design, allowable deformation is typically limited to 13 mm or less, so only separation and lateral restraint are mobilized in the pavement section. Although geosynthetics provide marked improvements in soil stabilization and pavement performance, a single approach to account for these improvements by separation and lateral restraint has not been well established. Various geosynthetics allow for different design considerations in varying climatic and load-intensity situations. This study focuses on geogrids but uses non-stabilized sections as control sections. Products were selected from a state department of transportation pre-approved materials list in order to remove bias in selection and to mimic the potential selection process in practice. Geosynthetics were installed at the interface of 250 mm of vibratory-compacted granular base course and weak subgrade in large-scale box tests. Cyclic loading was applied at eleven load intensities or until 25 mm maximum deformation was achieved. Permanent displacement at the surface of the base course and interface pressure beneath the geosynthetic (at the top of the subgrade) were recorded. Stress distribution angle and stress patterns at the bottom of the base course were observed. This paper discusses the effects of geogrid as a means of stabilization in terms of interface stress reduction as well as the ratio of permanent to resilient deformation. In this study, replacement of virgin aggregate with recycled concrete aggregate reduced the interface stress by 55%; addition of geogrid to both sections further reduced measured interface stresses. Addition of geogrid effected greater permanent deformation but a smaller incremental deformation in both VGB and RCA. The implications for pavement performance are also discussed. Tanya N. Walkenbach, Jie Han, Robert L. Parsons, Zexia Li
02/25/20February 2020Effect of Concrete Grinding Residue on Roadside Soil Propertieshttps://cptechcenter.org/ncc-projects/effect-of-concrete-grinding-residue-on-roadside-soil-properties/calcium, Chemical properties, Concrete pavements, Diamond grinding, electrical conductivity, Environmental impacts, Field studies, roadside, Waste products (Materials)During diamond grinding operations for smoothing concrete pavement surfaces, water is used to cool the diamond blades. This water, combined with cutting residue, generates a high pH and high alkaline slurry byproduct referred to as concrete grinding residue (CGR). Although spreading CGR along roadsides is one of the most commonly used disposal methods, it is always of concern because of its potential effect on roadside soil properties. A field study was therefore conducted in 2016 on two roadside slopes beside Highway I-90 in Minnesota on which CGR slurries were offloaded in 2009 and 2013, respectively. The chemical properties of soils that received this CGR were measured and compared with those of adjacent soils that had not received CGR. The areas after receiving CGR slurry exhibited that pH reduced by 0.78 while electrical conductivity (EC) and calcium concentration increased by 0.48 ds m-1 and 97 mg kg-1, respectively. Because spreading of CGR did not cause any perceptible reduction in soil quality, CGR was not deemed to be of long-term concern with respect to roadside environments. Bo Yang, Yang Zhang, Chenyl Luo, Bora Cetin, Halil Ceylan, Sunghwan Kim, Robert Horton
06/30/20June 2020National Road Research Alliance (NRRA): Short-Term Research Projectshttps://cptechcenter.org/ncc-projects/national-road-research-alliance-nrra-short-term-research-projects/Asphalt mixtures, Best practices, Bituminous overlays, Concrete overlays, Overlays (Pavements), sprays (materials)There will be four short-term projects: a) Mix Rejuvenator Synthesis - the objective is to identify the types of asphalt mix rejuvenators available and their performance to date; b) Concrete Pavement Restoration (CPR) for Bonded Concrete Overlays of Asphalt - the objective is to develop and publish a synthesis of best practices being used by NRRA state members in repairing Bonded Concrete Overlays of Asphalt; c) Service Life Enhancement of Substrates Overlaid with Thin Overlays - the objective is to determine the service lives for the three non-structural overlays and deduce the service life enhancements that these non-structural overlays contribute to the identified flexible substrates on which the overlays were placed based on the pavement management data from the NRRA member states; d) NRRA Spray on Rejuvenator Synthesis - the objective is to document the field projects constructed to evaluate spray on rejuvenators by NRRA member states, National Center for Asphalt Technology (NCAT), NCHRP, Minnesota cities and counties, including recent research projects performed by Missouri DOT with Applied Research Associates, Inc. Lisa Jansen
06/30/21June 2021Incorporation of Joint Faulting Model into BCOA-MEhttps://cptechcenter.org/ncc-projects/incorporation-of-joint-faulting-model-into-bcoa-me/Asphalt, Climate, Concrete overlays, Faulting, Web applicationsFaulting of joints has been observed to be a common distress in Bonded Concrete Overlays on Asphalt (BCOA). However, faulting is not considered in any of the current design procedures for BCOA. Faulting is caused by pumping forces which remove supporting materials either at the bottom of the overlay slab within the asphalt layer or below the asphalt in the granular layer. This location is dictated by the depth of joint propagation. Current faulting design procedures, such as those incorporated into Pavement ME, were developed considering only jointed plain concrete pavements (JPCP). It is possible to use the current design software to predict joint faulting for full-lane width BCOAs, but it is calibrated with JPCP faulting data. JPCPs are typically thicker than BCOAs and have longer panel lengths. There are also a number of equivalency concepts employed in the Pavement ME to simplify the analysis, including equivalent thickness, equivalent temperature gradient, and equivalent slab that are not appropriate for BCOAs. Work is underway at the University of Pittsburgh to incorporate a faulting model into the BCOA-ME design procedure. That work is being funded by PennDOT and focuses on the impact of the climate in Pennsylvania. To adopt this for NRRA member states, a significantly larger range of climatic conditions must be consider. The proposed work will be performed so that the faulting model developed under the PennDOT project can be expanded to include climate stations in NRRA member states.Julie Vandenbossche, John Donahue
01/31/21January 2021Repair of Joint Associated Distress Pavementshttps://cptechcenter.org/ncc-projects/repair-of-joint-associated-distress-pavements/Best practices, Concrete overlays, Concrete pavements, Pavement distress, technical reportsThe objective of this project is to produce a short technical brief and webinar containing the best practices for the repair of distressed joints in concrete pavements and overlays, particularly those used in National Road Research Alliance (NRRA) member states. The tech brief will include causes for the distresses, as well as case histories of successful and non-successful repair methods. A one-hour webinar will also be developed, delivered, and recorded for future reference. Peter Taylor
07/31/22July 2022Internal Friction Angle of Sands with High Fines Contenthttps://cptechcenter.org/ncc-projects/internal-friction-angle-of-sands-with-high-fines-content/cohesion, cohesionless materials, Concrete, Fines (materials), Friction, Piles (Supports), sandy soils, steelThere are three main objectives of this study. The first is to evaluate the effect of fines content on the value of internal friction angle of sand soils mixed with fines typically encountered in Louisiana. The second objective is to evaluate the effect of fines content on the interface friction angle between sand soils mixed with fines and both concrete and steel surfaces. Lastly, the study will determine the threshold percent of fines content beyond which the sand soils mixed with fines will behave as cohesive soils, rather than cohesion less soils, and the effect on design of driven piles. Zhongjie Zhang, Murad Abu-Farsakh
02/01/22February 2022Evaluation of Alternative Sources of Supplementary Cementitious Materials (SCMs) for Concrete Materials in Transportation Infrastructurehttps://cptechcenter.org/ncc-projects/evaluation-of-alternative-sources-of-supplementary-cementitious-materials-scms-for-concrete-materials-in-transportation-infrastructure/Cement, Clay, Concrete, Durability, Fly ash, Materials, PozzolanConcrete materials are present in almost all types of transportation infrastructure including roads, bridges, and airports. As such, concrete is an essential component of the transportation infrastructure. Supplementary cementitious materials (SCMs) are a key ingredient of modern concrete. SCMs improves the durability (e.g., decreases permeability and help mitigate deleterious reactions) and mechanical properties of concrete and significantly reduces its carbon footprint by reducing the utilization of clinker. In recent years, the decline in coal-fired power generation in the U.S. jeopardizes the wide availability of fly ash for concrete production. Since fly ash is vastly the most utilized supplementary cementitious material (SCM) in the US, there is an urgent need to find alternative sources of SCMs that can provide with a portfolio of alternatives. As a response to the expected shortage of fly ash, the objective of this project is to evaluate the much-needed alternative sources of SCMs which can include unconventional sources of fly ash (i.e., landfilled and impounded fly ash), natural pozzolans, and calcined clays to provide with high-quality, cost-effective, and readily-available SCM alternatives for the future of concrete production in Region 6. Momen Mousa, Gabriel Arce, Miladin Radovic, Zahid Hossain
02/01/22February 2022Determination of the Optimal Parameters for Self-Healing Efficiency of Encapsulated Bacteria in Concrete in a Simulated Subtropical Climatehttps://cptechcenter.org/ncc-projects/determination-of-the-optimal-parameters-for-self-healing-efficiency-of-encapsulated-bacteria-in-concrete-in-a-simulated-subtropical-climate/bacteria, Concrete, Durability, encapsulation, RepairingThe main objective of this research study is to optimize self-healing mechanisms of encapsulated bacteria in concrete, and to evaluate whether a higher bacteria cell concentration, better nutrient selection, or an alternative encapsulation method is needed. These parameters will be first tested in mortar beams with respect to self-healing efficiency, and depending on the results, further testing will be carried out in concrete specimens. The efficiency of the proposed bio-concrete will be tested to evaluate the bacteria’s effect on concrete’s intrinsic properties such as compressive strength and static modulus of elasticity, and monitor the self-healing efficiency through crack repair throughout 28 wet-dry cycles (consisting of 8 hours of water immersion and 16 hours of drying). If successful, this project will move to implementation through field-testing in Region 6, where it will help to preserve and enhance the performance of the concrete transportation infrastructure. Momen Mousa
02/15/22February 2022Durability of Rapid-Hardening-Cement Concretehttps://cptechcenter.org/ncc-projects/durability-of-rapid-hardening-cement-concrete/Durability, High early strength cement, Kansas Department of Transportation, Portland cement concreteCertain high importance paving applications such on-ramps and intersections or maintenance operations such as full depth pavement repair benefit from the application of high early strength materials that require minimal lane down time by allowing traffic in a matter of hours. These concrete mixtures can be produced using Type III portland cement with accelerating admixtures, but concrete mixtures with other modern rapid hardening cement formulations are also likely to be suitable. Rapid hardening hydraulic cement is specified in the KDOT Standard Specification, Section 2009. Section 1716 specifies pre-packaged rapid hardening patching materials. Depending on the particular paving or repair operation being conducted, concrete mixtures may be required to achieve a minimum of 1,800 pounds per square inch (psi) in compressive strength or 380 psi in flexural strength before the road is opened to traffic, as listed in Section 833 of the Kansas Standard Specifications for State Road & Bridge Construction (KDOT 2015). These novel cements have varying chemical formulations and are governed by ASTM C1600. The rapid hardening cements are able to easily meet the strength requirements within a few hours however to date there has been little testing to evaluate the durability of ASTM C1600 cement concrete and the testing that has been performed shows mixed results with significant vulnerabilities for certain conditions. KDOT requires ASTM C666 testing for such mixtures with Durability Factor not less than 90% nor expansion greater than 0.1%. It is assumed that the same mechanisms that affect portland cement concrete freezing and thawing durability are also relevant for rapid setting cement concrete and similar techniques for combating these mechanisms will be effective. In particular, air entrainment, the use of otherwise durable aggregates, and low mixture permeability after drying are all expected to beneficially impact freeze-thaw durability. Given the mixed results in evaluating the durability of high early strength portland cement concrete, investigating the suitability of ASTM C1600 cement concrete for paving operations in Kansas appears well justified. Furthermore, with commercially available rapid hardening cement concrete in the Kansas City metro area, developing the technical basis to evaluate the expected durability of these materials for KDOT is required. In the KTRAN project KSU-17-2, the durability of representative high early strength mixtures was assessed by measuring freeze-thaw resistance according to KTMR-22 procedures. Interestingly, only one tested mixture achieved the KDOT required KTMR expansion threshold and only three of six passed the required relative dynamic modulus of elasticity threshold. While this supported the field based observations that high early strength mixtures are not durable, the research offers few solutions to help KDOT better specify concrete patching mixture requirements. Additionally, it was observed that the calcium chloride accelerator significantly confused the interpretation of resistivity based measurements for the concrete by “short-circuiting” the resistivity test. Finally, it was anecdotally observed that achieving repeatable air content values with these mixtures was very difficult. In the ongoing project, KSU-20-5, the durability of high early strength concrete mixtures with non-calcium chloride accelerators are being assessed. In addition, the inclusion of highly active pozzolons such as metakaolin, microsilica, and ultra-fine fly ash are being evaluated to further reduce the cement quantity and permeability of the resultant concrete. Internal curing via the use of saturated lightweight aggregates is also under evaluation. Dan Wadley, Christopher Jones
08/31/22August 2022SPR-4513: Determining Optimal Traffic Opening Time through Concrete Strength Monitoring – Wireless Sensinghttps://cptechcenter.org/ncc-projects/spr-4513-determining-optimal-traffic-opening-time-through-concrete-strength-monitoring-wireless-sensing/Compressive strength, Concrete pavements, Construction scheduling, lane closure, Nondestructive tests (NDT), Optimization, Sensors, Stiffness, wireless communication systemsThe research team has successfully developed and implemented a nondestructive testing (NDT) method using piezoelectric sensors to measure real-time concrete strength and stiffness. However, the current hardware and software are bulky and inconvenient for field implements. This project will develop a wireless sensor with hand-held devices or portable terminals, and associated graphic interface, to make devices easy for field implementation. Na Lu
11/30/22November 2022SPR-4526: Predictive Analytics for Quantifying the Long-Term Cost of Defects During Bridge Constructionhttps://cptechcenter.org/ncc-projects/spr-4526-predictive-analytics-for-quantifying-the-long-term-cost-of-defects-during-bridge-construction/Asset management, Bridge construction, Bridge decks, Concrete bridges, cost estimating, Costs, Defects, Inspection, Life cycle costing, Mathematical predictionInspecting bridges during construction and in service, and ensuring quality construction prior to acceptance and proper maintenance, are critical to the life-cycle performance of the structure. The goal of this project is to develop predictive analytics that would allow a more effective asset management. This approach will be demonstrated using concrete bridge decks as an illustrative example. The project will provide the knowledge and tools needed to estimate the costs associated with the consequences of defects occurring during construction (i.e., substandard quality), and weigh those against cost and expected performance of additional measures that can be taken to reduce such defects (e.g., improved inspection procedures). Shirley Dyke, Julio Ramirez
12/20/20December 2020Bridge Decks: Mitigation of Cracking and Increased Durability—Materials Solution (Phase III)https://cptechcenter.org/ncc-projects/bridge-decks-mitigation-of-cracking-and-increased-durability-materials-solution-phase-iii/Admixtures, Bridge decks, Cracking, Durability, Lightweight aggregates, Mix design, Shrinkage, Slump test, Water cement ratioType K cement offers a lower slump than conventional concrete, even at a higher water-to-cement ratio. Therefore, a suitable chemical admixture should be added to the Type K concrete mix design at a feasible dosage to achieve and retain target slump. In this project, a compatibility study was performed for Type K concrete with commercially available water-reducing and air-entraining admixtures. Slump and air content losses were measured over a period of 60 minutes after mixing and a particular mid-range water-reducing admixture was found to retain slump effectively. Furthermore, no significant difference in admixture interaction between conventional and Type K concrete was observed. Another concern regarding the use of Type K concrete is that its higher water-to-cement ratio can potentially lead to higher permeability and durability issues. This study also explored the effectiveness of presoaked lightweight aggregates in providing extra water for Type K hydration without increasing the water-to-cement ratio. Permeability of concrete was measured to validate that the use of presoaked lightweight aggregates can lower water adsorption in Type K concrete, enhancing its durability. Extensive data analysis was performed to link the small-scale material test results with a structural test performed at Saint Louis University. A consistent relation was established in most cases, validating the effectiveness of both testing methods in understanding the performance of proposed shrinkage-mitigation strategies. Stress analysis was performed to rank the mitigation strategies. Type K incorporation is reported to be the most effective method for shrinkage-related crack mitigation among the mixes tested in this study. The second-best choice is the use of Type K in combination with either presoaked lightweight aggregates or shrinkage-reducing admixtures. All mitigation strategies tested in this work were proved to be significantly better than using no mitigation strategy. Robin Deb, Paramita Mondal, Ardavan Ardeshirilajimi
12/10/20December 2020Bridge Decks: Mitigation of Cracking and Increased Durability—Phase IIIhttps://cptechcenter.org/ncc-projects/bridge-decks-mitigation-of-cracking-and-increased-durability-phase-iii/Admixtures, Bridge decks, Cracking, deformation curve, Durability, Expansion, Finite element method, gypsum, Lightweight aggregates, Mix design, prototype tests, ShrinkageEarly-age cracking in concrete decks significantly reduces the service life of bridges. This report discusses the application of various concrete mixtures that include potential early mitigation ingredients. Large-scale (7 ft × 10 ft) experimental bridge prototypes with similar restraint conditions found in actual bridges were poured with different concrete mixtures to investigate mitigation techniques. Portland cement (control), expansive Type K cement, internally cured lightweight aggregate (LWA), shrinkage-reducing admixture (SRA), and gypsum mineral were investigated as mitigating ingredients. Seven concrete mixtures were prepared by using individual ingredients as well as a combination of different ingredients. The idea behind combining different mitigating techniques was to accumulate the combined benefit from individual mitigating materials. The combined Type K cement and LWA mixture showed higher concrete expansion compared with mixtures containing portland cement, Type K cement, LWA, and SRA in the large-scale experimental deck. Extra water provided by LWA significantly enhanced the performance of Type K cement’s initial expansion as well as caused larger total shrinkage over the drying period. A combination of Type K cement and gypsum mineral showed insignificantly higher expansion compared with the individual Type K mixture. Overall, the experimental deck containing SRA showed the least total shrinkage compared with other mixtures. Finite-element modeling was performed to evaluate and predict concrete stress-strain behavior due to shrinkage in typical bridges. A parametric study using finite-element analysis was conducted by altering the structure of the experimental deck. More restraint from internal reinforcement, less girder spacing, larger girder flange width, and more restrictive support conditions increased the concrete tensile stress and led to potential cracking in the concrete deck. Mohammad Rahman, Ahmed Ibrahim, Riyadh Hindi
04/29/19April 2019Effect of Joint Spacing and Pavement Thickness on Concrete Overlay Performancehttps://cptechcenter.org/ncc-projects/effect-of-joint-spacing-and-pavement-thickness-on-concrete-overlay-performance/AASHTOWare Pavement ME Design (software), Concrete overlays, Durability, international roughness index, Maintenance, pavement condition index, Pavement maintenance, Pavement performance, rehabilitation, Service lifeConcrete overlays provide cost-effective maintenance and rehabilitation strategies for pavement systems. A database has been developed in Iowa that records the historical performance of overlays based on records of international roughness index (IRI) and pavement condition index (PCI) over a 20-year period. Based on these data concrete overlay service life has been modeled for various joint spacings. The data demonstrate that durability and service life can be improved. A review of PCI data indicates that improving construction quality to eliminate premature failure has the potential to add at least 10 years to the service life of PCC overlays. Even though concrete overlay technology is not a new concept, most of its design procedures still follow empirical methods; therefore, this study applied AASHTOWare Pavement ME Design (Version 2.3.1) software to identify the effects of design para ms on concrete overlay service life. The theoretical insights provided by Pavement ME Design were compared with historical performance data and used to provide recommendations with respect to optimized joint spacing in overlay pavement structures. Comparison of the historical performance-related data with Pavement ME Design software results indicates that the Pavement ME Design software is conservative in predicting concrete overlay service life. Yu-An Chen, Peter C. Taylor, Halil Ceylan, Sunghwan Kim, Xuhao Wang
08/25/23August 2023Recommendations for Future Specifications to Ensure Durable Next Generation Concretehttps://cptechcenter.org/ncc-projects/recommendations-for-future-specifications-to-ensure-durable-next-generation-concrete/Best practices, Durability, Georgia Department of Transportation, Guidelines, high performance concrete, Performance based specifications, Performance tests, Test proceduresThe objectives of this research effort include: (1) to provide a review of current “best practices” for the development and implementation of performance-based specifications (PBS) for concrete for transportation projects, (2) to review available performance test methods and criteria for performance, relevant to environmental conditions and traffic patterns in the state, (3) to quantify savings to the state comparing prescriptive and performance specification, and (4) to generate guidelines for incorporating PBS as an option in Sections 430, 439, and 500. Sarah Lamothe, Kimberly Kurtis
02/20/22February 2022Recommendations for Nondestructive Testing (NDT) of Concrete Components for Performance-Based Specificationshttps://cptechcenter.org/ncc-projects/recommendations-for-nondestructive-testing-ndt-of-concrete-components-for-performance-based-specifications/Concrete tests, Nondestructive tests (NDT), Performance based specifications, Physical properties, physics, Recommendations, Test procedures, Transportation departments, ValidationThe proposed research will document the availability and the use of concrete nondestructive testing (NDT) tools by transportation agencies; study the critical concrete material properties and suitable acceptance criteria for performance-based concrete material specifications; understand the underlying physics and sensitivity of candidate NDT tools; and validate the most promising NDT tools. The objectives of the proposed research are to: (1) Document available concrete NDT tools and their use by transportation agencies; (2) Establish critical concrete material properties and suitable acceptance criteria for performance-based concrete material specifications; (3) Understand the underlying physics, reliability, and sensitivity of candidate NDT tools; and (4) Validate the most promising NDT tools to demonstrate overall effectiveness.Sarah Lamothe, Laurence J. Jacobs
08/18/23August 2023Recommendations for Extension in Service Life of ASR-Affected Concretehttps://cptechcenter.org/ncc-projects/recommendations-for-extension-in-service-life-of-asr-affected-concrete/Alkali silica reactions, Best practices, Concrete, Condition surveys, Recommendations, Repairing, Service lifeThe objectives of this research effort include: (1) providing a review of current technology and “best practices” for extending the service of alkali–silica reaction (ASR)-affected concrete, (2) developing approaches for assessing condition state in potentially ASR-affected concrete and determining potential for further reaction and damage, and (3) developing combined material and structural repair strategies to extend the service life of ASR-affected concrete. The effective assessment and repair techniques for extending the service life of ASR-affected concrete, will be presented in Georgia Department of Transportation (GDOT) Specification/Special Provision format. Supriya Kamatkar, Kimberly Kurtis
10/14/22October 2022Quality Assurance (QA) Aspects of Performance-Related Specifications (PRS)https://cptechcenter.org/ncc-projects/quality-assurance-qa-aspects-of-performance-related-specifications-prs/Fatigue (Mechanics), Laboratory tests, Mix design, Pavement performance, Performance based specifications, quality assurance, Rutting, SoftwareThe objective of this research is to develop guidance to integrate the performance predictive capabilities of the PASSFlexTM software and its suite of tools (FlexPAVETM version 2.0, FlexMATTM, and FlexMIXTM) within a statistically sound QA system in a PRS framework. The research shall address: (a) the use of the cyclic fatigue Sapp and SSR allowable traffic for rutting (ATR) index test parameters, index thresholds, and acceptance limits in support of performance engineered mixture design (PEMD) approaches and to facilitate further implementation of the tests and performance predictions, (b) material selection and mixture design changes that can impact the test results (cyclic fatigue, SSR, and their index parameters) and trends associated with owner agency specified performance thresholds, and (c) the major elements of a QA system (per TRB E-Circular 235, Glossary of Transportation Construction Quality Assurance Terms, http://onlinepubs.trb.org/onlinepubs/circulars/ec235.pdf) and associated buyer/seller and payment risks. Edward Harrigan, Randy West
11/23/20November 2020Long-Term Pavement Performance Data Analysis Program: Effect of Dowel Misalignment on Concrete Pavement Performancehttps://cptechcenter.org/ncc-projects/long-term-pavement-performance-data-analysis-program-effect-of-dowel-misalignment-on-concrete-pavement-performance/Concrete pavements, Cracking, Data analysis, Dowels (Fasteners), Pavement joints, Pavement performance, Spalling, Statistical analysis, TomographyMagnetic imaging tomography (MIT) scanning is a nondestructive method for measuring the alignment of dowels placed at transverse joints of jointed plain concrete pavements (JPCPs). Several highway agencies across the United States have adopted specifications for dowel alignment, with many using the joint score measure. However, this measure was developed intuitively and not based on any laboratory or field tests. National Cooperative Highway Research Program (NCHRP) Report 637 provides a methodology to determine an equivalent dowel diameter measure based on dowel misalignment (Khazanovich et al. 2009). This procedure was developed from laboratory tests and with limited field validation. The relationship between dowel misalignment and the performance of JPCP is unclear, but understanding it is imperative for developing construction guidelines. This report presents results of MIT scanning data collected on Long-Term Pavement Performance (LTPP) test sections and data analysis to assess the effects of dowel misalignment on JPCP performance. As part of this study, MIT scanning was performed on 121 Specific Pavement Studies-2 and 3 General Pavement Studies-3 test sections. Dowel alignment parameters, joint score, and equivalent dowel diameter were calculated as part of the analysis. Statistical analysis was performed to determine any relationship between the joint score and cracking and between the joint score and spalling. The analysis did not indicate any definitive relationship between the joint score and cracking or the joint score and spalling within the analysis range for most States, although some effect was observed for three States. This lack of relationship does not mean severely misaligned dowels have no effect on pavement performance, particularly localized distresses. Analysis of the equivalent dowel diameter as a measure of dowel misalignment for use with AASHTOWare Pavement ME Design software suggests that using the equivalent dowel diameter is a less-biased estimator of long-term load-transfer efficiency (LTE), as modeled using AASHTOWare Pavement ME Design, than using the actual dowel diameter, suggesting a relationship between dowel misalignment and long-term LTE (AASHTO 2014). However, there is considerable scatter in the LTE modeled using AASHTOWare Pavement ME Design versus actual LTE. The remaining bias and scatter suggests that the models (i.e., equivalent dowel diameter and LTE in AASHTOWare Pavement ME Design) could potentially be improved using data collected as part of this study. Shreenath Rao, Lax Premkumar
09/01/19September 2019Design and Performance of Mixes for Use as Ultra-Thin Overlayhttps://cptechcenter.org/ncc-projects/design-and-performance-of-mixes-for-use-as-ultra-thin-overlay/Aggregate gradation, Asphalt concrete pavements, Asphalt mixtures, bituminous binders, Overlays (Pavements), Pavement maintenance, Pavement performance, Performance tests, ThicknessFriction loss is one of the most critical issues faced by agencies responsible for maintaining and preserving pavement structures. Various methods are used for surface treatments, including seal coats, slurry seals, and ultra-thin asphalt concrete overlays. Ultra-thin overlays have increased in popularity due to their lack of noise and improved ride quality, as well as their reduced overall cost due to the reduced layer thickness. This study had two major objectives: (1) to determine the best aggregate structure for use as an ultrathin overlay; and (2) to evaluate the volumetric-based criterion that is currently used to determine the optimum binder content for mixes used in ultrathin overlays. The performance of different mix types was evaluated using laboratory techniques including the traditional and modified Hamburg wheel tracking method and the three-wheel polishing device. Of the six potential gradations or aggregate structures that could be used as an ultrathin overlay, three were found to be suitable based on the performance tests. The optimum binder content, as defined by the volumetric criterion, was also generally the optimum based on performance tests conducted in the laboratory. Ramez Hajj, Angelo Filonzi, Andre Smit, Amit Bhasin
12/01/18December 2018Experimental and Numerical Assessment of the Behavior of Geogrid-Reinforced Concrete and Its Application in Concrete Overlayshttps://cptechcenter.org/ncc-projects/experimental-and-numerical-assessment-of-the-behavior-of-geogrid-reinforced-concrete-and-its-application-in-concrete-overlays/Adina (computer program), Concrete overlays, Finite element method, Geogrids, Mechanics, Portland cement concrete, Reinforced concreteLimited research exists on the benefits of using geogrids to reinforce portland cement concrete structural and nonstructural members. Concrete pavement overlay is one application in which the use of geogrids can potentially enhance performance and in which the use of reinforcing steel bars is subject to various constraints and limitations. Preliminary research findings have shown that the inclusion of geogrids in portland cement concrete leads to a definitive improvement in postcracking behavior in terms of ductility, load capacity, and crack propagation control. Through a rigorous experimental program, this study aimed to verify and further enhance the current knowledge regarding the behavior of geogrid-reinforced concrete (GRC) elements compared to that of plain concrete and steel-reinforced elements. The findings were used in characterizing the behavior of GRC and applying it to a finite-element model developed using ADINA software. The model was then used to predict the behavior of a geogrid-reinforced concrete overlay and compare it to that of a conventional plain concrete overlay over a given flexible pavement structure. Zaher Al Basiouni Al Masri, Anas Daou, Rana Haj Chhade, Ghassan Chehab
11/01/20November 2020International Perspective on UHPC in Bridge Engineeringhttps://cptechcenter.org/ncc-projects/international-perspective-on-uhpc-in-bridge-engineering/Bridge engineering, Cement, Durability, Service life, Ultra high performance concrete (UHPC)Ultra-high performance concrete (UHPC) offers significant potential to address a variety of needs in bridge design, construction, and performance enhancement. Bridge owners have shown willingness to embrace novel solutions that could address specific challenges related to the cost, speed of construction, durability, and service life of their projects. There are hundreds of bridges worldwide that, largely in the past decade, have utilized UHPC. These applications range from minor field-cast closures to precast segments for long-span bridges to kilometer-long bridge deck overlays on a signature structure. The objective of this paper is to promote the application of this class of cementitious material in bridge engineering by presenting the progress that has been made in different regions of the world in the past two decades. Today, UHPC is being widely used in Malaysia to design and construct many bridges of different types and spans as they build out their roadway network. In South Korea, the unique characteristics of UHPC are being utilized to advance the state-of-the-art in long-span bridges. The French were early adopters and pioneers in building a strong foundation for using UHPC in a variety of bridge applications. In Switzerland, UHPC is employed to address major bridge rehabilitation needs. The United States bridge sector has embraced UHPC for a variety of field-cast connections. Current research and development efforts are promoting the use of UHPC in major rehabilitation projects and construction of primary bridge components. The adoption of UHPC solutions into the bridge sector is progressing rapidly because of the unique opportunities provided by the strength and durability of the material. It is expected that additional innovations and refinements of solutions will occur as knowledge of the material proliferates. Benjamin Graybeal, Eugen Brühwiler, Byung-Suk Kim, François Toutlemonde, Yen Lei Voo, Arash Zaghi
12/01/20December 2020Bridge Deck Replacement of Posttensioned Concrete Box-Girder Bridgeshttps://cptechcenter.org/ncc-projects/bridge-deck-replacement-of-posttensioned-concrete-box-girder-bridges/box girder bridges, Bridge construction, Bridge decks, Bridge superstructures, lane closure, Posttensioning, Rehabilitation (Maintenance), work zonesThis paper studies the feasibility of replacing damaged deck of posttensioned concrete box-girder bridges without the use of falsework to support the superstructure span. Parameters of the study included straight, curved, and skewed bridges, and simple versus multispan bridges. Deck replacement in posttensioned box-girder bridges requires special attention because the deck forms an integral part of the load-resisting mechanism and large precompression has been locked in by the posttensioning in the superstructure. The potential unfavorable stress reversals or redistribution during deck replacement should be carefully considered. In this study, practical options for lane closure and traffic rerouting were incorporated into the replacement strategies, and these options included temporal longitudinal and transverse replacements. Additionally, time-dependent properties for concrete and steel representatives of current construction practice were included in the finite-element model. Results indicated that full-depth deck replacement may be difficult and undesirable because the current AASHTO stress limits were violated in all four of the posttensioned box-girder bridges selected for the study. Additionally, the increase in permanent deflections through deck replacement was relatively large for these selected bridges, which is likely to result in degraded ride quality, safety, and poor drainage condition for the bridge. As a general trend, critical stresses at the top of the web and downward deflection of the girders were found to accumulate as the deteriorated deck was removed and a new deck cast. Youyou Zhang, Y. H. Chai
08/31/21August 2021Development of an Improved Protocol for Structural Evaluation of Dowel Load Transfer Systems for Concrete Pavementshttps://cptechcenter.org/ncc-projects/development-of-an-improved-protocol-for-structural-evaluation-of-dowel-load-transfer-systems-for-concrete-pavements/concrete pavement; dowel bars; load transfer systems; structural evaluationThis report describes the development of a test protocol for evaluating the structural behavior of alternate dowel load transfer systems for concrete highway pavement. The conceptual development and physical verification of the test are described, along with recommendations for incorporating the test in specifications for highway paving dowels. The test is based on the load- deflection test that is included in Section 5 of AASHTO T 253-02, a double-shear test of single dowels, except that the new test uses a circular load at the slab corner (rather than a 4,000 lb distributed load) and is applied to dowel groups across 4 ft wide concrete pavement joints (simulating a wheel path) rather than to single dowels that cross 1 ft wide joints. In addition, the test includes provisions for an optional 50% overload test condition. Replicate tests were performed using standard 1.25 in. epoxy-coated steel dowels in the AASHTO T 253 test and the new test. Finite element data and test results were analyzed to develop recommended evaluation criteria for the new test that would be consistent with the original AASHTO T 253 test but applicable to multidowel systems rather than individual dowels. Adoption of this new test protocol will allow agencies to more easily evaluate and implement newer, more efficient, and more durable pavement dowel technologies with confidence.Mark B. Snyder
01/13/20January 2020Effect of Recycled Aggregate on the Properties of Road Base Materialshttps://cptechcenter.org/ncc-projects/effect-of-recycled-aggregate-on-the-properties-of-road-base-materials/Aggregates, Base course (Pavements), Compressive strength, Moisture content, Recycled materials, Road materialsThe utilization of recycled aggregates in civil engineering is an effective way to deal with construction waste and conserve natural resource. This paper presents a study on the effect of recycled aggregate obtained from waste concrete on the properties of road base materials. The gradations of both natural aggregate and recycled aggregate were designed according to the upper limit, median value, and lower limit of standard gradation, respectively. The natural aggregate was replaced by recycled aggregate with the replacement of 25%, 50%, 75%, and 100% by volume, respectively. The maximum dry density, optimal moisture content, unconfined compressive strength, and drying shrinkage were investigated for road base materials. It was shown that aggregate prepared with upper limit gradation exhibited the better optimal moisture content, while the road base material prepared with median gradation aggregate showed the best 7-day unconfined compressive strength. The optimal moisture content and the maximum dry density of road base material would be both increased with increasing the replacement level of recycled aggregate. Recycled aggregate can improve the 7-day unconfined compressive strength of the road base material within a certain replacement percent. Hui Zhao, Wencui Yang, Yong Ge, Penghuan Liu, Dachuan Zhang
02/10/19February 2019Roller-Compacted Concrete for Rapid Pavement Constructionhttps://cptechcenter.org/ncc-projects/roller-compacted-concrete-for-rapid-pavement-construction/Admixtures, Concrete pavements, High performance concrete (HPC), Laboratory tests, Mix design, Pavement maintenance, Paving, Paving materials, Roller compacted concreteThe main objective of this research was to develop high-performance Roller Compacted Concrete (RCC) with enhanced solid skeleton to secure greater workability, mechanical properties, and frost durability. The study involved the development of a stepwise mixture design methodology to select aggregate proportioning and particle-size distribution of combined aggregates that can secure high packing density and lead to enhanced performance. RCC mixtures with high packing density of aggregate combination and suitable fresh and hardened properties were used to introduce air-entraining agent (AEA) at different dosages. The effect of binder content, AEA dosage, workability level, adjusted by varying the water-to-solid ratio, mixer type, and compaction energy on RCC performance was evaluated.Kamal H. Khayat, Nicolas Ali Libre, Zemei Wu
08/01/18August 2018Comparison of Performances of Structural Fibers and Development of a Specification for Using Them in Thin Concrete Overlayshttps://cptechcenter.org/ncc-projects/comparison-of-performances-of-structural-fibers-and-development-of-a-specification-for-using-them-in-thin-concrete-overlays/Concrete overlays, Concrete pavements, Fiber reinforced concrete (FRC), Fibers, Flexural strength, Overlays (Pavements), Pavement joints, Pavement performanceStructural fibers improve the long-term performance of concrete pavements and overlays and potentially are useful to reduce the slab thickness. These fibers are available in different parent material compositions, stiffness, shapes, and aspect ratios. The main objective of this study was to characterize the post-crack flexural and joint performance of fiber reinforced concrete to develop a specification for the selection of structural fibers for concrete overlays and/or pavements. The study included a literature review, an online survey, and a large-scale laboratory testing. It was found that the majority (almost 94%) of the FRC overlays in this country were constructed with structural synthetic fibers, which provided equal or better performance than projects using the steel fibers. In the laboratory study, a total of 43 different mixes were prepared with 11 different types of fibers. Fiber dosage, stiffness, and geometry significantly influenced the residual strength ratio (RSR) and residual strength (RS). In general, embossed, twisted, and crimped fibers performed better on average than straight-flat synthetic fibers when the comparison was made in terms of RSR or RS. From the joint performance testing, it was found that fibers can greatly improve the performance of the pavement with respect to load transfer efficiency (LTE), differential displacement, and differential joint energy dissipation. The findings from this were used to recommend the target ranges post-crack flexural performance, and joint performance parameters.Manik Barman, Bryce Hansen
09/15/18September 2018A Comprehensive Framework for Life-Cycle Cost Assessment of Reinforced Concrete Bridge Deckshttps://cptechcenter.org/ncc-projects/a-comprehensive-framework-for-life-cycle-cost-assessment-of-reinforced-concrete-bridge-decks/Environmental impacts, Life-cycle Cost, Reinforced Concrete Concrete Bridge DecksVarious environmental and mechanical stressors cause deterioration of concrete bridge decks. Normal wear and tear, freeze and thaw cycles, and chloride penetration due to deicing salts can cause aggressive deterioration that usually requires frequent interventions during the life-cycle of the bridge. These interventions include deck maintenance and repairs (e.g., application of sealers or overlay placement) as well as bridge deck replacement. The quantification of the life-cycle cost of bridge decks considering maintenance and repair activities represents a significant challenge facing local and state transportation agencies. The proposed research will attempt to fill in the knowledge gaps in quantifying the indirect costs associated with bridge deck maintenance and their impact on the overall bridge life-cycle cost. The proposed project focuses on introducing an approach that: (a) characterizes the life-cycle maintenance needs and repair intervals associated with bridge decks constructed using various reinforcement alternatives in FHWA Region-6, (b) develops a systematic methodology for quantifying the impact of bridge maintenance on indirect life-cost including the effect of increased travel time, work zone crashes, operating cost, greenhouse gas emissions, and social losses, and (c) compares different steel reinforcement materials (e.g., regular, epoxy coated, galvanized, stainless steel, and MMFX) based on their long term performance and maintenance requirements.Mohamed Soliman, Samir A Ahmed, Ligang Shen
06/30/14June 2014Rapid Retrofit and Strengthening of Bridge Componentshttps://cptechcenter.org/ncc-projects/rapid-retrofit-and-strengthening-of-bridge-components/Carbon fibers, Highway bridges, Retrofitting, Strengthening (Maintenance)The objective of this study is to (1) repair four bridges with high-performance carbon fiber materials developed at University of Kentucky; and (2) develop a guide and specifications for the use of this material. The advantage of the carbon fiber material is ease of application by a single worker and reduction in repair time, resulting in lower repair costs.R. Graves
11/30/20November 2020Application of Mechanistic-Empirical Pavement Design Approach into RCC Pavement Thickness Designhttps://cptechcenter.org/ncc-projects/application-of-mechanistic-empirical-pavement-design-approach-into-rcc-pavement-thickness-design/Axle loads, Construction, Construction management, Design, Highways, Mechanistic-empirical pavement design, Mix design, Pavement performance, Pavements, Roller compacted concrete pavements, ThicknessThe objectives of this research are to investigate factors that may impact roller compacted concrete (RCC) pavement performance, including, but not limited to, construction practices, mix design proportioning, joint spacing, cracking mechanism and combined temperature and loading effects; quantify the impact of different axle load magnitude on RCC pavement damage in term of fatigue cracking and load equivalent factors; evaluate the cracking mechanism and joint performance of RCC pavement relative to the performance of thin (less than 8 inch thickness) RCC pavements over different stabilized base material; develop representative performance prediction curves suitable for use in an RCC thickness design procedure; and develop an M-E RCC pavement thickness design procedure for the LADOTD and compare the actual versus predicted RCC pavement performance using the developed design procedure.Zhongjie Zhang, Zhong Wu
05/01/18May 2018Evaluation of Dowel Bar Alignment and Effect on Long-Term Performance of Jointed Pavementhttps://cptechcenter.org/ncc-projects/evaluation-of-dowel-bar-alignment-and-effect-on-long-term-performance-of-jointed-pavement/Alignment, Concrete pavements, Doweled joints (Pavements), Faulting, Load transfer, Pavement performance, Quality assurance (QA), Quality control (QC)Recent concerns of misaligned dowel bars led to a technical assistance project to investigate the roadways in question using a MIT-SCAN-2 device borrowed from the Federal Highway Administration (FHWA). The device worked extremely well, and the Louisiana Department of Transportation and Development (DOTD) is considering its use in quality control and assurance. Dowel bar alignment has rarely been questioned in Louisiana due to the inability to check and because dowel related issues have not materialized, so new guidelines for dowel bar placement alignment and testing need to be developed. Such guidelines should consider the minimum alignment requirements to mitigate premature pavement failure due to load transfer or faulting because of the misaligned dowel bars. The objective of this research is to utilize the MIT-SCAN-2 as a non-destructive dowel bar alignment measuring device to determine the effect of dowel bar alignment and its effects on jointed concrete pavement performance. Five to seven jointed concrete pavements of each of these ages will be measured at 0-10 years, 10-20 years, and 20+ years of age to determine the effects of dowel bar misalignment on pavement performance indicators such as faulting and load transfer.Tyson D Rupnow, Patrick Icenogle, Zachary Collier
12/31/21December 2021Effects of Concrete Cure Time on Epoxy Overlay and Sealant Performancehttps://cptechcenter.org/ncc-projects/effects-of-concrete-cure-time-on-epoxy-overlay-and-sealant-performance/Concrete, Concrete curingMDOT currently waits 28 days after the placement of all concrete decks, rigid overlays, and patches on bridge decks before placing epoxy overlays and sealants. Often this extended period conflicts with traffic and weather limitations. With more information on the crack development and moisture release characteristics of MDOT standard concrete materials (Grade D, DM, SFMC, LMC, etc.) and special/patching mixtures MDOT could potentially reduce the time required between placements.Upul Attanayake
05/31/22May 2022Evaluation of MDOT’s Long-Life Pilot Projectshttps://cptechcenter.org/ncc-projects/evaluation-of-mdots-long-life-pilot-projects/Evaluation and assessment, hot mix asphalt, Improvements, Pavement design, Paving, Perpetual Pavements, Pilot studies, Service life, SpecificationsAs a result of Public Act 175 of 2015 and the Roads Innovation Task Force (RITF) Report, the Michigan Department of Transportation (MDOT) committed to designing and constructing four long-life pavements using hot mix asphalt (HMA) and concrete. The four different long-life pavements are as follows: 30-year HMA on US-131 in the Grand Region, 30-year concrete on I-69 in the Bay Region, 50-year HMA on I-475 in the Bay Region, and a 50-year concrete on US-131 in the Grand Region. In 2017, the first of these pilot projects was constructed (30-year HMA on US-131). In 2018, three more will be let with two being built in 2018 and one in 2019. Several changes were made to standard designs and materials to increase the design life. These include increased structural support (increased layer thicknesses, etc.), improved material selection (HMA binder selection, etc.), improved construction specifications (lower initial ride requirements, etc.), and improved design aspects (increased drainage freeboard, etc.). Before further long-life projects can be planned, an assessment of the potential of the four pilot projects for meeting their intended design and services lives (50 and 75 years) should be performed. An evaluation of the effectiveness of all improvements will help transportation investments on future designs result in longer pavement life.
07/31/18July 2018Use of Internal Curing Materials to Improve Performance of Concrete Infrastructurehttps://cptechcenter.org/ncc-projects/use-of-internal-curing-materials-to-improve-performance-of-concrete-infrastructure/Concrete, Internal curing, RheologyThe project presented in this report seeks to develop a proper methodology to use saturated lightweight sand (LWS) to improve the performance and prolong the service life of concrete mixtures. High-performance concrete (HPC) approved by MoDOT was used for the baseline mixture and was modified with different types and contents of saturated LWS used for internal curing. This was done to evaluate the optimum dosage of LWSs and maximize their effectiveness on enhancing performance.Kamal H. Khayat, Weina Meng, Mahdi Valipour, Matthew Hopkins
06/30/22June 2022Fiber Reinforced Concrete for Bridge Decks and Overlayshttps://cptechcenter.org/ncc-projects/fiber-reinforced-concrete-for-bridge-decks-and-overlays/Bridge decks, Decision making, fiber reinforced concrete, Overlays (Pavements), Performance measurementsOverlay history suggests that cracking, curling, lack of ductility, and fatigue are common and collective failure modes of concrete overlays, all of which are positive contribution areas for fiber reinforcement. Improved resistance to crack propagation, controlled thermal and moisture stresses, increased elasticity, higher tensile, flexural, and fatigue strengths, and greater impact and abrasion resistance are some improvements in concrete performance that are generally achieved with the use of fiber reinforced concrete (FRC) compared to normal concrete overlays. Therefore, there is a need to (1) establish a systematic and functional process that can guarantee the success of the FRC overlay application, (2) develop performance criteria for acceptability, (3) establish defined protocols for agencies to be able to evaluate a product that is submitted for approval, and (4) identify methodologies that facilitate the decision-making process.Richard Kaczkowski
05/01/21May 2021Mitigation of Corrosion in Continuously Reinforced Concrete Pavementhttps://cptechcenter.org/ncc-projects/mitigation-of-corrosion-in-continuously-reinforced-concrete-pavement/Before and after studies, Continuously reinforced concrete pavements (CRC pavements), Corrosion, Corrosion protection, Cracking, Electron microscopy, Field tests, Laboratory testsAn evaluation of continuously reinforced concrete pavement (CRCP) was conducted in order to determine the extent of possible corrosion of CRCP on selected interstates in South Dakota. General observations showed there were sections of severe and localized reinforcement corrosion at some crack locations. Crack mapping, chloride tests profiles, scanning electron microscopy (SEM) analyses, and half-cell potential measurements were conducted in the field. Half-cell potential measurements and crack density were investigated for correlations to corrosion. Results showed there was a significant positive correlation between elevated half-cell potential measurements and crack density. Topically applied corrosion mitigation products were applied at test section CRCPs. Field testing consisted of evaluating the change in half-cell potential of the reinforcement before and after the corrosion mitigation products were applied to sections of an interstate highway. Laboratory testing consisted of casting reinforced concrete specimens that used mix designs similar to the pavements evaluated in the field. The half-cell potentials for each specimen were monitored during the duration of the research project. Four of the laboratory specimens were also tested using chloride ion analysis and SEM techniques.Allen Jones, Nadim Wehbe, Stephanie (Peters) Klay, Shaun Massen
04/01/20April 2020Application of Internal Curing to Improve Concrete Bridge Deck Performancehttps://cptechcenter.org/ncc-projects/application-of-internal-curing-to-improve-concrete-bridge-deck-performance/Benefits, Best practices, Bridge decks, Concrete bridges, Concrete curing, Cost effectiveness, Cracking, Feasibility analysis, Pavement performanceDue to the relatively high cement content and low water-to-cement ratio (w/c) used, bridge deck concrete is more prone to early age cracking. As shown in Figure 1 bridge deck cracking and deterioration, coupled with the application of deicing chemicals during winter operations have been a primary concern. Nebraska Department of Transportation (NDOT) has employed mitigating reactionary strategies such as crack sealing and overlay to address early age deck cracking. However, these strategies are costly and have impacts on traffic operations. NDOT would clearly benefit if concrete decks are free from premature cracking associated with initial construction. The overall goal of this study is to identify a cost-effective practice for internal curing of bridge deck concrete for NDOT. To achieve the goal, three specific objectives of this study are to: (1) summarize the best practice of internal curing concrete for bridge deck application through an extensive literature review and survey; (2) determine appropriate source and addition rate of LWFA for internal curing of Nebraska concrete bridge decks; and (3) evaluate the technical feasibility and benefits of internal curing for Nebraska bridge deck construction.Arman Abdigaliyev, Yong-Rak Kim, Jiong Hu
05/31/23May 2023Low-Cement Concrete Mixture for Bridge Decks and Railshttps://cptechcenter.org/ncc-projects/low-cement-concrete-mixture-for-bridge-decks-and-rails/Admixtures, Bridge decks, Cement content, Cracking of concrete pavements, Deterioration, Drying rate, Mix design, ShrinkageEarly-age cracking of concrete bridge decks and rails accelerates the penetration of water and chemicals into the concrete, which leads to reinforcement corrosion, delamination, and eventually spalling. This common deterioration problem results in shorter service life, road closures, and costly repairs/replacements. The early-age cracking of concrete decks and rails is primarily attributed to the drying shrinkage of restrained concrete immediately after construction. Concrete mixture design and curing procedure are key factors in reducing drying shrinkage and, consequently, early-age cracking.Jong Hu, George Morcous
05/15/22May 2022Durability of Low Carbon Concrete Mixtureshttps://cptechcenter.org/ncc-projects/durability-of-low-carbon-concrete-mixtures/Admixtures, Carbon, Chloride content, Corrosion, Deicing chemicals, Life cycle analysis, Salts, Sustainable transportationThe primary goal of this proposal is to develop a deeper understanding of the relative performance of a wide array of low-carbon concrete systems in environments where the concrete will be subjected to chlorides and other deicing salts. This goal will be met through the following objectives: (1) understand the chloride diffusion rate in low-carbon concrete mixtures; (2) understand the relative resistance of various low-carbon concrete mixtures to salt scaling; and (3) develop life-cycle expectancy models for various low-carbon concrete mixtures. The intended outcome of the project is to present a systematic approach to examining the durability of a wide array of low-carbon concrete mixtures. The information gathered will be used to predict life expectancy of the concrete in regards to onset of corrosion and likelihood of significant scaling.Matthew Adams, Matthew Bandelt
04/30/22April 2022Comparative Analysis of Rapid Chloride Penetration Testing for Novel Reinforced Concrete Systemshttps://cptechcenter.org/ncc-projects/comparative-analysis-of-rapid-chloride-penetration-testing-for-novel-reinforced-concrete-systems/Aggregates, Alternative analysis, Corrosion resistance, Durability tests, Recycled materials, Reinforced concreteTransportation agencies have been rapidly deploying emerging concrete materials to improve the sustainability and durability of reinforced concrete infrastructure. This project will focus on the chloride penetration behavior of several novel concrete materials in comparison to baseline ordinary portland cement concrete mixtures that are representative of systems used in transportation agencies in the northeast region of the United States. The goal of this research study is to create an understanding of how novel concrete materials such as ductile concrete systems (e.g., UHPC, ECC, HyFRC) and recycled aggregate concrete behave in rapid chloride environments. The intended outcome of the project is to support transportation agencies in selecting and implementing novel concrete materials to improve durability of the transportation infrastructure.Matthew Bandelt, Matthew Adams
12/31/18December 2018Recycling and Reuse of Materials in Transportation Projects: Current Status and Potential Opportunities Including Evaluation of RCA Concrete Pavements along an Oklahoma Interstate Highwayhttps://cptechcenter.org/ncc-projects/recycling-and-reuse-of-materials-in-transportation-projects-current-status-and-potential-opportunities-including-evaluation-of-rca-concrete-pavements-along-an-oklahoma-interstate-highway/Aggregate mixtures, Concrete aggregates, Interstate highways, Pavement performance, Portland cement concrete, Reclaimed asphalt pavements, Recycled materialsOklahoma Department of Transportation (ODOT) is committed to protect and enhance human and natural environment while developing a safe, economical, and effective transportation system. The first objective of this research was to evaluate the availability of the recycled materials and develop strategies for increasing use of recycled materials in ODOT transportation construction projects. In this objective, an extensive literature search was conducted to acquire information pertaining to properties, current practices, and available field investigations of the commonly used recycled materials. Use of recycled concrete aggregate in concrete paving mixtures (RCA-CPM) was determined to be the major focus in this research as applications of RCA-CPM by ODOT and other DOTs have been reported as a sustainable and durable construction practice. Subsequently, a review of the key findings pertaining to RCA material properties and effects of RCA on portland cement concrete pavement (PCCP) performance was performed. Additionally, a life cycle assessment addressing all the three aspects of sustainability (i.e., economic, social, and environmental) was performed to do a comparative assessment between RCA-PCCP and plain PCCP and project the benefits of using RCA-CPM. The second objective was to evaluate the long-term performance of existing PCCP made with RCA in Oklahoma. A jointed plain concrete pavement (JPCP) and a continuously reinforced concrete pavement (CRCP) section were selected and evaluated through various tests covering different aspects, which includes visual survey, determination of mechanical properties, petrographic examination, and evaluation of the existing base through falling weight deflectometer (FWD). From the lab and field studies, it was verified that good base support, strong load transfer, and shorter joint spacing are essential design considerations for JPCP made of RCA-PCC. CRCP using effective anti-corrosion measures might be more suitable for implementing RCA-PCC; CRCP could better protect the base from erosion caused by higher differential energy and help restrain high drying and thermal volume change of RCA-PCC.Anol Mukhopadhyay, Xijun Shi, Dan G. Zollinger
07/14/21July 2021Measuring Concrete Permeability with CHIPhttps://cptechcenter.org/ncc-projects/measuring-concrete-permeability-with-chip/Concrete, Permeability, Service life, Test procedures, Tracers (Chemistry), X-ray analysisThis project is a follow-on study of a previous IDEA project (NCHRP-199) that developed a prototype device to determine the permeability of hardened concrete using X-rays to measure the penetration of a tracer. In this follow-on project, the current instrument stage will be improved to know the locations from previous scans and to allow investigation of many different sample orientations, saving operator time and making the device easier to use. Currently, a potassium iodide solution is used as a tracer but there are other tracers that might give similar results more rapidly. Presently, samples are ponded for 7 days for diffusion coefficient measurement. So the measurement time may be shortened by using a different tracer and/or storing samples at an elevated temperature to speed diffusion. Both possibilities will be explored. The previously software also needs to be made more user-friendly, as it uses several different programs to scan, analyze, and predict the service life of the concrete. It is cumbersome to change between then programs and often confusing to the user. The new software will also incorporate service life models that will use basic input information within already established models to predict the service life of the structure, based on the measured diffusion coefficient. Oklahoma, Minnesota, and Illinois DOTs are collaborating to provide concrete samples during mixture design and construction and also after concrete placement and curing. Measurement of these samples are expected to provide would allow important insights into how these different processes impact the concrete permeability. Work in Stage 2 will develop precision and bias statement as well as an AASHTO test method. The repeatability of a single as well as multiple users to better understand the variability of the developed device will be determined by comparing the results on 20+ samples by multiple users. A rough draft for an AASHTO test method will be prepared for the developed technique. The final report will provide all relevant data, methods, models, and conclusions along with guidance on using the system to measure the permeability of hardened concrete.Tyler Ley
11/10/21November 2021Ultra-High-Performance Concrete (UHPC) Used as a High Friction Surface Treatment (HFST) on Pavements and Bridgeshttps://cptechcenter.org/ncc-projects/ultra-high-performance-concrete-uhpc-used-as-a-high-friction-surface-treatment-hfst-on-pavements-and-bridges/Bridge decks, Concrete, Friction, Pavement design, Surface friction (Geophysics), Ultra high performance concrete (UHPC)High Friction Surface Treatment (HFST) has been a successful strategy for the SCDOT to restore and improve the frictional properties of pavement surfaces, which subsequently helps motorists maintain better control in both dry and wet driving conditions. HFST involves the application of a thin layer of very high-quality aggregate (imported calcined bauxite) to the pavement surface using a polymerized binder. The benefits of HFST have been well documented, however, the high cost renders its use to limited situations. Research is needed to investigate and validate the use of Ultra-High Performance Concrete (UHPC) for HFST applications, which has the potential to employ locally produced materials and yield the benefits of HFST at a much reduced cost. The objective of this research is to review current HFST usage practices for pavements and bridges by DOTs around the country and explore the use of UHPC produced using local materials as a potential HFST that is economical and durable. The research will investigate the laboratory and field performance of local aggregates, the UHPC produced with the local aggregates, and then compare against the performance requirements of existing specifications for traditional HFST that require the imported calcined bauxite. The field performance evaluation component will comprise of a minimum of two projects that involve restoring frictional resistance on horizontal curves on pavement surfaces as well as on a bridge deck. Maintenance concerns as well as potential additional applications will be considered in the overall evaluation.Meredith Heaps
08/01/19August 2019Laboratory and Outdoor Exposure Site Evaluations of Portland Limestone Cementshttps://cptechcenter.org/ncc-projects/laboratory-and-outdoor-exposure-site-evaluations-of-portland-limestone-cements/ASR, Carbonation, Durability, Ettringite, Mechanical properties, PLC, Portland limestone cement, Sulfate attackThe research described in this report was funded by the Texas Department of Transportation (TxDOT), with an emphasis on portland limestone cements (PLCs) with higher limestone contents (e.g., greater than 15%), particularly in paving applications. The project was quite comprehensive and included the full-scale production of seven different cements at two Texas cement plants, with limestone contents as high as 30 percent. These cements were then evaluated in the laboratory and at outdoor exposure sites, studying a wide range of fresh, hardened, and durability properties of PLC concrete, including select mixtures in combination with supplementary cementing materials (SCMs) with limestone contents of up to 30% limestone, in selected combinations with supplementary cementitious materials (SCMs). The results show that PLCs can be produced that are constructible, durable, and sustainable, but a thorough understanding of PLCs and SCMs is needed to optimize the overall performance. More research and, particularly, more well-monitored, real-world applications of PLCs with higher limestone contents are needed to better correlate the results of laboratory tests to actual pavements or structures.Jose E. Garcia, Nicolas B. Tuburzi, Kevin J. Folliard, Thano Drimalas, Michael D.A. Thomas
08/31/20August 2020Establishment of Best Practices for Construction and Design of Cement Treated Materialshttps://cptechcenter.org/ncc-projects/establishment-of-best-practices-for-construction-and-design-of-cement-treated-materials/Base course (Pavements), Cement treated soils, Failure, Laboratory tests, Mix design, Performance testsCementitious stabilization of granular soils has been proven to be an economically viable option for sustainable construction and rehabilitation of pavement structures. The absence of a harmonized and rapid turnaround laboratory mixture design procedure, coupled with construction and inspection guidelines that need improvement have resulted in an ongoing challenge for Texas Department of Transportation (TxDOT), contractors, and users of the transportation facilities. In addition, due to the lack of field data and practical laboratory tests in the past, the fatigue performance models in the Texas Mechanistic Empirical Flexible Pavement Design System (TxME) have never been verified nor calibrated. Therefore, the main objective of this study was twofold: provide an update to the current mixture design specification based on comprehensive laboratory testing and develop and calibrate a new generation of fatigue performance model that accounts for strength as well as shrinkage cracking potential of cement treated materials. To accomplish these objectives, current practices for mixture design and construction of cement treated base, subbase and subgrade soils were documented. This information then served as the basis for the selection of the type and sources of base aggregates and subgrade soils for inclusion in the experiment matrix of the project. Eight different aggregate base materials including multiple sources of limestone, siliceous gravel, reclaimed concrete aggregate, full depth reclamation materials, and reclaimed asphalt pavement, as well as seven different subgrade soils with unique characteristics were incorporated in this research effort. All permutations of the experimental design were prepared with different levels of stabilizer content to cover a wide spectrum of treatments from light stabilization to heavily stabilized systems. This research also provided two alternative moisture susceptibility procedures to quantify the loss of orthogonal strength properties of cement treated virgin and reclaimed materials due to moisture intrusion. More than 3,000 specimens, were prepared, and subjected to various mechanical and physio-chemical laboratory tests to characterize the strength, resilient properties, and permanent deformation potential, clay activity, moisture adsorption potential, as well as other properties of cement treated systems. Microstructural analysis of the cement treated specimen using X-ray computed tomography was instrumental to provide the basis for using the gyratory compactor in lieu of the traditional impact hammer for laboratory specimen preparation. The trend analysis of the laboratory results, statistical reliability and repeatability analysis, practicality of test methods, and operator friendliness were the contributing factors to draft the update to the cement treatment specification. In addition to the laboratory efforts, a new generation of fatigue performance models were developed and calibrated in this study. The model incorporated indirect diametrical tensile (IDT) strength and shrinkage strain to account for the cracking potential in the cement treated layer due to overly rigid matrices. A comprehensive database of pavement profiles and material properties were developed using field-based nondestructive testing such as Falling weight deflectometer, ground penetrating radar, and deployment of Portable WIN (P-WIM) for traffic characterization in this study. The database was instrumental for the calibration of a newly developed fatigue performance model for flexible pavement structures with cement treated layers.Reza S Ashtiani, Mohammad Rashidi, Edgar Rodriguez, Margarita Ordaz, Hector Cruz Lopez, German Garay, Sergio Rocha, Jose Garibay
09/01/20September 2020Evaluation of Long-Term Strength and Durability Properties of Prestressed Concrete Girders with Microcrackinghttps://cptechcenter.org/ncc-projects/evaluation-of-long-term-strength-and-durability-properties-of-prestressed-concrete-girders-with-microcracking/Beams, Bridges, Concrete structures, Cracking, Durability, Fabrication, Mechanical properties, Precast concreteThe presence of unexplained surface microcracks in several in-service prestressed girders across Texas led to concerns of reduced service life due to loss in long-term strength and durability. This project was designed to estimate both this potential loss in service life and the likelihood of long-term strength and durability issues that might arise due to the presence of these microcracks. Measurements of crack width, strain, stiffness and resistivity were taken from full-scale in-service and overcast or rejected girders over two years. Cores were collected from the overcast girders for further laboratory investigation of cracking, strength, stiffness, and durability properties. While the girders exhibited an increase in cracking and shrinkage, they have not shown a significant loss in strength, stiffness, and durability due to the presence and temporal growth of the microcracks. Exposure to environment and presence of pre-existing cracks were major factors affecting the rate of increase in cracking, while external loading was not. This temporal data was used to generate an empirical model to estimate the remaining service life of the girders using non-destructive test measurements as input variables. The model had a regression coefficient and reliability index in the “Good” range, and an error of 359 days. Laboratory specimens were cast to determine a critical cracking index value of 18 mm/m (0.5755 in./yd). The empirical model under-predicted service life by 4–10 years for all girders when compared to Life-365®. As these girders are designed for a service life of 75 years, the present rate of growth in microcracking can reduce the service life of the in-service girders from 2 to 13 years depending on the girder and nature of cracking. Further reduction in service life is also possible under fatigue loading as the girders age. Thus, continuous monitoring of the girders, especially in the last two decades of the girders’ lives, is recommended. In addition, the behavior of these girders with surface microcracks under marine exposure was observed to determine the effect of the microcracks on chloride-induced corrosion. Exposure to the simulated marine environment led to the formation of microcracks in the low water-cement ratio concrete specimens. However, the presence of microcracks did not significantly impact corrosion potential in the timeframe of the study. A novel approach using guided ultrasonic waves and acoustic emission to monitor corrosion process in prestressing strands was explored, with encouraging results. Further research should explore the key parameters that can influence corrosion monitoring using guided ultrasonic waves and to determine the efficacy of using the guided wave ultrasonic method as part of the maintenance program.Raissa Ferron, Salamone Salvatore, Savitha Srinivasan, Michael Rung, Brennan Dubuc, Arvin Ebrahimkhanlou
03/01/21March 2021Assessment of Test Methods for New and Blended Materialshttps://cptechcenter.org/ncc-projects/supplementary-cementitious-materials-assessment-of-test-methods-for-new-and-blended-materials/Admixtures, Blends, Cement, Chemical reactivity, Evaluation and assessment, Fly ash, Performance tests, Sulfates, Test proceduresIn Texas, and most of the U.S., Class F fly ash is the most used supplementary cementitious material (SCM) due to the many benefits it provides to concrete. In recent years, the availability of Class F fly ash has decreased as many coal-fired power plants have shut down. Plants that have not shut down are required to install various emission control systems that can significantly alter the type of fly ash produced. As the face of fly ash production continues to change, the usability of non-traditional fly ashes and fly ash alternatives in concrete must be evaluated. As the number of new SCM sources rises to meet demand, rapid tests are necessary to screen out poor-performing materials and long-term performance testing is needed to qualify promising materials for use in concrete mixtures. In this study, both rapid SCM screening tests and long-term performance of non-traditional, blended fly ashes were examined.Saif Al-Shmaisani, Ryan Kalina, Katelyn O’Quinn, Jae Kyeong Jang, Michael Rung, Raissa Ferron, Maria Juenger
08/31/22August 2022Increase the Allowable Content of Recycled Crushed Concrete Fine Aggregate in Class P Concretehttps://cptechcenter.org/ncc-projects/increase-the-allowable-content-of-recycled-crushed-concrete-fine-aggregate-in-class-p-concrete/Aggregates by gradation, Crushed aggregates, Mix designsThe production of recycled crushed concrete coarse aggregate generates a substantial quantity of recycled crushed concrete fine aggregate, which is limited for use in Class P concrete. The current maximum allowable limit of 20% recycled crushed concrete fine aggregate is an arbitrary limit with little basis. This project will determine the limits of recycled crushed concrete fine aggregate that can be used in Class P concrete and still produce workable and durable concrete pavement. Researchers will conduct field trials with actual Class P mix designs with various recycled crushed concrete fine aggregates and conduct lab testing to validate mix designs developed, to include surface wear, carbonation, or durability testing, etc.Kevin Folliard
09/30/22September 2022Design of Fly Ash–Based Geopolymer Concrete-Filled FRP Tube Composite for Highly Durable and Environmentally Friendly Infrastructurehttps://cptechcenter.org/ncc-projects/design-of-fly-ash-based-geopolymer-concrete-filled-frp-tube-composite-for-highly-durable-and-environmentally-friendly-infrastructure/Composite materials, Fiber reinforced polymers, Fly ash, Geopolymer concrete, Pavement design, Sustainable development, TubingAlthough fly ash-based geopolymer (FAGPR) binders have been increasingly explored for the last decade, there is still an urgent demand for high-performance FAGPR binder to meet the requirement of more durable and environmentally friendly infrastructure. It is also necessary to identify viable strategies to compensate for the lower early-age strength, short setting time, and less-than-ideal flowability of FAGPR, which are considered as the main drawbacks that hinder its widespread application. To this end, this proposed project will build on the team’s patented FAGPR technology and develop a novel tube/concrete composite, which features promising load-bearing capacity, durability performance, and damping properties.Xianming Shi
09/30/22September 2022Sustainable nHPC Mixtures for Durable Overlay of Concrete Bridge Decks in Cold Regions: Proof of Concepthttps://cptechcenter.org/ncc-projects/sustainable-nhpc-mixtures-for-durable-overlay-of-concrete-bridge-decks-in-cold-regions-proof-of-concept/Bridge decks, Cement content, Concrete bases, Durability, Feasibility analysis, Frigid regions, Greenhouse gases, Mix design, Overlays (Pavements) Sustainable development, Ultra high performance concrete (UHPC), WorkabilityThe higher cement content in UHPC increases the energy and CO₂ footprints, and the use of supplementary cementitious materials (SCMs) to replace cement has been limited in the current design. Besides, the high compressive strength (> 150 MPa) of UHPC might be over-design for bridge deck overlay application. The combined use of very low w/b ratio (~ 0.2) and high dosage of fibers presents a great challenge for the construction of UHPC overlays in the field. In this context, the overarching goal of this project is to design sustainable nHPC mixtures for durable overlay of concrete bridge decks in cold regions through lowering initial cost of UHPC overlays and improving the workability and construction tolerance of UHPC for on-site application while maintaining dense microstructure and superior durability. The “n” before the HPC denotes for nano-engineering as well as the fact the durability of these mixtures will be a few times that of conventional UHPC. To achieve this goal, this study aims to: (1) identify and optimize eco-efficient mix designs for nHPC overlay, greatly reducing the use of cement, steel fiber and superplasticizer while tailoring the particle size gradation; (2) evaluate the engineering performance and durability of selected nHPC mixtures for cold-climate concrete deck overlay application; (3) enhance the thixotropy to ensure that fresh nHPC mix can hold the specified slope on the bridge deck; (4) conduct multiscale characterization of selected nHPC mixtures, to elucidate the role of individual constituents on the macroscopic behavior and performance.Christopher Shearer
06/30/22June 2022Development of Microcapsule-Based Self-Healing, High-Strength Engineered Cementitious Composites (SHHS-ECC)https://cptechcenter.org/ncc-projects/development-of-microcapsule-based-self-healing-high-strength-engineered-cementitious-composites-shhs-ecc/Cement, Composite materials, Durability, High strength materials, Hydration, Mix designs, Pavement cracking, Sustainable development, Tensile propertiesThe durability of high-strength engineered cementitious composites (HS-ECC) is severely challenged once cracks are formed in a HS-ECC structural member, especially for those exposed to harsh environments (e.g., laden with chloride or sulfates). In this context, the goal of this project is to design a self-healing HS-ECC by virtue of microcapsules encapsulating healing agent. The multi-scale self-healing ability of the HS-ECC will be achieved through the combined use of microcapsules and continuous hydration of cementitious materials, so as to maintain the superior durability of HS-ECC. To this end, this exploratory laboratory investigation aims to: (1) identify the mix designs of HS-ECC incorporating microcapsules, based on the micromechanics theory (2) evaluate the self-healing effectiveness of HS-ECC, in terms of restoration level of tensile and transport properties (3) study the effect of crack width and pre-cracking age on the self-healing efficiency of HS-ECC.Xianming Shi
06/30/22June 2022Develop an Innovative Self-Healing Concrete Technology for Bridge Deck Life Extensionhttps://cptechcenter.org/ncc-projects/develop-an-innovative-self-healing-concrete-technology-for-bridge-deck-life-extension/Bridge construction, Bridge decks, Concrete bridges, Fungi, Pilot studies, Repairing, Service lifeThe proposed research aims to conduct pilot study to develop a self-healing concrete technology that rapidly heal the cracks by use of microorganism fungi. Fungi is selected due to its capability to rapidly cover exposed surfaces of concrete cracks with its hyphae fiber. The recovery of mechanical properties will be achieved with fungi induced bio mineralization process, which glue the cracked surfaces together. Besides, the hydrophobic nature of the fungi fiber prevents water ingression and therefore mitigates the corrosion due to deicing salt. Fast and autogenous cracking healing of concrete will extend the service life of bridge decks and bring major cost and labor savings compared with conventional treatment procedures.Robin Kline
01/21/21January 2021Accelerated Construction of Urban Intersections with Portland Cement Concrete Pavement (PCCP)https://cptechcenter.org/ncc-projects/accelerated-construction-of-urban-intersections-with-portland-cement-concrete-pavement-pccp/Concrete pavements; Intersections; Pavement maintenance; Portland cement concrete; Road Construction; Urban highwaysThe frequent maintenance required on asphalt concrete (AC) pavement sections has made reconstruction with Portland Cement Concrete Pavement (PCCP) a feasible alternative. However, many constructability issues need to be addressed in order to realize the full potential of this alternative. The entire reconstruction of the intersection, including demolition of the AC pavement and its replacement with PCCP, took place over a period of three days, starting on Thursday evening and opening the intersection to the traffic on Sunday afternoon.Kamran M Nemati, Jeff S Uhlmeyer
06/30/22June 2022Durability of Transverse Sawcut Joints (Year 2)https://cptechcenter.org/ncc-projects/durability-of-transverse-sawcut-joints-year-2/Chlorides, Concrete pavements, Deterioration, Durability, Joint sealers, Sawed jointsThis proposed project is comprised of an investigation into the role and extent that joint sealant effectiveness plays on the durability of sealed transverse sawcut joints in jointed concrete pavement that are subjected to deicing salts and freeze-thaw conditions. Specifically, this research will address the circumstances associated with the deterioration that occurs under the effect of oxychloride formation.Dan Zollinger, Jenny Liu
07/31/22July 2022Reducing Shrinkage Cracking in Bridge Decks Using the Single- and Double-Ring Test Methodshttps://cptechcenter.org/ncc-projects/reducing-shrinkage-cracking-in-bridge-decks-using-the-single-and-double-ring-test-methods/Bridge decks, Concrete bridges, Cracking, Ring stress, Shrinkage, Test proceduresThe condition of concrete on bridge decks is one of the most costly parts of Wyoming Department of Transportation's budget and the cost of maintenance can result in inadequate roads or costly premature repairs. This proposal evaluates critical factors relating to early age shrinkage and proposes combining multiple mitigation methods to reduce early-age cracking that contributes to early degradation.Jennifer Tanner
06/14/21June 2021Durability and Microstructure Studies on Slag-Fly Ash-Glass Powder Based Alkali-Activated Pavement Quality Concrete Mixeshttps://cptechcenter.org/ncc-projects/durability-and-microstructure-studies-on-slag-fly-ash-glass-powder-based-alkali-activated-pavement-quality-concrete-mixes/Durability, GGBS, Glass powder, Microstructure, Pavement Quality Concrete, StrengthThe present study attempts a detailed assessment of the performance of air-cured Alkali Activated Concrete (AAC) mixes produced using powdered waste glass as one of the ingredient, designed for highway applications. The study reveal that, the AAC mixes display satisfactory performance for normal working environments for their use in roadway appliances.Shriram Marathe, I R Mithanthaya, Rahul Yekkar Shenoy
06/30/22June 2022Interfacial Shear Transfer of Reinforced Concrete with High-Strength Materialshttps://cptechcenter.org/ncc-projects/interfacial-shear-transfer-of-reinforced-concrete-with-high-strength-materials/Bridge design, High strength materials, Reinforced concrete bridges, Shear reinforcementThe shear friction design concept is applicable in conditions where direct shear must be transferred across a structural concrete plane or interface, such as an existing crack or an interface between dissimilar materials or concretes cast at different times (i.e., cold joint). Shear friction provisions are commonly used in the design of reinforced concrete and precast-prestressed concrete bridge elements and connections including corbels, dapped double tees, beam bearings, and diaphragms. These types of connections are critical because there is little or no redundancy, which makes them a critical part of the structure. This project will examine the applicability of current shear friction design approaches to concrete-to-concrete interfaces with high strength concrete and/or high strength steel, by means of assembling and evaluating a comprehensive database of test results collected from the literature, and to identify potential needs for revision to the AASHTO LRFD Bridge Design Specifications.Genda Chen, Lesley Sneed
07/14/21July 2021Development of an Innovative Bio-Mediated Self-Healing Concrete Technologyhttps://cptechcenter.org/ncc-projects/development-of-an-innovative-bio-mediated-self-healing-concrete-technology/Admixtures, Concrete pavements, Durability, Fungi, Innovation, Life cycle costing, Mechanical loads, Pavement performance, Procedures, Service life, StandardsThis project will develop and evaluate an innovative autogenously self-healing concrete technology based on bio-mineralization through fungi to improve the durability, service life, and performance of highway concrete. Work in Stage 1 will focus on developing fungi based self-healing agents for concrete mixture. The final report will provide all relevant data, methods,, and findings along with guidance on using the bio-mediated self-healing concrete technology.Xiong Yu
04/05/21April 2021Evaluation of Trigger Temperature for Concrete Pavement Growth Based on Joint Movement Datahttps://cptechcenter.org/ncc-projects/evaluation-of-trigger-temperature-for-concrete-pavement-growth-based-on-joint-movement-data/Blowups (Pavements), Buckling, Concrete pavements, Pavement joints, TemperatureThe failure of concrete pavement as a result of pavement growth has become a serious concern as it causes blow-up distress and damages the adjoining structures, such as bridge abutments and decks. This further adversely impacts the road user, and the roads thus require costly maintenance and reparations. Pavement growth is caused by pressure generated from rising temperature and moisture content in the concrete pavement. The trigger temperature for pavement growth (TTPG) is the temperature at which all transverse cracks and contraction joints between the expansion joints begin contracting and generating an axial compressive force in the pavement section. This is a critical factor affecting pavement growth. However, the evaluation of TTPG has not been documented yet. TTPG is affected by the accumulation of concrete slab expansion resulting from the alkali-silica reaction, amount of incompressible material infiltrated in the joint or cracking. The rate of this accumulation depends on the environmental conditions, pavement age, pavement configuration, and pavement materials. Therefore, this study examines the factors affecting TTPG of in-service pavements, using the Long-Term Pavement Performance Seasonal Monitoring Program database. According to the results, TTPG is significantly affected by pavement age, precipitation, and joint spacing. The paper further presents an empirical equation to estimate the TTPG of concrete pavement under the given conditions based on the generalized linear modeling regression method.Lyhour Chhay, Young Kyu Kim, Seung Woo Lee
04/30/21April 2021Synthesis of Information Related to Highway Practices, Topic 53-07: Curing Practices for Concrete Pavementhttps://cptechcenter.org/ncc-projects/synthesis-of-information-related-to-highway-practices-topic-53-07-curing-practices-for-concrete-pavement/Concrete curing, Concrete pavements, Literature reviews, quality assurance, Quality control, State departments of transportation, State of the practice, SurveysThe curing of concrete is widely recognized as a critical step for achieving high-quality long-lasting concrete pavements. While the most common curing practice is the application of mem-brane-forming curing compounds, the compound specifications, including application rates and the quality control/quality assurance (QC/QA) practice, differ among state departments of transportation (DOTs). The timing of the curing application—which is critical to the success of the curing process—also differs among state DOTs. State DOTs may also adopt additional curing measures during adverse weather conditions. The objective of this synthesis is to document state DOT practices for curing pavement concrete including procedures, materials, application rates, timing, QC/QA procedures, and specific measures adopted when paving under adverse weather conditions. Information will be gathered through a literature review, a survey of state DOTs, and follow-up interviews with selected agencies for the development of case examples. Information gaps and suggestions for research to address those gaps will be identified.Jamshid Armaghani
12/01/20December 2020Using an Ultra-Accelerated Test Method to Evaluate Aggregate and Cement Combinations to Use Recycled Concrete Aggregate in New Concrete Constructionhttps://cptechcenter.org/ncc-projects/using-an-ultra-accelerated-test-method-to-evaluate-aggregate-and-cement-combinations-to-use-recycled-concrete-aggregate-in-new-concrete-construction/Accelerated tests, Airport runways, Alkali silica reactions, Cement, Concrete aggregates, Concrete construction, Durability, Laboratory tests, Recycled materials, Test proceduresThe Rocky Mountain Region has experienced considerable difficulty due to the presence of alkali-silica reaction (ASR) in concrete construction. Several sources of aggregate that have produced poorly performing concrete have been removed from service. As an example, DIA runways were damaged by ASR and the repair cost exceeded 30 million. On a positive note, Wyoming Department of Transportation (WYDOT) was successful in using RCA on Interstate 1-80 and with limited ASR damage. In this portion of the road, WYDOT observed a 30 year service life. This performance, coupled with data from a previous study help confirm that using recycled concrete aggregate (RCA) combined with natural aggregates produces durable long-term concrete that will benefit the transportation network in this region. This study intends to provide experimental data that permits RCA to be used in applications beyond base fill for roads.Jennifer Tanner, Md Tarik Hossain
06/01/21June 2021Evaluation of Chemical Solutions to Concrete Durability Problemshttps://cptechcenter.org/ncc-projects/evaluation-of-chemical-solutions-to-concrete-durability-problems/Admixtures, Alkali silica reactions, Bridge decks, Corrosion resistant materials, DurabilityThe reinforced concrete infrastructure in Texas has been plagued by various durability-related issues over the years, including deterioration from alkali-silica reaction (ASR), delayed ettringite formation (DEF), and corrosion of reinforcing steel. For many of these durability problems, fly ash has been the remedy of choice; however, with changes in fly ash quality and quantity spurred by new emissions standards and changes in fuel sources, concern has arisen that fly ash may not be as available or effective in the future. Thus, there exists a need to evaluate other solutions to reinforced concrete durability problems besides the traditional use of fly ash. This need formed the basis for the research described in this report. A range of materials were tested, including corrosion inhibitors (calcium nitrite, calcium nitrate, others), ASR and/or DEF inhibitors (lithium nitrate), integral water repellants, nanoparticles (silica and dispersible calcium silicate hydrates (C-S-H)), and gypsum as an additive to improve sulfate resistance of Class C fly ash. These materials were tested under a comprehensive laboratory testing program, with tests including heat of hydration, strength, electrical resistivity, corrosion potential, chloride diffusivity, sorptivity, and expansion (due to ASR, DEF, or sulfate attack). Corresponding field specimens were stored at three different outdoor sites in Texas and evaluated for ASR and/or DEF, as well as for corrosion potential (marine site). Lastly, the research team performed a forensic evaluation of a bridge deck in Amarillo, focusing on possible causes of cracking and remedies for future decks. Several products evaluated in this project showed some potential for improved durability and increased service lives for concrete infrastructure. Although there was no single product that was able to improve all durability aspects (like Class F fly ash), there may be opportunities for some of the products to be used in targeted applications to address specific durability requirements.Bruno Fong-Martinez, Jeremy Wheeless, Thano Drimalas, Kevin Folliard
11/30/21November 2021Alkali-Silica Reactivity (ASR) Risk Assessment and Mitigation in Tennesseehttps://cptechcenter.org/ncc-projects/alkali-silica-reactivity-asr-risk-assessment-and-mitigation-in-tennessee/Aggregates, Alkali carbonate reactions, Alkali silica reactions, Concrete pavements, Pavement cracking, Risk assessmentAlkali-silica reaction (ASR) is recognized as a major cause of concrete deterioration. Identifying the aggregate reactivity to ASR is one of the most efficient ways for preventing concrete cracking damage in practice. Many aggregates, especially the surface aggregates, used in Tennessee have a relatively high siliceous content (e.g. gravels, siliceous limestones, granites, and quartzite). Aggregates with ASR potential in Tennessee could have been used in the existing concrete structures and will be probably used even more in the future high-volume transportation projects. This report summarizes the findings of a two-phase research project to assess and mitigate the risk of Alkali-Aggregate Reaction (AAR) in the state of Tennessee. ASR reactivity of surface aggregates from 76 different local sources in Tennessee was evaluated in Phase I. Mitigation alternatives to minimize the ASR risk of reactive aggregates were proposed in Phase II. Category guideline on the ASR reactivity property of the aggregates within Tennessee has been developed. A statewide aggregate ASR risk database with detailed field and laboratory performance is presented which can be used to prevent ASR cracking damage of statewide transportation structures.Ammar Abd-Elssamd, John Z Ma
02/01/21February 2021Evaluation of Ultra-High-Performance Concrete for Use in Bridge Connections and Repairhttps://cptechcenter.org/ncc-projects/evaluation-of-ultra-high-performance-concrete-for-use-in-bridge-connections-and-repair/Bond strength (Materials), Bridge construction, Concrete bridges, Joints (Engineering), Repairing, Ultra high performance concrete (UHPC)The project described in this report evaluated available proprietary ultra-high performance concrete (UHPC) materials and UHPC mix designs made with local materials for applicability to bridge joint installation and repair in Oklahoma and developed recommendations for continued usage of UHPC in bridge construction in Oklahoma. Phase 1 of the project developed a promising UHPC mix design, J3,using local materials.Two specific applications of UHPC were considered: deck slab joints and girder continuity connections. Initial investigation of deck slab joint details was conducted using small-scale flexural specimens to evaluate bond strength between UHPC and base concrete. Laboratory-scale full-depth joints were cast and tested using both the proprietary UHPC material and the OU developed J3 mix design. Laboratory-scale UHPC connections for live load continuity between precast girders were also designed and tested to failure. Two different connection details were used, one representing new construction and one representing retrofit of an existing structure. Afield test involving retrofit of an existing expansion joint with UHPC joint headers was conducted on a bridge identified in conjunction with ODOT and was monitored for almost three years.Phase 2 involved slab testing for a partial depth slab joint detail, examination of reinforcement bond, and durability testing of both proprietary and non-proprietary UHPC. UHPC bond to concrete substrate was also examined for different surface preparations and base concrete saturation levels. The findings of the research indicate that UHPC provides improved performance relative to conventional materials for the applications tested and the J3 mix design exhibits similar performance to proprietary UHPC.Royce W Floyd, Jeffery S Volz, Chandler K Funderburg, Amy S McDaniel, Trevor Looney, Jake Choate, Stephen Roswurm, Connor Casey, Raina Coleman, Maranda Leggs, Kim Serey Vuth Chea
07/08/21July 2021Portland Cement Concrete Pavement Joint Sealant Practices and Performancehttps://cptechcenter.org/ncc-projects/portland-cement-concrete-pavement-joint-sealant-practices-and-performance/Case studies, Concrete pavements, Construction management, Interviewing, Literature reviews, Pavement joints, Sealing compounds, State departments of transportation, State of the practice, SurveysThis report compiles and documents information regarding the current state of practice of joint sealing Portland cement concrete (PCC) by state departments of transportation. The objective of this synthesis is to document current practices with PCC pavement joint sealant in new construction and the maintenance protocols of existing joint sealants for PCC pavements. The synthesis documents use of PCC pavement joint sealants, types of materials used for these sealants, and construction methods. It also summarizes the use of data from AASHTO’s National Transportation Product Evaluation Program for PCC pavement joint sealant product approval, inspection and/or acceptance procedures, and evaluation of long-term product performance. Last, the report compiles issues surrounding PCC joint sealant usage or effectiveness, such as water presence or movement and noise contributions, and alternative methods being used in lieu of sealants. Information in this study was acquired through a review of the literature, a survey of representatives of state departments of transportation, and follow-up interviews that informed the development of six case examples regarding joint sealing practices for PCC pavements.Jinho Kim, Dan G Zollinger
05/01/20May 2020Performance-Based Specifications of Fiber-Reinforced Concrete with Adapted Rheology to Enhance Performance and Reduce Steel-Reinforcement in Structural Membershttps://cptechcenter.org/ncc-projects/performance-based-specifications-of-fiber-reinforced-concrete-with-adapted-rheology-to-enhance-performance-and-reduce-steel-reinforcement-in-structural-members/Admixtures, Bridge construction, Corrosion resistance, Cracking, Durability, fiber reinforced concrete, Flexural strength, Performance based specifications, Shrinkage, Steel fibers, Structural analysisThe main objective of this research is to propose novel materials for the construction and retrofitting of bridges, including Economical Crack-Free High-Performance Concrete (Eco-Bridge-Crete, or EBC) and Fiber-Reinforced Super-Workable Concrete (FR-SWC). The project seeks to optimize the coupled effect of fiber characteristics, expansive agent (EA), saturated lightweight sand (LWS), and external moist curing on mechanical properties, shrinkage, and corrosion resistance of such classes of high-performance concrete. The project also aims to replace steel reinforcement in flexural members with steel fibers partially. In Task I, Eco-Bridge-Crete mixture design was optimized to reduce drying and restrained expansion and secure high mechanical properties. Eco-Bridge-Crete mixtures were optimized using various shrinkage mitigating strategies, including the use of different contents of CaO-based EA, LWS, and steel fibers as well as different moist curing conditions. The study revealed some synergistic effects among the EA, LWS, and fiber contents and external curing that led to lower shrinkage and restrained expansion and greater strength. The combined use of EA, along with LWS, was shown to reduce concrete conductivity and improve corrosion resistance. Overall, the use of synthetic fibers, EA along with LWS, increased moist curing duration, and concrete cover depth was identified as suitable strategies for improving the corrosion resistance of Eco-Bridge-Crete mixtures. In Task II, the structural performance of reinforced concrete beams cast with FR-SWC mixtures made with different fiber types and reinforcing steel densities was evaluated. The testing involved casting of beam elements with different steel reinforcement densities (0.4 to 0.8 in.² of steel area in the tension zone).Kamal H Khayat
03/01/21March 2021Large Box Study on Granular Base Options for Portland Cement Concrete Pavementshttps://cptechcenter.org/ncc-projects/large-box-study-on-granular-base-options-for-portland-cement-concrete-pavements/Concrete aggregates, Concrete pavements, Deformation, Geosynthetics, Granular bases, Modulus of resilience, Portland cement concrete, Recycled materials, Stabilized materials, Unpaved roadsWith the depletion of natural resources and limited funding for necessary pavement construction and rehabilitation, recycled concrete aggregate (RCA) and reclaimed asphalt pavement (RAP) are potential alternatives to the virgin granular base (VGB) typically used. The addition of geosynthetics at the interface of base course and subgrade can stabilize base course sections through separation, lateral restraint, and a tensioned membrane effect. This large-scale box study focused on two different granular base options (VGB and RCA) with geosynthetic stabilization for concrete pavement applications. Unpaved road tests under cyclic loading were first conducted on these granular bases over weak subgrade to evaluate the benefits of three types of geosynthetics (nonwoven geotextile, woven geotextile, and triaxial geogrid) and replacement of VGB with RCA in the improved performance (permanent deformation and stress reduction) and properties (resilient modulus and modulus of subgrade reaction). The nonwoven geotextile was selected for three concrete paved roads with VGB and RCA over the same subgrade under cyclic loading. Displacement transducers and earth pressure cells were placed in the test sections to monitor resilient and permanent deformations on the section surface and vertical interface stresses between base course and subgrade. For the unpaved test sections, the measured resilient and permanent deformations and the interface stress reduction were analyzed to evaluate the benefits of geosynthetics and replacement of VGB with RCA. The modified Burmister solution and the stress reduction method were used to back-calculate the resilient moduli (Mr) of the granular bases for all the test sections. Back-calculated resilient moduli were correlated with the accumulated permanent deformations to assess these methods. The American Association of State Highway and Transportation Officials (AASHTO, 1993) design chart was used to estimate the composite subgrade reaction moduli of the unpaved test sections based on the back-calculated resilient moduli (Mr) of the granular bases. The three concrete paved sections and the benefits of the nonwoven geotextile and the replacement of VGB with RCA were evaluated in terms of their total and permanent displacements and base course-subgrade interface stresses. Based on the measured vertical displacements at the loaded corner, Westergaard’s (1926) method was used to back-calculate the subgrade reaction moduli of these sections and estimate the tensile stresses in the concrete slabs. The back-calculated subgrade reaction moduli of these concrete paved sections were compared with those calculated based on the unpaved road sections. The key findings of this study are: (1) geosynthetics were effective in reducing the permanent deformations of both VGB and RCA base courses over the weak subgrade in unpaved and concrete paved roads under cyclic loading; (2) RCA was stronger and stiffer than VGB and replacement of VGB with RCA reduced the permanent deformations in unpaved and concrete paved roads under cyclic loading; (3) the resilient modulus of the base course in an unpaved road section back-calculated by the modified Burmister solution with the mechanistic-empirical damage model was correlated well with the accumulated permanent deformation of the unpaved road section; (4) the modulus of subgrade reaction of a base over a subgrade estimated by the AASHTO design chart with the back-calculated resilient modulus of the base from an unpaved road test was similar to that back-calculated by the Westergaard solution based on the displacement at the loaded corner; (5) the accumulated permanent deformation of an unpaved or concrete paved section increased with the reduction of the subgrade reaction modulus in a semi-logarithmic relationship; and (6) geosynthetic stabilization and/or replacement of VGB with RCA increased the resilient modulus and the subgrade reaction modulus of a test section.Tanya N Walkenbach, Jie Han, Robert L Parsons, Zexia Li
01/15/21January 2021Evaluation of Premature Cracking in Urban Concrete Pavementhttps://cptechcenter.org/ncc-projects/evaluation-of-premature-cracking-in-urban-concrete-pavement/Concrete pavements, JPCP, MIRA, Premature CrackingThis study investigated the causes for premature, transverse cracking on urban jointed plain concrete pavements in Illinois. A field survey of 67 sections throughout Illinois coupled with ultrasonic evaluation was completed to synthesize the extent of premature cracking on urban jointed plain concrete pavements (JPCP). The visual survey showed some transverse and longitudinal cracks were a result of improper slab geometry (excessive slab length and width). Ultrasonic tests over the contraction joints determined some notched joints had not activated and adjacent transverse cracks were likely formed as a result. Three-dimensional finite-element analyses confirmed that cracking would not develop as a result of normal environmental factors and slab-base frictional restraint. The concrete mixture also did not appear to be a contributing factor to the premature cracks. Finally, the lack of lubrication on dowel bars was determined to potentially be a primary mechanism that could restrain the transverse contraction joints, produce excessive tensile stresses in the slab, and cause premature transverse cracks to develop.Jeffery Roesler, John DeSantis
08/15/21August 2021Evaluation of Geosynthetics Use in Pavement Foundation Layers and Their Effects on Design Methodshttps://cptechcenter.org/ncc-projects/evaluation-of-geosynthetics-use-in-pavement-foundation-layers-and-their-effects-on-design-methods/Base course (Pavements), Geosynthetics, Pavement design, Specifications, Subgrade (Pavements)This report presents findings of a research effort aimed at reviewing and updating existing Illinois Department of Transportation (IDOT) specifications and manuals regarding the use of geosynthetic materials in pavements. The project consisted of three tasks: evaluate current IDOT practice related to the use of geosynthetics; review research and state of the practice on geosynthetics applications, available products, design methods, and specifications; and propose recommendations for geosynthetic solutions in pavements to modernize IDOT’s practices and manuals. The review of IDOT specifications revealed that geotextiles are the most used geosynthetic product in Illinois, followed by geogrids. Several of IDOT’s manuals have comprehensive guidelines to properly design and construct pavements with geosynthetics, but several knowledge gaps and potential areas for modernization and adoption of new specifications still exist. Based on the review of the available design methods and the most relevant geosynthetic properties and characterization methods linked to field performance, several updates to IDOT’s practice were proposed. Areas of improvement are listed as follows. First, establish proper mechanisms for using geogrids, geocells, and geotextiles in subgrade restraint and base stabilization applications. This includes using shear wave transducers, i.e., bender elements, to quantify local stiffness enhancements and adopting the Giroud and Han design method for subgrade restraint applications. Second, update IDOT’s Subgrade Stability Manual to include property requirements for geogrids, geotextiles, and geocells suitable for subgrade restraint applications. Third, establish proper standards on stabilization, separation, and pumping resistance for geotextiles by incorporating recent research findings on geotextile clogging and permeability criteria. Fourth, promote the use of modern geosynthetic products, such as geotextiles with enhanced lateral drainage, and fifth, elaborate on proper methods for construction/quality control measures for pavements with geosynthetics.Issam I A Qamhia, Erol Tutumluer
09/01/20September 2020Development of IDOT’s Proposed Smoothness Specification Based on the International Roughness Index (IRI)https://cptechcenter.org/ncc-projects/development-of-idots-proposed-smoothness-specification-based-on-the-international-roughness-index/Benefit cost analysis, Comfort, Life cycle analysis, Service life, Smoothness, SpecificationsThe existing smoothness specification implemented by the Illinois Department of Transportation (IDOT) was based on profile-index measurement, which was also widely used by other agencies. There is a national and international trend, however, toward using the international roughness index (IRI) as a standard smoothness index for pavement management as well as construction acceptance. Therefore, the primary objective of this study was to develop an IRI-based smoothness specification for IDOT. It was desired that IRI thresholds be developed objectively by quantifying the benefit of pavement smoothness. The benefits quantified within the framework of life cycle cost analysis and benefit-cost analysis generally revealed that smoother pavements are anticipated to exhibit increased service life, reduced life cycle cost (including agency and user costs), and improved safety. IRI is also a crucial component of user comfort, especially for high-speed facilities. IDOT’s new IRI-based specification was developed while considering these benefits along with the increased cost quantified as the incentive payments to be made for smoother pavements. In addition, several aspects of IRI thresholds and the smoothness assessment schedule were investigated for achievability and risk. Although the risk of moving from a profile-index-based specification to an IRI-based specification was found to be relatively low (i.e., 4.4% and 6.6% risk assessed for high-speed and low-speed facilities, respectively), it indicated that IDOT and IDOT’s contractors may need to work together to adapt to the new specification and continue to refine the IRI-based specification as more experience is gained.Hyung S Lee, William Vavrik
01/31/22January 2022Improved Resilience of Rigid Pavement Systemshttps://cptechcenter.org/ncc-projects/improved-resilience-of-rigid-pavement-systems/Concrete, Resilience (Materials), Rigid pavementThis study will evaluate the impact that inundation may have on concrete pavements; it will identify cost-effective and implementable solutions to improve the resilience of new and existing rigid pavement systems subjected to the combined effects of flooding and sea level rise.Hyung Lee
11/01/20November 2020Durability Evaluation of Ternary Mix Designs for Extremely Aggressive Exposures (Phase II)https://cptechcenter.org/ncc-projects/durability-evaluation-of-ternary-mix-designs-for-extremely-aggressive-exposures-phase-ii/Cement, Chloride content, Concrete, Durability, Electrical resistivity, Laboratory tests, Mix design, Permeability, Test procedures, ValidationConcrete made with low transport properties can be very durable even in extremely aggressive environments. This study examined the ability of resistivity testing to determine transport properties for concrete containing ternary blends of portland cement with supplemental cementitious materials. The penetrability of the concrete was tested using rapid chloride migration, rapid chloride permeability, water absorption, water permeability, volume of permeable voids, surface resistivity, bulk resistivity, and bulk diffusion. These tests were performed between 28 and 365 days of age of concrete. Extracted pore solution resistivity was measured to calculate the concrete formation factor. Chloride binding measurements were used to calculate effective diffusion coefficients. Little benefit was seen in increasing the silica fume dosage above 6% in rapid chloride migration test (RCMT) and bulk resistivity tests. Resistivity samples cured in simulated pore solution (SPS) showed better correlations to secondary absorption rate and water permeability than fog-room-cured samples. Formation factor performed marginally better for SPS-cured samples against secondary absorption rate than bulk resistivity. Chloride ingress calculations performed using formation factor were shown to conservatively simulate measured profiles. Chloride ingress simulated using formation factor from moist-room-cured samples were shown to be closer to the measured profiles than samples cured in simulated pore solution. Measurements performed on samples collected from piles with 12 years of marine exposure validated the laboratory results.Kyle A Riding, Christopher C Ferraro, Hossein Mosavi, Mohammed Hussein Alyami, Mohammed Almarshoud, Raid Alrashidi
09/14/18September 2018Development of Improved Guidelines and Designs for Thin Whitetopping: Environmental Response of Full-Scale BCOA Sectionshttps://cptechcenter.org/ncc-projects/development-of-improved-guidelines-and-designs-for-thin-whitetopping-environmental-response-of-full-scale-bcoa-sections/Asphalt concrete, Asphalt pavements, Asphalt rubber, Concrete overlays, Data collection, High strength concrete, Materials tests, Mix design, Pavement maintenance, WhitetoppingFifteen bonded concrete overlay of asphalt (BCOA) sections were built at the UCPRC facility in Davis, California, from February 23 to 25, 2016. The concrete mixes included Type II/V and Type III portland cements and calcium sulfoaluminate cement, and they were designed to provide 2.8 MPa (400 psi) flexural strength after either 4 or 10 hours. Six of the 15 sections were instrumented with a total of 245 sensors to measure the responses to environmental actions and cement hydration. Based on the analysis of the data collected by these sensors up until May 31, 2017, preliminary conclusions were drawn regarding how the different section configurations and concrete types responded to moisture and temperature-related actions. A clear link between drying shrinkage, concrete relative humidity, and environmental conditions was verified. Very high levels of drying shrinkage were measured in all portland cement mixes. For these mixes, the topical use of a shrinkage-reducing admixture proved to be an effective and efficient way to reduce drying shrinkage. Due to the low water/cement ratio of the portland cement mixes, very high levels of autogenous shrinkage occurred except in the mix that had been internally cured with pre-wetted lightweight aggregates. Autogenous shrinkage barely occurred in the internally cured mix. The mix with calcium sulfoaluminate cement did not present any autogenous shrinkage and presented much lower drying shrinkage than the mixes with portland cement. Despite the high levels of drying shrinkage in the mixes with portland cement, the concrete and asphalt remained fully bonded. For all the mixes, the apparent coefficient of thermal expansion was clearly influenced by the environmental conditions. Overall, thermal deformations of the mixes were much higher than predicted using the coefficient of thermal expansion determined in the laboratory under saturated conditions.Angel Mateos, John Harvey, Fabian Paniagua, Julio Paniagua, Rongzong Wu
01/01/16January 2016Effectiveness of Silane in Mitigating Alkali-Silica Reaction (ASR) in the Bibb Graves Bridgehttps://cptechcenter.org/ncc-projects/effectiveness-of-silane-in-mitigating-alkali-silica-reaction-asr-in-the-bibb-graves-bridge/Alkali silica reactionsAlkali-silica reaction (ASR) is a detrimental reaction in concrete that can cause severe expansion and cracking in structures. The Bibb Graves Bridge is a reinforced concrete bridge that was constructed in 1931, and is located in Wetumpka, Alabama. Both arches of span 5 have severe cracking and surface deposits caused by ASR. A silane-based, ASR mitigation was applied to spans 4 and 5 of the Bibb Graves Bridge during October and November of 2010. The goal of this mitigation procedure was to lower the internal relative humidity of the ASR-affected concrete to below 80 percent so that continued ASR-related expansions do not occur. After the application of the mitigation procedure, monitoring of the internal relative humidity, concrete expansion, and new crack development in the bridge was performed for 35 months to evaluate the effectiveness of the mitigation procedure. Analysis of the 35 months of data revealed that there were few signs of decreasing relative humidity or slowed expansion rates in the ASR-affected concrete. Analysis of the in-situ concrete strain data indicates that the ASR expansion in span 5 is continuing at the same pace as it was before mitigation. This was shown by the onset of new cracking and strong, linear trends with high expansion rates in a majority of the span. Some of the highest expansion rates in the two arches of span 5 range from 344 to 546 microstrains per year. It is concluded that the silane sealer was ineffective, and alternative mitigation options should be considered. It is recommended to continue in-situ monitoring to quantify the effects of ASR in this bridge.Darren K Johnson, Robert L Warnock
08/30/21August 2021FHWA Research and Technology Evaluation: High Friction Surface Treatmentshttps://cptechcenter.org/ncc-projects/fhwa-research-and-technology-evaluation-high-friction-surface-treatments/Friction course, Highway safety, Impacts, Research, State departments of transportation, Surface treatingThis evaluation assesses how the Federal Highway Administration’s (FHWA’s) investment in research on high friction surface treatments (HFSTs) and related activities impact the availability and quality of such research; awareness, knowledge, and attitudes toward HFSTs in the United States; adoption of HFSTs as a safety measure; and safety performance of HFSTs on the U.S. transportation system. Although measuring the effect of specific FHWA activities is difficult, this evaluation found evidence that FHWA improved awareness, knowledge, and attitudes toward HFSTs and expanded the breadth of HFST research and performance data available to States considering technology deployment. The findings suggest FHWA played a key role in accelerating the consideration of HFSTs as a topic of interest, facilitated the exchange of knowledge between States at differing levels of adoption, and helped influence States’ deployment of HFSTs. Many States saw a decrease in roadway-departure crashes. While FHWA cannot claim direct responsibility for this reduction, their continued research and promotion of HFSTs have enhanced roadway safety in the United States.Kaitlin Coppinger, Matthew Keen, Jennifer Gissel, Lydia Rainville
03/01/21March 2021Reduced Cementitious Material in Optimized Concrete Mixtureshttps://cptechcenter.org/ncc-projects/reduced-cementitious-material-in-optimized-concrete-mixtures/Admixtures, Cement, Concrete pavements, Laboratory tests, Pavement performance, Test tracksThis document reports the activities and observations of a research team that performed on-site and laboratory testing of concrete mixtures with reduced cementitious materials content placed in two cells at the MnROAD facility in Albertville, Minnesota. The overall objectives of this research project included investigating the early age characteristics of concrete paving mixes containing reduced cementitious contents as well as their long-term performance. It was observed that while workability was marginal in the mixture proportioned with 470 lb/yd³, all other properties of the test sections were similar to those of the control section.Peter Taylor, Seyedhamed Sadati
10/01/20October 2020Design and Performance of Unbonded PCC Overlayshttps://cptechcenter.org/ncc-projects/design-and-performance-of-unbonded-pcc-overlays/Concrete overlays, Geotextiles, Pavement distress, Pavement interlayersDue to increased traffic congestion and reduced budgets, National Road Research Alliance (NRRA) states are seeking effective rehabilitation techniques for older concrete pavements. Unbonded concrete overlays have a successful history as a rehabilitation option, and there is interest by NRRA member states to assemble information on best practices for the design, construction, and maintenance that relate to field performance. The goal of this project is to produce a brief technical document synthesizing the design, construction, maintenance, best practices, and performance observations of unbonded concrete overlays in NRRA member states.Joseph Korzilius, Spencer Neff, Renae Kuehl
02/01/23February 2023Use of Rice Husk Ash (RHA) as Stabilizing Agent for Poor Subgrade Soils and Embankmentshttps://cptechcenter.org/ncc-projects/using-of-rice-husk-ash-rha-as-stabilizing-agent-for-poor-subgrade-soils-and-embankments/Embankments, Feasibility analysis, Soil stabilization, Subgrade materials, Waste products (Materials)Arkansas produces the largest amount of rice in the United States. About 20% of the paddy is rice hull (RH). When burnt, 20% of RH is transformed into rice husk ash (RHA). Riceland Foods Inc., a family farmer-owned business in Arkansas, is the largest rice miller in the U.S. with an annual production of about 100 million bushels. A significant portion of RHA generated by Riceland is being treated as waste. RHA is a cementitious material, and Riceland's RHA contains about 75% silica in an amorphous form and has an extremely high surface area. RHA is also economically beneficial in stabilizing poor subgrade soils and embankments, but its performance as a construction material has been investigated very little. RHA can potentially be used as a stabilizing agent for poor subgrade and embankment soils, which are very common in Arkansas, Oklahoma, and other states. The main objective of the proposed collaborative study between Arkansas State University (A-State) and Oklahoma State University (OSU) is to assess the feasibility of the use of RHA in stabilizing poor subgrade and embankment soils through laboratory investigation. Based on the laboratory testing and results of this project, the investigators of this project will have a good understanding of the important features and efficacy of RHA as a stabilizing agent for poor soils. In particular, if there are short-term and long-term reactions, whether there are new minerals form as a result of the reactions, and whether the stabilization/modification processes are temporary or permanent will be understood. The outcome of the proposed study is expected to be important in setting the direction of the sustainable use of RHA and be a significant cost saving for transportation agencies in Region 6, which consists of Arkansas, Oklahoma, Louisiana, Texas, and New Mexico. In the long run, the outcomes of the proposed study will help local farmers to be economically sustainable as they are striving to find new markets for RHA. Furthermore, the A-State and OSU teams would like to utilize their resources and expertise in a unified and close collaboration way in maximizing the research outcome for likely adoption of this industrial by-product by transportation departments and other agencies within Region 6, and across the US. Therefore, a quite comprehensive and detailed study is proposed by both universities. This study will develop tools and materials for longer-lasting infrastructure, assess the feasibility of using local industry-generated RHA in the Mississippi Delta area, and establish strong collaborative records among partner institutions and local industries in the region. The benefits of the proposed study are multifold: (a) reuse of waste materials in transportation construction projects, (b) enhance training opportunities for students in the region, (c) help local farmers to be economically sustainable in the long run, (d) establish a new collaborative partnership with two major universities in Region 6, and (e) build a future workforce. This study supports multiple focus areas of Tran-SET: (1) Improving durability and extending the life of the infrastructure; (2) Preserving the environment; and (3) Other Regional priorities. The proposed study is aligned with a FAST track regional priority “Multiscale characterization of recyclable waste materials in transportation applications for achieving economical and material sustainability,” having a primary focus of “Recycling infrastructure assets.” RHA is a locally available waster material, which can be used to improve the quality of local materials, which are typically poor to withstand increasing traffic loads and extreme environmental events. On the other hand, RHA causes huge environmental burdens. Besides regional priorities, this project strongly supports the Center’s FAST focus areas 4 and 5.Momen Mousa, Zahid Hossain, Rifat Bulut
01/16/24January 2024Optimizing Aggregate Gradation to Reduce Concrete’s Permeabilityhttps://cptechcenter.org/ncc-projects/optimizing-aggregate-gradation-to-reduce-concretes-permeability/Admixtures, Aggregate gradation, Concrete, Mix design, Permeability, WorkabilityThe first objective is to measure the influence of aggregate gradation on concrete’s permeability. The second is to optimize concrete mixture designs that meet strength, permeability, and workability criteria for construction.Samuel Cooper, Jose Milla
02/01/23February 2023Low-Cost Sustainable Engineered Geopolymer Composites (EGCs) for Repair and New Construction of Transportationhttps://cptechcenter.org/ncc-projects/low-cost-sustainable-engineered-geopolymer-composites-egcs-for-repair-and-new-construction-of-transportation/Clay, Composite materials, Fiber reinforced materials, Fly ash, Geopolymer concrete, Polyvinyl acetate, RepairingEngineered Geopolymer Composites (EGCs) are ductile strain-hardening geopolymer (GP) based materials that have been recently introduced as an eco-friendly and sustainable alternative to Engineered Cementitious Composites (ECCs). While EGCs exhibit mechanical properties exceedingly superior to those of conventional Portland cement concrete (PCC), mass adoption of these emerging composites is expected to be hindered by their cost, which is mainly driven by the use PVA reinforcing fibers, silica fume, and manufactured microsilica sand. To address this key shortcoming, the multidisciplinary team form Louisiana State University and Texas A&M university will develop and characterize novel low-cost EGC materials for repair and new construction of transportation infrastructure in Region 6 by evaluating the use of: (1) calcined clays and fly ash as replacements of commonly used silica fume for GP binders; (2) low-cost PP fiber, PVA fiber, and hybrid systems of PP and PVA fiber; and (3) natural sand instead of commonly used manufactured microsilica sand. To achieve this objective, several GP matrices, and fiber-reinforced GP composites will be developed and comprehensively studied to identify fundamental relationships between materials composition, properties, and microstructure. In turn, this will allow for rational material design and optimization.Momen Mousa, Gabriel Arce, Miladin Radovic
01/16/24January 2024Influence of Internal Curing on Concrete’s Permeability in Simulated Field Conditionshttps://cptechcenter.org/ncc-projects/influence-of-internal-curing-on-concretes-permeability-in-simulated-field-conditions/Concrete curing, Electrical resistivity, PermeabilityThe first objective is to assess the influence of internal curing on concrete’s transport properties using appropriate curing conditions. The second objective is to validate the surface resistivity results with bulk diffusion testing.Samuel Cooper, Jose Milla
02/01/23February 2023Development of Ultra-High Performance Engineered Geopolymer Composites (UHP-EGCs)https://cptechcenter.org/ncc-projects/development-of-ultra-high-performance-engineered-geopolymer-composites-uhp-egcs/Ductility, fiber reinforced concrete, Geopolymer concrete, Ultra high performance concrete (UHPC)The emergence of ultra-high strength ultra-high ductility cementitious composites such as ultra-high performance Engineered Cementitious Composites (UHP-ECCs) for construction application are promising for the future of civil infrastructure as these materials overcome important weaknesses of conventional concrete materials including their low tensile strength and brittle nature. However, these materials use large amounts of ordinary Portland cement (OPC), which limit their sustainability. The objective of this study is to develop novel Ultra-High Performance Engineered Geopolymer (GP) Composites (UHP-EGC) as materials for repair and new construction of transportation infrastructure in Region 6. The developed composites will be mainly made utilizing locally available resources (kaolin clays, natural sand, etc.) to enhance practicality and cost-effectiveness of these materials. To achieve this objective, a multidisciplinary team from Louisiana State University and Texas A&M University will develop several high-strength GP matrices reinforced with functionalized Ultra-High-Molecular-Weight Polyethylene (UHMWPE) microfibers. Material properties will be thoroughly evaluated to identify composition-microstructure-property relationships necessary for systematic design of the novel composites. Furthermore, UHP-EGCs’ cracking characteristics, dimensional stability, and bonding properties with regular concrete will be assessed to determine the feasibility of the developed composites for repair applications.Momen Mousa, Gabriel Arce, Miladin Radovic
02/01/23February 2023Development and Implementation of Low-Cost Engineered Cementitious Composites (ECCs) in Rural Roads in the State of Louisianahttps://cptechcenter.org/ncc-projects/development-and-implementation-of-low-cost-engineered-cementitious-composites-eccs-in-rural-roads-in-the-state-of-louisiana/Cement, Composite materials, Friction, Rural highwaysOver the recent years, the research team has successfully developed novel low-cost Engineered Cementitious Composite (ECC) mixtures for future implementation in pavement infrastructure in Louisiana. The mechanical properties of these mixtures have been successfully validated through laboratory testing. The main objective of this study is to facilitate the implementation of the best performing mixture in the field under real world conditions. To achieve this objective, the functional properties (i.e., frictional properties) of this mixture will be adjusted and validated through laboratory testing. Once validated, the final mixture will be applied as an overlay in a rural road in the state of Louisiana in partnership with the Louisiana Department of Transportation and Development (DOTD). Over the project duration, the field performance of the ECC overlay will be assessed through regular field surveys.Momen Mousa
02/01/23February 2023Characterizing Corrosion Control and Prevention Methods for RC Elements Based on Hybrid Protection Mechanismhttps://cptechcenter.org/ncc-projects/characterizing-corrosion-control-and-prevention-methods-for-rc-elements-based-on-hybrid-protection-mechanism/Coatings, Corrosion protection, Inhibitors (Chemistry), Materials, Reinforced concreteA team comprised of Texas A&M University (TAMU) and University of Texas at San Antonio (UTSA) proposes a study that will include integration from the civil engineering, materials sciences and corrosion science technical communities to characterize and select the corrosion and mitigation methods for reinforced concrete (RC) elements regarding the corrosion of steel used in transportation applications. The proposal includes: (1) different corrosion control mechanisms including the mass transport resulted from the physical barrier (organic coatings), sacrificial or charge transfer mechanisms (cathodic protection, galvanic coupling) and homogeneous processes influencing redox inhibition (corrosion inhibitor) for corrosion of rebar steel embedded in concrete structures; (2) the characterization of RC elements with either or a combination of three different corrosion control methods, and evaluation of their performance to understand their influence on corrosion and its rates; and (3) identification of the most suitable and efficacy corrosion control strategy and quantify the uncertainties associated with methods for testing and monitoring corrosion of steel in RC elements in laboratory and field conditions. RC structures are frequently exposed to aggressive/corrosive environments that can promote deterioration of their structural properties and shortening of their service life. Chloride-induced corrosion of reinforcing steel in concrete represents one of the most severe and common forms of RC degradation. The high alkaline pH of concrete leads to the formation of a passive film on the reinforcing steel. Diffusion and accumulation of chloride ions within the concrete matrix promotes breakdown of the ferrous passive film and initiation of localized corrosion at the steel surface. This passive film breakdown process requires a critical chloride concentration, commonly known as “threshold” chloride concentration. In the case where a sacrificial inorganic layer such as Zinc is applied on the rebar, corrosion initiation could be defined as the failure of the Zn layer at a certain location. The localized attack can be influenced, as mentioned previously, by the chloride content, but also by other parameters such as temperature, corrosion products thickness, etc. Previous works and efforts have been mostly focused in the threshold chloride concentration at the steel/concrete interface. The literature on galvanized steel is limited; however, it is known that the threshold chloride concentration for this material is greater than for bare steel. Furthermore, the addition of a physical barrier will add another approach to the corrosion control actions used in the RC elements and infrastructure in general. There have been attempts in which either one of the corrosion control action have been used but not as integration or balance between them at the same time. A collaborative research study is proposed to investigate the medium and long-term durability of RC system by using different control actions and optimize the materials design for transportation infrastructure in Region 6. As a part of the integral study, performance tests under corrosive environment are to be conducted on different control action systems over different periods of time. Both material characterization studies related to laboratory and field conditions will be carried out as a part of this effort. Field conditions will illustrate and correlate the results founded in laboratory scale conditions. It is apparent that DOT can benefit greatly if a research project is undertaken to develop effective corrosion control methods. The proposed study and the design guidelines for hybrid or integrated systems would be beneficial to all state DOTs within the Tran-SET membership, as it will provide new approach for eco-friendly and corrosion resistant materials used for transportation infrastructure in Region 6. The proposed research with hybrid protection mechanisms (HPM), should provide a sustainable and alternative technology applicable to the existing RC infrastructures to increase their life cycle. Therefore, the proposed collaborative study focuses on these Tran-SET’s areas: Area 4: Improving durability and extending the life of the infrastructure (Sub-area: Application of new materials and technologies); Area 6: Preserving the existing transportation system. Two doctoral students will work with PIs in the execution of the proposed research tasks. The expected deliverable from this project is a technical report summarizing all tasks from both institutions, including necessary design guidelines of HPM. Results of this project will be also disseminated in related workshops and conferences, and presented to the industrial partners.Momen Mousa, Homero Castanada, Brendy Rincon
07/31/22July 2022Beneficial Reuse of Landfilled Fly Ash in Transportation Infrastructurehttps://cptechcenter.org/ncc-projects/beneficial-reuse-of-landfilled-fly-ash-in-transportation-infrastructure/Admixtures, Fly ash, Recycled materialsIn this study, researchers from Colorado State University and the University of Wyoming will work jointly with the concrete industry partners in the region to understand the role that landfilled fly ash (LFA) plays in controlling concrete properties in the fresh and hardened state. The overarching goal of this study is to determine if LFA that may not meet the prescriptive limits set forth in ASTM C618 and AASHTO M295 can show adequate performance in service and whether a new classification can be introduced based on their inherent heterogeneity in physicochemical properties and performance data.Denver Tolliver, Mahmoud Shakouri, Khaled Ksaibati, Chengyi Zhang
02/01/23February 2023Alternative Supplementary Cementitious Materials in Ultra-High Performance Concretehttps://cptechcenter.org/ncc-projects/alternative-supplementary-cementitious-materials-in-ultra-high-performance-concrete/Admixtures, Cement, Durability, Fly ash, Mix design, Pozzolan, Ultra high performance concrete (UHPC)Ultra-high performance concrete (UHPC) is an advanced fiber reinforced composite material with compressive strengths greater than 17,000 psi (120 MPa), flexural strengths greater than 1450 psi (10 MPa), and exceptional durability properties. UHPC is produced with a high cementitious materials content, and silica fume and high-range water reducing admixtures are used to produce a dense microstructure that can result in compressive strengths greater than 29,000 psi (200 MPa). The superior durability and corrosion resistance provided by UHPC provides the potential to increase service life and lower repair costs in concrete structures. New Mexico State University (NMSU) research has shown that non-proprietary UHPC produced with local materials can cost less than proprietary mixtures, primarily by using class F fly ash to replace much of the more expensive silica fume that is used as a supplementary cementitious material (SCM). Non-proprietary UHPC produces slightly lower strengths than proprietary mixtures, but durability properties of non-proprietary mixtures have been comparable to those of proprietary mixtures. UHPC mixtures developed at NMSU have been specified by New Mexico Department of Transportation (NMDOT) for pre-cast, pre-stressed bridge girders and bridge deck overlays. Unfortunately, class F fly ash production has decreased sharply as the energy industry has reduced coal consumption and moved to renewable energy technologies to produce electricity. NMDOT expects that by as early as 2022 the supply of class F fly ash will be insufficient to meet their needs for concrete construction, so alternative SCMs are needed for all concrete mixtures including the non-proprietary UHPC mixtures. This research project will assess the potential for using alternative SCMs such as a natural pozzolan, metakaolin, and ground-granulated blast furnace slag in non-proprietary UHPC mixtures. The research project includes a comprehensive literature review to identify the most important characteristics of SCMs for use in UHPC and to expose critical concerns for UHPC mixtures produced with these materials. A suite of mixture proportions utilizing the SCMs considered in the project will then be developed. Each of the new UHPC mixtures will be evaluated for fresh and hardened properties including workability, compressive strength, and flexural strength. The most promising UHPC mixtures will then be tested for durability related properties including rapid chloride permeability, surface resistivity, shrinkage, and frost resistance. Results from the testing program will be compared to results from existing mixtures containing silica fume and class F fly ash in the final research report. The implementation phase of the project includes documenting and disseminating the results of the research in the final report for the project, publication of journal papers, publication of conference papers, and presentations at conferences. The NMSU research team is led by the PI, Professor Craig Newtson, who has over 25 years of concrete related research experience on projects totaling more than $2,300,000 in funding and has received national recognition for his research.Momen Mousa, Craig Newtson
12/31/22December 2022Reducing Greenhouse Gas Emissions from Construction of Washington Transportation Infrastructurehttps://cptechcenter.org/ncc-projects/reducing-greenhouse-gas-emissions-from-construction-of-washington-transportation-infrastructure/Asphalt, Benchmarks, Building materials, Concrete, Construction, Cost effectiveness, Greenhouse gases, Infrastructure, Specifications, steelThis research project aims to (1) benchmark greenhouse gas emissions from the construction of WSDOT’s projects based on existing specifications and sourcing practices; (2) identify needs for additional testing and research by WSDOT’s HQ Materials Laboratory based on current gaps related to decarbonization; and (3) provide recommendations on easily-implementable, cost-effective strategies for reducing WSDOT’s carbon footprint where strategies and testing already exist. The research scope will include concrete, asphalt, and steel products on the pre-approved products and vetting process for WSDOT’s qualified product list (QPL). This research will provide a first step in identifying opportunities for WSDOT to reduce greenhouse gas emissions related to construction by focusing on opportunities related to standard specifications and practices that can be implemented across WSDOT projects.Jon Peterson
08/01/23August 2023Effectiveness Assessment of E-Ticketing Technology Adopted to Mitigate Covid-19 Challenges for Inspectors and Field Engineers in Transportation Projects: Guidebook Development for E-Ticketing (Electronic Track of Material Delivery) Implementationhttps://cptechcenter.org/ncc-projects/effectiveness-assessment-of-e-ticketing-technology-adopted-to-mitigate-covid-19-challenges-for-inspectors-and-field-engineers-in-transportation-projects-guidebook-development-for-e-ticketing-electro/Automation, Construction projects, Data collection, Inspection, MaterialsAs construction of transportation projects require significant amount of financial resources, cost savings play a significant role in these projects. E-Ticketing, is a new technology which reduces project costs through less need for inspection workforce, increased accuracy in delivery of construction materials (concrete, asphalt mix, etc.), improved documentation process, and reduced project schedule. In addition, this technology increases safety of inspectors, as they do not need to locate in danger zones of projects adjacent to traffic in order to exchange paper tickets with truck drivers. Although, E-Ticketing is a very beneficial technology in construction of transportation infrastructures, several DOTs hesitate to adopt the technology and only few DOTs such as Iowa DOT and Kentucky Transportation Cabinet have pilot tested the technology. The reason behind this resistance is due to lack of sufficient research results to support the cost and schedule savings of the technology as well as lack of implementation standards and guidelines. Therefore, this study aims to analyze the effectiveness of the E-Ticketing for construction of transportation infrastructures based on cost savings, schedule reductions, and health and safety enhancement. In this regard, this study develops two quantitative models measuring the cost savings and schedule reductions using E-Ticketing in transportation projects. Moreover, this study evaluates the health benefits of E-ticketing adoption for field inspectors as face-to-face interactions between truck drivers and field inspectors are eliminated. Survey, interviews, and quantitative data analysis and modeling techniques will be used. This study will develop project-based standards for E-Ticketing adoption by State Transportation Agencies. This study also develops a decision-making tool for adoption of E-Ticketing in different transportation projects based on their projects size, project type, complexity level, location (rural vs. urban), project timeline, and other characteristics.Momen Mousa, Sharareh Kermanshachi
06/30/22June 2022Developing High-Performance Nanocomposite Coating for Steel Reinforcement Protection in Chloride-Rich Concretehttps://cptechcenter.org/ncc-projects/developing-high-performance-nanocomposite-coating-for-steel-reinforcement-protection-in-chloride-rich-concrete/Chloride content, Corrosion protection, high performance concrete, Nanostructured materials, Protective coatings, Reinforcement (Engineering), steelAnti-corrosion coating is one of the most widely used technologies to mitigate corrosion of steel reinforcement in chloride-contaminated concrete. The durability of epoxy-coated reinforcement commonly used is of great concern due to its failure record in high chloride environments and localized corrosion conditions. In this context, this project aims to design a long-lasting, high-performance rebar coating that increases the service life of the rebar in concrete by reducing corrosion at the interface between the rebar and the surrounding chloride-contaminated concrete. A two-layer coating will be applied on steel rebar, with an inhibitor-loaded epoxy nanocomposite coating as the primer and a minerals-loaded epoxy-polyurethane nanocomposite coating as the top coat. Electrochemical corrosion tests, surface analyses, and mechanical tests will be conducted to assess and elucidate the effect of different constituents on the protective performance of such novel epoxy-based nanocomposite coatings.Xianming Shi
09/30/23September 2023Enhancing the Durability of Bridge Decks by Incorporating Microencapsulated Phase Change Materials (PCMs) in Concretehttps://cptechcenter.org/ncc-projects/enhancing-the-durability-of-bridge-decks-by-incorporating-microencapsulated-phase-change-materials-pcms-in-concrete/Bridge decks, Concrete bridges, Feasibility analysis, Freeze thaw durability, Overlays (Pavements), Roads, Winter maintenanceIn Rhode Island and other New England states, combined effects of freeze-thaw-induced damage and chloride ingress (from deicing salts) make it very challenging to maintain the quality of concrete on bridges and road surfaces. This project will develop, evaluate, and assess the feasibility of incorporating microencapsulated phase change materials (PCMs) into the concrete to reduce freeze-thaw/chloride ingress-induced degradation. Under freezing ambient conditions, when PCMs freeze, they release a large amount of heat that helps keep the deck/pavement warmer. As a result, PCMs can reduce the number of freeze-thaw cycles in bridge decks which can lead to a significant reduction in damage/ingress of salt and an increase in life expectancy. In this project, a series of comprehensive experiments will be performed to evaluate the influence of PCM-incorporated concrete overlays on the freeze-thaw damage response and durability of concrete against chloride ingress. Moreover, the experimental results will be synergistically integrated with a robust performance prediction tool to enable efficient design of PCM concrete overlays specifically targeted for winter weather conditions in Rhode Island and other northeastern states.Sumanta Das, Mayrai Gindy
03/15/22March 2022Assessing the Feasibility of Utilizing UAS-Based Point Cloud in Pavement Smoothness/Roughness Measurementhttps://cptechcenter.org/ncc-projects/assessing-the-feasibility-of-utilizing-uas-based-point-cloud-in-pavement-smoothness-roughness-measurement/Data collection, Drones, Pavements, Roughness, SmoothnessThis proposed effort will assess the feasibility of utilizing unmanned aerial system (UAS)-based point clouds in measuring pavement roughness, and this will be accomplished through the following tasks: (1) Establish a framework to process and calculate International Roughness Index (IRI) from UAS data. The proposed framework will take UAS-based point clouds as input, remove noise, extract pavement, create a terrain model, and generate profiles to extract roughness information. All the methods and approaches will be tailored targeting a more accurate and reliable IRI assessment. (2) Perform rigorous accuracy assessment for UAS data. This project will primarily use the UAS data that was collected in the Oregon Coastal area where terrestrial lidar data is also collected and can be served as ground truth to compare against: (a) Point-based: compare terrestrial lidar point cloud on a per-point basis; (b) Model-based: compare terrain models and IRI assessment results generated from terrestrial lidar point cloud and UAS data; and (c) Sensitivity analysis: test the sensitivity of different parameters and approaches used in noise removal, modeling, and roughness assessment. (3) Provide recommendations for UAS data acquisition and processing procedures for the purpose of assessing pavement roughness. For example, regarding to data collection, the selection of ground sampling distance (GSD) can be very important because it directly affects the resolution and precision of the model. In post-processing, there are many parameters and settings that can substantially impact the point cloud and model generated from UAS data. This task will optimize these acquisition and processing parameters and provide recommendationsErzhuo Che
07/31/23July 2023Investigating Thermal and Mechanical Inputs for Rigid Pavement Design in North Carolinahttps://cptechcenter.org/ncc-projects/investigating-thermal-and-mechanical-inputs-for-rigid-pavement-design-in-north-carolina/Aggregates, Concrete pavements, Mechanistic-empirical pavement design, Rigid pavementsNorth Carolina Department of Transportation (NCDOT) is planning to incorporate PMED into the design process for rigid pavements. The NCDOT conducted a research project completed in 2016 as an initial step to conduct the characterization of concrete materials (FHWA Report No. NC/2015-03) which provided a database of concrete material inputs incorporating Piedmont, Coastal, and Mountain coarse aggregates along with a manufactured sand and a natural sand. Although this project provided a range of useful inputs, it is understood that there are differences in aggregates from other areas of North Carolina, including areas where rigid pavements are anticipated to be constructed. So, there is a need to characterize the concrete paving mixes prepared with these coarse aggregates and potentially other variables to obtain a more detailed catalog of PMED inputs for rigid pavement design, and subsequently, to evaluate the effects of the obtained material inputs on the design and performance analysis of rigid pavements.Gauhar Sabih, Tara Cavalline
04/30/22April 2022Low-Carbon Concrete Pilot Programhttps://cptechcenter.org/ncc-projects/low-carbon-concrete-pilot-program/Admixtures, Aggregates, Carbon, Performance, PollutantsConcrete is responsible for about 8.6% of the world’s CO2 emissions, despite the production of concrete having a relatively low carbon intensity compared to other building materials. The excessive release of CO2 from concrete is due to the vast quantities of the material produced each year. The goal of the proposed work is to provide the Port Authority with the ability to significantly reduce the embodied carbon of the concrete mixtures used in their construction activities. This will support agency wide greenhouse gas (GHG) reduction target of 80% by 2050. The intended outcome of the project is to provide concrete mixtures that can significantly decrease embodied carbon in Port Authority concrete placements. Additionally, the work will improve other areas of sustainability by working to close materials loops in the local region for waste glass and demolition waste. This study will also result in significant research progress in the comparison and development of LECC systems that will benefit the construction community at large.Reza Moini, Matthew Adams
04/15/23April 2023Performance of Cost-Effective Non-Proprietary UHPC in Thin Bonded Bridge Overlayhttps://cptechcenter.org/ncc-projects/performance-of-cost-effective-non-proprietary-uhpc-in-thin-bonded-bridge-overlay/Admixtures, Bridge decks, Cost effectiveness, Overlays (Pavements), Ultra high performance concrete (UHPC)The use of Ultra High-Performance Concrete (UHPC) for thin bonded overlays for bridge deck rehabilitation has been successfully used in some pilot studies in Iowa, Delaware, and New York, and more extensively in Europe. Such innovative material can enable the construction of thin bonded overlays of 1 to 2 inch in thickness for the rehabilitation of bridge decks and restoration of the structural capacity of bridges. Despite encouraging results with some field applications, the high material unit cost of proprietary materials limits the wide acceptance of UHPC for bridge deck rehabilitation. The PI has developed a new class of cost-effective, non-proprietary UHPC mixtures that are self-consolidating to facilitate placement and finishing. The main objective of the proposed project is to evaluate the constructability and performance of non-proprietary thixotropic UHPC for thin bonded bridge deck overlay construction.Kamal Khayat, John Myers
10/31/23October 2023Ultra-High Performance Concrete Reinforced with Multiscale Hybrid Fibers and its Durability-Related Propertieshttps://cptechcenter.org/ncc-projects/ultra-high-performance-concrete-reinforced-with-multi-scale-hybrid-fibers-and-its-durability-related-properties/Building materials, Durability, fiber reinforced concrete, Mechanical properties, Mix design, Specifications, Ultra high performance concrete (UHPC)MassDOT is seeking to improve the quality and durability of fiber-reinforced concrete (FRC) and ultra-high performance concrete (UHPC) for longevity and constructability of new structures and repair of existing structures. There exist critical gaps in understanding the efficiency of mixture design and fibers on concrete performance, especially the mechanical and durability-related properties. A better understanding of FRC and UHPC will promote the development and applications of high-quality concrete to satisfy the performance expectation of future transportation infrastructure.Jianqiang Wei, Sergio Brena
09/30/22September 2022Construction and Materials Best Practices for Concrete Sidewalks: Phase 2https://cptechcenter.org/ncc-projects/construction-materials-best-practices-for-concrete-sidewalks-phase-2/Best practices, Concrete pavements, Durability, Materials tests, SidewalksDeterioration, such as scaling of concrete sidewalks, is one of the most urgent challenges that need to be tackled. There are currently extensive knowledge gaps in developing durable concrete. MassDOT is seeking to improve the durability of concrete sidewalks under extreme weather conditions in Massachusetts to reduce the maintenance and reconstruction costs. Specifically the project will achieve the following: (1) Research proper concrete sidewalk workmanship for sidewalks placed under hot weather conditions. (2) Determine whether curing/sealing compounds can replace moist curing to enable faster placement and return to use. (3) Determine if penetrating sealers are effective at limiting chloride penetration from commercially available chemical deicers. (4) Perform extensive testing on fresh and hardened concrete to identify processes responsible for concrete deterioration. (5) Document the performance of sidewalks through detailed visual and photographic inspection to support lab testing. (6) Perform hardened concrete testing using petrographic methods and chloride ingress testing to identify conditions that may lead to observed degradation in the field.Kara D Peterman, Sergios Brena
09/30/22September 2022Implementing the AASHTO Mechanistic-Empirical Pavement Design Guide: Phase IIhttps://cptechcenter.org/ncc-projects/implementing-the-aashto-mechanistic-empirical-pavement-design-guide-phase-ii/Calibration, Handbooks, Mechanistic-empirical pavement design, Pavement distress, Plan implementationMassDOT is striving to improve its highway infrastructure's resiliency to climate change, environmental impacts, and traffic loading by implementing new technologies that can provide valuable return on investment. These improvements should begin with the pavement design process which currently utilizes antiquated empirical design methods from the 1960's. AASHTO's new Mechanistic-Empirical (M-E design) pavement design method is currently used or being evaluated by at least 33 state agencies and would be a significant improvement in design. AASHTO ME design predicts pavement distresses utilizing prediction models that were developed and nationally calibrated using in-service pavements. To accurately predict the design performance in Massachusetts, these models need to be calibrated according to Massachusetts local conditions. Due to the complexity of the research problem, a multi-phase (four phase) approach over several years was suggested. The objectives for this second phase are: (1) Develop an AASHTOWare® Pavement M-E user manual & local experimental plan and sampling template. (2) Continue initial testing of already sampled mixtures to accelerate future phases of this research.Walaa S. Mogawer
06/30/23June 2023Calibration Refinement of AASHTO PaveME Pavement Design Softwarehttps://cptechcenter.org/ncc-projects/calibration-refinement-of-aashto-paveme-pavement-design-software/Calibration, Mechanistic-empirical pavement design, SoftwareExisting calibration factors were developed based on earlier versions of AASHTO’s PaveME software. Recently, AASHTO released tools which allow for streamlined local calibration of the software’s most recent version. This project will refine local calibration of PaveME software based on pavement design and management information collected from Kentucky projects. The updated software can be used to refine the existing web-based design tool and develop more efficient designs that better utilize funding resources. The updated software may also be used to provide more efficient specialized designs for rehabilitation projects and new projects which fall outside the web-based design tool’s scope.Clark Graves
08/31/23August 2023Developing AI-Assisted In Situ NDT Method for Air Void Distribution Testing in Fresh and Hardened Concretehttps://cptechcenter.org/ncc-projects/developing-ai-assisted-in-situ-ndt-method-for-air-void-distribution-testing-in-fresh-and-hardened-concrete/Air voids, Artificial intelligence, Concrete pavements, Durability, Field tests, Nondestructive tests (NDT), Test proceduresThis project will develop a field-deployable NDT method to evaluate the air void distribution in fresh and hardened concrete. The benefits of this program include 1) improving concrete pavement quality and long-term durability; 2) avoiding poor concrete quality and related materials, in-house labor and equipment cost; and 3) avoiding over design, and lower construction and maintenance cost.Na Lu, Guang Lin
05/30/24May 2024Real-Time Monitoring of Concrete Strength to Determine Optimal Traffic Opening Timehttps://cptechcenter.org/ncc-projects/real-time-monitoring-of-concrete-strength-to-determine-optimal-traffic-opening-time/Concrete construction, Construction scheduling, Electrical impedance, Field test, Mechanical impedance, Mechanical properties, Monitoring, Nondestructive tests (NDT), Patching, Piezoelectricity, Sensors, Specifications, Work zone traffic control LINKSThe aim of this project is to develop a reliable in-situ sensing method to evaluate the concrete properties for determining optimal traffic opening time of patching job or new construction with fly ash or other supplementary cementitious materials. This goal will be achieved by using piezoelectric sensors coupled with electromechanical impedance (EMI) analyzers to determine the very early age properties of concrete (i.e. Stiffness, setting time, hydration, etc.). This novel method will address the deficiency of current testing methods for determining traffic opening, for instance extensive calibration of maturity test and inefficiency of flexural strength test. The impact of this study can be revolutionary as it does not require any conventional mechanical testing and expensive and heavy test setups in the field. It only requires commercially available piezoelectric sensors (~$10 per sensor) and a portable EMI analyzer for data analysis and interpretation. There is no need for calibration for each different mix design. The associated benefits of using this novel non-destructive sensing method include (1) determining optimal traffic opening time based on reliable data of concrete properties; (2) reducing pre-mature failure of concrete pavement, bridge deck, patching, and other concrete structures; (3) enabling significant cost and schedule savings in construction projects due to reduced testing samples and testing time; and (4) reducing construction worker safety issues and jobsite accident rates in construction zones.Tommy Nantung
06/30/24June 2024Thickness Design for Cement-Treated Base Pavementshttps://cptechcenter.org/ncc-projects/thickness-design-for-cement-treated-base-pavements/Base course (Pavements), Falling weight deflectometers, Full-depth reclamation, Pavement design, Pavement performance, ThicknessCement-treated base (CTB) pavements are widely utilized by Illinois local road agencies. The CTB lift may include existing hot-mix asphalt surface, old bituminous surface treatments, aggregate base/subbase, and subgrade soil. The process is typically labeled “full-depth reclamation.” The objective of the project is to develop (in cooperation with the Illinois Department of Transportation) a CTB thickness design procedure and supporting policies. Project activities will focus on falling weight deflectometer testing (per Illinois Department of Transportation) and further performance surveillance of projects considered in previous projects and the additional CTB projects identified by Illinois Department of Transportation and the project's principal investigator.Marshall Thompson
09/30/21September 2021Concrete Pavement Mixtures with High Supplementary Cementitious Materials Content: Volume 3https://cptechcenter.org/ncc-projects/concrete-pavement-mixtures-with-high-supplementary-cementitious-materials-content-volume-3/Cementitious Material, Concrete, Fly ash, partical groupFly ash is a byproduct of coal combustion, made up of particles that are collected through various methods. This byproduct has been used successfully as a partial Portland cement replacement in concrete, but the performance predictions of fly ash in concrete have been difficult to predict, especially at high fly ash replacement rates. This study focuses on comparing the performance of concrete with a variety of fly ash mixtures as well as the particle distribution and chemical makeup of fly ash. The slump, unit weight, compressive strength, and isothermal calorimetry tests were used to measure the performance of concrete at 0%, 20%, and 40% fly ash replacement levels. The particle distribution of fly ash was measured with an automated scanning electron microscope. Additionally, the major and minor oxides from the chemical makeup of fly ash were measured for each mixture and inputted into a table. The particle distribution and chemical makeup of fly ash were compared to the performance of slump, unit weight, compressive strength, isothermal calorimetry, and surface electrical resistivity.Tyler Ley, Zane Lloyd, Shinhyu Kang, Dan Cook
09/30/21September 2021Early-Age Properties of High-Volume Fly Ash Concrete Mixes for Pavement: Volume 2https://cptechcenter.org/ncc-projects/early-age-properties-of-high-volume-fly-ash-concrete-mixes-for-pavement-volume-2/Concrete, Fly ash, Foam Index, Hydration, Limestone, Maturity, Noncontact Ultrasound, Setting TimeHigh-volume fly ash concrete (HVFAC) is more cost-efficient, sustainable, and durable than conventional concrete. This report presents a state-of-the-art review of HVFAC properties and different fly ash characterization methods. The main challenges identified for HVFAC for pavements are its early-age properties such as air entrainment, setting time, and strength gain, which are the focus of this research. Five fly ash sources in Illinois have been repeatedly characterized through x-ray diffraction, x-ray fluorescence, and laser diffraction over time. The fly ash oxide compositions from the same source but different quarterly samples were overall consistent with most variations observed in SO3 and MgO content. The minerals present in various fly ash sources were similar over multiple quarters, with the mineral content varying. The types of carbon present in the fly ash were also characterized through x-ray photoelectron spectroscopy, loss on ignition, and foam index tests. A new computer vision– based digital foam index test was developed to automatically capture and quantify a video of the foam layer for better operator and laboratory reliability. The heat of hydration and setting times of HVFAC mixes for different cement and fly ash sources as well as chemical admixtures were investigated using an isothermal calorimeter. Class C HVFAC mixes had a higher sulfate imbalance than Class F mixes. The addition of chemical admixtures (both PCE- and lignosulfonate-based) delayed the hydration, with the delay higher for the PCE-based admixture. Both micro- and nano-limestone replacement were successful in accelerating the setting times, with nano-limestone being more effective than micro-limestone. A field test section constructed of HVFAC showed the feasibility and importance of using the noncontact ultrasound device to measure the final setting time as well as determine the saw-cutting time. Moreover, field implementation of the maturity method based on wireless thermal sensors demonstrated its viability for early opening strength, and only a few sensors with pavement depth are needed to estimate the field maturity.Aniruddha Baral, Jeffery Roesler, Janryu Fu
09/30/21September 2021High-Volume Fly Ash Concrete for Pavements Findings: Volume 1https://cptechcenter.org/ncc-projects/high-volume-fly-ash-concrete-for-pavements-findings-volume-1/Cementitious Material, Concrete, Fly ash, Foam Index, Hydration, Limestone, Maturity, Noncontact Ultrasound, Particle Group, Setting TimeHigh-volume fly ash concrete (HVFAC) has improved durability and sustainability properties at a lower cost than conventional concrete, but its early-age properties like strength gain, setting time, and air entrainment can present challenges for application to concrete pavements. This research report helps with the implementation of HVFAC for pavement applications by providing guidelines for HVFAC mix design, testing protocols, and new tools for better quality control of HVFAC properties. Calorimeter tests were performed to evaluate the effects of fly ash sources, cement–fly ash interactions, chemical admixtures, and limestone replacement on the setting times and hydration reaction of HVFAC. To better target the initial air-entraining agent dosage for HVFAC, a calibration curve between air-entraining dosage for achieving 6% air content and fly ash foam index test has been developed. Further, a digital foam index test was developed to make this test more consistent across different labs and operators. For a more rapid prediction of hardened HVFAC properties, such as compressive strength, resistivity, and diffusion coefficient, an oxide-based particle model was developed. An HVFAC field test section was also constructed to demonstrate the implementation of a noncontact ultrasonic device for determining the final set time and ideal time to initiate saw cutting. Additionally, a maturity method was successfully implemented that estimates the in-place compressive strength of HVFAC through wireless thermal sensors. An HVFAC mix design procedure using the tools developed in this project such as the calorimeter test, foam index test, and particle-based model was proposed to assist engineers in implementing HVFAC pavements.Aniruddha Baral, Jeffery Roesler, Tyler Ley
06/30/24June 2024Utilizing a Particle Packing Approach for an Illinois-Specific, Nonproprietary, Low-Shrinkage UHPChttps://cptechcenter.org/ncc-projects/utilizing-a-particle-packing-approach-for-an-illinois-specific-nonproprietary-low-shrinkage-uhpc/Building materials, Costs, Durability, Mix design, Optimization, Particles, Piles (Supports), Strength of materials, Ultra high performance concrete (UHPC)The objective of the project is to develop optimum mix designs of UHPC for general use in the state of Illinois. The main goal of pursuing this research is to facilitate the production of non-proprietary UHPC having optimal particle packing and made with locally available materials, which include fine aggregates (e.g., sand, silica powder, and fine quartz), cement, chemical and mineral admixtures, and steel fibers. In fact, to advance UHPC applications in the United States, and specifically in IDOT, two conditions need to be met: the cost of UHPC raw materials must be reduced to less than $1000/yd³, compared to the cost of about $2000/yd³ for prebagged materials, and structural systems must be developed to capitalize on the unique capabilities of UHPC to allow for reduction of member weight by about 50% while maintaining adequate strength and stiffness and preserving the high durability of the material.Nishant Garg, Mathew Gombeda
12/31/24December 2024Low-Shrinkage Concrete Mixtures for Arkansashttps://cptechcenter.org/ncc-projects/low-shrinkage-concrete-mixtures-for-arkansas/Bridge decks, Cracking, Expansive concrete, Mix designThe goal is to find low-shrinkage material combinations using regional aggregate and cement sources in order to prevent early-age bridge deck cracking. The project will suggest mix designs for low-shrinkage concrete based on the locally available sources in each district.Cameron Murray, Micah Hale
12/31/18December 2018Highly Abrasion-Resistant and Long-Lasting Concretehttps://cptechcenter.org/ncc-projects/highly-abrasion-resistant-and-long-lasting-concrete/Abrasion resistance, Concrete, Laboratory tests, Life cycle analysis, Mix design, Optimization, SurveysStudded tire usage in Alaska contributes to rutting damage on pavements resulting in high maintenance costs and safety issues. In this study binary, ternary, and quaternary highly-abrasion resistant concrete mix designs, using supplementary cementitious materials (SCMs), were developed. The fresh, mechanical and durability properties of these mix designs were then tested to determine an optimum highly-abrasion resistant concrete mix that could be placed in cold climates to reduce rutting damage. SCMs used included silica fume, ground granulated blast furnace slag, and type F fly ash. Tests conducted measured workability, air content, drying shrinkage, compressive strength, flexural strength, and chloride ion permeability. Resistance to freeze-thaw cycles, scaling due to deicers, and abrasion resistance were also measured. A survey and literature review on concrete pavement practices in Alaska and other cold climates was also conducted. A preliminary construction cost analysis comparing the concrete mix designs developed was also completed.Carolyn Morehouse
12/31/20December 2020Steel Fiber Reinforced Rubberized Concrete Material Monitoringhttps://cptechcenter.org/ncc-projects/steel-fiber-reinforced-rubberized-concrete-material-monitoring/Crumb rubber, Evaluation and assessment, Fiber reinforced concrete (FRC), Fiber reinforced materials, Pavement performance, Recommendations, Steel fibersExperimental feature monitoring of the installed Steel Fiber Reinforced Rubberized Concrete (SFRRC) installed summer 2017 on Abbot Road in Anchorage, AK. This project will monitor and collect pavement data for 3 years post-construction. Specifically, material wear, operations, and pavement condition compared to control sites. At the end of the evaluation period, a synopsis will be provided that includes recommendations on the use of SFRRC in Alaska. It will also contain information concerning what pitfalls or construction .maintenance issues to resolved with improved specifications, construction plans, and/or practices.Carolyn Morehouse
08/27/21August 2021Rapid Slab Repair and Replacement of Airfield Concrete Pavementhttps://cptechcenter.org/ncc-projects/rapid-slab-repair-and-replacement-of-airfield-concrete-pavement/Airport runways, Concrete pavements, Cost effectiveness, Guidelines, Pavement maintenance, RepairingWhether in a commercial service or general aviation airport, the closure of a critical pavement asset has a significant impact on operations, especially if that asset is the runway at a single-runway airport. This report will assist airport personnel in planning, designing, and constructing appropriate rapid slab repair and replacement (RSRR) activities to cost-effectively minimize the impact of pavement-related closures. Airports can benefit from guidance on these activities, since their execution can differ from traditional pavement repair and replacement.Jeff Stempihar, Jose Medina, Thomas Van Dam, Linda Pierce, James Bruinsma, Kurt Smith, David Peshkin
06/01/16June 2016Bridge Decks: Mitigation of Shrinkage Cracking and Increased Durabilityhttps://cptechcenter.org/ncc-projects/bridge-decks-mitigation-of-shrinkage-cracking/Bridge decks, Bridges, Cracking, Deck model, Durability, Expansive concrete, Finite element model, Fly ash, Lightweight aggregates, Mitigation, Parametric analysis, Shrinkage, Silica fume, SRAThe application of pre-soaked lightweight aggregates (LWA) as an internal curing agent in concrete to reduce the cracking due to drying shrinkage is thoroughly studied in this report. It is determined that although LWA can significantly reduce autogenous shrinkage, its effect on drying shrinkage is minimal and in some cases it can even increase the drying shrinkage. Moreover, the combined effects of LWA and expansive cement (Type K) and LWA and shrinkage-reducing admixtures (SRAs) on drying shrinkage is also studied. It is shown that addition of Type K cement or SRA to mixtures containing LWA can significantly reduce drying shrinkage and make the mixture more volumetrically stable.Ardavan Ardeshirilajimi, Di Wu, Piyush Chaunsali, Paramita Mondal, Ying Tung Chen, Mohammad Mahfuzur Rahman, Ahmed Ibrahim, Will Lindquist, Riyadh Hindi
08/01/15August 2015Comparative Evaluation of Concrete Bridge Deck Sealershttps://cptechcenter.org/ncc-projects/comparative-evaluation-of-concrete-bridge-deck-sealers/Alternatives analysis, Bridge decks, Concrete bridges, Epoxides, Evaluation and assessment, Sealing compoundsThe main objective of this research was to compare the performance of five bridge deck sealer products using a synthesis of two testing methods: National Cooperative Highway Research Program (NCHRP) Report 244 Series II tests and standards developed by the Alberta Ministry of Transportation (BT Series). This research also sought to develop an improved method for future evaluation of bridge deck sealer products for the Alabama Department of Transportation (ALDOT). The sealer products were evaluated for their resistance to moisture and chloride ingress, performance after simulated traffic wear, and depth of sealer penetration into the concrete. The products tested included four epoxy-based sealer products and one sodium silicate sealer product. The sealers were evaluated on three different concrete mix designs representing the range of bridge deck concrete in service with ALDOT. Concrete cube specimens were fabricated, sealed, conditioned, and subjected to different tests. One test evaluated the waterproofing performance of sealers before and after abrasive conditioning (representing traffic wear). Another test determined the products’ ability to resist chloride penetration and their waterproofing performance in a saltwater solution. The chloride content was measured by potentiometric titration with silver nitrate and X-ray fluorescence spectroscopy (XRF). Sealer penetration depth was determined by a dye method and scanning electron microscopy (SEM). Initial (pre-abrasion) waterproofing performance results generally showed a good correlation to chloride resistance. XRF and titration analyses provided nearly identical results for measuring chlorides in concrete; however, XRF is a preferred method for determination of chloride content because it is much faster than titration. Two epoxy sealers outperformed all products for all evaluation criteria. A third epoxy sealer had good overall performance, but many specimens sealed with this product developed cracks that warranted further investigation. The sodium silicate sealer performed poorly compared to all four epoxy-based sealers. The epoxy-based sealers did not exhibit any measurable sealer penetration into the concrete and the sodium silicate sealer penetrated less than 100 µm into the concrete.Eric R Giannini, Jay K Lindly, J Riley Dunn
03/01/18March 2018Durability Evaluation of Ternary Mix Designs for Extremely Aggressive Exposureshttps://cptechcenter.org/ncc-projects/durability-evaluation-of-ternary-mix-designs-for-extremely-aggressive-exposures/Admixtures, Concrete, Durability tests, Florida, Highways, Laboratory tests, Materials, Pavements, PermeabilityConcrete mixtures can be made to be durable, even in extremely aggressive environments common in Florida. Deterioration is often caused by water and ion ingress into concrete through the concrete pore network. The resistance to water and ion movement into concrete, or penetrability, is measured by direct and indirect measures of the concrete pore system. As part of this phase I study, concrete specimens were made to test using surface resistivity (AASHTO T 358, bulk resistivity (AASHTO TP 119), rapid chloride permeability test (ASTM C1202), rapid chloride migration test (NT Build 492), volume of permeable voids (ASTM C642), water permeability, water absorption (ASTM C1585), concrete bulk diffusion (ASTM C1556), and concrete sulfate durability (ASTM C1012). This report documents the materials and mixtures used in this testing, methods used, and results.Kyle A Riding, Christopher C Ferraro, Mohammed Almarshoud, Seyedhossein Mosavi, Raid Alrashidi, Alyami, Mohammed Hussein
09/30/22September 2022Impacts of Internally Cured Concrete Paving on Contraction Joint Spacinghttps://cptechcenter.org/ncc-projects/impacts-of-internally-cured-concrete-paving-on-contraction-joint-spacing/Concrete curing, Concrete pavements, Contraction joints, Field studies, Overlays (Pavements), Pavement performanceThe primary research objective of this research study is to perform a full-scale field demonstration of the internally cured (IC) technology and its efficient performance benefits for Iowa's city and county roadways and state highways. In consultation with the project TAC, two upcoming construction projects conducted by the city, county, or Iowa DOT will be identified for IC concrete field demonstration. As already noted, such technology is suitable for use in a variety of transportation infrastructure components, including roads, bridges, sidewalks, rest areas, etc. Two potential sites of interest to Iowa county engineers are W61 Riverside Road in Washington County, Iowa, and County Road W34 in Winneshiek County, Iowa. At least one of these two sites, IC concrete technology would be implemented in a concrete overlay project to evaluate the performance of such pavement systems, and there is a strong likelihood that it would be found beneficial to implement both pavement sections using IC concrete technology. A focused project management strategy, essential for the successful completion of the project, is represented by the specific objectives of this project to be achieved through the execution of the following proposed research tasks: Task 1: Kick-off TAC meeting and identify potential sites for field implementation projects. Task 2: Laboratory characterization and evaluation of internal curing mixtures for use in field implementation projects. Task 3: Develop field implementation and evaluation plan. Task 4: Execute field implementation and evaluation plan. Task 5: Data analysis. Task 6: AASHTOWare Pavement ME modeling and analysis. Task 7: Economic analysis for field implementation projects. Task 8: Develop preliminary draft report. Task 9: Revise draft report based on TAC comments and discussion. Task 10: Final Report and presentation.Peter Taylor, Halil Ceylan, Yang Zhang
04/01/21April 2021Impacts of Internally Cured Concrete Paving on Contraction Joint Spacing: Phase II—Field Implementation of Internally Cured Concrete for Iowa Pavement Systemshttps://cptechcenter.org/ncc-projects/impacts-of-internally-cured-concrete-paving-on-contraction-joint-spacing-phase-ii-field-implementation-of-internally-cured-concrete-for-iowa-pavement-systems/Concrete curing, Concrete pavements, Field tests, Fine aggregates, Laboratory tests, Life cycle analysis, Pavement cracking, Pavement joints, Pavement performance, Permeability, WarpageThe aim of the work described in this report was to investigate the impacts of internally cured (IC) concrete paving on warping in test pavements built in Iowa. The study involved both laboratory investigations and field implementation of internally cured concrete for Iowa pavement systems. In summary, the technique does appear to be of benefit for reducing the potential for early-age cracking, improving ride and increasing the longevity of relatively thin overlays.Amin Daghighe, Peter Taylor, Halil Ceylan, Yang Zhang
01/31/21January 2021Improving the Foundation Layers for Concrete Pavements: Lessons Learned and a Framework for Mechanistic Assessment of Pavement Foundationshttps://cptechcenter.org/ncc-projects/improving-the-foundation-layers-for-concrete-pavements-lessons-learned-and-a-framework-for-mechanistic-assessment-of-pavement-foundations/Concrete pavements, Lessons learned, Mechanistic-empirical pavement design, Pavement performance, Perpetual Pavements, Portland cement concrete, quality assurance, Service life, Subbase (Pavements), Subgrade (Pavements)This report summarizes the key findings and lessons learned from the series of field, laboratory, and advanced numerical studies performed under Federal Highway Administration (FHWA) Transportation Pooled Fund Study TPF-5(183). This research program was established by the partnering state departments of transportation (DOTs) to identify opportunities to document the as-constructed conditions and advance the quality and economy of the foundation layers for portland cement concrete (PCC) pavements, leading to improved support for long-life pavement systems. The key findings and lessons learned are drawn from detailed pavement foundation test programs in the participating states of California, Iowa, Michigan, Pennsylvania, and Wisconsin.David J. White, Pavana K. R. Vennapusa, Bora Cetin
03/17/21March 2021Reducing Shrinkage in Concrete Bridge Decks Using Single- and Double- Ring Test Methodshttps://cptechcenter.org/ncc-projects/reducing-shrinkage-in-concrete-bridge-decks-using-single-and-double-ring-test-methods/Bridge decks, Concrete bridges, Cost effective, Mix designs, Overlays (Pavements), Shrinkage, Test proceduresThe objectives of this project are as follows: (1) Evaluate the effects of single methods to mitigate shrinkage; (2) Quantify the beneficial effects of multiple methods to mitigate shrinkage; (3) Propose solutions for WYDOT using standard mix designs for two types of aggregates; (4) Provide guidance on the use of internal curing for concrete mix designs. As an example of maintenance costs, a single 6,000 ft² bridge deck can reach up to $250,000.00. This considers two rigid overlays and one epoxy overlay with a 10 percent class II-A and 5 percent class II-B repairs. These costs do not include the traffic control and safety mobilization that can add another $100,000.00 to this single hypothetical bridge deck. If overlays can be deferred or eliminated by reducing or eliminating early age shrinkage cracking, this could result in a significant savings for WYDOT.Jennifer Tanner
05/31/21May 2021Summary Findings of Re-Engineered Continuously Reinforced Concrete Pavement: Volume 1https://cptechcenter.org/ncc-projects/summary-findings-of-re-engineered-continuously-reinforced-concrete-pavement-volume-1/Cement, Concrete curing, Continuously reinforced concrete pavements (CRC pavements), Cost effectiveness, Cracking, Falling weight deflectometers, Field tests, Laboratory tests, Pavement design, Pavement performance, Paving, Post tensioningThis research project conducted laboratory testing on the design and impact of internal curing on concrete paving mixtures with supplementary cementitious materials and evaluated field test sections for the performance of crack properties and continuously reinforced concrete pavement (CRCP) structure under environmental and falling weight deflectometer (FWD) loading. This report volume summarizes the three year research effort evaluating design, material, and construction features that have the potential for reducing the initial cost of CRCP without compromising its long-term performance.Jeffrey Roesler, Sachindra Dahal, Dan Zollinger, Jason Weiss
Stainless Steel Coated Rebar for Chloride Resistant Concrete Highways and Bridgeshttps://cptechcenter.org/ncc-projects/stainless-steel-coated-rebar-for-chloride-resistant-concrete-highways-and-bridges/Coatings, Corrosion resistant materials, Reinforcing bars, ThicknessThis project will develop low-cost, highly corrosion-resistant multilayer metallic composite steel rebars for concrete reinforcement. The work is being carried out in two stages. Work in Stage 1 primarily involves laboratory-scale testing of the stainless-clad steel rebars to determine optimal coating composition for corrosion resistance. The tolerance of the rebar to mechanical bending without damage to the corrosion-resistant coating will also be investigated. Prototype rebars with different coating grades will be produced. There are a variety of grades commercially available, including austenitic (FCC) steels and ferritic (BCC) steels. Cladded rebars with a minimum of four distinct coating grades, with and without molybdenum, will be produced. The produced prototype rebars will be tested for corrosion resistance and performance. Immersion testing in NaCl solution and salt spray testing will be conducted to investigate the coating performance in accelerated corrosion conditions. The rebars will also be subjected to various types of bend testing (90, 180 degree bends, bend/re-bend) to determine whether coating cracking during bending is a significant issue. If the issue is found to be significant, annealing experiments will be conducted to thermally repair the deformed microstructure of the coating and enhance ductility. Bend tests will then be performed on annealed samples to see if annealing resolves the issue. Bend tests will comply with industry standards established by the Concrete Reinforcing Steel Institute (CRSI). Work in Stage 2 will involve optimization of the rebar coating thickness. Tests to be conducted will include simulating coating damage to understand the impact of coating flaws/defects on performance as well as in-concrete mechanical pullout test. Since the production cost of the developed rebar will be related to the coating thickness, it is critical to determine the minimum thickness with the desired coating properties. After selecting a final coating grade from Stage 1 findings, prototypes will be produced with coating thicknesses of approximately 25, 50, 75, and 100 microns, and corrosion and bend tests will be conducted to determine the acceptable rebar thickness coating range. Abrasion, adhesion, and indentation tests also will be conducted on the coated rebars to assess their resistance to mechanical damage. Additionally, coating “holidays” will be created and defected rebars as well as bent rebars will be subjected to accelerated corrosion testing. Bonding between the coated rebar and concrete will be evaluated through rebar pullout testing. It is anticipated that the stainless-clad rebar will perform significantly better than epoxy-coated bar and will be comparable to uncoated rebar. The final report will provide all relevant data, methods, models, and conclusions along with guidance on how to implement the stainless-clad rebar in a pilot state DOT installation.Inam Jawed, Samuel McAlpine
06/01/20June 2020Laboratory Investigation of Workable and Durable Concretes for Bridge Repairhttps://cptechcenter.org/ncc-projects/laboratory-investigation-of-workable-and-durable-concretes-for-bridge-repair/Admixtures, Bridges, Compressive strength, Concrete, Cracking, Durability, Fibers, Fly ash, Laboratory tests, Portland cement, Repairing, Silica fume, water reducing agents, WorkabilityConcretes for bridge repair that attained 3,000 psi compressive strength within 10 hours, 1 day, and 7 days and had high workability and durability were investigated in the laboratory. Supplementary cementitious materials (SCMs) were used in concrete with portland cement to make the mixture resist the penetration of harmful solutions and chemical attack. These concretes were air entrained for proper resistance to cycles of freezing and thawing. When high early strength was needed, high amounts of portland cement and low water–cementitious materials ratios were used in these concretes that made them prone to cracking. However, fibers were investigated to control the cracking. Mixtures with rapid setting cement were also tested for high early strengths. Test results indicated that with high amounts of portland cement with an SCM or the use of rapid setting cement, desired strength can be achieved within 10 hours. To achieve 3,000 psi in 1 day and 7 days, lower amounts of portland cement with an SCM and overall lower paste contents were used, making them less prone to cracking. The study recommends that high amounts of portland cements with SCMs be used to achieve 3,000 psi within 10 hours with setting times long enough for mixing and delivery by truck mixers and placement. These concretes may need to be insulated at the jobsite to retain heat to ensure early strengths are achieved. If shorter setting times can be accommodated using on-site mobile mixers, rapid setting cement can be used to achieve a 3,000 psi compressive strength within a few hours, i.e., much less than 10 hours. For longer times, more than 1 day, to attain 3,000 psi, portland cements containing SCMs with a low cementitious materials content should be used; they are cost-effective, easier to make, and have less cracking potential than the high early strength mixtures with portland cement with an SCM. If cracking is anticipated, fibers can be added. In the laboratory, an efficient pan type mixer was used to obtain uniform blending of ingredients and good distribution of fibers. In future field work, large quantities of material would be mixed and delivered in ready mixed concrete trucks or mobile mixers, which are not as efficient as laboratory mixers. Use of ready mixed trucks and mobile mixers to provide the recommended mixtures needs to be investigated to identify any issues and to streamline the implementation of the mixtures.H. Celik Ozyildirim, Mary Sharifi
10/01/21October 2021Life-Cycle Impact Assessment of Recycled Pavement Projects in Virginiahttps://cptechcenter.org/ncc-projects/life-cycle-impact-assessment-of-recycled-pavement-projects-in-virginia/Asphalt pavements, Cold in-place recycling, Environmental impacts, Full-depth reclamation, Global warming, Life cycle analysis, Service lifeThis report describes a study conducted to evaluate the performance and quantify the potential environmental benefits of recycled asphalt pavement projects completed in Virginia. The performance of the recycled projects was assessed by evaluating collected stiffness data and by the development of performance prediction models based on data obtained from the Virginia Department of Transportation (VDOT) pavement management system. Quantifying the potential environmental impacts for these projects was completed following recommendations by Harvey et al. in Pavement Life Cycle Assessment Framework. Modeling of unit processes in the various pavement life cycle stages was tailored to represent conditions and practices used in Virginia to the extent possible. The global warming (GW) score and a Single Score Index were used to assess pavement recycling projects completed in Virginia. The study found that approximately 98% of the total GW score result came from pavement smoothness during the use stage. During the cradle-to-laid (material production, transportation, and construction) stage, the results showed that pavement recycling projects used for interstate reconstruction and primary route restorative maintenance were more environmentally friendly—as they yielded lower GW scores—compared to the conventional approaches. The results found that full depth reclamation (FDR) projects used as reconstruction on primary routes sometimes had a higher GW score compared to conventional projects, especially in instances when cement was used as a stabilizing agent (cement production at the plants is associated with high greenhouse gas emissions). When considering the entire life cycle, most of the GW score impacts came from the use stage. The results of the structural evaluation showed that there were no large changes in the stiffness of the recycled layers for FDR projects when comparing data from 36-month and 10-year testing periods. The predicted functional service life of all recycling projects ranged from 6 to more than 30 years using thresholds based on either ride quality or a distress index. For FDR projects, cement-stabilized projects were generally predicted to last longer when compared to the asphalt-stabilized projects. The study recommends that VDOT consider reoccurring structural evaluation of all completed pavement recycling projects to better evaluate the trends observed in this report. To reduce environmental impacts, VDOT should encourage (or even incentivize) practices that improve the initial pavement smoothness for recycling projects and use structural designs that are expected to have a low annual rate of deterioration. To better account for the actual deterioration of pavement recycling projects with the agency pavement management system, VDOT should develop a set of recycling-specific deterioration models to better reflect their anticipated longer service lives. Finally, VDOT should develop a framework to implement life cycle assessment practices to complement the current selection and design process, for pavement maintenance and rehabilitation projects, that will result in reduced environmental impacts.Brian K. Diefenderfer, Gerardo W. Flintsch, Samer W. Katicha, Eugene A. Amarh
01/01/21January 2021Evaluation of Sustainable and Environmentally Friendly Stabilization of Cohesionless Sandy Soil for Transportation Infrastructurehttps://cptechcenter.org/ncc-projects/evaluation-of-sustainable-and-environmentally-friendly-stabilization-of-cohesionless-sandy-soil-for-transportation-infrastructure/cohesionless soils, geopolymer, Infrastructure, Pavements, Stabilization, sustainabilityOrdinary Portland cement (OPC) is generally used to stabilize cohesionless sandy soils that are often found in coastal areas. Due to its high carbon footprint, many studies are being conducted to identify a suitable green alternative for stabilizing cohesionless soils. Previous studies have shown that partially replacing OPC with waste materials such as nano-silica and coal waste reduces the overall carbon footprint without significantly impacting the performance. Geopolymer (GP) received a lot of attention in the past few decades owing to its similar properties to that of OPC yet with a lower carbon footprint. This study investigated the feasibility of stabilizing cohesionless sandy soils with metakaolin-based GP. Engineering and characterization tests such as shrinkage, strength, pH, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) were performed to evaluate various characteristics of the stabilized mixes with different dosages of geopolymer and relate them to microstructural changes. Notably, GPtreated soils did not deteriorate during the durability tests, whereas the OPC-treated soil only retained about 75% of its strength. This is an indication that GP could be a better choice than OPC in coastal areas where cohesionless soils often experience heavy rainfall and flooding. Overall, an optimum dosage of GP improved both the mechanical properties and durability of cohesionless soils.Puppala Radovic
08/31/21August 2021Perform Feasibility Study on Use of Innovative Tools and Techniques to Accelerate Pavement Constructionhttps://cptechcenter.org/ncc-projects/perform-feasibility-study-on-use-of-innovative-tools-and-techniques-to-accelerate-pavement-construction/Construction and maintenance, Decision making, Flaw detection, Inspection equipment, Nondestructive tests (NDT), Pavement maintenanceThe Texas Department of Transportation is facing an increase in pavement reconstruction projects over the next several years. However, many roadways needing reconstruction and widening are in metro areas where traffic handling and user delay costs are a major expense. This project investigated innovative tools and techniques to accelerate pavement construction.Darlene Goehl, Tom Scullion, Kunhee Choi, Charles Gurganus, Bryan Wilson
01/31/2022January 2022Use of Recycled Concrete Aggregate in Concrete Pavement Mixeshttps://cptechcenter.org/ncc-projects/use-of-recycled-concrete-aggregate-in-concrete-pavement-mixes/fresh properties, hardened properties, mix proportioning, paving concrete, recycled concrete aggregateNatural virgin aggregates (NVAs) have become gradually exhausted across the state of Tennessee. There is a growing need for the Tennessee Department of Transportation (TDOT) to replace NVAs with more sustainable recycled concrete aggregates (RCAs). It is the intention of the project to quantitatively assess various RCAs available in Tennessee and to explore their suitability for TDOT new paving concrete mixes. This report documents the main findings of the project. A total of eight RCAs were collected representing different concrete origins of pavement, returned concrete, and mixed sources including buildings. Their basic properties were evaluated, including size and gradation, specific gravity, absorption, LA abrasion loss, chloride content, and pH value. These properties were observed to vary widely with RCA sources. This report also covers how RCAs affected the performance of concrete. It becomes evident that RCAs from good quality concrete origins such as pavements can be used in new paving concrete when adequately designed and proportioned. They demonstrated similar performance as NVAs. However, RCAs from unknow or mixed sources should be used with cautions as they may have inconsistent quality. Poor quality RCAs reflected by high absorption, high LA abrasion loss, and low specific gravity due to unsound adhered paste are not recommended for paving concrete because they will substantially reduce the strength and durability of concrete. RCAs with nondurable aggregate origins are also unsuitable for paving concrete applications.Zhifu Yang, Kevin Overall, Heather J. Brown
06/01/20June 2020Determining Bridge Deck Chloride Quantities with Ground Penetrating Radarhttps://cptechcenter.org/ncc-projects/determining-bridge-deck-chloride-quantities-with-ground-penetrating-radar/Bridge decks, Chloride content, Chlorides, Concrete bridges, Cores (Specimens), Corrosion, Ground penetrating radar, Nondestructive tests (NDT), samplingThe focus of this project is the investigation of a new method for determining chloride quantity in bridge decks using nondestructive ground penetrating radar (GPR) technology in combination with a limited number of cores for calibration. Traditional measurement techniques involve core sampling and laboratory testing of concrete samples. While this gives an accurate measure of chloride at the location of the core, it cannot readily determine the distribution of chlorides throughout the deck or the maximum or minimum chloride amounts unless a great number of cores are taken. The GPR method developed here has the potential to provide that information and provide bridge owners with detailed information on the quantity and location of chlorides in their bridge decks. GPR signal attenuation in bridge deck concrete occurs as a result of the conductive nature of the concrete when water and chlorides are introduced. The current research approach focuses on the use of radar to determine the quantity of chloride in the concrete, and specifically to demonstrate the possibility of utilizing GPR along with limited coring (two or three core samples) and laboratory chloride measurements to produce an accurate and quantitative, spatial mapping of chlorides in bridge decks. The results of this research show that this is possible, based on in-situ field testing and is further confirmed by analytical modeling and laboratory experimentation. It should be noted, however, that these results are based on limited experimental data and further testing of the accuracy and reliability of the method is recommended. A three-pronged approach was taken consisting of (1) the development of an analytical model, which describes through mathematical derivation the GPR losses or attenuation in chloride contaminated concrete, (2) laboratory experimentation with sand and gravel test specimens with varying concentrations of chloride and moisture, and (3) field testing on an asphalt overlaid, concrete bridge deck using laboratory chloride measurements to calibrate GPR attenuation. In each of these approaches the attenuation-chloride relationship for bridge deck concrete has been derived and quantified. Together, they define the fundamental theory for this technique and the methodology for putting it into practice.Anthony J. Alongi
02/01/22February 2022Longitudinal Cracking Investigation on I-72 Experimental Unbonded Concrete Overlayhttps://cptechcenter.org/ncc-projects/longitudinal-cracking-investigation-on-i-72-experimental-unbonded-concrete-overlay/Concrete overlays, Cracking, Interstate highways, Longitudinal cracking, Pavement interlayersA research study investigated longitudinal cracking developing along an experimental unbonded concrete overlay (UBOL) on I-72 near Riverton, Illinois. The project evaluated existing literature on UBOL (design, construction, and performance), UBOL case studies, and mechanistic-empirical design procedures for defining the mechanisms that are contributing to the observed distresses. Detailed distress surveys and coring were conducted to assess the extent of the longitudinal cracking and faulting along the longitudinal lane-shoulder joint. Coring over the transverse contraction joints in the driving lane showed stripping and erosion of the dense-graded hot-mix asphalt (HMA) interlayer was the primary mechanism initiating the longitudinal cracks. Cores from the lane-shoulder joint confirmed stripping and erosion was also occurring there and leading to the elevation difference between the driving lane and shoulder. Field sections by surrounding state departments of transportation (DOTs), such as Iowa, Michigan, Minnesota, Missouri, and Pennsylvania, with similar UBOL design features to the I-72 section were examined. Site visits were performed in Illinois, Michigan, Minnesota, and Pennsylvania, while other sections were reviewed via state DOT contacts as well as Google Earth and Maps. Evidence from other DOTs suggested that HMA interlayers, whether dense graded or drainable, could experience stripping, erosion, and instability under certain conditions. An existing performance test for interlayers, i.e., Hamburg wheel-tracking device, and current models reviewed were not able to predict the distresses on I-72 eastbound. Adapting a dynamic cylinder test is a next step to screen HMA interlayers (or other stabilized layers) for stripping and erosion potential. To slow down the cracking and faulting on I-72 eastbound, sealing of the longitudinal lane-shoulder joint and driving lane transverse joints is suggested. To maximize UBOL service life, an HMA overlay will minimize water infiltration into the interlayer system and significantly slow down the HMA stripping and erosion mechanism that has led to longitudinal cracking and lane-shoulder faulting.John DeSantis, Jeffery Roesler
Airfield Pavement Management Framework Using Advanced Modeling Techniqueshttps://cptechcenter.org/ncc-projects/airfield-pavement-management-framework-using-advanced-modeling-techniques/Airports, landing fields, Pavement maintenance, Pavement management systems, Pavements, Service lifeAirport authorities constantly collect pavement condition data and utilize life-cycle cost analysis to select construction and maintenance alternatives. The current Federal Aviation Administration (FAA) Advisory Circular 150/5380-7B recommends using pavement condition index (PCI) to assess airfield pavement condition for planning of maintenance and rehabilitation (M&R) treatments. It is well-recognized that structural and functional performance of airfield pavement may deteriorate differently, and hence, two pavement sections with the same PCI may have different deteriorations and need different M&R treatments. As such, the structural condition index (SCI) and foreign object damage (FOD) should be considered along with the PCI to help airport authorities determine the time and type of pavement repair. This project aims to develop a comprehensive airfield pavement management framework that can predict the service life of airport key components (runway, taxiway, and apron) in terms of PCI, SCI, and FOD based on airport conditions and without the need for frequent monitoring of pavement conditions.Momen Mousa
Efficacy, Cost and Impacts of Non-Chloride Deicers: An Educational Primer and Product Information Sheetshttps://cptechcenter.org/ncc-projects/efficacy-cost-and-impacts-of-non-chloride-deicers-an-educational-primer-and-product-information-sheets/Deicing chemicals, Winter maintenanceThe goal of this project is to synthesize available information on non-chloride deicers to allow for a more comprehensive understanding by winter maintenance professionals and allow for easy comparison between products and with sodium chloride (salt brine, rock salt). This will be accomplished through a literature search, survey, and evaluation of currently used standards and tests. Laboratory testing may be used to provide supplemental information. The outcomes will include a comprehensive literature review document, one to two-page product summaries and product information sheets for key non-chloride deicers.Laura Fay
Performance Index Rating and Maintenance Cost Assignment for Ramps, Acceleration and Deceleration Lanes in Louisianahttps://cptechcenter.org/ncc-projects/performance-index-rating-and-maintenance-cost-assignment-for-ramps-acceleration-and-deceleration-lanes-in-louisiana/acceleration lanes, Classification, Costs, deceleration lanes, Guidelines, Pavement maintenance, Preservation, ramps, RoughnessThe objectives of this study are as follows: (1) Ascertain whether there are differences in International Roughness Index (IRI) and Performance Index (PI) values of analysis lanes as compared to ramps, acceleration lanes and deceleration lanes at project and network level. (2) Propose a framework for measuring and characterizing IRI and PI values for ramps, acceleration lanes and deceleration lanes; and (3) Establish and propose guidelines to address additional treatment costs specific to ramps, acceleration lanes and deceleration lanes at the project and network levels.Qiming Chen, Moses Akentuna
02/28/22February 2022Evaluation of Penetrating Sealers for Concrete TR-765https://cptechcenter.org/ncc-projects/evaluation-of-penetrating-sealers-for-concrete-tr-765/Concrete pavements, Durability, Evaluation and assessment, Pavement joints, Rigid pavements, Sealing compounds, Test proceduresJoints in a rigid pavement can act as local reservoirs trapping deicing salts and moisture. Such a harsh micro-environment inside the joints impacts the durability of concrete in cut joint surfaces, resulting in premature distress even in cases where the bulk of pavement exhibits proper durability against frost action and chemical attack by deicing salts. The use of sealers can be considered an effective means for enhancing joint durability. However, with the growing interest in the use of concrete sealers, there has been an increase in the number of manufacturers, types of sealers, and commercial products available. This has resulted in problems for the owner agencies who lack the robust tools to evaluate such products. The work presented in this research proposal addresses the effect of sealers on the durability of joints in Iowa’s rigid pavements, as well as proposing testing protocols for the evaluation of the sealer material’s long-term durability.Peter Taylor
05/15/23May 2023 Optimal Approach for Addressing Reinforcement Corrosion for Concrete Bridge Decks in Illinois: Phase IIhttps://cptechcenter.org/ncc-projects/optimal-approach-for-addressing-reinforcement-corrosion-for-concrete-bridge-decks-in-illinois-phase-ii/Bridge decks, Corrosion resistance, Life cycle costing, Literature reviews, Reinforced concrete, Reinforcing bars This report presents the expansion of a previously introduced life-cycle cost calculation framework for concrete bridge decks in Illinois. In addition to the alternative reinforcement options examined in the Illinois Center for Transportation and Illinois Department of Transportation project R27-SP49, two additional reinforcing bar types—stainless steel–clad carbon core and textured epoxy-coated bars—are the main subjects of this study. The results of a comprehensive literature review of these two additional bar options will highlight their cost-benefit characteristics toward optimizing the life span of a concrete bridge deck, most notably trade-offs between often increased upfront material costs and enhanced durability over a design 100-year service life. Additionally, the scope of this study includes the development of a more robust methodology to account for the effect of the relatively high nominal yield strength and corresponding reduced ductility of A1035 bars, one of the alternate reinforcement options examined in R27-SP49. The researchers used a numerical moment-curvature-based analysis methodology to facilitate the development of a design-friendly modified high-strength reinforcement factor that supersedes the nominal yield strength factor proposed in the original version of the life-cycle cost framework. The outcomes of this project and R27-SP49 will collectively expand upon and aim to enhance the effectiveness of the originally proposed life-cycle cost framework. The outcomes will be demonstrated by presenting updated life-cycle costs and via a parametric study of two hypothetical bridge deck examples, each falling into significantly different categories for traffic demands and select performance expectations. Matthew J. Gombeda, Zoe N. Lallas, Estevan River Jr.
05/16/22May 2022Optimal Approach for Addressing Reinforcement Corrosion for Concrete Bridge Decks in Illinoishttps://cptechcenter.org/ncc-projects/optimal-approach-for-addressing-reinforcement-corrosion-for-concrete-bridge-decks-in-illinois/Bridge decks, Corrosion, Life cycle analysis, Reinforced concrete bridges, Reinforcement (Engineering) This report presents the results of a comprehensive literature review focusing on corrosion performance of reinforced concrete bridge decks, with a particular emphasis on the relative performance of alternative corrosion-resistant reinforcement types. Examples of alternative corrosion-protection options examined herein include epoxy-coated, galvanized, stainless-steel, and A1035 bars, considering conventional black reinforcing bars as the standard. Based upon the results of the literature review, a framework for determining the optimal reinforcement option for a bridge deck is presented as a function of the properties of each reinforcement type and other factors, such as design service life, location of the bridge, estimated maintenance/repair cycles, and relative costs. Several examples are also provided to demonstrate the procedure for using the framework and its applicability for different bridge types with varying design considerations, such as a congested urban artery and a rural interstate. The literature review findings and the optimal approach framework were crafted for use by bridge design engineers as preliminary guidance when determining the type of reinforcement for a given bridge deck and its corresponding conditions. Furthermore, the approach can also be used by Illinois Department of Transportation officials when deciding whether to invest in higher performing corrosion-protection systems for a given application or for updating current bridge design policies to reflect the latest developments in alternative corrosion-resistant reinforcement options. Matthew J. Gombeda, Zoe N. Lallas, Estevan River Jr.
01/01/22January 2022Compacted Concrete Pavementhttps://cptechcenter.org/ncc-projects/compacted-concrete-pavement/Durability, fiber reinforced concrete, Field tests, Mechanical properties, Roller compacted concrete pavements, ShrinkageThe main objective of this project was to evaluate construction issues and characterize the long-term performance of compacted concrete pavement (CCP). Three CCP test cells were designed and constructed in Scott County, Missouri, as part of a larger construction project. The total pavement length was 42 ft for the three cells. Cell 1 and Cell 2 were prepared without fibers and had a length of 15 and 12 ft, respectively. Cell 3 was prepared with 5 lb/yd³ (pcy) of synthetic fibers and had a length of 15 ft. The moisture content of the concrete was kept between 5% and 6%, and the water-to-cementitious material ratio was maintained between 0.31 and 0.38. Test results showed that the incorporation of fibers enhanced the mechanical properties (compressive and flexural strengths) of CCP mixtures when proper compaction was provided, as in the case of cast-in field samples. Also, fibers changed the flexural failure mode of saw-cut and cast-in-field CCP samples from brittle to ductile failure. The incorporation of fibers had a restraining effect on the drying shrinkage of CCP mixtures. The use of fibers did not have a significant effect on the performance of CCP mixtures, as shown from the falling weight deflectometer (FWD), truck loading tests and curling and warping. This can be mainly related to the extremely dry consistency of the CCP mixtures (Vebe consistency > 60) that can hinder bond strength in the interfacial transition zone with the matrix. This was more accentuated in the saw-cut samples from the paved CCP as the paving process in the field did not provide enough compaction. As for the size of slabs, results showed that the size of CCP slabs was more effective in the curling and warping measurements. The slab with longer length (15 ft) showed higher variations in curing and warping along the diagonal, transverse and longitudinal lengths over time. Therefore, the use of fibers in CCP can be recommended provided that the CCP mixture has adequate workability and sufficient compaction energy applied during construction.Kamal H. Khayat, Nima Farzadnia, Ahmed Abdelrazik
Development of a Test to Measure Concrete Permeability Admixture Effectivenesshttps://cptechcenter.org/ncc-projects/development-of-a-test-to-measure-concrete-permeability-admixture-effectiveness/Admixtures, Chloride content, Permeability, Pozzolan, Test proceduresThe research objective of this project is to determine appropriate test method(s) to measure the chloride penetration resistance of concrete containing PRAs and applicable acceptance criteria for use in Florida Department of Transportation (FDOT) construction projects. Acceptable and relative performance of PRAs will be evaluated through comparison with the performance of a concrete mixture containing pozzolans that meets current mixture design requirements described in FDOT specification Table 346-2 and Table 346-3.Ronald Simmons, Kyle Riding
12/14/24December 2024NEXTGEN Concrete – Tests of the Future: Chloride and Sulfate Durabilityhttps://cptechcenter.org/ncc-projects/nextgen-concrete-tests-of-the-future-chloride-and-sulfate-durability/Chlorides, Concrete, Electrochemical processes, Materials tests, Mix design, Protection against environmental damage, Sulfate resisting cementThe two objectives of this project are the following: (1) To investigate and recommend the appropriate thresholds to use for Bulk (TP 119) and Surface (T 358) Resistivity for a concrete mix designed for an extremely aggressive chloride environment. (2) To investigate and recommend the appropriate thresholds to use for a Rapid Sulfate Electrochemical Test for a concrete mix designed for an extremely aggressive sulfate environment.Tim Ruelke, Dan Su
05/31/24May 2024NEXTGEN Concrete – Tests of the Future: Shrinkagehttps://cptechcenter.org/ncc-projects/nextgen-concrete-tests-of-the-future-shrinkage/Bridge decks, Concrete, Materials tests, Mix design, Shrinkage, Testing equipmentThe objectives of this project are the following: (1) Design and fabricate the most advantageous test apparatus that will accommodate concrete with #57 while adapting to AASHTO T334. (2) Define the dimensions and specifications for the new test apparatus. (3) Create the resulting Florida Test Method. (4) Use the new apparatus to assess FDOT approved mix designs over the spectrum of shrinkage risk. (5) Develop a shrinkage profile analysis protocol or recommend commercially available software. (6) Develop an FDOT calibration/baseline mix recipe for use by all in a “comparative” approach and the shrinkage profile of a proposed mix compared to the baseline mix. (7) Set preliminary threshold for bridge deck concrete exclusion based on the results of the developed analysis protocol.Tim Ruelke, Christopher Ferraro
03/31/26March 2026Use of Fiber-Reinforced Polymer Composites for Bridge Repairs in Montanahttps://cptechcenter.org/ncc-projects/use-of-fiber-reinforced-polymer-composites-for-bridge-repairs-in-montana/Bridges, Feasibility analysis, Fiber reinforced polymers, RepairingNew methodologies are needed for repairing and strengthening the aging and failing transportation infrastructure. The use of fiber-reinforced polymer (FRP) composites for repair has gained popularity over the last decade as these methods have been shown to be affordable, effective, and easy to implement. FRPs in general offer several key advantages over conventional building materials. Specifically, they have high strength to weight ratios, have increased durability and corrosion resistance, and are generally “greener” than conventional materials in terms of embodied energy. FRPs are composed of either thermoset or thermoplastic resins reinforced with (usually) glass or carbon fibers, GFRP and CFRP, respectively. FRPs can be used for strengthening in several forms, such as near-surface mounted (NSM) bars and externally applied wrapping. The use of FRPs as a repair method for bridges has been investigated by several state departments of transportation in recent years. For example, FRPs have been used to restore the original flexural strength of damaged reinforced concrete bridge girders, strengthen simple-span reinforced concrete slab bridges, and seismically retrofit bridge columns. It should also be noted that Montana Department of Transportation (MDT) has used externally bonded FRPs with mixed results. The primary objective of the research is to investigate and help implement the use of FRPs to enhance the performance of Montana bridges. Specifically, the research will (1) conduct an updated and thorough literature review to investigate the feasibility of using FRPs in various bridge applications in Montana, (2) identify the most promising applications of this technology for use in the state, (3) fill any minor research gaps with laboratory testing that may affect/limit the successful application in Montana’s unique climate, (4) assist in implementing the application(s) of this material in a bridge demonstration project in the state, and (5) monitor the performance of this bridge after the demonstration project. FRP composites could provide a viable solution to the repair/strengthening needs of Montana’s aging infrastructure. This research will provide the necessary step to capitalizing on the inherent benefits of these composites.Vaneza Callejas, Kirsten Matteson, Michael Berry
06/10/23June 2023Assessment of Urban Heat Island in the Phoenix Metropolitan Regionhttps://cptechcenter.org/ncc-projects/assessment-of-urban-heat-island-in-the-phoenix-metropolitan-region/Evaluation and assessment, Human beings, Metropolitan areas, Temperature, Urban areasWilliam Stone
Durability of Concrete Using Low Slag Cement Contentshttps://cptechcenter.org/ncc-projects/durability-of-concrete-using-low-slag-cement-contents/Compressive strength, Corrosion resistance, Durability, Mix design, Slag cement, Test proceduresThis study will identify what quantities of slag cement less than 50% will provide both long-term durability and the required compressive strength. It will also identify if the reduced slag cement percentages can be used for all environmental conditions or with certain restrictions based on sulfate/chloride resistance results. Lastly, it will identify a short-term qualification procedure/test methods to expedite approvals of these concrete mix designs.Frank Thomas, Kyle Riding
03/31/23March 2023Establish Policies and Procedures for Use of Subgrade Stabilization in Michiganhttps://cptechcenter.org/ncc-projects/establish-policies-and-procedures-for-use-of-subgrade-stabilization-in-michigan/Cost effectiveness, Drainage, Pavement performance, Soil stabilization, Subgrade (Pavements)MDOT has, on occasion, stabilized the subgrade as part of a pavement reconstruction project. These have generally been in situations where it was more cost-effective than undercutting the subgrade, or when building a longer life pavement. MDOT would like to explore the use of subgrade stabilization more often. Projects where subgrade stabilization has been used appear to be performing very well. However, MDOT does not have any criteria for when/where subgrade stabilization would be a cost-effective choice to improve the performance of the constructed pavement. Where it has been used, special provisions outline the mix design process and testing protocol, but is this the optimum methodology? Multiple versions of these specifications with different allowable stabilization agents, acceptance methods and testing requirements have been used. These need to be unified. Traditionally, fine-grained soils have been viewed as candidates for stabilization due to their lower support characteristics and high loss of modulus in moist conditions. There has been some interest in exploring stabilization of coarse-grained soils to see if pavement performance can be increased. However, does the potential loss of drainage through the subgrade outweigh the potential increase in support? The work completed and documented in research report RC-1635, “Performance Evaluation of Subgrade Stabilization with Recycled Materials” started some of this analysis. This project will use the information from this previous project to create policies for when stabilization of the subgrade can be used, what the construction procedures should be, and finalize inputs used in the pavement design process.Nishantha Bandara
07/31/24July 2024SPR-4724: Detection and Assessment of Sulfates in the Pavement Subgradehttps://cptechcenter.org/ncc-projects/spr-4724-detection-and-assessment-of-sulfates-in-the-pavement-subgrade/Costs, Detection and identification, Liming of soils, Soils, Subgrade (Pavements), SulfatesThe aim of the project is to determine whether detection of sulfates in lime-treated subgrade soils that have been in service for a number of years is the result of false positives from test ITM 510. Detection of sulfates in lime-treated soils is problematic because it requires removal of the soils. This is a costly outcome, given that the subgrade soils have been in service for a number of years and the pavement may not have shown signs of distress. The problem is becoming significant given the number of maintenance and rehabilitation projects that are ongoing or planned.Antonio Bobet, Marika Santagata
12/31/22December 2022Develop a Study of Geosynthetic (Geogrid and Woven Geotextile) Materials for Use in Reducing Pavement Section Thickness (NDOT 227-21-803)https://cptechcenter.org/ncc-projects/develop-a-study-of-geosynthetic-geogrid-and-woven-geotextile-materials-for-use-in-reducing-pavement-section-thickness-ndot-227-21-803/Geogrids, Geosynthetics, Geotextiles, Pavement design, Pavement layers, ThicknessState Departments of Transportation (DOTs) are continuously seeking to increase the value of pavement rehabilitation and maintenance investments by identifying design and construction practices that reduce rehabilitation costs and increase pavement life. DOTs commonly use geosynthetics as filters, separation layers, and subgrade restraint to facilitate construction on weak subgrades. Subgrade restraint is the use of geosynthetic at the subgrade/sub-base or subgrade/base interface. Recently, geosynthetics have been used to reinforce aggregate base courses, which increases the support from the base to the pavement structure. While laboratory studies are informative, prior to making a substantial change in design or construction practices, it is wise to begin validating findings with field studies. The research objective is to develop a study to evaluate and quantify structural benefits from use of geosynthetics placed within or at the bottom of aggregate base layers only under Nevada conditions. This is the first project of a multi-phased project. The primary deliverable is a plan to support a controlled field demonstration, with input regarding design, specifications and standards, all of which will allow for adjustments as needed in the time between the different phases of the overall field study (planning, construction, data collection, and data analysis).Peter Schmalzer, Lucy Koury, Adam Hand, Elie Hajj, Thomas Van Dam
05/31/24May 2024Steel-Free Concrete Bridge Decks (3.18)https://cptechcenter.org/ncc-projects/steel-free-concrete-bridge-decks-3-18/Bridge decks, Composite construction, Composite materials, Concrete bridges, Durability, Fiber reinforced materials, GuidelinesIn order to realize a potentially transformational improvement in concrete bridge deck durability, the proposed research program intends to validate a deck design by which little to no conventional reinforcement is required. The design relies on the development of so-called arching action to maintain compressive stresses in the concrete thereby minimizing the risk of cracks that adversely affect long term durability. The project will move the technology forward by both validating the structural parameters by which the arching action is invoked, and by developing a suitable concrete mix reinforced with small non-metallic fibers that will meet the structural and long-term durability requirements. The outcome of the project will be a set of guidelines by which a field demonstration project can be developed.Denise Dunn, Eric Landis, Bill Davids
12/31/22December 2022CCTRP 20-03: Protection Against Corrosion of Steel in Concrete Using Epoxy/LDH Coatingshttps://cptechcenter.org/ncc-projects/cctrp-20-03-protection-against-corrosion-of-steel-in-concrete-using-epoxy-ldh-coatings/Chlorides, Concrete structures, Corrosion protection, Electrochemical corrosion, Epoxy coatings, Hydroxides, Reinforced concrete, steelChloride-induced corrosion of steel is one of the most critical causes for the deterioration of reinforced concrete structures. This corrosion severely impacts the durability and service life of the reinforced concrete structures. In salt-contaminated environments, chloride ions diffuse into the concrete surrounding the steel reinforcement and act as a catalyst (rather than as a direct reactant) to promote corrosion of the steel. The corrosion of steel reinforcement is an electrochemical process and consists of two half-cell reactions. Both the anodic and cathodic areas are located on the steel surface. As a typical physical protection approach, the purpose of epoxy coating is to block the penetration of water (chloride is typically transported via water) and oxygen, two of the most critical compounds inducing corrosion. The barrier properties of epoxy coating against water and oxygen are decent but not ideal. Consequently, in the past few decades, numerous attempts have been made to improve the barrier properties of epoxy coatings. While some progress has been achieved, it is not sufficient to meet the demanding requirements for long-term protection of steel in concrete. Additionally, various chemical protection strategies have been developed and shown to be effective, but their complexity and expense militate against their displacement of the well-accepted epoxy coating method. In this research, the study team aims to seamlessly integrate both physical and chemical protection strategies into epoxy coating, the most widely adopted method to mitigate the corrosion of steel reinforcement, so that the developed technology can show superior corrosion protection over currently available strategies and have a relatively high chance to be commercialized.Melanie Zimyeski, Luyi Sun, Montgomery Shaw
12/31/24December 2024Predicting Resilience and Reducing Failure of SCMs to Extreme Storm Eventshttps://cptechcenter.org/ncc-projects/predicting-resilience-and-reducing-failure-of-scms-to-extreme-storm-events/Drainage structures, Failure, Runoff, Storms, Water quality managementThe state of North Carolina has been struck by several extreme rainfall events over the past few years, which have caused failures in stormwater infrastructure (including but not limited to Stormwater Control Measures (SCMs) regulated under the Department’s NPDES stormwater permits (NCS000250)). While SCMs are designed to treat runoff, their principal focus has been treating moderately sized rain storms. How these SCMs fared during larger events, and the restorative maintenance efforts associated with SCM damage is a significant concern for North Carolina Department of Transportation (NCDOT). The Department has a substantial investment in stormwater management assets with over 1900 SCMs having been constructed to treat runoff from roadways, bridges, rest areas, and maintenance yards across the state. Moreover downstream stormwater infrastructure is protected by SCMs (e.g., swales and other conveyance channels). Fortunately, NCDOT has conducted quantitative monitoring of several of these SCMs installed as part of its NPDES permit-required Retrofit Program. NCDOT would benefit understanding at what storm size do typically designed SCMs no longer provided hydrologic mitigation. At what point do SCMs likely fail with significant structural degradation (both to the SCM and downstream) that would lead to costly reconstructive repair? Moreover, are there simple retrofits to existing SCMs (or design features for to-be-built SCMs) that can enhance or extend hydrologic mitigation and reduce the chances of failure?​John Kirby, William Hunt III
07/31/25July 2025RES2023-11: The Effect of Extreme Climate Shifts to Pavement Infrastructure in Tennesseehttps://cptechcenter.org/ncc-projects/res2023-11-the-effect-of-extreme-climate-shifts-to-pavement-infrastructure-in-tennessee/Climate change, Forecasting, Pavement maintenance, PavementsWhile climate change manifestations such as extreme rains are considered a global phenomenon, its impacts tend to be regional and local as evident from recent hurricanes and tornadoes. Building transportation departments’ institutional capacity is the key to the management of adverse climate change effects. Much of the capacity lies within planning and design through operation and maintenance of the infrastructure. To quantify needed capacity building, state departments of transportation (DOTs) should establish the status of present infrastructure against the current climate and predict the status of a future infrastructure for projected climate change. The study will implement big-data analytics combined with machine learning approaches to quantify the current and future status of the Tennessee Department of Transportation (TDOT) infrastructure to provide short-term and long-term planning for the department capacity building with specific focus on pavement infrastructure.Mbakisya Onyango
07/31/23July 2023RES2023-13: Chemical Stabilization of Pavement Subgradehttps://cptechcenter.org/ncc-projects/res2023-13-chemical-stabilization-of-pavement-subgrade/Soil stabilization, Subgrade (Pavements)Roadway alignments are typically dictated by constraints other than the existing conditions. For reason, the design of the roadbed and pavement section must accommodate the conditions at each site even when poor, low strength soils are present in the subgrade. Tennessee Department of Transportation's (TDOT’s) current practice in these situations has been to either remove low quality materials or design a thicker pavement section, both at substantial cost to the state and its residents. Chemical stabilization is often a cost-effective alternative to either of these approaches and should be considered on more TDOT projects. TDOT’s usage and experience with stabilization has declined with time. In order to reverse this trend, TDOT needs to gain knowledge and experience with all aspects of the chemical stabilization process from exploratory and laboratory testing through design to construction.Daniel R. VandenBerge
01/31/24January 2024RES2023-16: Optimized Aggregate Gradations for Concrete Mixture Designshttps://cptechcenter.org/ncc-projects/res2023-16-optimized-aggregate-gradations-for-concrete-mixture-designs/Tennessee is part of the performance-engineered concrete mixtures initiative, led by the Federal Highway Administration (FHWA), aiming to improve the durability, economy, and sustainability of the concrete infrastructure using both prescriptive and performance specification provisions and emerging technologies. The Performance Engineered Mixtures (PEM) addresses concrete pavements durability and performance issues rather than designing and accepting concrete primarily on strength. Tennessee does not currently have procedures and/or specification requirements that fully support the use of optimized gradations in concrete. The current prescriptive specifications adapted by Tennessee Department of Transportation (TDOT) and many state departments of transportation (DOTs) and agencies may preclude the acceptance of mixtures that have superior economy, durability, sustainability, and satisfactory mechanical performance. Thus, it is urgent to create new procedures to allow producers creating more durable and equal and/or higher strength concrete mixtures through optimizing aggregate gradation.Zhongguo Ma
06/30/24June 2024SPR-2305: Connecticut Advanced Pavement Laboratory (CAP Lab)https://cptechcenter.org/ncc-projects/spr-2305-connecticut-advanced-pavement-laboratory-cap-lab/Asphalt pavements, LaboratoriesThe Connecticut Advanced Pavement Lab (CAP Lab) is a laboratory specializing in transportation construction materials, but particularly asphalt pavement and is located at the University of Connecticut. The CAP Lab supports the Connecticut Department of Transportation (CTDOT) research activities and initiatives with regard to pavements including new products and techniques. The CAP Lab acts as an independent agent between CTDOT and the asphalt industry with regard to the performance of materials, and provides an objective review of issues, as requested. The CAP Lab also provides technical expertise to CTDOT when problems arise with existing pavements.Melanie Zimyeski, James Mahoney
03/31/24February 2024SPR-4714: Use of Machine Learning Methods to Obtain a Reliable Predictive Model for Resilient Modulus of Subgrade Soilhttps://cptechcenter.org/ncc-projects/spr-4714-use-of-machine-learning-methods-to-obtain-a-reliable-predictive-model-for-resilient-modulus-of-subgrade-soil/Machine learning, Modulus of resilience, Soils, Subgrade (Pavements)This research will use machine learning to develop/train data model(s) for predicting the resilient modulus of soil in the state of Indiana. The developed model(s) will reduce the need for routine iterative laboratory testing conducted for obtaining the resilient modulus of soil, which is complicated, resource intensive, time consuming, and expensive. In addition, based on the developed model(s), recommendations will be provided for future sampling locations.Sara Khoshnevisan, Medhi Norouzi
VKelly Slipform Paving Vibration Testhttps://cptechcenter.org/ncc-projects/vkelly-slipform-paving-vibration-test/Portable equipment, Slip form paving, Vibration tests, WorkabilityThe aim of the work is threefold: (1) Make the test more user friendly and portable; (2) Understand the science behind the method to guide mixture proportioning and field operations based on test results; (3) Broaden the applicability to include structural and pumping mixtures. The long-term vision of this work is to develop an understanding of how mixtures can be proportioned that are relatively insensitive to vibration abuse or are ideal for the vibration system planned for use on a given site. In addition, it is desirable that a real-time test be available on a site so that as a mixture is delivered, it can be tested for workability variances due to batching or transport, thus providing the operator with guidance on how to tune the placing equipment for a truckload for a given workability. Data can also be provided to the batch plant to guide proportions for the next truck to maintain uniformity. At present, the output from the method is a so-called VKelly Index that has been tested in the field to assess upper and lower limits for slipform paving. Initial laboratory test data using a smart vibrator that also reports the voltage required to maintain a constant vibration frequency also indicates the potential to assess a number of other mixture properties. Based on this information there is a need to fully understand the mixture and equipment factors that influence the rate at which the ball sinks under vibration and how it can be used to guide mixture proportioning and construction processes.Khyle Clute
12/31/22December 2022UHPC Mixture Design for Accelerated Bridge Constructionhttps://cptechcenter.org/ncc-projects/uhpc-mixture-design-for-accelerated-bridge-construction/Accelerated bridge construction, Girders, Mechanical properties, Mix design, Precast concrete, Shrinkage, Ultra high performance concreteEngineers at the Kansas Department of Transportation aim to use accelerated bridge construction (ABC) techniques on a bridge currently scheduled for construction in 2022. This approach to construction results in a need for long and narrow closure strips between adjacent precast girders. The concrete used for these closure strips must (1) be strong enough to allow short (e.g. 6 in.) reinforcement lap splices, (2) gain strength rapidly to allow the new bridge to open days after the last concrete placement, and (3) exhibit relatively little shrinkage to limit crack widths along the joint between the closure strips and precast members. Ultra-high performance concrete (UHPC) is a class of materials suitable for this application; UHPC has high compressive and tensile strengths and gains strength rapidly, satisfying two of the three criteria listed above. However, UHPC is also typically sourced from vendors that consider the mixture design proprietary. Some UHPC mixtures also exhibit significant shrinkage, rendering some mixtures unsuitable for the intended purpose of this project. There is a need for a non-proprietary UHPC mixture design that exhibits relatively little shrinkage for use in upcoming KDOT projects. The scope of this project includes trial-batching non-proprietary UHPC mixture designs reported by others (making modifications as necessary), experimenting with methods for reducing shrinkage, measuring fresh-state properties to ensure workability, measuring the mechanical properties of hardened concrete (including the rate of strength gain and the tensile and compressive strengths), and delivering final mixture design recommendations by early summer 2021.Remy Lequesne
12/31/22December 2022CCTRP 20-03: Protection Against Corrosion of Steel in Concrete Using Epoxy/LDH Coatingshttps://cptechcenter.org/ncc-projects/cctrp-20-03-protection-against-corrosion-of-steel-in-concrete-using-epoxy-ldh-coatings-2/Chlorides, Concrete structures, Corrosion protection, Electrochemical corrosion, Epoxy coatings, Hydroxides, Reinforced concrete, steelChloride-induced corrosion of steel is one of the most critical causes for the deterioration of reinforced concrete structures. This corrosion severely impacts the durability and service life of the reinforced concrete structures. In salt-contaminated environments, chloride ions diffuse into the concrete surrounding the steel reinforcement and act as a catalyst (rather than as a direct reactant) to promote corrosion of the steel. The corrosion of steel reinforcement is an electrochemical process and consists of two half-cell reactions. Both the anodic and cathodic areas are located on the steel surface. As a typical physical protection approach, the purpose of epoxy coating is to block the penetration of water (chloride is typically transported via water) and oxygen, two of the most critical compounds inducing corrosion. The barrier properties of epoxy coating against water and oxygen are decent but not ideal. Consequently, in the past few decades, numerous attempts have been made to improve the barrier properties of epoxy coatings. While some progress has been achieved, it is not sufficient to meet the demanding requirements for long-term protection of steel in concrete. Additionally, various chemical protection strategies have been developed and shown to be effective, but their complexity and expense militate against their displacement of the well-accepted epoxy coating method. In this research, the study team aims to seamlessly integrate both physical and chemical protection strategies into epoxy coating, the most widely adopted method to mitigate the corrosion of steel reinforcement, so that the developed technology can show superior corrosion protection over currently available strategies and have a relatively high chance to be commercialized.Melanie Zimyeski, Luyi Sun, Montgomery Shaw
08/31/24August 2024SPR-4729: Evaluation of the Accuracy of Non-Destructive Testing (NDT) Methods for the Condition Assessment of Bridge Decks and Integration of NDT into the Asset Management Programhttps://cptechcenter.org/ncc-projects/spr-4729-evaluation-of-the-accuracy-of-non-destructive-testing-ndt-methods-for-the-condition-assessment-of-bridge-decks-and-integration-of-ndt-into-the-asset-management-program/Accuracy, Asset management, Bridge decks, Condition surveys, Nondestructive tests (NDT)This project will study non-destructive testing (NDT) methods to evaluate their accuracy and dependability in assessing the actual condition of bridges decks and reliably detecting anomalies. Recommended processes and guidelines for implementing an NDT-based measure into the state’s bridge asset management program will be developed. This research project is focused on comparing NDT results to actual bridge deck conditions and using the findings to incorporate NDT into the asset management program.Christopher Williams, Samuel Labi
07/31/23July 2023RES2023-13: Chemical Stabilization of Pavement Subgradehttps://cptechcenter.org/ncc-projects/res2023-13-chemical-stabilization-of-pavement-subgrade-2/Soil stabilization, Subgrade (Pavements)Roadway alignments are typically dictated by constraints other than the existing conditions. For reason, the design of the roadbed and pavement section must accommodate the conditions at each site even when poor, low strength soils are present in the subgrade. Tennessee Department of Transportation's (TDOT’s) current practice in these situations has been to either remove low quality materials or design a thicker pavement section, both at substantial cost to the state and its residents. Chemical stabilization is often a cost-effective alternative to either of these approaches and should be considered on more TDOT projects. TDOT’s usage and experience with stabilization has declined with time. In order to reverse this trend, TDOT needs to gain knowledge and experience with all aspects of the chemical stabilization process from exploratory and laboratory testing through design to construction.Daniel R. VandenBerge
SPR-4723: Investigate Resilient Modulus Improvements to Bases and Subgrades from Geosynthetic Reinforcementhttps://cptechcenter.org/ncc-projects/spr-4723-investigate-resilient-modulus-improvements-to-bases-and-subgrades-from-geosynthetic-reinforcement/Base course (Pavements), Geosynthetics, Modulus of resilience, Pavement design, Stiffness, Subgrade (Pavements)This research will employ state-of-the-art methods, i.e., automated plate load testing (APLT) and bender element (BE) field sensors to directly measure geosynthetic reinforcement stiffness improvements to base and subgrade layers. Testing results will be used to develop geosynthetic reinforcement design guidelines for Indiana Department of Transportation (INDOT) pavement design (e.g., recommended resilient modulus values due to geosynthetic reinforcement and the related mechanically stabilized base course modulus profile with depth, optimum geosynthetic layouts, Mechanistic-Empirical Pavement Design Guide (MEPDG) implementation, etc.).E. Tutumluer, Peter Becker
12/31/24December 2024SPR-4727: Practical Implementation of Superabsorbent Polymers for Internally Cured Concretehttps://cptechcenter.org/ncc-projects/spr-4727-practical-implementation-of-superabsorbent-polymers-for-internally-cured-concrete/Admixtures, Concrete curing, Curing agents, PolymersThis project will determine practical ways to utilize superabsorbent polymer (SAP) internal curing agents in concrete mixtures composed ofType IL cement and other supplementary cementitious materials, including slag, silica fume, and E5® nanosilica. Evidence-based guidance will be provided on specific implementation strategies, including SAP delivery method, batching sequence, mixing requirements, and external curing needs for SAP-concrete mixtures.Kendra Erk, Jan Olek
12/31/23December 2023Automated Distress Measurement for Pavement Managementhttps://cptechcenter.org/ncc-projects/automated-distress-measurement-for-pavement-management/Automation, Data collection, Evaluation, Pavement distress, Pavement management systems, Plan implementationThe SDDOT currently collects pavement distress data through automated and manual processes. In the automated process, a data collection vehicle driving at highway speeds measures pavement roughness and rutting and acquires intensity and elevation images of the pavement surface over the entire state highway network. Analysis software uses a set of rules to interpret the images to identify and quantify some types of cracking. Automated data is primarily used for reporting to the Federal Highway Administration’s Highway Performance Monitoring System (HPMS). In the manual process, two teams of transportation interns driving 15 mph on the roadway shoulder visually rate the severity and extent of pavement distresses compared to records from the prior year. A technician may also examine pavement images on a computer to rate pavement distresses. The Pavement Management System (PMS) uses this data to identify pavement surface needs and prioritize improvement projects. Concerns with manual collection include the safety of the interns exposed to traffic, the level of effort required, and the subjectivity of the rating process. As data collection technology has improved, using automated distress data for both federal reporting and pavement management has become more feasible. Research is needed to determine whether automated data collection can provide all of the distress data needed by the PMS and to identify changes needed to the PMS and SDDOT’s data collection and processing methods. Objectives are as follows: (1) Describe SDDOT’s pavement distress data requirements for federal reporting, pavement management, and other pavement engineering purposes. (2) Evaluate the capability of SDDOT’s automated data collection equipment and process to acquire the needed pavement distress data. (3) Identify modifications needed to SDDOT’s data collection and pavement management processes to accommodate the use of automated distress data. (4) Evaluate the suitability of the modified data collection and pavement management processes using automated pavement distress data collected during 2022. (5) Develop an implementation plan for using fully automated collected distress data for pavement management beginning in 2023.Andy Vandel, John DeBoer
08/17/24August 2024Evaluation of Multi-Layer Polymer Concrete Overlayshttps://cptechcenter.org/ncc-projects/evaluation-of-multi-layer-polymer-concrete-overlays/Bridge decks, Concrete overlays, Corrosion protection, Cracking, Materials and structures protection, PolymersMulti-layer polymer concrete overlays, also known as two-coat and broom and seed polymer concrete bridge deck overlays, have been used in Kansas and other states for a number of years, primarily to extend the life of existing bridge decks. The system involves the application of a polymer on which aggregate is broadcast, followed by a second layer of polymer and aggregate. The system has the advantage of filling existing cracks and providing a waterproof membrane to limit future penetration of water and deicing chemicals to the level of the reinforcing steel. There is, however, a great deal that is not known about the system; specifically, the effectiveness of multi-layer polymer concrete overlays as a corrosion protection system for reinforcing steel in bridge decks has never been evaluated. Key questions involve the impact of wear, age, crack formation, and exposure on the effectiveness of this system. Furthermore, the system is also used in new construction, which places special emphasis on its response to the formation and growth of cracks. In addition, because aggregate is integral with the system, cracks that may penetrate the overlay will be exceedingly difficult to identify in the field. The cost of the overlay is on the order of $40/yd2, not including other costs involved in construction; this represents an approximately 20% increase in the cost of new construction. Although this topic was previously studied in a KTRAN project, the effect of cracks was not. The objective of the study is to evaluate the effectiveness of multi-layer polymer concrete overlays, as applied in Kansas, to protect the concrete and the reinforcing steel in concrete bridge decks when used as both a retrofit and in new construction. The research will evaluate the effects of age, crack formation, and exposure. To accomplish this objective research will involve both laboratory (bench-scale) and field test specimens subjected to realistic exposure conditions. The approach taken in the tests will parallel that used to evaluate other corrosion protection systems, including tests that have been used to evaluate corrosion-resistant reinforcing steel, corrosion inhibitors, and alternative deicing chemicals. Both the laboratory and field tests will evaluate the effectiveness of the system to fill existing cracks and to handle the formation of cracks that occur during the life of a bridge deck, the latter being especially important for application of the system for new deck construction. The scope of the research will be tailored to the needs of the Kansas Department of Transportation (KDOT), including the selection of representative, commercially available versions of the system. Typically, laboratory tests (which provide accelerated aging) are run for two years and field tests for a minimum of five years. Only the first year of the performance of the field specimens will be evaluated, with additional testing funded under an ad hoc contract, if so agreed to by KDOT. The specimens will be monitored for corrosion potential and corrosion rate, and the concrete will be sampled to determine chloride penetration. Overlays will be prepared in accordance with Section 729 of the 2015 Standard Specifications.David Darwin, Matthew O'Reilly
02/01/21February 2021Evaluation of Silica-Based Materials for Use in Portland Cement Concretehttps://cptechcenter.org/ncc-projects/evaluation-of-silica-based-materials-for-use-in-portland-cement-concrete-2/Ash content, Evaluation, Paving materials, Portland cement concrete, Silicates The purpose of this research was to evaluate the mechanical performance and long-term durability of concrete containing alternative supplementary cementitious materials (ASCM) available in the state of Florida that were identified in a previous research project (FDOT BDV-31-977-06) as warranting further investigation. The ASCM chosen were two types of Florida sugarcane bagasse ash, ground sand, ground recycled container glass, and ground volcanic rock, all of which were identified as potential substitutes to class F fly ash for future use in concrete. Both Type I/II and Type IL cements were included in the investigation to account for the increasing use of IL cements in industry. Mixes containing Class F fly ash, Class C fly ash, and silica fume were used for comparison and Class C fly ash was used for all ternary mixes. Raw material testing included elemental and mineralogical compositions determined by x-ray fluorescence (XRF) and x-ray diffraction (XRD), chloride content, particle size distribution employing laser particle size analysis, apparent specific gravity determined with a helium pycnometer, specific heat capacity using a differential scanning calorimeter (DSC), and quantity and rate of heat generation of the cementitious materials found by isothermal calorimetry. Fresh properties of mortars and concretes examined included mortar flow, time of set, slump, temperature, density, and air content. Hardened mechanical properties measured included compressive strength, splitting tensile strength, flexural strength, modulus of elasticity, and coefficient of thermal expansion. Durability testing included surface and bulk resistivity, resistance to alkali-silica reaction and resistance to sulfate attack. Ground glass produced the most promising results of all the ASCM that were evaluated. Sugarcane bagasse ash performed well in some regards but has a variety of barriers towards implementation. Volcanic rock and ground sand produced results indicating that both are likely filler materials with little pozzolanic reactivity. Christopher Ferraro, Jerry Paris, Kyle Riding, Timothy Townsend, Eduard Tora Bueno
10/31/25October 2025Design Resilient Modulus for Coarse-Grained Subgrade Soilshttps://cptechcenter.org/ncc-projects/design-resilient-modulus-for-coarse-grained-subgrade-soils/Coarse grained soils, Mechanistic-empirical pavement design, Modulus of resilience, Subgrade (Pavements)In 2018, the Virginia Department of Transportation (VDOT) implemented AASHTO Mechanistic Empirical Pavement Design Guide (MEPDG) for new, reconstruction, and lane widening projects in primary and interstate roadways. To facilitate the pavement design, MEPDG recommends the resilient modulus (MR) to characterize the subgrade soils. As part of the VDOT MEPDG implementation efforts, Materials Division Soils Lab collected both fine- and coarse-grained soil samples from around the state and performed MR tests on them. For fine-grained soils (A-4, A-5, A-6, and A-7), with a sufficient amount of the test results statewide, average MR values were able to be determined. These average values have been currently used in the design of low volume (AADT < 10,000) roadways. In addition, the correlations with the results of Unconfined Compression Strength (UCS) test that were developed from a VTRC study (2014) are currently being used to estimate design MR for high volume (AADT > 10,000) projects as an alternative to actual MR testing. However, no statewide average MR values or correlations are currently available for coarse-grained soils (A-1, A-2 and A-3). Although some actual measured values are available, it has also been noted from the data that MR of coarse-grained soil is measured significantly lower than AASHTO recommended MR values (MEPDG default) which needs to be further investigated. The objectives of the proposed project are to develop recommended MR values for local coarse-grained subgrade soils and to establish correlations (if available) with other simple conventional soil tests to estimate MR values for coarse-grained subgrade soils that can be used when necessary. The findings from this study are expected to facilitate proper pavement design for Virginia roadways and help in VDOT’s efforts in implementing MEPDG.M. Hossain, Harikrishnan Nair
10/12/24October 2024Development of an Ohio Calibration of AASHTOWare Pavement ME Designhttps://cptechcenter.org/ncc-projects/development-of-an-ohio-calibration-of-aashtoware-pavement-me-design/Calibration, Mechanistic-empirical pavement design, Optimization, SoftwareThe Ohio Department of Transportation (ODOT) began ME related research in the late 1990's and more recently had a local calibration effort for Ohio completed by Applied Research Associates in 2009. This 2009 effort indicated the national calibration either over or under predicted the distresses and smoothness based on the available Long Term Pavement Performance (LTPP) data from sections constructed in Ohio. Based on the recommendations from the 2009 research, ODOT has been compiling the additional distress and material information to perform a more comprehensive local calibration. In Spring 2020, ODOT attempted to use the newly released Calibration Assistance Tool provided as a companion to the AASHTOWare Pavement ME Design (PMED) software. The project data was compiled to locally calibrate for ODOT conditions using Pavement Condition Rating (PCR) and Highway Performance Monitoring System (HPMS) distress data, both methods did not yield valid calibration coefficients for the models attempted. Due to the unsuccessful local calibration efforts by ODOT, a more thorough evaluation of the department's available data and development of local calibration coefficients is needed for ODOT to be able to incorporate PMED into the existing design and analysis process. Without this Ohio calibration, ODOT cannot move forward with a responsible implementation of PMED. The goal of this research is to assist ODOT in optimizing the pavement design process, based on critical performance parameters associated with the PMED software. The objectives of this research include the following: (1) Determine implementable calibration coefficients representative of the unique conditions, materials, and construction in Ohio. (2) If implementable calibration coefficients cannot be determined for any model evaluated, develop a detailed plan of the steps ODOT would need to take for future local calibration of these models as applicable.Jennifer Spriggs, Wouter Brink
07/31/23July 2023Durability and Volumetric Stability of Non-Proprietary Ultra High Performance Concrete Mixes Batched With Locally Sourced Materialshttps://cptechcenter.org/ncc-projects/durability-and-volumetric-stability-of-non-proprietary-ultra-high-performance-concrete-mixes-batched-with-locally-sourced-materials/Durability, Local materials, Mix design, Ultra high performance concreteUltra High Performance Concrete (UHPC) has received widespread attention for its ability to outperform traditional concrete in nearly every aspect. Due to its superior performance, the application of UHPC does not follow the traditional rules and expectations of standard cementitious materials. So far, commercial premixes, such as Ductal®, CEMTEC multi-scale, and CERACEM have dominated the construction industry when it comes to UHPC applications. Although the performance of these UHPC proprietary mixes is exceptional, they are very expensive. To counter this high cost, a significant amount of research has been performed on materials classified as UHPC, including non-proprietary mix designs developed by transportation agencies in other regions. Non-proprietary mix designs developed using locally available materials can result in significant cost savings by eliminating the need to purchase expensive proprietary UHPC mixes from specialized commercial suppliers. The research proposed herein is to examine the durability and volume stability of a locally sourced mix design. These two items are of specific interest to local transportation agencies as the typical application of UHPC is for bridge closure pours.Denver Tolliver, Andrew Sorensen, Srishti Banerji
06/30/23June 2023Stabilizing Embankment by Using Geosynthetic Reinforcementhttps://cptechcenter.org/ncc-projects/stabilizing-embankment-by-using-geosynthetic-reinforcement/Design, Embankments, Geosynthetics, Geotechnical engineering, Guidelines, Road construction, Soil stabilization, SpecificationsOn some highway construction projects limited rock quantities are available to use as stable embankment material. Stabilizing embankments with geosynthetic reinforcement is a suitable option in situations like these and is now a common practice. This project will develop best practices guidance on geosynthetic reinforcement and its use in construction and design applications including guidelines for identifying and assessing the optimal condition of soil, performance measures, construction specifications, design criteria, and embankment geometry.Charlie Sun
06/30/23June 2023Best Practices for MOT on Interstate Pavement Rehabilitation Projectshttps://cptechcenter.org/ncc-projects/best-practices-for-mot-on-interstate-pavement-rehabilitation-projects/Best practices, Construction projects, Interstate highways, lane closure, Pavement maintenance, Rehabilitation (Maintenance), Road construction, State departments of transportation, Traffic lanes, WidthOn interstate pavement rehab projects, the Kentucky Transportation Cabinet (KYTC) often finds it challenging to maintain two lanes of traffic in each direction. The standard practice is to use a full-width shoulder as a thru lane while work is done on adjacent lanes. But difficulties arise when the shoulder is not wide enough to operate as a thru lane — particularly when the required depth for rehabilitation demands more lateral clearance for lanes under construction. Designers can also face maintenance of traffic (MOT) challenges at interchanges due to the widths of mainline bridges, lateral clearances of cross-road structures, and ramp lengths. Researchers will review ongoing and completed interstate rehab projects where KYTC found it challenging to maintain desired lane widths during construction and document negative impacts of MOT on completed facilities. The objective of this study is to develop best practices for MOT to help Project Managers mitigate risks on pavement rehab projects.Jeff Jasper, Rachel Catchings
03/31/19March 2019Friction and Texture Retention of Concrete Pavementshttps://cptechcenter.org/ncc-projects/friction-and-texture-retention-of-concrete-pavements/In the late 1980s and early 1990s, the Alabama Department of Transportation (ALDOT) noticed a decline in skid trailer numbers on concrete pavements shortly after grinding operations. The engineers at the time suspected that the coarse aggregate led to decline of skid trailer numbers and the resulting conclusion led to a ban of carbonate aggregates in mainline concrete pavement that is still in place. Recently, ALDOT has decided to reexamine the ban on carbonate aggregates in mainline concrete pavement and perform a comprehensive and detailed study of the issue. It appears that there is sufficient data to begin using carbonate aggregates in mainline concrete pavements in Alabama provided each source is properly and fully tested. Both the researchers and ALDOT have provided sets of recommended specification language to this end.Satyavati Komaragiri, Ali Algarni, Michael Rung, David Whitney, David Fowler, Amit Bhasin, Matthew Fetner, Atolo Tuinukuafe, Armen Amirkhanian
10/31/25October 2025Alkali-Silica Reaction (ASR) Mitigation in High Alkali Content Cementshttps://cptechcenter.org/ncc-projects/alkali-silica-reaction-asr-mitigation-in-high-alkali-content-cements/Alkali silica reactions, Cement, Concrete, Materials tests, Mix design, Specifications, Test proceduresVDOT has been requested to approve the use of locally produced cement with alkali content exceeding 1%. However, to prevent deleterious alkali-silica reaction (ASR), current VDOT specifications limit the alkali content of cement to 1%. A rational approach to allow for the use of cement with alkali content above 1% while preventing ASR is to consider the alkali loading in concrete (instead of solely focusing on the alkalis in the cement). Nonetheless, this approach is not presently considered in VDOT specifications. In addition, the performance-based ASR mitigation approach of the 2020 Virginia Road and Bridge Specifications relies on a withdrawn test procedure (ASTM C227). As a response, the main purpose of this study is to update ASR provisions in the Virginia Road and Bridge Specifications to: (1) consider the alkali loading in concrete; and (2) incorporate a currently acceptable ASR evaluation test method. In turn, this will help to more effectively mitigate the ASR distress and therefore increase the service life of concrete infrastructure in Virginia. Specifically, this study will evaluate the effect of cement alkali content, concrete alkali loading, and supplementary cementitious materials (SCMs) type and dosage on ASR in routine concrete mix designs used in VDOT projects.Amir Behravan, Gabriel Arce, Celik Ozyildirim
08/31/25August 2025Artificial Intelligence for Pavement Condition Assessment from 2D/3D Surface Imageshttps://cptechcenter.org/ncc-projects/artificial-intelligence-for-pavement-condition-assessment-from-2d-3d-surface-images/Artificial intelligence, Automatic data collection systems, Computer vision, Evaluation and assessment, Image analysis, machine learning, Surface course (Pavements)While manual quality assurance is inefficient and expensive, the proprietary data storing and processing methods have prevented Texas Department of Transportation (TxDOT) from developing automated methods for data validation. Recently, with the national initialization of standard format for two-dimensional/three-dimensional (2D/3D) pavement surface images and the development of Artificial Intelligence (AI)/Machine Learning (ML) in Computer Vision, TxDOT sees the opportunity of developing new methods for automated pavement condition assessment, with more independence from vendors and their equipment. The main objective of this research is to develop ML-based application software to assess pavement conditions using the standard format 2D/3D pavement surface images. The three main components of this research include the development of a standard format 2D/3D pavement surface image library, a set of ML models for pavement distress measurement, and application software for pavement condition evaluation. The proposed project will assist TxDOT to enhance the quality of the automated pavement condition data, which would eventually help the State of Texas improve its pavement performance.Jade Adediwura, Feng Wang
09/30/23September 2023Assessing the condition of pavement structures using Non-destructive Evaluation (NDE) technologieshttps://cptechcenter.org/ncc-projects/assessing-the-condition-of-pavement-structures-using-non-destructive-evaluation-nde-technologies/Nondestructive tests (NDT), Pavement maintenanceThis research will continue assessment of the condition of pavement structures using Non-destructive Evaluation (NDE) technologies.Mike Adams
08/31/25August 2025Develop Design Details for CRCP Whitetopping at Intersectionshttps://cptechcenter.org/ncc-projects/develop-design-details-for-crcp-whitetopping-at-intersections/Continuously reinforced concrete pavements (CRC pavements), Deflection, Design methods, Nondestructive tests (NDT), Overlays (Pavements), WhitetoppingThe research teams will establish a method to evaluate the existing pavement structural condition and design continuously reinforced concrete pavement (CRCP) overlays, both thin and thick. The design methods will include non-destructive (NDT) pavement evaluation techniques and tools, deflection based CRCP slab thickness design procedures, and CRCP reinforcing design details. The research teams will identify state-of-the-art practices that can be implemented as well as areas that need additional research. The findings from this research will result in procedures that will be used to design CRCP overlays, both thin and thick.Wade Odell, Moon Won
08/31/24August 2024Develop Efficient Prediction Model of Highway Friction on an Annual Basis on Texas Networkhttps://cptechcenter.org/ncc-projects/develop-efficient-prediction-model-of-highway-friction-on-an-annual-basis-on-texas-network/Data collection, Friction, Highways, Mathematical prediction, Skid resistance, TextureThe number of wet-weather crashes is a significant problem in Texas, consequently, the provision of pavement surfaces with adequate skid resistance or friction is of utmost importance for promoting public safety and saving lives. Measuring skid numbers for the entire Texas roadway network on an annual basis is challenging and inefficient because of the regular stops necessary to refill the water tanks. Fortunately, recent laser technology allows the measurement of texture at high resolution and speed in an efficient manner. Today, a contractor collects only macrotexture for TxDOT and delivers mean profile depth (MPD), which is a very poor predictor of skid. Consequently, TxDOT personnel have to go out and collect skid data at a high cost to calculate skid numbers. Currently TxDOT collects skid resistance on about 33% of their network on an annual basis (approximately 50% of the Interstate system and 25% of the non-Interstate system). The objective of this project is to (i) continue the work that started under TxDOT’s Project 0-7031, (ii) enhance the system that was developed as part of that project and (iii) update the models developed by collecting texture and skid on, at least 3,000 additional pavement sections distributed in at least six different districts. This information will be used to calibrate and validate equations to predict friction and skid numbers with a high degree of accuracy. This research would result in an enhanced system to collect texture data at highway speed for the entire Texas on-system network on an annual basis. The system is intended to be compact and capable of retrofitting to any surveying vehicle with minimal time and effort. This will provide not only savings but additional safety to operations.Shelley Pridgen, Jorge Prozzi
05/31/26May 2026Evaluation of Nano-Materials in Concrete for Improved Durabilityhttps://cptechcenter.org/ncc-projects/evaluation-of-nano-materials-in-concrete-for-improved-durability/Concrete, Degradation failures, Durability, Fly ash, Nanotechnology, Service lifeThe application of nanotechnology in the construction industry has led to significant advancements in enhancing the mechanical properties of concrete through changing concrete’s structure at the nanolevel. However, advancements in understanding how to leverage nanomaterials to combat durability issues has lagged behind the progress made on the mechanical property side. Concrete is susceptible to various physical and chemical degradation mechanisms that can reduce its service life. Historically, Class F fly ash has been used to address many of these degradation issues. However, with changes in fly ash quality and availability, identifying other materials that Texas Department of Transportation (TxDOT) can use to protect concrete against durability issues are needed. Over the last 20 years, much progress has been made in using nanomaterials in concrete mixtures, for example, nanoparticles have even been used in high-volume fly ash cementitious systems to offset the negative effects of fly ash on rate of hydration and early-age strength gain. This project will investigate the use of nanomaterials on the properties of concrete mixtures, with special emphasis placed on durability properties and self-healing capabilities. Various nanomaterials will be used, alone and in combination with supplementary cementing materials (SCMs). The most promising mixtures will be selected for field trails to validate laboratory findings.Jade Adediwura, Raissa Douglas Ferron
10/01/25October 2025Mobile Concrete Testing Trailer to Deploy Performance Engineered Mix Design for Concrete, Deploy New Test and Technologies, and Provide National Leadership for Concrete Pavementshttps://cptechcenter.org/ncc-projects/mobile-concrete-testing-trailer-to-deploy-performance-engineered-mix-design-for-concrete-deploy-new-test-and-technologies-and-provide-national-leadership-for-concrete-pavements/Concrete, Concrete pavements, Construction projects, Demonstration projects, Materials tests, Mix design, quality assuranceThis project will advance new technologies through demonstration on active State construction projects and will provide workshop on best practices for pavement Quality Assurance and technical guidance on specification improvements.
08/31/25August 2025Project Level Performance Database for Rigid Pavements in Texas, Phase IIIhttps://cptechcenter.org/ncc-projects/project-level-performance-database-for-rigid-pavements-in-texas-phase-iii/Data collection, Databases, Pavement performance, Rigid pavementsThe primary tasks in this project will consist of: (1) collecting field performance information on rigid pavements; (2) gathering field performance information on experimental and special sections in Texas; (3) evaluating the effectiveness of special or innovative techniques tried in Texas; and (4) developing a platform for storing all the information collected in this study in a central server with various features embedded so that the information could be easily accessible in a systematic way.Martin Dassi, Moon Won
08/31/23August 2023 Guidelines for Optimizing Roadway Cross-Section on Texas Highwayshttps://cptechcenter.org/ncc-projects/texas-guidelines-for-optimizing-roadway-cross-section/Access control (Transportation), Highway design, Recommendations, Traffic lanes, Turning traffic This project compiled and reviewed existing road cross-section guidance (for urban, suburban, and rural environments) from across the United States, along with research findings, to identify content that would be appropriate for inclusion in Texas-based guidelines for road cross-section optimization. A separate project task focused on considering the data needs for assessing a proposed cross-section treatment, using the results from previous efforts to determine if existing guidance and data are sufficient to develop cross-section optimization guidelines. Based on the information obtained in those tasks, this report provides recommended guidelines for selecting optimal cross-sections for highways in Texas. Those guidelines include suggested revisions to the TxDOT Roadway Design Manual and Access Management Manual. Marcus Brewer, Srinivas Geedipally, Michael Pratt, Karen Dixon
03/01/2023March 2023Alkali-Silica Reaction Mitigation Strategies for ITD Concrete Mixeshttps://cptechcenter.org/ncc-projects/alkali-silica-reaction-mitigation-strategies-for-itd-concrete-mixes/Admixtures, Alkali silica reactions, Concrete, Mineral aggregates, PozzolanEvery year, Idaho Transportation Department (ITD) spends millions of dollars to repair deteriorated concrete structures around Idaho. One of the leading causes for deterioration of concrete is Alkali-Silica Reaction (ASR), a chemical reaction that develops between the reactive silica in the aggregates and the alkalis within the cement paste, causing expansion and cracking to the structure over a number of years. ASR will eventually compromise the durability and structural integrity of structures and pavements. ITD is currently experiencing problems with secondary cementitious materials (SCMs) test results in terms of consistency and quality of materials. SCMs are critical for concrete durability, longevity, cost, workability, strength, and as a mitigation method to reduce ASR reactions that lead to premature concrete failure. Fly ash is typically used as an SCM by Contractors and Concrete Suppliers. Recently, fly ash production has been decreasing on a national scale, while demand has been increasing. This results in shortages, cost increases, and the need for agencies to accept lower quality materials. Fly ash supplies will become increasingly scarce as coal is replaced by cleaner energy sources in the U.S. Therefore, the supply chain for ITD concrete SCMs is in jeopardy. There are various mineral admixtures commercially available in the United States and Idaho. However, the effectiveness of these admixtures in reducing ASR has not been independently verified in Idaho. The two mineral admixtures that ITD would like to investigate are diatomaceous earth (DE) and natural pozzolans (NP). These two products can be produced locally within the state or in adjacent states. Currently, fly ash used for mitigating ASR is being shipped in from the Midwest or Canada. Given the lack of independently verified data and observations to evaluate the performance of these two mineral admixtures in Idaho, ITD would like to better understand the costs and performance benefits of these admixtures that ITD contractors can obtain locally. Another mitigation approach is the use of nano-silica (NS) admixtures when combined with Idaho aggregates. These tend to be liquid admixtures that are added to the concrete when batched. Very little information is available as to the effectiveness of NS on ASR mitigation. NS admixtures are very consistent and can be easily implemented into existing concrete batch plants. Past studies have shown that a majority of the aggregate sources in Idaho will react with alkalis in cement and thus, do not qualify under the AASHTO T 380 test (expansion ≤ 0.04% is passing). Additionally, using a non-reactive aggregate in concrete for all ITD projects is unrealistic. Therefore, to reduce ASR and provide durability to Idaho’s infrastructure, identification of effective ASR mitigation methods is critical. While there are many manufacturers of mineral admixtures who claim that their product is the best solution, independent testing and verification is required to assure durability of concrete structures in Idaho as well as building confidence for ITD contractors to select the right solutions that would work in Idaho. To accomplish this, ITD seeks researchers to conduct the testing, verification, and cost analysis as well providing recommendations and guidance for implementing the research outcomes.
09/30/22September 2022Assessment and validation of concrete durability testing procedures in support of AASHTO PP-84https://cptechcenter.org/ncc-projects/assessment-and-validation-of-concrete-durability-testing-procedures-in-support-of-aashto-pp-84/Concrete curing, Durability tests, Mix designThis research will investigate the sensitivity of the bucket test to mixture design variations (e.g., w/cm, air content, paste/aggregate ratio, and components (SCMs)) that might impact curing rates.David Mensching
05/01/23May 2023Development of Pore Solution Sensor for Concretehttps://cptechcenter.org/ncc-projects/development-of-pore-solution-sensor-for-concrete/Alkalinity, Cement, Electrical properties, Pore space, SensorsThis study features the advance development of a sensor to determine the electrical properties of the pore solution of cement based materials.Robert Spragg
09/30/24September 2024Examining chemical and physical methods and relationships for Detection and Mitigation of ASRhttps://cptechcenter.org/ncc-projects/examining-chemical-and-physical-methods-and-relationships-for-detection-and-mitigation-of-asr/Alkali silica reactions, PavementsThis research involves advance ASR mitigation strategies using the chemical ASR test. The Federal Aviation Administration (FAA) and several state agencies are assisting in this effort.Terry Arnold
Idaho Degradation Test Studyhttps://cptechcenter.org/ncc-projects/idaho-degradation-test-study/Aggregate tests, Materials, Specifications, Test proceduresThe Idaho Degradation Test (IT-15) is a modified version of a degradation test developed by Washington State DOT in 1959 and is one of several tests used to qualify or disqualify aggregate sources and products. With time, the original research data and the criteria that established the Idaho Degradation Specification has been lost. This lack of data prevents ITD from full understanding the significance of the test results. The test itself has poorly defined procedures causing variability in results between individuals and labs. This test was developed and implemented when ITD performed the source testing and consistency may not have been an issue. At this time, it is unknown if variations are inherent in the test procedure or attributable to differences in how the test is being performed by the individual testing firms. This test needs validation to gain a better understanding of the test method and its results as it relates to aggregate quality. This research will be the first step to quantify the differences within the test, establish clear direction in how to process the aggregates for testing and compare results to other nationally recognized test procedures on the exact same material. As current aggregate sources become depleted and a need for developing new sources arises, ITD needs to ensure that the specification is established on sound and current data. This will enable ITD to prevent the use of low-quality aggregate on the roadways while allowing for an appropriately conservative specification. This research will gather all existing documentation into one place. New data will be generated and categorized to create a dataset that can be expanded in the future. ITD will have updated data to support the Idaho Degradation Specification or potentially propose new or modified specifications. Further, the research could lead to the addition of other degradation tests used to establish the suitability of aggregates.Adrienne Woods
09/30/23September 2023Pavement Preservation in Urban Environments: Best Practices in Materials, Technologies, and Applicationshttps://cptechcenter.org/ncc-projects/pavement-preservation-in-urban-environments-best-practices-in-materials-technologies-and-applications/Best practices, Materials selection, Pavement maintenance, Paving, Paving materials, Preservation, Urban areasThe project selection, materials, and construction of Pavement Preservation Treatments focused on the specific challenges of Urban Environments.Morgan Kessler
02/28/25February 2025SPR-4717: Assessment of Temperature Correction Factors for Falling Weight Deflectometer Deflectionshttps://cptechcenter.org/ncc-projects/spr-4717-assessment-of-temperature-correction-factors-for-falling-weight-deflectometer-deflections/Data quality, Deflection, Falling weight deflectometers, TemperatureThis study will develop an enhanced method of temperature correction on the FWD deflections to minimize temperature effects during FWD data analysis. The field investigation and numerical analysis will be conducted to identify the relationship between FWD deflections and testing temperatures. Based on the identified relationship, the FWD temperature correction guidelines will be established.Seonghwan Cho, John Haddock
04/30/25April 2025SPR-4718: Influence of Nanomaterials‐based Admixtures on the Entrained Air Void System and Freeze‐Thaw (FT) Resistance of Concretehttps://cptechcenter.org/ncc-projects/spr-4718-influence-of-nanomaterials%e2%80%90based-admixtures-on-the-entrained-air-void-system-and-freeze%e2%80%90thaw-ft-resistance-of-concrete/Admixtures, Air voids, Bridge construction, Concrete, Freeze thaw durability, Nanostructured materials, SilicaThis project has following Objectives: (1) evaluate the effect of nanosilica admixtures on the air-void characteristics of concretes used for construction of bridges and bridge deck overlays, (2) examine the influence of the characteristics of the air-void system on the freeze-thaw resistance of concrete, (3) compare the influence of the concrete production method (lab vs. field) on the durability of concrete, (4) examine, in partnership with INDOT’s Division of Materials & Tests, the effect of non-traditional (microsphere type) air entrainment products on the quality of the air-void system in concretes with nanosilica admixtures.Mirian Velay-Lizancos, Jan Olek
06/01/22June 2022Patching Materials and Techniques for Long-lasting Repair of Concretehttps://cptechcenter.org/ncc-projects/patching-materials-and-techniques-for-long-lasting-repair-of-concrete/Concrete pavements, Full-depth reclamation, Patching, Pavement maintenance, Paving materialsThis study will develop a program utilizing the PTF to identify patching materials and installation techniques that result in long-lasting partial-depth and full-depth repair of concrete pavements.Robert Spragg
Reduce Concrete Cracking through Mix Designhttps://cptechcenter.org/ncc-projects/reduce-concrete-cracking-through-mix-design/Maintenance practices, Reinforced concrete, Reinforced concrete bridgesConcrete cracking affects the long-term condition and performance of both bridge and culvert structures. Shrinkage cracking is perceived to be a deterrent to placing exposed decks/slabs during bridge and culvert rehabilitation and replacement projects. Concrete cracking during bridge construction allows oxygen, moisture and salts into the structure accelerating corrosion and deterioration. Understanding methods to avoiding cracking at the mix design level will allow exposed decks to be more often considered as a viable option. This is especially critical as more rapid bridge projects are proposed. Different construction and specification methods have been previously explored to reduce concrete cracking at bridge curb locations. This research will explore alternates to current mix design practice including lightweight concrete, changes to PCC and pozzolan content, etc., to reduce concrete cracking. Stand alone, off structure concrete placement like sidewalks, concrete slabs, etc., could be used as test areas for observation. The NHDOT Bureau of Bridge Maintenance will work with the researchers at those locations as well as considering placement in bureau projects.Deirdre Nash, Dave Eshan
09/30/25September 20252317 Effectiveness of Magnesuim-Alumino-Liquid-Phosphate-Based concrete as a Repair Material (MALP)https://cptechcenter.org/ncc-projects/2317-effectiveness-of-magnesuim-alumino-liquid-phosphate-based-concrete-as-a-repair-material-malp/Corrosion, Freeze thaw durability, Magnesium compounds, Phosphates, Portland cement concrete, Reinforcing steel, RepairingThe purpose and goals of this research is to address the corrosion performance of conventional reinforcing steel in uncracked and cracked Magnesuim-Alumino-Liquid-Phosphate-Based (MALP) concrete in simulated repairs of Portland cement of both high and low quality. Reinforcing bars will be evaluated in both a clean and passive state and in an activity corroding state. The project will evaluate the ability of MALP concrete to withstand freeze-thaw cycles both as an individual material and in conjunction with Portland cement concrete.Walt Peters, Gary Hook, David Darwin, Matthew O'Reilly
09/30/23September 2023Advance and Validate Performance Engineered Mixtures (PEM) tests and procedureshttps://cptechcenter.org/ncc-projects/advance-and-validate-performance-engineered-mixtures-pem-tests-and-procedures/Concrete, Durability tests, Engineered materialsThis research will develop thresholds for concrete durability tests to indicate pavement quality.https://cptechcenter.org/ncc-projects/advance-and-validate-performance-engineered-mixtures-pem-tests-and-procedures/
12/01/21December 2021Geometry Verification for Concrete Resistivity Testinghttps://cptechcenter.org/ncc-projects/geometry-verification-for-concrete-resistivity-testing/Concrete, Electrical resistivity, Measurement, MethodologyThis project will develop a method for normalizing resistivity measurements on different sized specimen.Robert Spragg
10/01/23October 2023PEM: Influence of Curing Regimes on Formation Factorhttps://cptechcenter.org/ncc-projects/pem-influence-of-curing-regimes-on-formation-factor/Concrete, Curing agents, Pavement cracking, Resistivity method, ShrinkageThis study will investigate new techniques for quantifying curing effectiveness of concrete materials. The study focuses on the reduction of early age shrinkage cracking.Robert Spragg
10/01/21October 2021PEM: Quantification of Calcium Oxychloride Formationhttps://cptechcenter.org/ncc-projects/pem-quantification-of-calcium-oxychloride-formation/Calcium chloride, Concrete, Frigid regions, Optimization, Pavement joints, Test proceduresThis study will validate and optimize test procedure for quanitifying calcium oxychloride formation, a problem of national significance affecting concrete joints in colder regions.Robert Spragg
05/01/22May 2022Showcasing and Rodeo of Emerging Concrete Technologies at TFHRChttps://cptechcenter.org/ncc-projects/showcasing-and-rodeo-of-emerging-concrete-technologies-at-tfhrc/Adsorption, Air voids, Concrete, Fly ash, Fresh concrete, TechnologyThis study presents a critical evaluation of promising concrete technologies; two related to rapid assessment of fresh concrete air void systms and one related to fly ash adsorption capacity.Robert Spragg
02/01/22February 2022Utilization of XRF for ASRhttps://cptechcenter.org/ncc-projects/utilization-of-xrf-for-asr/Alkali silica reactions, Pavements, Spectrometers, X ray fluorescenceThis research will investigate the applicability of wavelength dispersive XRF and handheld versions for use in conduct of chemical ASR test.Terry Arnold
Evaluation of Surface Treatments to Mitigate ASRhttps://cptechcenter.org/ncc-projects/evaluation-of-surface-treatments-to-mitigate-asr/Alkali silica reactions, Barriers (Roads), Concrete pavements, Cracking, Freeze thaw durability, Interstate highways, Pavement maintenance, Sealing compounds, SilanePremature cracking of the barrier wall and pavement on I-49 south of Fayetteville, Arkansas due to a combination of Alkali-Silica Reaction (ASR) and freeze-thaw has led to ASR and freeze-thaw research at the University of Arkansas. Potential for further expansion (PFET), Damage Rating Index (DRI), and mitigation of freeze-thaw and ASR with sealers testing and results are contained herein. PFET results indicated that the pavement will not continue to expand from ASR. With other interstate pavements deteriorating prematurely throughout Arkansas, DRI has shown that most are damaged not only by ASR but by freeze-thaw too. Recommendations for freeze-thaw’s inclusion into DRI are included. Results for a sealer that will limit ASR and freeze-thaw expansion are given and have shown that silanes with 40% silane work effectively to reduce ASR and freeze-thaw expansion.
07/01/21July 2021Effect of Clay Content on Alkali-Carbonate Reactive (ACR) Dolomitic Limestonehttps://cptechcenter.org/ncc-projects/effect-of-clay-content-on-alkali-carbonate-reactive-acr-dolomitic-limestone/Alkali aggregate reactions, Alkali carbonate reactions, Clay, Limestone, Portland cement concreteThis study aimed to evaluate whether an aggregate’s clay content plays an overarching role in Alkali-Carbonate Reactive (ACR) expansion and deterioration within the limestone sources that have been approved for use in portland cement concrete in Louisiana. A total of 29 aggregate sources from the Louisiana Department of Transportation and Development (DOTD) approved materials list were screened for chemical analysis to determine whether the aggregates were potentially expansive based on their calcium oxide, magnesium oxide, and alumina contents. Twelve out of 29 aggregates were found to be potentially reactive and therefore were selected for concrete prism tests per ASTM C1105 to verify their expansive potential. The results showed that none of the aggregates tested exhibited deleterious expansion after 12 months. In addition, the clay content (based on the aggregate’s alumina composition) did not directly affect the selected group of aggregates’ reactivity.Jose Mila, Tyson Rupnow, William Saunders
11/01/20September 2020Development of Corrosion Inhibiting Geopolymers based Cement for Transportation Infrastructurehttps://cptechcenter.org/ncc-projects/development-of-corrosion-inhibiting-geopolymers-based-cement-for-transportation-infrastructure/Cement additives, Chlorides, Corrosion, Geopolymer concrete, Reinforced concreteGeopolymers are gaining attention as affordable, sustainable, and eco-friendly replacement for Ordinary Portland Cement (OPC) in concrete civil structures. More importantly, Geopolymer-based Cement (GPC) provide sustainable and environmentally friendly alternative to OPCs as GPC can be processed at room temperatures from aqueous solutions of waste materials (e.g., fly ash) or abounded natural sources (e.g., clay) and thus reduce significant CO₂ production associated with processing of OPC. Although, a lot of work has been done on improving mechanical properties of GPC over the last two decades, there are only a few studies on effects of GPC concrete on steel rebar reinforcement. Even though all those studies indicate that GPC inhibits corrosion of reinforcing streel when compared to OPC, the inhibition mechanism is still unclear and geopolymer composition is yet to be optimized to achieve the best inhibition properties. A collaborative research study is formulated by a team from TAMU to investigate the long-term durability of reinforced GPC concrete against chloride-induced corrosion. Various parameters of GPC such as Si/Al, water/solids, alkali ion/Al ratios would affect various structural and mechanical properties of GPC. Therefore, GPCs will need to be studied thoroughly in order to optimize the use of local waste and natural materials for transportation infrastructure in Region 6. As a part of the proposed study, durability tests under simulated marine environment are to be conducted on reinforced GPC concrete over long periods of time. Both material characterization studies related to micro to macro behavioral changes during long-term exposure of reinforced GPC concrete and steel rebar will be carried out as a part of this research.Homero Castaneda-Lopez, Miladin Radovic, Changkyu Kim, Oscar Huang
02/15/21February 2021Influence of Powder Activated Carbon (PAC) in Fly Ash on the Properties of Concrete [supporting dataset]https://cptechcenter.org/ncc-projects/influence-of-powder-activated-carbon-pac-in-fly-ash-on-the-properties-of-concrete-supporting-dataset/Admixtures, Air content, Air voids, Carbon, Cement, Data, Electrical resistivity, Fly ash, Fresh concrete, Laboratory tests, Mechanical propertiesClass C Fly Ash (CFA) is commonly used as supplementary cementitious material (SCM) in producing concrete by ready-mix concrete contractors in Arkansas. However, CFA can be used as a partial replacement of Ordinary Portland Cement (OPC) if it meets certain ASTM requirements. It is believed that the presence of powder activated carbon (PAC) in CFA increases the demand of the air-entraining agent (AEA) to achieve specified air content, and this is a concern to transportation agencies such as the Arkansas Department of Transportation (ARDOT) and concrete producers in recent years. Thus, the main goal of this research is to assess the influence of PAC in fly ash on the properties of concrete. To achieve the goal of this study, a total of 14 mixes (12 laboratory and two plant mixes) were evaluated to determine the fresh concrete properties (e.g., air content, workability, and unit weight) as well as hard concrete properties (e.g., compressive, tensile and flexural strength, modulus of elasticity, and long-term durability). Besides the Pressure Meter method, a Super Air Meter (SAM) and a Miller 400A resistivity meter were used in this study to determine the air quality and electric resistance, respectively, of the prepared fresh concrete. Two CFAs containing the different percent of PAC (i.e., 0%, 0.25%, 0.50%, and 0.75% by the mass of CFA) were used to prepare the mixes where the dosage of AEA was selected based on the manufacture recommendation. Air content measurements of two selected hard concrete mixes were also made in the laboratory. The results showed that the PAC content had a significant effect on the air content of the fresh concrete. The air contents of plant mixes agreed with those of the laboratory mixes. The SAM test was found to be an effective test method to measure the air-void quality of fresh concrete mixes; the air content and quality measurements of fresh concrete were comparable with air voids of hard concrete. The long-term durability (alkali-silica-reactivity and scaling resistance) was found to be influenced by the PAC content as well as the source of CFA. The findings of this study can help to better understand the effect of PAC content in CFAs in producing durable concrete.Zahid Hossain, Sumon Roy
02/15/21February 2021Eco-Friendly Stabilization of Sulfate-Rich Expansive Soils using Geopolymers for Transportation Infrastructurehttps://cptechcenter.org/ncc-projects/eco-friendly-stabilization-of-sulfate-rich-expansive-soils-using-geopolymers-for-transportation-infrastructure/Geopolymer concrete, Soil stabilization, Stabilized materials, Subgrade (Pavements), Sulfates, Sustainable transportationThe utilization of traditional calcium-based stabilizers, such as lime or cement, for the treatment of sulfate-rich expansive soil, is a cause of concern for geotechnical engineering practitioners. The major problem associated with the application of such stabilizers is that when calcium ions from the stabilizers are exposed to soluble sulfate in the presence of sufficient soil moisture, they form a highly expansive mineral ettringite. This study aims to investigate the feasibility of stabilizing sulfate-rich expansive soils using a novel eco-friendly metakaolin (MK)-based geopolymer (GP) for the long-term durability of transportation infrastructure. Laboratory studies were undertaken to understand the influence of the geopolymer composition and dosage percentage for different curing periods in stabilizing the sulfate-rich expansive soils. Engineering tests such as the linear shrinkage and unconfined compressive strength tests were performed to compare the behavior of natural, lime-stabilized, and geopolymer-stabilized soils over different curing periods. Microstructural characterization using field emission scanning electron microscopy (FESEM) with energy-dispersive x-ray spectroscopy (EDXS) was performed to compare the morphological and chemical changes between geopolymer-treated and untreated natural soil. The results indicated that the geopolymer treatment of sulfate-rich expansive soils could result in significant reductions in shrinkage and subsequently help in a greater strength gain than lime-treated high-sulfate soil.Jungyeong Jang, Anand J. Puppala, Sayantan Chakraborty, Nripojyoti Biswas
11/01/20November 2020Evaluation of Bagasse Ash as Cement and Sand Replacement for the Production of Engineered Cementitious Composites (ECC)https://cptechcenter.org/ncc-projects/evaluation-of-bagasse-ash-as-cement-and-sand-replacement-for-the-production-of-engineered-cementitious-composites-ecc/Ash content, Cement, Composite materials, Concrete, Durability, Evaluation, Mix design, Pavements, RepairingThe objective of this study was to develop novel Engineered Cementitious Composites (ECC) materials implementing sugarcane bagasse ash (SCBA). To this end, the effects on the mechanical and physical properties of ECC materials of: (1) Louisiana raw SCBA (RBA) as a partial and complete replacement of sand (i.e., class S mixtures); (2) Louisiana postprocessed SCBA (PBA) as a partial replacement of cement (i.e., class C mixtures); and (3) Ecuador raw SCBA (EBA) as a partial and complete replacement of sand (i.e., class S-E mixtures) were studied. Sand replacement levels with RBA and EBA evaluated were 25, 50, 75, and 100% (by volume), while cement replacement levels with PBA studied were 40, 50, and 60% (by mass). RBA and EBA were subjected to minor processing by drying and sieving to remove moisture and coarse impurities. On the other hand, PBA was produced by further processing of RBA through burning and grinding. RBA and EBA were mainly composed of silica; yet, presented high carbon content and large particle size relative to cement. Conversely, PBA exhibited low carbon content and small particle size. Tests conducted for class S and class C mixtures included compressive strength, uniaxial tensile, surface resistivity, shrinkage, coefficient of thermal expansion, and slant shear tests. In the case of S-E mixtures, tests conducted included compressive strength and flexural strength tests. The use of RBA as sand replacement caused minor reductions in the compressive strength of ECC (up to 11%), yet it produced a dramatic improvement in the tensile ductility (up to 311%). Moreover, the tensile strength of all RBA admixed ECC also improved (up to 22.3%). Implementation of RBA also produced a decrease in surface resistivity and an increase in shrinkage. For class S-E mixtures, the implementation of EBA as sand replacement produced an increase in compressive strength and flexural strength. For class C mixtures, the implementation of PBA as cement replacement produced significant reductions in compressive strength (up to 39.1%) and tensile strength (up to 28.1%). Nevertheless, it increased the tensile ductility of the composites (up to 85%). Furthermore, the surface resistivity and shrinkage of PBA admixed ECC increased with the increment in cement replacement with PBA.Gabriel A. Arce, Marwa M. Hassan, Sujata Subedi, Ana Rivas, Samantha Hidalgo, Hugo Eguez
03/01/22March 2022Composite Repair for Concrete Bridges Subjected to Alkali-Silica Reactionhttps://cptechcenter.org/ncc-projects/composite-repair-for-concrete-bridges-subjected-to-alkali-silica-reaction/Alkali silica reactions, Composite materials, Concrete bridges, Failure analysis, Fiber reinforced polymersThis report presents a comparative experimental study on the axial behavior of concrete subjected to alkali-silica reaction (ASR) with and without confinement by carbon-fiber reinforced polymer (CFRP) sheets. A total of 120 cylinders are cast using two types of coarse aggregates to represent variable levels of ASR: rhyolite (reactive) substitutes granite (non-reactive) at a replacement ratio ranging from 0% to 100%. As per a test standard, the cylinders are conditioned in a sodium hydroxide (NaOH) solution. The physical properties of the concrete and the solution are measured over time to examine the reciprocal action between the NaOH and rhyolite, followed by microscopic observations on the progression of ASR through the concrete. Sixty cylinders are confined and all specimens are monotonically loaded to failure. The load-carrying capacity of the confined cylinders noticeably increases compared with that of the plain concrete, while the degree of improvement is controlled by the ASR-damaged concrete core. The average toughness of the cylinders decays with ASR, accompanied by irreversible energy dissipation and degraded CFRP-concrete interaction. The failure characteristics of both plain and confined cylinders are also influenced by ASR, dependent upon the replacement ratio, particularly for the integrity of the core. An analytical model is formulated to understand the implications of ASR, including an assessment of an existing design approach, and is further used for design recommendations.Y. J. Kim
12/01/17December 2017Advanced Analysis, Validation and Optimization of Virtual Cement and Concrete Testinghttps://cptechcenter.org/ncc-projects/advanced-analysis-validation-and-optimization-of-virtual-cement-and-concrete-testing/Computer models, Concrete tests, Microstructure, Mix design, Optimization, Portland cement concrete, Properties of materials, Validation, Virtual realityComputational models that predict the behavior of cement and concrete seek to reduce industry reliance on predictive empirical relationships through simulation of the micro-scale chemical and thermal phenomena of cement hydration and their influence on macro-scale material properties. Models such as the Virtual Cement and Concrete Testing Laboratory (VCCTL) provide a deterministic link between measurable characteristics of aggregate Computational models that predict the behavior of cement and concrete seek to reduce industry reliance on predictive empirical relationships through simulation of the micro-scale chemical and thermal phenomena of cement hydration and their influence on macro-scale material properties. Models such as the Virtual Cement and Concrete Testing Laboratory (VCCTL) provide a deterministic link between measurable characteristics of aggregate and mineral binders, the temperature and moisture of the curing environment, and the evolving properties of paste, mortar, and concrete. The following report summarizes efforts to explore the as-delivered capabilities of the VCCTL, and identify and rectify its limitations.Christopher C. Ferraro, Benjamin Watts, Chengcheng Tao, Forrest Masters
07/01/19July 2019Requirements for Use of Field-Cast, Proprietary Ultra-High-Performance Concrete in Florida Structural Applicationshttps://cptechcenter.org/ncc-projects/requirements-for-use-of-field-cast-proprietary-ultra-high-performance-concrete-in-florida-structural-applications/Cast in place concrete, Cement, Construction, Tensile strength, Ultra high performance concreteUltra-high-performance concrete (UHPC) is a groundbreaking cementitious material that has the potential for innovative structural use that makes lighter, more durable, and overall lower cost structures. Very low water-to-cementitious material ratios and high dosages of fibers are used to give UHPC high compressive strength, high tensile strength, and high toughness. Because the high tensile strength and toughness are key benefits of, and reasons to use, UHPC in Florida structures, a method to measure the UHPC tensile stress-strain relationship is needed. A specification for material acceptance and construction using field-cast, proprietary UHPC materials is also needed. Part of this study included a literature review, surveys of departments of transportation, and reviews of UHPC material specifications from other countries to help establish UHPC material and construction requirements for Florida. An experimental program was created to test UHPC flexural and tensile strengths. Based on the survey and experimental results, recommendations were made for a UHPC tensile test method, and material and construction specifications.Kyle A. Riding, Christopher C. Ferraro, H. R. Hamilton, Megan S. Voss, Raid S. Alrashidi
02/01/21February 2021Testing Methods for the Next Generation of Concretehttps://cptechcenter.org/ncc-projects/testing-methods-for-the-next-generation-of-concrete/Cracking, Portland cement concrete, Quality control, Service life, Structures, Testing The Florida Department of Transportation is working towards the evaluation of structural portland cement concrete to ensure the service life requirements for concrete structures are met based on material performance. As the industry moves toward performance specifications, there is a need to evaluate the performance of the composite concrete sample, rather than the individual components. Therefore, the objective of this project was to perform a thorough literature review to determine if there are existing test methods that can quantify the performance of concrete with respect to heat evolution, cracking, and durability at the mix design phase. Based upon the exhaustive literature search performed, there are a large number of tests available to evaluate composite concrete specimens for heat evolution, cracking potential, and durability. The majority of these test methods did not meet the criteria of FDOT without any modifications; the few methods that met all of the qualifications do not provide sufficient information to be recommended for FDOT quality assurance/quality control (QA/QC). Recommendations for a future study to investigate these methods further and determine acceptance criteria is as follows. To evaluate potential for cracking of concrete, a Florida Method based on AASHTO T 334 should be created. Additionally, a Florida Method based on the LCPC QAB semi-adiabatic calorimetry test should be developed to measure heat evolution of concrete. Lastly, characteristics regarding chloride and sulfate durability require fundamental research into the accelerated curing regimes, especially for concrete using SCMs prior to a Florida Method being developed to assess these characteristics.Christopher C. Ferraro, Kyle A. Riding, Jerry M. Paris, Caitlin M. Tibbetts
01/01/19January 2019Assessment of Construction Points for Grade Control and Reference in 3Dhttps://cptechcenter.org/ncc-projects/assessment-of-construction-points-for-grade-control-and-reference-in-3d/Best practices, Case studies, Drones, Questionnaires, Referencing, Road construction, SurveysThe objective of this research is to investigate the causes of inaccuracies of grade elevations from current practices and identify best practices for grade control and referencing on transportation infrastructure construction projects in Georgia. A nationwide questionnaire survey was conducted with contractors, engineers, surveyors, and owners, and the following causes of the discrepancies are identified: (1) long time gap between design and construction phases; (2) poor techniques in surveying; and (3) long interval between survey points. Through an actual case study with an ongoing highway construction project, the following conclusions and recommendations are made: (1) a mandatory field survey before earth moving is recommended; (2) unmanned aerial vehicle (UAV) and Mobile Mapping System (MMS) are effective for 3D grade control in planning and site cleaning phases; (3) terrestrial laser scanning (TLS) is appropriate for 3D grade control in a subgrade grading stage; and (4) robotic total station (RTS) is recommended for the final grading stage.Young Kwon Cho
12/01/19December 2019Development of Possible Solutions to Eliminate or Reduce Deck Cracking on Skewed Bridges Built by Using the Accelerated Bridge Construction Methodhttps://cptechcenter.org/ncc-projects/development-of-possible-solutions-to-eliminate-or-reduce-deck-cracking-on-skewed-bridges-built-by-using-the-accelerated-bridge-construction-method/Bridge construction, Bridge decks, Bridges, Cracking, Finite element method, Jointless bridges, Skewed structuresThe Georgia Department of Transportation (GDOT) employed Accelerated Bridge Construction (ABC) technology to reduce construction impacts and delays when replacing the State Route 299 bridge at I-24 in Dade County, Georgia, over a single weekend in May 2017. Self-Propelled Modular Transporters(SPMTs) were used for the bridge replacement. A few months after the replacement, GDOT observed a large number of visible cracks on the bridge deck. This study investigates possible causes of deck cracking observed on the SR299 bridge at I-24 in Dade County, Georgia. The research team has documented the distress observed in the SR299 bridge by creating a crack map, studying the material compositions, and conducting a finite element analysis. Design and construction details associated with thermal restraints are studied. In addition, displacements and forces imposed on the cast-in-place concrete bridge deck are studied. The main goal of this research is to establish a decision matrix for determining possible causes of cracking in the skewed bridge decks used for ABC, leading to the development of solutions to eliminate or reduce such cracking and recommendations for preventive measures. It is concluded from this study that skewed decks are more susceptible to cracking than straight decks due to asymmetric expansion and contraction. When skewed deck geometries exist in a semi-integral abutment bridge, the skewed corners on the abutment sides are vulnerable to developing cracks, regardless of the bearing details at expansion joint locations. Therefore, when designing a skewed bridge, a semi-integral abutment design should be avoided, if possible. If such design is necessary in conjunction with ABC technologies, bearings require greater consideration in order to minimize cracks resulting from temperature changes. Asymmetric thermal movements should be expected when an asymmetric deck geometry exists; thus, bearings and steel reinforcement in the deck must be designed accordingly.Mi G. Chorzepa, Chnar Solae, Stephan Durham, Sonny S. Kim
02/01/18February 2018Central Iowa Expo Pavement Test Sections: Pavement and Foundation Construction Testing and Performance Monitoringhttps://cptechcenter.org/ncc-projects/central-iowa-expo-pavement-test-sections-pavement-and-foundation-construction-testing-and-performance-monitoring/Asphalt concrete pavements, Compaction, Falling weight deflectometers, Fiber reinforced materials, Fly ash, Geogrids, Geotextiles, hot mix asphalt, Pavement layers, Pavement performance, Portland cement concrete, Reinforcement (Engineering), Soil stabilization, Structural health monitoring, Subgrade (Pavements)The Central Iowa Expo facility located in Boone, Iowa, needed to be reconstructed in 2012 to provide an improved pavement foundation for pavement with hot mix asphalt (HMA) and portland cement concrete (PCC). This rework created a unique opportunity to conduct pavement foundation research using a range of stabilization construction and testing technologies on about 4.8 miles of roadway. The Iowa Department of Transportation (DOT) initiated a research project to build the pavement foundation layer (Phase I), construction of the pavement layers (Phase II), and performance monitoring of the pavement systems (Phase III). During Phase I, 16 test sections were constructed, that used woven and non-woven geotextiles and geogrids at subgrade/subbase interfaces; 4 in. and 6 in. geocells in the subbase layer + non-woven geosynthetics at subgrade/subbase interfaces; portland cement (PC) and fly ash stabilization of subgrades; PC stabilization of recycled subbase; PC + fiber stabilization of recycled subbase with polypropylene fibers and monofilament-polypropylene fibers; mechanical stabilization (mixing subgrade with existing subbase); and high-energy impact compaction. A series of laboratory tests were conducted to characterize the soils, determine compaction characteristics, unconfined compressive strength tests on chemical stabilized samples, and freeze-thaw durability. In situ strength and stiffness-based test measurements were performed during construction (in July 2012), about three months after construction (in October 2012), seven months after construction (in January 2012) during frozen condition, and about nine to ten months after construction (in April/May 2013) during spring-thaw. During Phase II, asphalt compaction was monitored using intelligent compaction technology along with in situ point testing. Phase III monitoring involved testing on the asphalt layer, conducting ground penetrating radar testing to evaluate layer thicknesses and moisture conditions over time. This project generated significant information regarding the mechanistic properties for pavement foundation support for a range of foundation improvement/stabilization methods. The test sections at this facility are unique in terms of the range of technologies used and for the fact that the performance data particularly isolates the influence of the seasonal changes without any loading. Some significant lessons learned from this project and the limitations of the findings are identified in this report.David White, Pavana Vennapusa, Jesus Rodriguez, Yang Zhang, Christianna White
06/01/18June 2018Prevention of Longitudinal Cracking in Iowa Widened Concrete Pavement https://cptechcenter.org/ncc-projects/prevention-of-longitudinal-cracking-in-iowa-widened-concrete-pavement/14 lanes, Concrete pavements, Finite element method, Longitudinal cracking, Pavement cracking, Pavement design, Pavement widening, Paving, Portland cement concrete, Road shoulders, Transverse joints, Widened lanesIowa has adopted 14 ft widened concrete slabs (as opposed to the standard 12 ft concrete slabs) in jointed plain concrete pavement (JPCP) design and construction since the 1990s. The additional 2 ft slab paved beyond the normal traffic path is intended to reduce stresses and deflections at the critical concrete pavement edge location by effectively moving the normal traffic path well away from the edge. However, many widened concrete pavements are now approaching 20 years of service life, and some 14 ft widened concrete pavements are experiencing sudden and significant amounts of longitudinal cracking. To understand the causative factors contributing to longitudinal cracking in widened JPCP and to provide recommendations for preventing its occurrence, field investigations were performed at 12 sites in spring and summer 2017. These sites included widened JPCPs of various ages, shoulder types, mix design aspects, environmental conditions during construction, and traffic levels. The location and extent of existing longitudinal cracking, including transverse cracking, were well documented. The amount and severity of cracks were linked to traffic level and shoulder type. Concrete cores were also examined to better understand how the cracking had developed. It was found that the 14 ft widened slabs with tied PCC shoulders outperformed the others in terms of producing less cracking, even though they had experienced higher levels of truck traffic. Widened slabs with granular shoulders were the worst performers, producing higher cracking compared to others. ISLAB 2005 and EverFE 2.25 finite element analysis (FEA) programs were also utilized to demonstrate through numerical analysis the potential of top-down longitudinal cracking for widened JPCP. Transverse joints and wheel paths were found to be critical locations for longitudinal cracking. Widened slabs with skewed joints were also found to have higher potential for longitudinal cracking. Shoulder design alternatives used in Iowa were compared for their effect on longitudinal cracking when they were used adjacent to widened and regular-sized slabs.Halil Ceylan, Sunghwan Kim, Shuo Yang, Orhan Kaya, Kasthurirangan Gopalakrishnan, Peter Taylor
12/01/17December 2017Updating Physical and Chemical Characteristics of Fly Ash for Use in Concretehttps://cptechcenter.org/ncc-projects/updating-physical-and-chemical-characteristics-of-fly-ash-for-use-in-concrete/Admixtures, Chemical composition, Fineness, Fly ash, Glass, Pastes, Physical properties, Statistical analysisWhen incorporated in concrete mixtures, fly ashes are known to influence both its fresh and hardened properties. An accurate and quick technique to predict the extent of this influence based on the characteristics of fly ash would be highly beneficial in terms of field applications. The current study was an attempt to quantify the effects of fly ashes on the properties of pastes as a function of: (a) the mean particle size of the fly ash particles, (b) their fineness and (c) their chemical composition. In addition, since the type and the amount of glass present in the fly ash significantly affect its reactivity, this property was also included in the investigation. Twenty different fly ashes (both, ASTM Class C and Class F), obtained from power plants in and around Indiana, were characterized during the Phase 1 of the study. The information collected included: physical characteristics, chemical composition and the amount and type of glass present. Phase 2 of the study consisted of evaluation of various properties of binary paste systems (portland cement with 20% of cement of fly replacement). The evaluated properties included: the set time, the heat of hydration, the strength activity index, the non-evaporable water content and the amount of calcium hydroxide formed at different ages. These results obtained from both phases of the study were used to build statistical models for prediction of previously evaluated properties for any hypothetical fly ash with similar characteristics. The models included only the most significant variables, i.e., those which were found to most strongly affect any specific property. The variables to be included in the model were selected based on the adjusted R2 values. As a result of the modeling process, it was found that the sets of statistically significant variables affecting the properties consisted of both physical and chemical characteristics of the fly ash and that the combination of these variables was unique for each property evaluated. When applied to a set of results from two additional (not previously used) fly ashes, the models provided the following residuals of predicted properties: (a) Initial set time – 100 minutes for Class F ashes and over 300 minutes for Class C ashes; (b) Peak heat of hydration – 0.7 W/kg; (c) Time of peak heat – 375 minutes; (d) Total heat of hydration – 96 J/kg; (e) Calcium hydroxide content at various ages – 0.25% for early ages (1 and 3 days) and 0.5% for later ages (7 and 28 days); (f) Non-evaporable water content – 0.7% for early ages (1 and 3 days) and 5% for later ages (28 days); and (g) Strength activity index – range of 1% in Class C ashes and 1% to 2% in Class F ashes (from 7 days to 28 days). Phase 3 of the study consisted of evaluating the same set of properties but using ternary paste systems (cement and two different fly ashes). The goal for this study was to ascertain the applicability of the weighted sum of the models chosen for the binary paste systems to predict the properties of ternary binder systems. In addition, the analysis as to which of the chosen variables has the maximum effect on the properties was performed. It was found that the properties of the ternary binder systems were not additive in nature, except for strength activity index at 28 days. Lastly, the percent influence of each of the chosen independent variables, which affect the mentioned properties, was calculated along with the unexplained variation (error percentage). The error percentages varied for each of the properties, with set time having the maximum error (almost 50%).Prasanth Tanikella, Jan Olek
02/28/22February 2022Performance Evaluation of Stabilized Support Layers for Concrete Pavementshttps://cptechcenter.org/ncc-projects/performance-evaluation-of-stabilized-support-layers-for-concrete-pavements/Concrete pavements, Falling Weight Deflectometer, Hamburg Wheel-tracking Device, Jointed Plain Concrete Pavements, MIRA A research investigation was conducted on the erosion potential of stabilized subbases under concrete pavements and asphalt layers supporting concrete overlays. Through field surveys and testing in Illinois, this project evaluated if existing concrete pavements with stabilized subbases and concrete overlays were exhibiting potential erosion of the underlying support layer. The field evaluation testing included falling weight deflectometer testing, distress surveys, coring, and ultrasonic tomography scanning. A laboratory performance test was also established using the Hamburg wheel-tracking device to assess the erodibility of the various stabilized subbase layers for new construction and existing asphalt layers available for a concrete overlay. The analyzed field test results were coupled together with the laboratory performance testing to provide recommendations for updating the Illinois Department of Transportation’s “Bureau of Design and Environment Manual” guidance. No changes were recommended for hot-mix asphalt stabilized subbases, but testing using the Hamburg wheel-tracking device should be considered for Portland cement concrete stabilized support layers (e.g., CAM II) under concrete pavements. For testing of asphalt support layers for concrete pavement overlays, the Hamburg wheel-tracking device is recommended with performance criteria similar to flexible pavements for appropriate functional classes. John DeSantis, Jeffery Roesler
08/01/15August 2015Evaluation of Sealers and Waterproofers for Extending the Life Cycle of Concretehttps://cptechcenter.org/ncc-projects/evaluation-of-sealers-and-waterproofers-for-extending-the-life-cycle-of-concrete/Concrete pavements, Deicers (Equipment), Pavement joints, Pavement maintenance, Polystyrene, Portland cement concrete, Seal coats, Sealing compoundsConcrete pavements represent a large portion of the transportation infrastructure. While the vast majority of concrete pavements provide excellent long‐term performance, a portion of these pavements have recently shown premature joint deterioration. Substantial interest has developed in understanding why premature joint deterioration is being observed in jointed portland cement concrete pavements (PCCP). While some have attributed this damage to insufficient air void systems, poor mixture design, or chemical reaction between the salt and the paste, it is the hypothesis of this work that a component of this damage can be attributed to fluid absorption at the joints and chemical reactions between the salt and chemistry of the matrix. This paper discusses the role of soy methyl ester‐polystyrene blends (SME‐PS) as a potential method to extend the service life of concrete pavements by limiting the ingress of salt solutions. The report discusses field application of the SME‐PS blends for field investigation in Lafayette and Fishers. Low temperature‐differential scanning calorimetry (LT‐DSC) techniques identified noticeable differences between plain mortar samples and mortar treated with SME‐PS. The report also discusses the development of a test to assess chloride solution ingress during temperature cycling. The aim of this work is to provide background on some aspects that can lead to joint deterioration and provide early documentation showing that sealers may help to reduce the impact of deicers on joint damage, thereby extending the life of the concrete pavement. It should be noted that these sites as well as others are still ongoing and should be monitored for long term performance. Application procedure for SME‐PS should follow manufacturer’s recommendation.Andrew Wiese, Yaghoob Farnam, Wesley Jones, Paul Imbrock, Bernie Tao, Jason W. Weiss
04/01/19April 2019Determination of Constructed Pavement Layer Thicknesses Using Nondestructive Testing (NDT)https://cptechcenter.org/ncc-projects/determination-of-constructed-pavement-layer-thicknesses-using-nondestructive-testing-ndt/Ground penetrating radar, Magnetic induction, Nondestructive tests (NDT), Pavement layers, ThicknessUsing nondestructive testing (NDT) to measure the thickness of pavement layers can improve the overall life of a new concrete and/or asphalt pavement. Conventional test methods require the extraction of a core from the pavement section to verify its thickness. Currently, two NDT technologies are commercially available which eliminate or reduce the need to core the existing pavement for thickness verification. The MIT-Scan-T2 (T2) utilizes magnetic pulse induction coupled with preset metal plates to obtain a thickness value. Measurements can be obtained quickly to an accuracy of +/– 2 mm. Ground Penetrating Radar (GPR) uses electromagnetic radiation to determine pavement layer thickness. However, GPR data need to be calibrated with an actual core during the post-processing phase to obtain the highest accuracy. Additionally, the dielectric properties of pavement sections being assessed with GPR must first stabilize to accurately measure thickness. Generally, stabilization occurs approximately 28 days after the initial placement of the pavement.Brad Rister, Jamie Creech, Kean Ashurst
11/01/20November 2020Evaluation of Bonded Concrete Overlays over Asphalt under Accelerated Loadinghttps://cptechcenter.org/ncc-projects/evaluation-of-bonded-concrete-overlays-over-asphalt-under-accelerated-loading/Asphalt pavements, Bond strength (Materials), Concrete overlays, Cracking, Load tests, Pavement performanceBonded concrete overlay of asphalt (BCOA), previously known as ultra-thin whitetopping (UTW), has been widely used to repair aged asphalt concrete (AC) pavements with moderate distress in many states in the United States. Due to the increasing costs of roadway maintenance, Louisiana has a great interest in determining if the thin bonded concrete overlay (usually 2-6 in.) is a suitable and cost-effective alternative to the current practice of roadway maintenance. The objective of the study was to evaluate the structural performance and load carrying capacity of BCOA pavements and to characterize the influence of in-situ bond strength on the performance of BCOA pavements. In this study, three full-scale BCOA test sections with 6-in., 4-in., and 2-in. Portland cement concrete (PCC) over an aged asphalt pavement were tested under accelerated pavement test (APT) loading under a typical pavement condition in southern Louisiana. The aged asphalt pavement consists of 3-in. AC over 8.5-in. crushed stone and 10 in. cement treated subgrade. A heavy load simulation device – ATLaS30, equipped with a hydraulically-adjusted dual-tire wheel load, was used. Each section was trafficking-loaded to a failure (i.e., all the slabs in loading path were cracked) under alternated load magnitudes of 9 kips and 16 kips of the ATLaS dual-tire wheel load. It was found that the 6-in. PCC overlay had a superior load carrying capacity compared to the 4-in. and 2-in. concrete overlays. The predicted pavement lives for the 6-in., 4-in, and 2-in. BCOA sections were 8.9-, 3.5-, and 1.2- million ESALs, respectively. As expected, the majority of load-induced cracks were not at a slab corner but along the wheel path (or longitudinal direction), presumably because the accelerated load in this study was applied along the centerline of the slabs. The load-induced tensile strains (measured at bottom of the slabs) also revealed a longitudinal cracking potential. Several Non-Destructive Test (NDT) methods indicated that the crack initiation of a BCOA slab could be coupled with a possible debonding at the slab-asphalt interface. A trench cutting investigation further revealed that a good bond was established between the PCC and AC layer. A performance review and in-situ pull-off test (also known as bond test) of the BCOA slabs suggests that the main distresses, such as longitudinal and corner cracks, develop primarily as a result of debonding of the asphalt layer from the concrete overlay. Debonding, which reduces the contribution from the underlying asphalt layer, increases the stress in the concrete layer, leading to the development of cracks. Therefore, under what level the bond strength should be specified in a BCOA pavement design is still debatable. Based on the results, it is recommended that a 6-in. BCOA pavement may be used in a medium to high volume pavement design where heavy and overloaded trucks are abundant and a 4-in. BCOA may be suitable to be used in a pavement rehabilitation project with a medium volume traffic. A newly-developed Short Joint Portland Concrete Pavement (SJPCP) module in the Pavement ME software was employed to predict the performance of the BCOA sections of this study. The predicted results were discovered to be roughly comparable to the in-situ cracking performance of this study. Finally, a failure criterion in terms of fatigue cracking and bond strength was proposed and the corresponding construction cost savings when implementing BCOA pavement as a design option for a medium to high volume pavement were estimated.Moinul I. Mahdi, Zhong Wu, Tyson Rupnow
02/01/18February 2018Reliable Early Opening Strength for Concrete Pavements and Patch Workhttps://cptechcenter.org/ncc-projects/reliable-early-opening-strength-for-concrete-pavements-and-patch-work/Concrete pavements, High early strength cement, Patching, Pavement maintenance, Rehabilitation (Maintenance), Strength of materialsThe requirements for opening concrete pavement repairs to traffic vary greatly around the country. The reasons states and their transportation departments specify these different requirements includes traffic opening requirements, environmental conditions, and locally available materials, among other things. This project reviewed the practices and requirements for early-opening-to-traffic concrete used by other state DOTs. The transportation agency has a need to specify the most efficient and effective early opening strengths and would benefit from understanding the latest thinking and practices adopted by similar agencies. Knowing the best approach to take can lead to dependable concrete, increased use of travel lanes, and a reduced cost of the materials and construction methods. A comprehensive literature review of state specifications and rehabilitation policy was completed. Current and former research on the use of high early strength concrete in pavement rehabilitation was reviewed as well as various material and equipment requirements specified by states in pavement rehabilitation. This report also reviewed responses from a recent National Concrete Consortium state survey which compiled responses on opening and rehabilitation criteria from states across the country. The current Louisiana opening specification for full-depth corner patching, full-depth jointed concrete patching, partial-depth patches of jointed concrete pavement, and continuously reinforced concrete pavement is an opening strength of 3000 psi. The state of Louisiana also allows the use of the maturity method to determine concrete strength on a project by project basis, with the approval of the Chief Construction Engineer. The current specifications are based solely on compressive strength and are not necessarily based on the mechanics of materials. The authors recommend changing the 3000 psi requirement for early opening to traffic to the SHRP-206 findings of 2000 psi. To gain the maximum benefit of early opening, the authors also recommend full adoption of the maturity method for estimating in-place strength.Zachary Collier, Amar Raghavendra, Tyson Rupnow
11/01/21November 2021Influence of Internal Curing on Measured Resistivityhttps://cptechcenter.org/ncc-projects/influence-of-internal-curing-on-measured-resistivity/Cement, Coarse aggregates, Concrete curing, Electrical resistivity, Lightweight aggregatesThe objective of this study was to evaluate the influence of internal curing and coarse aggregate type on concrete’s 28-day strength, as well as surface resistivity over time (at days 7, 14, 28, 56, 90, and 180). A total of 96 concrete mixtures were prepared to identify the effects of three coarse aggregate types, two water-to-cementitious (w/cm) ratios, three fine lightweight aggregate (LWA) sources, and four variations of supplementary cementitious materials (SCMs). The compressive strength tests showed that in most cases, the presence of lightweight aggregate had a positive effect on strength (i.e., either had equal or better strength). Concerning surface resistivity, the statistical analyses determined that the use of SCMs, w/cm ratio, coarse aggregate type, and presence of LWAs had significant effects. The use of SCMs caused significant increases in surface resistivity for all groups due to their pozzolanic activity, and significantly outperformed the specimens prepared with only portland cement. The w/cm ratio had a high impact on resistivity as expected, where the lower w/cm ratio consistently produced higher resistivity values over time for all specimen groups. The presence of LWAs had an overall positive effect on resistivity, where each of the LWA sources had an equal or better performance than the control specimens based on the findings from the statistical analyses. Lastly, the coarse aggregate type affected resistivity, albeit predominantly based on the porosity of the aggregate itself rather than the mineralogy.Jose Milla, Tyson Rupnow, William Saunders, Samuel Cooper III
01/01/20January 2020Investigating Available State-of-the-Art Technology for Determining Needed Information for Bridge Rating Strategieshttps://cptechcenter.org/ncc-projects/investigating-available-state-of-the-art-technology-for-determining-needed-information-for-bridge-rating-strategies/Bridges, Load factor, Nondestructive tests (NDT), RatingsIn this report, nondestructive test (NDT) methods are evaluated in the context of providing input parameters to perform bridge load rating calculations for different bridge types. Relevant NDT methods are identified based on diverse technologies including mechanical impact, acoustic, electromagnetic, electrical and chemical, cuclear, and miscellaneous methods. The required parameters for successful bridge load rating of concrete precast slab (COPCSS), concrete slab (COSLAB), concrete prestress channel (COPSCH), prestressed girder bridges, and steel bridges are identified and the available NDT methods to provide these parameters are presented. These parameters are categorized in three basic groups that consist of as-built geometric parameters, as-built strength parameters, and as-inspected strength parameters. All the available NDT techniques that can be used to obtain each parameter have been presented. Finally, the NDT methods are rated by cost, ease of use, and reliability of data using a three-level rating system and the most cost effective, feasible, and reliable methods have been recommended.In this report, nondestructive test (NDT) methods are evaluated in the context of providing input parameters to perform bridge load rating calculations for different bridge types. Relevant NDT methods are identified based on diverse technologies including mechanical impact, acoustic, electromagnetic, electrical and chemical, cuclear, and miscellaneous methods. The required parameters for successful bridge load rating of concrete precast slab (COPCSS), concrete slab (COSLAB), concrete prestress channel (COPSCH), prestressed girder bridges, and steel bridges are identified and the available NDT methods to provide these parameters are presented. These parameters are categorized in three basic groups that consist of as-built geometric parameters, as-built strength parameters, and as-inspected strength parameters. All the available NDT techniques that can be used to obtain each parameter have been presented. Finally, the NDT methods are rated by cost, ease of use, and reliability of data using a three-level rating system and the most cost effective, feasible, and reliable methods have been recommended.
Development of an Improved Design Procedure for Unbonded Concrete Overlayshttps://cptechcenter.org/ncc-projects/development-of-an-improved-design-procedure-for-unbonded-concrete-overlays/Calibration, Cracking, Field studies, Laboratory studies, Mechanistic-empirical pavement design, Overlays (Pavements), Pavement interlayers, Portland cement concrete, SoftwareAn unbonded portland cement concrete overlay of concrete pavements (UBOL) is a rehabilitation technique in which the new overlay is isolated from the existing distressed pavement using a separator layer. Typically, a 1-to 2-in asphalt separator layer (or interlayer) is used. Recent innovations in the unbonded overlay technology have led to the adoption of new types of interlayers, such as non-woven geotextile fabric, as well as the use of overlays with joint spacings and layouts that are much shorter than conventional joint spacings. The effect of these design alternatives on the performance of the UBOL cannot be accounted for using currently available design procedures. This report documents the development of a new mechanistic-empirical design procedure for UBOL. It presents the results of laboratory and field studies; the calibration of an advanced structural (Totski) model that better captures the effects of the interlayer and separation between the overlay and the existing pavement; and the development of cracking and faulting performance prediction models for UBOL. The performance prediction models were incorporated into a rudimentary software tool, Pitt UBOL-ME, that can be used for the design and analysis of UBOL. Unlike prior UBOL design procedures, Pitt UBOL-ME can be used to quantify the effect of the performance of the interlayer on the performance of the UBOL and can be used for both conventional and short joint spacings.Lev Khazanovich, Julie Vandenbossche, John DeSantis, Steve Sachs
09/30/19September 2019Bridge Design System Analysis and Modernizationhttps://cptechcenter.org/ncc-projects/bridge-design-system-analysis-and-modernization/Bridge design, Evaluation and assessment, Modernization, Software, Systems analysisThe Bridge Design System (BDS) is an in-house software program developed by the Michigan Department of Transportation’s (MDOT) Bridge Design Unit. The BDS designs bridges according to the required specifications, and outputs corresponding design drawings and calculations. It has been the primary design tool for MDOT’s bridges over the last several decades. Because of the BDS’s longevity of use and development, MDOT has experienced a high level of comfort, familiarity, and efficiency with it. However, components of the BDS have been added and removed over the years, and little associated documentation exists today. The code itself has seen nearly 60 years of evolution in the Fortran programming language. Migration to another software system is likely to require significant changes to MDOT business processes and may require multiple software systems rather than the unified design system of the BDS. Also, long-term viability of the BDS would require documentation of the existing architecture and operation of the system as well as development of a plan for future compatibility and functionality of the software. Therefore, the Center for Technology & Training at Michigan Tech was contracted to document, analyze and propose modernization options for the BDS. This report describes the tools used to conduct this assessment and the results of this task.Tim Colling, Chris Gilbertson, Gary Schlaff, Mike Pionke
07/01/21July 2021Performance Benefits of Fiber-Reinforced Thin Concrete Pavement and Overlayshttps://cptechcenter.org/ncc-projects/performance-benefits-of-fiber-reinforced-thin-concrete-pavement-and-overlays/Concrete overlays, Concrete pavements, fiber reinforced concrete, Pavement distress, Pavement joints, Test proceduresThis study investigates the performance benefits of synthetic structural fibers in mitigating distresses in thin concrete pavements and overlays. In this study, two ultra-thin (3 and 4 inches thick) and four thin (5 and 6 inches thick) concrete pavements placed on a gravel base along with two thin unbonded concrete overlay cells (5 inches thick) placed on an existing concrete pavement were constructed at the Minnesota Road Research (MnROAD) facility in 2017. This report discusses the objectives and methodology of the research, including the construction of the test cells, instrumentation, traffic load application, and data collection and analysis procedures. The structural responses and distresses observed over three years, such as fatigue cracking and faulting, as well as the joint performance measured in each cell, were discussed and compared in this report.Manik Barman, Souvik Roy, Amarjeet Tiwari, Tom Burnham
08/01/21August 2021Evaluation of Long-Term Impacts of Early Opening of Concrete Pavementshttps://cptechcenter.org/ncc-projects/evaluation-of-long-term-impacts-of-early-opening-of-concrete-pavements/Concrete curing, Concrete pavements, Durability, Pavement performance, Road construction, Strength of materialsDue to an increase in demand to shorten construction time as much as possible, the purpose of this project was to determine the optimum strength for concrete pavement before opening it to traffic and without jeopardizing long-term performance. Six test cells in MnDOT’s MnROAD project were constructed in 2017 with varying degrees of early loading. Various tests were performed during and immediately following construction and, four years later, ride quality and load transfer efficiency were used to quantify long-term damage. A finite element analysis was then performed using ISLAB2000 to determine the effects of load location and temperature gradient on the Portland cement concrete (PCC) longitudinal stresses to explain the absence of premature failure. A mechanistic-based early opening damage analysis procedure was created to determine the optimum timing for opening of a concrete pavement to traffic. The procedure accounts for the effect of site conditions and pavement characteristics. A web-based tool was developed to facilitate implementation of this procedure.Lev Khazanovich, Katelyn Kosar, Haoran Li
09/30/22September 2022Enhanced Entrained Air Void System Characterization for Durable Highway Concretehttps://cptechcenter.org/ncc-projects/enhanced-entrained-air-void-system-characterization-for-durable-highway-concrete/Air voids, Concrete pavements, Durability tests, Freeze thaw durability, Microscopy, Test proceduresThe air void system in concrete provides a strong influence on the behavior of cementitious materials in both the fresh and hardened state, especially as it relates to freeze-thaw resistance and deicer scaling. The most common test procedure to characterize the air void system is ASTM C457 – Standard Test method for Microscopical Determination of Parameters of the Air-Void System in Hardened Concrete, which involves microscopic determination of the air content, paste content, air-void size distribution, and spatial dispersion of a sawn concrete sample. This procedure is reliant on the user to make hundreds of critical decisions per sample, which requires significant time, and is potentially subject to human error. Additionally, ASTM C457 provides minimal guidance regarding the exact steps and equipment necessary to prepare a sample for evaluation. The outcome of this research not only provides specific information regarding sample preparation for hardened concrete air void analysis, it also develops an alternative characterization technique that drastically minimizes evaluation time, human error, and increases reliability of key hardened air void characterization parameters. Specific results show on average air void difference of 0.5% and 0.7% between the alternative method versus ASTM C457 Procedure A and B, respectively. The results also show a significant reduction of analysis time from approximately 2 – 4 hours per sample to 15 minutes per sample when using the alternative method.Anthony Torres, Federico Aguayo
07/01/21July 2021Improve Material Inputs into Mechanistic Design Properties for Reclaimed HMA & Recycled Concrete Aggregate (RCA) Roadwayshttps://cptechcenter.org/ncc-projects/improve-material-inputs-into-mechanistic-design-properties-for-reclaimed-hma-recycled-concrete-aggregate-rca-roadways/Concrete aggregates, hot mix asphalt, Pavement design, Reclaimed asphalt pavements, Recycled materialsThe use of recycled materials promotes sustainability in roadway construction by reducing the consumption of energy and emission of greenhouse gases associated with mining and the production of virgin aggregate (VA). Recycled asphalt pavement (RAP) and recycled concrete aggregate (RCA) have comparable characteristics to VA that have been used in roadway base course applications. This study develops a database for RAP and RCA material characteristics, including gradation, compaction, resilient modulus (Mᵣ), California bearing ratio (CBR), and saturated hydraulic conductivity (Kₛₐₜ). In addition, this study summarizes construction specifications provided by several departments of transportation (DOTs) regarding the use of recycled aggregates in pavement systems. The effects of the presence of RAP and RCA in aggregate matrices on the engineering and index properties of aggregates are investigated and some trends are observed. For example, the study finds a higher RAP content reveals a higher summary Mr (SMr), and a higher RCA content causes an increase in optimum moisture content (OMC) and a decrease in maximum dry unit weight (MDU). In addition, a series of AASHTOWare Pavement Mechanistic-Empirical (ME) Design (PMED) analyses are conducted for three traffic volumes [low (1,000 AADTT), medium (7,500 AADTT), and high (25,000 AADTT)] with the material inputs collected for the database to determine whether different values of different characteristics of RCA and RAP can be used in flexible/rigid pavement designs. Results show that Mr has a higher effect on pavement distress predictions compared to gradation and saturated hydraulic conductivity (Kₛₐₜ).Bora Cetin, Ida Gheibi, Tuncer B. Edil, Mustafa Hatipoglu, Haluk Sinan Coban
04/01/22April 2022Performance of Wicking Geotextile (H2Ri) to Mitigate Pavement Pumping – Phase 2https://cptechcenter.org/ncc-projects/performance-of-wicking-geotextile-h2ri-to-mitigate-pavement-pumping-phase-2/Drainage, H2Ri wicking geotextile, Pavement pumping, Unsaturated soilsPumping is one of the major factors contributing to pavement failures, which reduces the pavement life, affects road safety, and increases maintenance costs. Existing methods that are used as drainage systems can drain gravitational (free) water under saturated conditions but not the capillary water under an unsaturated condition. The objective of this study is to explore and identify the feasibility of using a new wicking geotextile for pumping mitigation in pavement shoulder via laboratory tests and field test section monitoring. Results obtained from monitoring the field test section for more than three years verified the effectiveness of using wicking geotextile to reduce water content, especially where the pavement is prone to pumping damage. As a result, the generation of positive pore water pressure is delayed if not completely prevented. In this way, one of the requirements of pavement pumping is eliminated.Javad Galinmoghadam, Xiong Zhang
03/01/21March 2021Development of Non-Proprietary Ultra-High Performance Concretehttps://cptechcenter.org/ncc-projects/development-of-non-proprietary-ultra-high-performance-concrete/Abrasion tests, Admixtures, Bridge construction, Compressive strength, Durability tests, fiber reinforced concrete, Freeze thaw durability, Modulus of elasticity, Performance measurement, Permeability, Shrinkage, Tensile properties, Ultra high performance concreteUltra-high performance concrete (UHPC) has mechanical and durability properties that far exceed those of conventional concrete. Particularly, UHPC has compressive and post-cracking tensile strengths of around 20 ksi and 0.72 ksi, respectively. Thus, elements made with UHPC are thinner/lighter than elements made with conventional concrete. The enhanced durability properties of UHPC also allow for longer service lives and decreased maintenance costs. However, using UHPC in conventional concrete applications has been cost prohibitive, with commercially available/proprietary mixes costing over 20 times conventional concrete mixes.The overall objective of this research was to develop and characterize economical non-proprietary UHPC mixes made with materials readily available in Montana. This objective was achieved by first identifying and obtaining suitable/economical materials to be used in UHPC. Specifically, the materials identified and used in this research were simply Type I/II portland cement, class F fly ash, fine masonry sand, silica fume, and high range water reducer. UHPC mixes were then developed/characterized/optimized by using a statistical experimental design procedure (response surface methodology). An optimal mix that provided desired workability and strength was selected for further evaluation through a suite of mechanical and durability tests. The mixes developed as part of this research obtained compressive strengths of approximately 20 ksi with flows of 8-11 inches. The mechanical properties tested in this research were compressive and tensile strength, elastic modulus, and shrinkage. Durability tests included alkali-silica reactivity, absorption, abrasion, chloride permeability, freezethaw resistance, and scalingMichael Berry, Richard Snidarich, Camylle Wood, Riley Scherr, Kirsten Matteson
10/01/21October 2021Bridge Deck Cracking Evaluationhttps://cptechcenter.org/ncc-projects/bridge-deck-cracking-evaluation/Bridge decks, Concrete bridges, Moisture damage, Service life, Shrinkage, Transverse crackingTransverse cracking of concrete bridge decks continues to be an issue for the Montana Department of Transportation (MDT) and is considered a common issue reported among many state departments of transportation (DOTs). In the last 25 years with the introduction of high performance concrete (HPC) in bridge decks to lower permeability and with the use of finer ground cements (to increase early age strength gain and construction schedule), the susceptibility of bridge deck cracking has increased. Cracking commonly leads to a reduction in service life and increased maintenance costs, primarily due to accelerated corrosion of reinforcing steel in the deck. Identifying the causes of bridge deck cracking and providing prevention can be complex and challenging, but is very important for maintaining longevity of the bridge deck. To assist MDT with diagnosing and mitigating the causes of transverse cracking of bridge decks, WJE implemented a multi-disciplinary approach including a literature review, field inspections, bridge deck instrumentation, laboratory evaluations, and finite element modeling (FEM). From this research, WJE found the primary causes were related to non-uniform moisture gradients, drying shrinkage, and specific winter curing procedures. Based on these findings, WJE recommended improvements to mixture proportions, construction practices, and design considerations.Todd Nelson, Le Pham, Paul Krauss, Elizabeth Wagner, Eisa Rahmani, Jack Dai
09/01/21September 2021Alkali-Silica Reactivity in the State of Montanahttps://cptechcenter.org/ncc-projects/alkali-silica-reactivity-in-the-state-of-montana/Aggregate mixtures, Alkali silica reactions, State departments of transportation, Test proceduresThe primary objective of this research was to evaluate the potential for deleterious Alkali Silica Reactivity (ASR) in the state of Montana. In connection with this goal, (1) a literature review was conducted to summarize the ASR practices used by various state departments of transportation, as well as several federal agencies, (2) potential cases of ASR damage in the state were identified and investigated, and (3) existing testing methods were used to test the reactivity of several aggregate sources throughout Montana. It was found that the neighboring Canadian provinces and all investigated states (sans North Dakota), directly address ASR in their material specifications, to varying degrees. Overall, while there is not an overwhelming amount of evidence of ASR being a major problem in Montana, this research clearly demonstrated the potential for deleterious ASR in the state. Several sites around the state showed distress from ASR, and all of the tested aggregates showed some reactivity.Ashton Siegner, Michael Berry, Kirsten Matteson
06/30/17June 2017Improved Data for Mechanistic-Empirical Pavement Design for Concrete Pavementshttps://cptechcenter.org/ncc-projects/improved-data-for-mechanistic-empirical-pavement-design-for-concrete-pavements/CTE, Mechanistic, Pavement-METhe Mechanistic-Empirical Pavement Design Guide (M-EPDG) is a state-of-the-practice tool for pavement analysis and design. M-EPDG has been incorporated into the AASHTOware Pavement ME Design software program, and local calibration is necessary for optimal performance. To support NCDOT in use of the Pavement ME Design software for design and analysis of portland cement concrete (PCC) pavements, as well as to meet the need to support the decision to move forward with PLC concrete specifications for future NCDOT projects, a variety of PCC pavement mixtures were developed, batched, and tested. Mixtures included several coarse aggregates, Type I/II ordinary portland cement (OPC), PLC, fly ash from two sources, and fine aggregates (manufactured sand and a natural sand) used in North Carolina (NC). PLC used in these mixtures were produced by intergrinding with one of the OPCs used in the study. Tests to determine the mechanical and thermal properties of the concrete mixtures, as well as several durability performance tests were performed. A catalog of PCC characteristics for use as inputs in the Pavement ME Design software was prepared, and the impact of the new suggested inputs on NC concrete pavement design were evaluated. The cement type (OPC or PLC) used does not highly influence the results for the suite of tests used to determine the concrete inputs for MEPDG. Comparable performance of the PLC provides incentive to NCDOT for use of this more sustainable alternative to OPC. Although the type of coarse aggregate utilized in this study did not highly influence the laboratory test results supporting the recommended M-EPDG PCC inputs, the fine aggregate type utilized in the mixture (manufactured sand versus natural sand) did have a significant influence on two thermal PCC inputs: coefficient of thermal expansion (CTE) and thermal conductivity. A sensitivity analysis was performed to identify the changes in predicted distresses for a range of each PCC input. Several typical North Carolina concrete pavements were analyzed using previous and newly suggested PCC inputs using the original design constraints. Findings offer insight into the potentially longer service life of concrete pavements designed and constructed in the past by NCDOT. Use of the new PCC input values may result in the design of slightly thinner concrete pavements in the future. Thinner pavements will reduce the amount of materials used in pavement construction, resulting in lower costs and environmental impact of concrete pavement. The benefits of deciding to reduce PCC thickness should be weighed against the risks associated with under-prediction of traffic or section loss associated with one or more diamond grinding treatments during the service life of the pavement, as well as the service life benefits that could be obtained by using a thicker PCC pavement. As expected, results indicate use of fly ash in pavement concrete should improve durability performance. Use of PLC alone (without fly ash) did not provide distinct durability performance advantages, when compared to OPC. However, if PLC is utilized with fly ash in concrete mixtures, enhanced durability performance could be anticipated. Due to the delayed strength gain of fly ash mixtures, use of 28-day compressive strength as a PCC input in MEPDG may be unsuitable. A strong correlation was found between surface resistivity test results and rapid chloride permeability test (RCPT) results for all mixtures included this study. Findings of a limited LCA offered insight into the decrease in predicted total criteria air pollutant emissions associated with increased use of fly ash and PLC, providing confidence to NCDOT that use ofTara L. Cavalline, Brett Q. Tempest, Edward H. Blanchard, Clayton D. Medlin, Rohit R. Chimmula
06/06/19June 2019Economic Resilience and Long-Term Highway/Transportation Infrastructure Investmenthttps://cptechcenter.org/ncc-projects/economic-resilience-and-long-term-highway-transportation-infrastructure-investment/Decision making, Economic factors, Highways, Infrastructure, Investments, Policy, Risk assessment, Social factors, Sustainable transportationThe concept of strategic planning for transportation infrastructure investment has been expanding to include a response to issues of sustainability and resilience. Although the question of resilience from impacts resulting from large-scale disruptions such as natural disasters or economic changes has seen a growing library of research and documentation, major questions remain about how to incorporate these concepts into a transportation plan with sufficient analytical backup presented and in a format easily understood by decision-makers. The increasing competition for funds in a context of decreasing resources renders investment decisions even more critical. From the perspective of transportation systems in general and highway components in particular, this is a concern that is escalating in importance as questions of effective infrastructure investment strategies proliferate with consequent effects to a state’s or region’s economy. The process of analyzing conflicting demands on long-term strategic investment planning must address three fundamental areas: the economic, social, and environmental values or objectives of a state or region or locality.Sarah Weilant, Aaron Strong, Benjamin Miller
02/15/24February 2024LTPP Data Analysis: Guidelines to Improve Use of FWD and Longitudinal Profile Measurementshttps://cptechcenter.org/ncc-projects/ltpp-data-analysis-guidelines-to-improve-use-of-fwd-and-longitudinal-profile-measurements/Data analysis, Deflection, Falling weight deflectometers, Guidelines, Pavement performance, Roughness, TemperatureThe Long-Term Pavement Performance Program (LTPP) Seasonal Monitoring Program (SMP) was initiated to obtain data on the influence of temporal variations on pavement deflection and roughness. However, the temporal and diurnal data contained in the LTPP database (see Special Note A) have not been applied to improve the practices of measuring deflection and roughness, and their use has not been demonstrated. Also, recent work completed under NCHRP Project 20-50(22), “LTPP Data Analysis: Feasibility of Using LTPP data to improve Use of FWD and Longitudinal Profile Measurements” identified some of the issues related to the use of FWD and longitudinal profile measurements and proposed a preliminary research plan for addressing these issues (see Special Note B). However, additional research is needed to further define and address the issues associated with the effects of temporal and diurnal variations on FWD and longitudinal profile measurements, and to develop guidelines to improve these measurements and their use in evaluating pavement condition.Linda Pierce
10/18/21October 2021Synthesis of Information Related to Highway Practices. Topic 51-16. Maintenance and Surface Preparation Activities Prior to Pavement Preservation Treatmentshttps://cptechcenter.org/ncc-projects/synthesis-of-information-related-to-highway-practices-topic-51-16-maintenance-and-surface-preparation-activities-prior-to-pavement-preservation-treatments/Literature reviews, Pavement maintenance, Preservation, State departments of transportation, SurveysPavement preservation ensures that roads last longer at a lower cost compared to traditional pavement rehabilitation. Most departments of transportation (DOTs) have established pavement preservation programs. However, even when the right treatment for the right road at the right time is identified, preliminary maintenance and surface preparation activities are often required to ensure that the preservation treatment will perform successfully. These proactive maintenance and surface preparation activities can include crack sealing, patching, leveling, drainage repair, rut filling or removal, and concrete repairs. The objective of this synthesis is to document the types of maintenance and surface preparation activities performed by DOTs before pavement preservation treatments are applied. The synthesis will include both concrete and asphalt pavement preservation treatments. Information will be collected through literature review, survey of DOTs, and follow-up interviews with selected agencies for the development of case examples. The survey should be directed to the DOT voting members of the AASHTO Committee on Maintenance. Information gaps and suggestions for research to address those gaps will be identified.David Peshkin
01/01/20January 2020Development of a Non-Destructive Testing (NDT) Tool for in-Situ Assessment of Prestressed Componentshttps://cptechcenter.org/ncc-projects/development-of-a-non-destructive-testing-ndt-tool-for-in-situ-assessment-of-prestressed-components/Concrete, Girder, Presstress loss, UltrasonicThe research objective is to develop a non-destructive testing (NDT) method to evaluate the prestress loss in prestressed concrete bridge girders using ultrasonic waves. The work principle is based on acoustoelastic effect - ultrasonic wave velocity varies with stress level in prestressed concrete. A self-reference test setup was proposed to measure wave velocity in two orthogonal directions (prestress and unstressed directions) in the girder. This setup will be able to reduce effects of material variation and temperature change. The concept was first validated on small concrete specimens (cylinders and beams) in laboratory. A signal analysis algorithm was developed to reliably measure P wave velocity change with stress, i.e. the acoustoelastic coefficient. Then the proposed technique was applied to a full-scale prestressed concrete bridge girder (131 ft long) to monitor the stress release process. The stress change monitored by the ultrasonic test showed good agreement with the result from the strain measurement. In both the small beam test and the large girder test, the measured acoustoelastic coefficients were in the range of 0.7%/ksi. The temperature effects on acoustoelastic coefficient were investigated on two prestressed concrete members. Experimental results showed a slight difference between temperature induced velocity changes in the prestress and unstressed directions. Although temperature variation can cause large change of velocity, the self-reference setup will be able to correct about 80% of temperature effect. The relationship between relative wave velocity changes and stress changes in two orthogonal directions after temperature correction can be used to predict the stress level in concrete and reduce environmental influences.Bibo Zhong, Jinying Zhu, George Morcous
01/31/20January 2020Feasibility Study of Development of Ultra-High Performance Concrete (UHPC) for Highway Bridge Applications in Nebraskahttps://cptechcenter.org/ncc-projects/feasibility-study-of-development-of-ultra-high-performance-concrete-uhpc-for-highway-bridge-applications-in-nebraska/Bridge construction, Durability, Feasibility analysis, Field tests, Highway bridges, Mechanical properties, Mix design, Ultra high performance concreteUltra-high performance concrete (UHPC) is a new class of concrete that has superior mechanical, durability, and workability properties that far exceed those of conventional concrete. To achieve these properties, a specific mix design with a very dense internal structure, fiber reinforcement, and low water-to-binder ratio (w/b) is commonly used. The goal of this research is to develop a non-proprietary UHPC mix with constituent materials that are readily available in the state of Nebraska for bridge construction applications. In developing this mix, the particle packing model is used, and an experimental study of the impact of various design parameters on the key properties of UHPC is conducted. Multiple series of UHPC mixtures are investigated with different types and quantities of aggregate, fibers, cement, supplemental cementitious materials (SCMs), high range water reducer (HRWR), w/b, total binder content, and mixers. Mix design with type I/II cement, 8% of silica fume (by mass of binder), and 30% of slag (by mass of binder) is recommended. The developed mix exhibits sufficient flowability and stability to ensure the successful implementation in bridge components and connections. A comprehensive evaluation of mechanical properties demonstrated that the mix exhibits excellent mechanical properties, including compressive strength, modulus of elasticity, Poisson’s ratio, flexural strength, splitting tensile strength, direct shear strength, slant shear strength, and bond strength. The developed mix also exhibits excellent durability properties, including mass loss of less than 1% based on freezing/thawing resistance test, very low chloride ion penetration based on surface resistivity test, and no cracking based on restrained shrinkage test. The unit cost of the developed mix is approximately $682 per cubic yard, which is approximately one-third of the current commercial products. The batching, handling, placing, and curing of the developed mix was demonstrated in a field-scale panel connection casting, which resulted in a satisfactory performance.Flavia Mendonca, Mostafa Abo El-Khier, George Morocus, Jiong Hu
04/10/20April 2020Development and Implementation of a Moving Nondestructive Evaluation Platform for Bridge Deck Inspectionhttps://cptechcenter.org/ncc-projects/development-and-implementation-of-a-moving-nondestructive-evaluation-platform-for-bridge-deck-inspection/Bridge decks, Concrete bridges, Data collection, Data fusion, Deterioration, Global Positioning System, Inspection, Laser radar, Nondestructive tests (NDT), Overlays (Pavements), Structural health monitoringDegradation in concrete bridge decks is typically manifested as rebar corrosion, concrete delamination, and surface cracks. Nondestructive evaluation and testing (NDE/NDT) technologies have been increasingly used in concrete bridge deck evaluation to identify, localize, and quantify deterioration in bridge decks. Each NDE method has its advantages and limitations on the type of defect that can be detected. Therefore, combining multiple NDE technologies is needed in order to give comprehensive and reliable information about the bridge deck condition. For effective application of multiple NDE tests, we need to use automated positioning for each NDE to facilitate post-processing and data fusion of different NDE data. In this research work, the research team developed an NDE platform that will allow multiple NDE data collections either simultaneously or in sequence, with real time position information on bridge decks. The NDE platform consists of two main components: the data collection unit and the localization box. The data collection unit is made of a series of single board computers that were linked together to acquire data from many different channels. Any NDE technology with open data connection can be connected to the platform. The localization box incorporates localization devices including light detection and ranging (LiDAR), differential global positioning system (DGPS), and a camera as distance measurement instrument to accurately locate the signals captured by data collection unit. The moving NDE platform can be attached to hitch extension of a vehicle to provide a completely mobile solution. Three Nebraska bridges were surveyed using four NDE technologies: Vertical Electrical Impedance (VEI), ground penetrating radar (GPR), acoustic scanning system, and high definition imaging. Each bridge has different overlay type: no overlay, concrete overlay, and asphalt overlay. For each bridge deck, post-processed NDE data were analyzed, combined using two advance data fusion algorithms, and the final results are presented in 2D image maps.Sepehr Pashoutani, Jinying Zhu, Brian Mazzeo, Spencer Guthrie, Chungwook Sim
12/31/20December 2020Best Practices to Address Issues of Excess Aggregate Dust in Nebraskahttps://cptechcenter.org/ncc-projects/best-practices-to-address-issues-of-excess-aggregate-dust-in-nebraska/Aggregates, Best practices, Concrete construction, Dust, Fines (materials), Performance tests, Quality controlThe negative impacts of an excessive amount of dust on concrete performance have been known and reported in different states. The extent and impact of dust on concrete performance, which depends not only on quantity but also on the nature of dust could be complicated. For example, clay coatings showed a more harmful impact on concrete performance compared with carbonates (limestone dust) or stone dust. While clays that weakly adhere to aggregate will be dispersed in the mixing water and could lead to the workability or air entrainment issues, clays that are strongly bonded to the aggregate surface will remain at the aggregate surface after the mixing process and may disrupt the aggregate-paste bond and results in strength and durability issues. The upper limits of aggregate dust (fines) content currently included in most state agencies' specifications are not necessarily sufficient to prevent aggregate issues. This study includes five different types of aggregates, limestone, gravel, dolomite, granite, and quartz, collected from Nebraska, South Dakota, and Wyoming. A comprehensive evaluation of the aggregate dusts was performed using sieve analysis, washing test, sand equivalent test, methylene blue test, and X-ray powder diffraction. Besides the evaluation of fresh, hardened, and durability properties of concrete, advanced tests were used to characterize aggregate-paste bonding inside concrete prepared with different aggregate types and cleanliness. While aggregate collected in this study all appear to meet the current NDOT criteria of coarse aggregate fine content and fine aggregate sand equivalent value, additional test such as methylene blue value could provide more insights into the type of dust on the aggregate surface, especially the coarse aggregate. Modified Methylene blue value (MMBV) could potentially be used to control the coarse aggregate dust. However, future investigation is needed to establish a correlation between MMBV and field concrete performance that can be eventually used to set up criteria for quality control.Jiong Hu, Yong-Rak Kim, Temirlan Barissov, Shaya Gholami, Julia Grasley
05/01/21May 2021Field Demonstration of GPR and UAV Technologies for Evaluation of Two US 75/77 Bridgeshttps://cptechcenter.org/ncc-projects/field-demonstration-of-gpr-and-uav-technologies-for-evaluation-of-two-us-75-77-bridges/Bridges, Ground penetrating radar, machine learning, Nondestructive tests (NDT), Unmanned aircraft systemsTwo Nebraska bridges with asphalt overlay were selected for nondestructive testing and evaluation (NDT/NDE). Three NDT techniques were conducted on these two bridges, including Ground Penetrating Radar (GPR), Half-Cell Potential (HCP) and Unmanned Aerial Vehicle (UAV) imaging. NDT data were collected during three construction stages of the bridges: (1) before repair on existing asphalt overlay, (2) on bare concrete after asphalt removal, (3) and after repairing delaminated concrete. A machine learning technique, autoencoder, was used to build quantitative relationships between different NDT datasets. On bare concrete, the GPR amplitude and HCP voltage show a strong linear relationship. Then a threshold for GPR amplitude (-6.4 dB) can be determined based on the well-established HCP criteria. The GPR amplitudes on asphalt overlay also show a clear correlation with GPR amplitudes on bare concrete. Direct comparison of two GPR amplitude maps indicates GPR data collected on asphalt overlay could detect most severely deteriorated areas but may miss some mild deterioration. A big data image pipeline was created for mapping cracks and repair patches with images collected from an UAV. Comparing surface defects on asphalt overlay with HCP and GPR data suggests that UAV images may be used as an initial screening tool for extending NDT inspection of bridge decks. Further studies are needed to evaluate the performance of UAV imaging based visual inspection through quantitative analysis of surface defects and severity of deterioration.Sepehr Pashoutani, Jinying Zhu, Jinying, Sim, Chungwook, Lee, Ji Young
01/01/20January 2020The Use of Resistivity Testing for Quality Control of Concrete Mixtureshttps://cptechcenter.org/ncc-projects/the-use-of-resistivity-testing-for-quality-control-of-concrete-mixtures/Admixtures, Concrete, Concrete construction, Mix design, Pavement design, Resistivity methodThis study proposes a new quality control and compliance method for concrete mixture design using standard surface resistivity testing. This method helps in determining key mixture parameters such as fly ash content and w/cm of placed concrete. Based on the gain in resistivity over time, it was found that the slope of the surface resistivity versus time curve could be used to differentiate fly ash content. And, the resistivity value obtained at a sample age of 14 and 28 days could be used for identifying the water-to-cementitious material ratio of a concrete mixture containing no fly ash and containing up to 20% fly ash. Several other parameters such as, aggregate type and admixture addition are also evaluated for their effect on the outcome of a resistivity test. The proposed resistivity method could be used as a means for quality acceptance of mixture design during the construction stage. Three methodologies (Procedure A, B and C) for OkDOT Classes A and AA concrete mixtures are developed and trialed as part of a field study. In addition, the influence of laboratory ambient temperature and curing temperature was also investigated. It was found that if resistivity testing is performed in a standard temperature-controlled environment, resistivity variances are negligible. Finally, with all quality control material testing, an alternative test method is investigated in the event the primary lab specimen fails to meet the specification. The secondary compliance testing method targets the adequacy of concrete constructed onsite. In the end, the outcomes of the project can aid a DOT in devising a strategy for implementation of the resistivity method. The new tool enables control of placed concrete with respect to the approved mixture design.Julie Ann Hartell
11/30/21November 2021Use of Machine Learning to Predict Long-Term Skid Resistant of Concrete Pavementhttps://cptechcenter.org/ncc-projects/use-of-machine-learning-to-predict-long-term-skid-resistant-of-concrete-pavement/Algorithms, Concrete pavements, Friction, Neural networks, Skid resistanceAn adequate level of skid resistance over the service life of concrete pavements is crucial for the safety of drivers, especially in wet weather. It has been known that frictional properties of concrete pavements are influenced by concrete mixture proportions, type/properties of aggregates, surface texturing, and degree of surface polishing. Several experimental studies have attempted to establish regression correlations between these factors with time-dependent frictional properties of concrete pavements. While these experiments are necessary, they are costly and labor-intensive. As such, the current project intends to use the datasets and body of information generated by these past studies to develop a robust prediction algorithm for frictional properties of concrete pavements using the power of machine learning. More specifically, artificial neural network (ANN) is employed to resolve highly complicated relationships between frictional properties of concrete pavements and the parameters that influence such properties (e.g., aggregate mineralogy, concrete mixture proportions, etc.). Both the time-dependent frictional properties and terminal friction values are investigated. This report also provides a broad literature review on the subject.Rajabipour Farshad, Jinyoung Yoon
09/01/18September 2018Jointed Plain Concrete Pavement Design and Construction Reviewhttps://cptechcenter.org/ncc-projects/jointed-plain-concrete-pavement-design-and-construction-review/Admixtures, Aggregate gradation, Concrete pavements, Costs, Durability, Field tests, Freeze thaw durability, Mix design, Optimization, Pavement joints, Sealing compounds, WorkabilityAn experimental research study was conducted to develop optimized concrete mixtures for jointed plain concrete (JPC) pavements and field evaluation of newly constructed JPC pavement sections along South Dakota highways. Using South Dakota aggregates, different concrete mixtures were assessed for optimum workability, durability, and cost. The optimized mixtures incorporated 1.5" aggregate top size and reduced cement content. Mixtures containing pea rock exhibited poor freeze-thaw durability. Mixtures with 1.0" aggregate top size and 65/35 coarse-to-fine aggregate ratio exhibited low workability. A new laboratory technique that involves measuring the “specific work” of fresh concrete was developed to compare workability of different mixtures. Field data obtained from newly constructed JPC pavements demonstrated the following: thicker concrete pavement results in greater change in joint gap width, while the presence of asphalt underlayment results in lesser change in joint gap width, unsealed transverse joints allow for significantly higher moisture ingress than silicone sealed or hot-pour sealed joints, silicone sealed joints exhibited the least moisture ingress, treating the freshly placed JPC pavement with 1.5 times the normal amount of curing compound had a significant effect on maintaining pavement smoothness with time, high initial load transfer efficiency was achieved at joints with reduced dowel bar arrangements, and joint faulting was negligible across joints with either standard dowel bar configuration or reduced dowel bar configuration.Nadim Wehbe, Richard Reid, Jason Stripling, Brooke Edgar, Hesham Mahgoub, Mason Underberg
01/01/18January 2018Proper Overlay Type and Designs for PCC Pavementhttps://cptechcenter.org/ncc-projects/proper-overlay-type-and-designs-for-pcc-pavement/Bond strength (Materials), Concrete overlays, Continuously reinforced concrete pavements (CRC pavements), Deflection tests, Finite element method, Mechanistic-empirical pavement design, Pavement maintenance, Portland cement concrete, Rehabilitation (Maintenance)As of 2016, Texas Department of Transportation (TxDOT) managed a total of 16,327 lane miles of Portland cement concrete (PCC) pavement, which represents an important asset to TxDOT. As PCC pavements in Texas built in the 1960s through 1980s have already exceeded or are approaching the end of their design lives, many of these projects will require some form of rehabilitation. Considering the expected steady increase in truck traffic in the future, PCC overlays represent one of the best options for that rehabilitation. Currently, guidelines on PCC pavement overlays on PCC pavement focus on overlay slab thickness determination, but do not provide clear directions on (1) whether existing PCC pavement is a good candidate for concrete overlay, or (2) if the pavement is a good candidate, which overlay type—bonded concrete overlay (BCO) or unbonded concrete overlay (UBCO)—is appropriate. Sound guidelines are needed for the selection of an optimum overlay type, especially for continuously reinforced concrete pavement (CRCP) overlays, which could extend the performance period of structurally deficient PCC pavements in Texas at a reasonable cost. Three primary tasks conducted in this study were (1) the evaluations of PCC overlay performance of various BCO and UBCO projects built in Texas, (2) the development of BCO design procedures based on mechanistic-empirical principles, and (3) the development of threshold deflection values to determine whether existing pavements are good candidates for overlays. The structural behavior and performance of PCC overlays were investigated by deflection testing, bond strength testing, and material property evaluations. Three-dimensional finite element analyses were conducted to investigate structural responses of various PCC overlay systems under wheel and environmental loadings. Based on the analysis results and field performance of PCC overlays, a BCO design program was developed. For the UBCO system, detailed analyses were conducted to evaluate the soundness of the 1993 American Association of State Highway and Transportation Officials (AASHTO) design procedures. To facilitate the implementation of the research findings as well as to help TxDOT engineers select an optimum overlay type, the project team compiled the extensive information collected and made recommendations.Pangil Choi, Hoonill Won, Fei Yu, Moon C. Won
01/01/21January 2021Development of Pavement Performance Models for Pavement Management Incorporating Treatment Typehttps://cptechcenter.org/ncc-projects/development-of-pavement-performance-models-for-pavement-management-incorporating-treatment-type/Calibration, Data analysis, Deterioration, Forecasting, Maintenance management, Pavement management systems, Pavement performance, Rehabilitation (Maintenance)Texas Department of Transportation's (TxDOT’s) Pavement Management Information System (PMIS) has been recently replaced by Pavement Analyst (PA), a system for archiving, managing, and mapping data, reporting performance prediction, conducting optimization analysis for decision-making, etc. Pavement performance models comprise a key component of PA, these models quantify pavement deterioration for the planned horizon and predict the effect of maintenance and rehabilitation actions on performance. The accurate prediction of pavement performance is important for efficient management of the transportation infrastructure. By reducing the prediction error of pavement deterioration, agencies can obtain significant savings through timely intervention and accurate planning. As part of this project, the authors reviewed the current performance models, calibrated them, and updated them in a manner compatible with their implementation into PA. Extensive data analysis was conducted by using traditional and advanced data analysis techniques. Specifically, the models developed addressed the following technical objectives: (1) existing models were calibrated, correcting for biases and inefficiencies, (2) models were updated to incorporate historical construction data, (3) models were updated to incorporate the effect of maintenance and rehabilitation activities, and (4) alternative models were proposed that are free of some of the limitations of the existing models but are simple and straightforward enough to incorporate into PA.Hongbin Xu, Moo Yeon Kim, Christian Sabilon, Lu Gao, Jorge A Prozzi
08/01/2016August 2016Accuracy of In-Situ Water-to-Cement Meters for Concretehttps://cptechcenter.org/ncc-projects/accuracy-of-in-situ-water-to-cement-meters-for-concrete/Admixtures, Dielectric properties, Electrical resistivity, Microwave devices, Moisture meters, Statistical analysis, Water cement ratioConcrete’s water to cementitious (w/cm) ratio is the most important indicator of the overall strength and durability of the structure. A method to determine the w/cm ratio on-site is important and needed for quality assurance and quality control. There are currently limited standardized techniques for the measurement of w/cm on-site and those techniques can be very time consuming. A developed in-situ microwave moisture meter exists that relies on the difference in the dielectric constant of concrete from that of water to estimate the w/cm ratio. In this report, the accuracy and precision of the meter is studied. Several paste, mortar, and concrete mixes with known w/cm ratios as well as aggregates with known moisture contents were measured with the Cementometerᵀᴹ device. An AASHTO T318-02 microwave test was also performed in comparison to the Cementometerᵀᴹ on known w/cm values. Statistical methods included a t-test determining the accuracy of the device.For precision, linear regression analysis, absolute difference, and sum of squared error calculations were made between the Cementometerᵀᴹ predicted w/cm and actual w/cm contents of the mixtures. Overall, the Cementometerᵀᴹ device was found to precisely measure moisture levels in aggregates, but in concrete none of the modes were precise (all R² values were less than 0.065) nor accurate (p-value less than 0.044). On the other hand, the in-lab AASHTO microwave method produced statistically precise (R² of 0.62 or more) and accurate (p-value of 0.91) readings, and thus the in-lab AASHTO T318-02 method is recommended over the in-situ Cementometerᵀᴹ for w/cm ratio determination.Jafar Allahham, Amanda Bordelon
10/01/17October 2017Low Cracking Concretes for the Closure Pours and Overlays of the Dunlap Creek Bridgehttps://cptechcenter.org/ncc-projects/low-cracking-concretes-for-the-closure-pours-and-overlays-of-the-dunlap-creek-bridge/Admixtures, Bridge construction, Cement, Compressive strength, Cracking, fiber reinforced concrete, Joints (Engineering), Overlays (Pavements), Permeability, Silica fumeJoints, wide cracks, and poor-quality concretes facilitate the intrusion of chlorides, causing corrosion in bridge decks and substructures. In this study, joints were replaced with closure pours (link slabs) consisting of low permeability fiber-reinforced concretes resistant to wide cracking, overlays consisted of concretes with a low cracking potential and low permeability. Closure pours and overlay concretes had portland cement and a supplementary cementitious material for low permeability. Three different fibers, polyvinyl alcohol, polypropylene, and steel, were used in the closure pours, a compressive strength of 3,000 psi at 24 hours was sought. Latex-modified concrete with Rapid Set cement but without fibers was also included since it is commonly used in closure pours. In the overlays, five different materials were used: (1) latex-modified concrete with Rapid Set cement, (2) silica fume concrete (SFC) alone, (3) SFC with shrinkage reducing admixture, (4) SFC with lightweight coarse aggregate, and (5) SFC with lightweight fine aggregate. A compressive strength of 3,000 psi at 3 days was sought. Two parallel bridges located on Route 64 over Dunlap Creek in Alleghany County, Virginia, each with five simple spans, were selected for study. The performance of the closure pours and overlay concretes was observed after two to three winters. Fiber-reinforced concretes with the desired strength and low permeability were achieved in the closure pours. The surveys after two to three winters indicated mostly tight cracks (<0.1 mm [0.004 in] in width) that would resist penetration of solutions. The overlays also achieved the specified strength and low permeability. There were minimal tight cracks except in one section with the latex-modified concrete with Rapid Set cement in the left lane of the westbound bridge. There were extensive cracks in that section that were attributed to plastic shrinkage from adverse weather conditions at placement and the fact that a truck had caught fire in that lane. The study recommends that fiber-reinforced concretes be used when early strengths are needed. Further experimental installations with different fibers would indicate the optimum type and amounts for crack control. SFC overlays with shrinkage reducing admixture, with lightweight coarse aggregate, or with lightweight fine aggregate are ready for implementation in the field.Celik Ozyildirim, Harikrishnan Nair
06/01/18June 2018Bridge Service Life Designhttps://cptechcenter.org/ncc-projects/bridge-service-life-design/Admixtures, Bridge decks, Bridge design, Design standards, Life cycle costing, Reinforced concrete bridges, Service lifeHigh costs and traffic disruption associated with the deterioration of reinforced concrete bridge decks because of corrosion have sparked renewed interest in service life design. Reinforced concrete bridge decks are exposed to chlorides from deicing salts, when the chlorides reach the steel reinforcement, they initiate corrosion. This study supports the adoption of the methodology described in fib Bulletin 34, Model Code for Service Life Design, for reinforced concrete bridge decks in Virginia. Concrete mixture properties and environmental exposure conditions were characterized. Values particular to regions within Virginia and suggested default values were identified and organized in a database to support the development of service life design guidelines. The predicted service life for eight bridge decks using low-cracking concrete and corrosion-resistant reinforcement (VDOT Reinforcement Class I, MMFX, ASTM 1035) was evaluated. The service life model was also implemented in a life-cycle cost analysis for a case study bridge, which found superior reliability of corrosion-resistant reinforcement from a life-cycle perspective. In addition to supporting the implementation of service life design, several investigations identified key assumptions and variables in the service life model and identified critical areas for future characterization. The partial differential equation for apparent chloride diffusion was solved with both an approximate analytical approach and a numerical approach. Delays in the application of deicing salt were investigated using the numerical approach, and a ramp-type function for surface chloride concentration was explored using the analytical approach. Aging coefficients based on curing were also considered. A sensitivity analysis identified the aging coefficient and the surface chloride concentration as the most critical variables. The study concluded that sufficient data are available to implement the fib Model Code for Service Life Design, but that caution in interpreting results is warranted because of the high uncertainty associated with the most critical variables. According to the results of the service life analyses, the regional climatic variability and differences in mix design across Virginia indicate that a “one-size-fits-all” approach to bridge deck specifications may not be appropriate. The use of corrosion-resistant steel and low-cracking concrete mixtures can provide a substantial (greater than 100 years) bridge deck service life.Elizabeth Rose Bales, Venkatasaikrishna Chitrapu, Madeleine M. Flint
08/01/18August 2018Implementation of a Precast Inverted T-Beam System in Virginia: Part II: Analytic and Field Investigationshttps://cptechcenter.org/ncc-projects/implementation-of-a-precast-inverted-t-beam-system-in-virginia-part-ii-analytic-and-field-investigations/Bridge superstructures, Design methods, Finite element method, Live loads, Load tests, Precast concrete, Stresses, TemperatureThe inverted T-beam superstructure is a bridge system that provides an accelerated construction alternative for short-to-medium-span bridges. The system consists of adjacent precast inverted T-beams with a cast-in-place concrete topping. This bridge system is expected to not experience the reflective cracking problems manifested in short-to-medium-span bridges constructed with traditional adjacent voided slab or adjacent box beams. This report presents the results of three phases of a comprehensive research project to develop and implement an inverted T-beam system for Virginia. The three phases are: investigation of time-dependent and temperature effects, investigation of end zone stresses, and live load testing. The first investigation is of time-dependent effects in composite bridges with precast inverted T-beams. The analysis was performed for a two-span continuous bridge. An analytical study was performed to quantify the stresses generated as a result of differential shrinkage, creep and temperature gradient at various sections in both directions. At the cross-sectional level, an elastic sectional analysis approach using the age-adjusted effective modulus method was used to perform the investigation. At the structure level, the effects of uniform temperature changes, thermal gradients and differential shrinkage and creep were investigated and quantified in terms of axial restraint forces and restraint moments. It is shown that, by paying attention to detailing and by selecting a mix design for the cast-in-place topping that has relatively low shrinkage and high creep, the potential for excessive cracking can be reduced. The second investigation is of the stresses in the end zones of such a uniquely shaped precast element. The transfer of prestressing force creates vertical and horizontal tensile stresses in the end zones of the beam. A series of three-dimensional (3D) finite element analyses were performed to investigate the magnitude of these tensile stresses. Various methods of modeling the prestressing force, including the modeling of the transfer length, were examined and the effect of notches at the ends of the precast beams was explored. Existing design methods were evaluated; strut-and-tie models, calibrated to match the results of 3D finite element analyses, are proposed as alternatives to existing methods to aid designers in sizing reinforcing in the end zones. The final section reports the results of live load testing performed on the first inverted T-beam bridge in Virginia on U.S. 360 over the Chickahominy River. A finite element model of Phase I of the U.S. 360 Bridge was created and the live load distribution factors were analytically determined. Live load tests using a stationary truck were performed on Phase I of the U.S. 360 Bridge with the purpose of quantifying live load distribution factors and validating the results from the finite element analyses. It is concluded that it is appropriate to estimate live load distribution factors using AASHTO provisions for cast-in-place slab span bridges.Fatmir Menkulasi, Thomas Cousins, C. L. Roberts-Wollmann
07/01/20July 2020Full Depth Reclamation With Thin Surface Treatment for Low Volume Road Maintenancehttps://cptechcenter.org/ncc-projects/full-depth-reclamation-with-thin-surface-treatment-for-low-volume-road-maintenance/Asphalt concrete, Chip seals, Full-depth reclamation, Low volume roads, Pavement management systems, Pavement performance, Seal coats, Surface course (Pavements)The Virginia Department of Transportation (VDOT) maintains more than 100,500 lane-miles of pavement on the secondary network. Of this total, more than 95% of the lane-miles have an annual average daily traffic of less than 3,500 vehicles. Pavement recycling techniques (such as full depth reclamation [FDR] and cold in-place recycling) can be used to fix many underlying issues in an existing pavement and when combined with thin surfacings, where appropriate, can help VDOT maintain low volume roads and provide significant cost and environmental savings. However, VDOT has limited experience using pavement recycling techniques (especially FDR) where pavement is overlaid with thin surfacings. The purpose of this study was to document the performance baseline for a series of FDR sections having thin surfacings on lower volume traffic routes since the performance of these types of pavements was previously unknown. This study summarized the construction and initial performance of the FDR field projects on Rte. 602 in Surry County in VDOT’s Hampton Roads District and at Estates at Leeland in Spotsylvania County in VDOT’s Fredericksburg District; in addition, an inventory was conducted and the performance of past VDOT FDR projects on lower traffic routes was evaluated. The study found that the initial performance of the FDR project on Rte. 602 (having three thin surfacing treatments) and the FDR project at Estates at Leeland (having a 2-in. asphalt concrete surface) was promising at early ages. However, the information gathered to date is not sufficient to make conclusions about the long-term performance of FDR with thin surfacings. In general, for the past FDR projects reviewed, based on visual surveys and data from VDOT’s Pavement Management System, FDR with 2 to 4 in. of asphalt concrete surface performed well at ages of 7 to 13 years after construction. The study recommends continued performance assessment of the FDR sites surveyed in this study and additional field trials on the secondary network system using FDR with thin surfacings. Further research is also recommended to develop a framework to consider using performance data from VDOT’s Pavement Management System to predict the future conditions of pavement sections on the secondary network. Being able to identify those sections that could benefit from FDR treatments in the future would allow VDOT to allocate funding proactively for those sections based on early findings from this study.Harikrishnan Nair, Brian K. Diefenderfer
05/01/16May 2016Development of an SPS-2 Pavement Preservation Experimenthttps://cptechcenter.org/ncc-projects/development-of-an-sps-2-pavement-preservation-experiment/Concrete pavements, Pavement maintenance, Pavement performance, Rehabilitation (Maintenance), Research projects, Rigid pavements, Test sections This report outlines the current availability of the Long Term Pavement Performance (LTPP) SPS-2 experiment – strategic study for structural factors for rigid pavements – and proposes several options for potential future experiments that could be completed with the existing data for a comprehensive study of concrete pavement preservation techniques. The original core experiment sections were utilized in an experiment design comparing multiple maintenance treatments while the supplemental sections were included in a dowel bar retrofit study. Additionally, the proposed experiment could likely be expanded to include using the wealth of existing pavement performance data from the SPS-2 experiment to potentially use the predicted performance curves from AASHTOWare Pavement ME Design as the control sections and thus eliminating the need for paired sections and allowing for doubling of the experimental sections that could be used. This report for Phase I summarizes the work completed thus far evaluating and recommending possible experiments based on existing data. Nicole Dufalla, Kevin Senn, Pete Schmalzer
08/01/14August 2014Laboratory Study of High Performance Curing Compounds for Concrete Pavement – Phase IIhttps://cptechcenter.org/ncc-projects/laboratory-study-of-high-performance-curing-compounds-for-concrete-pavement-phase-ii/Bleeding (Pavements), Concrete curing, Durability, Emulsions, high performance concrete, Pavement performance, Sealing compoundsThe purpose of this study is to understand the relationship between the existence of bleed water on the surface of the concrete at the time of curing compound application and the concrete's resistance to scaling. This study hopes to advance the findings from the Phase I study, without repeating the Phase I tests. Out of the six treatments (five curing compounds, one wet room curing) used in Phase I, one has been dropped and five remain. The five curing treatments that will be tested are standard wet room curing, linseed oil emulsion, wax emulsion, PAMS and acrylic sealing compound. The CRE sealing compound was dropped from Phase II because the acrylic sealing compound over all mix types had superior durability performance, coupled with the fact that the VOC's released by the CRE were flammable making it impractical for most applications.Steven Cramer
09/01/14September 2014Evaluating the Risk of Alkali-Silica Reaction in Wyoming: Continued Evaluation of Field Specimens and Proposed Mitigation Strategieshttps://cptechcenter.org/ncc-projects/evaluating-the-risk-of-alkali-silica-reaction-in-wyoming-continued-evaluation-of-field-specimens-and-proposed-mitigation-strategies/Aggregates, Alkali silica reactions, Concrete, DurabilityA comprehensive study was performed to evaluate the alkali-silica reactivity (ASR) of eight Wyoming aggregates. State-of-the-art and standardized test methods were performed and results were used to classify these aggregate sources. Of the eight aggregates: one is highly reactive; one is moderately/highly reactive; three are moderately reactive; one is potentially reactive; and two are nonreactive. The Concrete Prism Test (CPT) and unboosted large scale field blocks provided the most accurate data.Margaret Kimble, Ryan Fertig, Darby Hacker, Jennifer Eisenhauer Tanner
08/30/18August 2018Evaluating the Effectiveness of Fly Ashes to Mitigate ASR and Using Recycled Concrete Aggregate in New Constructionhttps://cptechcenter.org/ncc-projects/evaluating-the-effectiveness-of-fly-ashes-to-mitigate-asr-and-using-recycled-concrete-aggregate-in-new-construction/Alkali silica reactions, Concrete aggregates, Durability, Evaluation and assessment, Expansion, Field tests, Fly ash, Recycled materials, Test proceduresA comprehensive study was performed to evaluate mitigation options to reduce premature expansion due to alkali-silica reaction (ASR) for selected Wyoming aggregates. State-of-the-art and standardized test methods were performed and results were used to compare expansion levels. Four different fly-ash sources were tested. All of the sources mitigated the moderately reactive aggregates; the most highly expansive aggregate was mitigated by two out of the four fly ash sources. An exploratory test, the Autoclave Concrete Prism Test (ACPT) was evaluated by comparing results with the University of Wyoming and the University of Alabama. Test data shows agreement between two independent laboratories.Bryce Fiore, Md Tarik Hossain, Margaret Kimble, Fayez AlMutawa, Jennifer Eisenhauer Tanner
12/01/20December 2020Development of Caltrans Concrete Overlay on Asphalt Pavement Design Catalog Tables Using Pavement MEhttps://cptechcenter.org/ncc-projects/development-of-caltrans-concrete-overlay-on-asphalt-pavement-design-catalog-tables-using-pavement-me/bonded concrete overlay of asphalt, pavement rehabilitation, Pavement-ME, Rigid pavement, WhitetoppingThis report summarizes the work completed to develop the concrete overlay on asphalt (COA) tables of the new Caltrans Highway Design Manual (HDM) Rigid Pavement Design Catalog. The tables consider the different pavement structures that are candidates for rehabilitation with COA with short transverse joint spacing on the Caltrans road network. The tables were developed using Pavement ME (version 2.5.5) with the nationally calibrated COA cracking model. Pavement ME inputs were determined by considering the state’s climate, traffic, materials, and construction practices. The design tables reflect the recommendations from previous Caltrans research about COA, including slab size, shoulder type, and load transfer efficiency. The Pavement ME inputs for developing the tables include a design life of 20 years, 10% target cracking, and 95% design reliability. The tables will be included in the printed version of the new HDM Rigid Pavement Design Catalog.Angel Mateos, John Harvey
10/01/19October 2019Concrete Overlay on Asphalt Pilot Project at Woodland SR 113: Constructionhttps://cptechcenter.org/ncc-projects/concrete-overlay-on-asphalt-pilot-project-at-woodland-sr-113-construction/bonded concrete overlay of asphalt, pavement rehabilitation, rapid-strength concrete, Rigid pavement, rubberized asphalt, WhitetoppingThis report documents the design and construction of a concrete overlay on asphalt (COA) pavement on State Route 113 in Woodland, California, one of the first COA projects in the Caltrans road network. The project site extended over approximately 4 mi. of a two-lane secondary road. The concrete slabs were a half-lane wide (6×6 ft.) and 6 in. thick. The transverse joints were undoweled, but tie bars were installed at all the longitudinal joints. The outside slabs were 2 ft. wider than the interior slabs to provide a concrete shoulder. The project included a section with newly placed, rubberized, gap-graded asphalt mix base. A rapid-strength concrete mixture with Type II/V portland cement designed to be opened to traffic in 24 hours was used for construction of the overlay. The northern part of the project (PM 14.760 to PM 17.580) was built in October and November 2018, while the southern part (PM 11.860 to PM 12.890) was built in April and May 2019. The concrete mixture was produced in a fixed plant and transported in ready-mix trucks 25 mi. to the construction site. A slipform paver was used to consolidate and finish the concrete. A number of the quality control/quality assurance (QC/QA) tests and evaluations summarized in this report were conducted before, during, and after the construction of the concrete overlay. These QC/QA tests and evaluations revealed no major design or construction issues with the concrete overlay, but they did show that the condition of the asphalt base was very poor, particularly in the northern part of the project.Angel Mateos, John Harvey, Miguel Angel Millan, Rongzong Wu, Fabian Paniagua, Jessica Cisneros, Julio Paniagua
09/01/20September 2020Pavement ME Sensitivity Analysishttps://cptechcenter.org/ncc-projects/pavement-me-sensitivity-analysis/jointed plain concrete pavement, Pavement design, Pavement-ME, sensitivityThe Mechanistic-Empirical Pavement Design Guide (MEPDG) is a comprehensive tool developed in 2002 by the American Association of State Highway and Transportation Officials (AASHTO) to analyze and design both flexible and rigid pavements. The models in the MEPDG are implemented in software called Pavement ME, a program calibrated using Long-Term Pavement Performance (LTPP) sections from throughout the United States, including some from California. The MEPDG recommends that nationally calibrated models be validated using local data, and if necessary, recalibrated, which makes sense when considering the climate and materials differences between California and the rest of the nation. The first step in recalibrating Pavement ME is to perform a sensitivity analysis to identify which variables are most important and to look for results that do not match expected performance. The factorial for the sensitivity analysis was designed to identify sensitivity and is not the factorial to be used for the development of design tools. This report presents the results of a sensitivity analysis showing the effects of design input variables controlled by the designer, and those not known to the designer. The sensitivity analysis shows that the overall jointed plain concrete pavements (JPCP) performance prediction by Pavement ME is reasonable. The distresses predicted by Pavement ME did not show any unexpected trends for any of the variables considered in this sensitivity analysis. Over the course of this study, no major issues were identified in running Pavement ME. The next steps are to complete the calibration using California pavement management system data and then to develop the design tool with the calibrated Pavement ME coefficients.Ashkan Saboori, John Harvey, Jeremy Lea, Jon Lea, Rongzong Wu, Angel Mateo
12/01/20December 2020Pavement Recycling: Shrinkage Crack Mitigation in CementTreated Pavement Layers — Phase 2a Literature Review and FDR-C Test Road Construction and Monitoringhttps://cptechcenter.org/ncc-projects/pavement-recycling-shrinkage-crack-mitigation-in-cementtreated-pavement-layers-phase-2a-literature-review-and-fdr-c-test-road-construction-and-monitoring/cement stabilization, cement treatment, crack mitigation, FDR-C, Full-depth recycling with cement, microcracking, shrinkage crackingThe California Department of Transportation has been using full-depth recycling (FDR) as a rehabilitation strategy since 2001. Early projects were recycled with foamed asphalt and cement, but cement-only treatments were permitted from 2015 to improve the properties of more marginal materials. However, shrinkage cracking associated with the hydration and curing of the cement-treated layers remains a concern, especially with regard to crack reflection through asphalt concrete surfacings and the related problems caused by water ingress. Considerable research has been undertaken on crack mitigation, and a range of measures related to improved mix designs and construction practices have been implemented by road agencies. One of the most promising measures, used in conjunction with appropriate mix designs, is that of microcracking the cement-treated layer between 24 and 72 hours after construction. In theory, this action creates a fine network of cracks in the layer that limit or prevent the wider and more severe block cracks typical of cementtreated layers. Limited research to assess microcracking as a crack mitigation measure had been completed on a number of projects in the United States. Recommendations from these studies were first implemented by the Texas Department of Transportation and then later by other state departments of transportation. However, longer-term monitoring of a range of projects revealed that microcracking has not always been successful in preventing cracking, with some projects showing reflected transverse and block cracks in a relatively short time period, attributable to a number of factors including but not limited to cement content, cement spreading, the method of curing, and the interval between base construction and placement of surfacing. The research discussed in this report builds on earlier work with a focus on gaining a better understanding of microcracking mechanisms and identifying key factors influencing performance, including, but not limited to aggregate properties, cement content, the time period before microcracking starts, layer moisture contents, roller weights and vibration settings, the number of roller passes, the field test methods and criteria used to assess the degree of microcracking, and the effects of early opening to traffic. In this phase of the study, a 36-cell test road was designed, constructed, and monitored to evaluate shrinkage crack mitigation procedures. The main findings from the study included revised mix design procedures based on the initial consumption of stabilizer and target unconfined compressive strengths of 450 psi (3.1 MPa) with a maximum permissible limit of 600 psi (4.1 MPa), the importance of appropriate curing, and a revised microcracking window of between 48 and 56 hours after compacting the layer. It is further recommended that a stiffness reduction target of 40% of the stiffness prior to microcracking, measured with the soil stiffness gauge, be considered instead of the current method specification.Stephanus Louw, David Jones, Joseph Hammack, John Harvey
12/01/18December 2018Development of Thin Bonded Concrete Overlay of Asphalt Design Method: Evaluation of Existing Mechanistic-Empirical Design Methodshttps://cptechcenter.org/ncc-projects/development-of-thin-bonded-concrete-overlay-of-asphalt-design-method-evaluation-of-existing-mechanisticempirical-design-methods/The California Department of Transportation (Caltrans) is interested in advancing the technology needed to implement thin bonded concrete overlay of asphalt (BCOA) on its road network. Recent accelerated pavement tests showed that thin BCOA exhibited promising results for structural performance and constructability in California’s dry environment when made with the high early-strength concrete mixes typically used by Caltrans. However, to continue moving forward, Caltrans needs to adopt a thin BCOA design method since the current Caltrans Highway Design Manual does not consider this type of pavement. In order to help Caltrans decide how to adopt a thin BCOA design method, this technical memorandum includes an evaluation of two existing mechanistic-empirical methods: BCOA-ME, developed by the University of Pittsburgh, and MEPDG, as implemented in Pavement ME Design versions 2.3 (2016) and later. The evaluation includes a sensitivity analysis that considered the most important factors in thin BCOA performance. The evaluation results show that the BCOA-ME and MEPDG methods are both based on sound mechanistic-empirical principles, but that they currently have technical and practical limitations that render them difficult to use for thin BCOA design in California. Based on the analysis presented in this technical memorandum, it is recommended that additional model development be performed to produce a design method that is more suitable for thin BCOA for the Caltrans road network. If Caltrans chooses this option, it is recommended that the new design method incorporate some models already used in BCOA-ME and MEPDG. Regardless of whether Caltrans decides to adopt an existing design method without changes or to further develop models to produce a more suitable method, the selected method will still need to be calibrated for California-specific materials and construction practices, in particular, the use of high early-strength materials; traffic; and climate conditions, with a focus on the prolonged drying that occurs throughout the state.Angel Mateos, John Harvey
06/01/15June 2015Pavement Recycling: Literature Review on Shrinkage Crack Mitigation in Cement-Stabilized Pavement Layershttps://cptechcenter.org/ncc-projects/pavement-recycling-literature-review-on-shrinkage-crack-mitigation-in-cement-stabilized-pavement-layers/Full Depth Recycling, pavement, Portland cementThe California Department of Transportation (Caltrans) has been using full-depth reclamation (FDR) as a rehabilitation strategy since 2001. Most projects to date have used a combination of foamed asphalt and portland cement as the stabilizing agent. Recently, the increasing cost of asphalt binder coupled with the relatively complex mix-design procedure for foamed asphalt has generated interest in the use of portland cement alone as an alternative stabilizing agent, where appropriate. However, shrinkage cracking associated with the hydration and curing of the cement-stabilized layers remains a concern, especially with regard to crack reflection through asphalt concrete surfacings and the related problems caused by water ingress.Stephanus Louw, David Jones
01/01/16January 2016Development of Recommended Guidelines for Preservation Treatments for Bicycle Routeshttps://cptechcenter.org/ncc-projects/development-of-recommended-guidelines-for-preservation-treatments-for-bicycle-routes/bicycle ride quality, bicycle vibration, chip seal, IRI, Macrotexture, MPDThis project was a continuation of a previous study that focused on the effects of pavement macrotexture on bicycle ride quality using input from bicycle club members and their bicycles on state highways, and considered changes to Caltrans chip seal specifications that resulted in seals with larger maximum size stones being typically used. This second project included a wider range of bicycle riders and bicycle types, considered pavement roughness and distresses in addition to macrotexture, and included measurements on urban preservation treatments and city streets as well as on treatments on state highways and county roads. This study also examined preservation treatment aggregate gradations and the mechanistic responses of bicycles to pavement macrotexture and roughness. The results of both projects were used to prepare recommended guidelines for the selection of preservation treatments that are best suited to bicycle routes on California’s state highways and local streets. Macrotexture, roughness, and pavement distresses were measured for different preservation treatments on 67 road sections distributed in five northern California and Nevada cities (Davis, Richmond, Sacramento, Reno, and Chico) and on a number of Caltrans highway sections and county roads. Bicycle ride quality surveys were conducted with a total of 155 participants. Correlations of the measurements and ride surveys were preliminarily explored. Models for bicycle ride quality and physical rolling resistance were also developed. Long-term monitoring of pavement macrotexture for larger stone seals on highway LA-2, SLO-1, and Mon-198.H. Li, J. Buscheck, J. Harvey, D. Fitch, D. Reger, R. Wu, R. Ketchell, J. Hernandez, B. Hayne
07/28/20July 2020SR-222 Micro Surfacing Project Performancehttps://cptechcenter.org/ncc-projects/sr-222-micro-surfacing-project-performance/bicycle ride quality, bicycle vibration, chip seal, IRI, Macrotexture, MPDMicrosurfacing is a widely used pavement preservation and preventative maintenance technique. This advanced form of slurry seal which uses the same basic ingredients, including emulsified asphalt, water, fine aggregate, mineral filler, and combines them with advanced polymer additives. It is generally considered a highly specialized process, and public highway agencies often depend on the experience of a microsurfacing contractor and emulsion supplier for design and construction. Though micro surfacing has been used frequently by city and county agencies, the Department has little experience with this pavement rehabilitation technique. The goal of this project is to evaluate micro-surfacing as a strategy to extend the life of a pavement from three to five years prior to a more extensive rehabilitation strategy such as milling and resurfacingAbdenour Nazef
01/01/16January 2016Effectiveness of Crack Relief Techniques to Mitigate Reflective Cracking in Asphalt Overlaid Concrete Pavementhttps://cptechcenter.org/ncc-projects/effectiveness-of-crack-relief-techniques-to-mitigate-reflective-cracking-in-asphalt-overlaid-concrete-pavement/This study focused primarily on evaluating the effectiveness of five crack relief treatments to mitigate reflective cracking of asphalt overlaid concrete pavement including 0.5 inch Superpave 9.5 mm Nominal Maximum Aggregate Size (NMAS) structural course (SP-9.5), 1.5 inch SP-12.5, 2.5 inch SP-12.5, 1.0 inch Open-Graded Crack Relief (OGCR), and 0.5 inch Asphalt Rubber Membrane Interlayer (ARMI). Pavement performance was evaluated in terms of deflection, ride quality, rutting and cracking. Also, an evaluation of cracking performance based on the dissipated energy concept using Falling Weight Deflectometer (FWD) load-deflection time history data was presented. The results indicated that 0.5 inch SP-9.5, 1.5 inch SP-12.5, and 2.5 inch SP-12.5 treatments show relatively greater potential for reflective crack mitigation efficiency than the 1 inch OGCR or 0.5 inch ARMI. More reflective transverse cracks corresponding to the Portland Cement Concrete (PCC) base slab joints occurred in areas with thinner Asphalt Concrete (AC) overlay and were most predominant in the 0.5 inch ARMI section. Areas with more transverse cracks had relatively greater dissipated energy indicating a higher potential for pavement deterioration and/or damage rate. Therefore, the dissipated energy approach can be used as a reliable indicator of pavement cracking performance. Thinner AC overlay may reduce the reflective cracking mitigation potential of crack relief layers.Sanghyun Chun, Abdenour Nazef, Edward Offei, James Greene, Bouzid Choubane
07/30/17July 2017Portland Cement Concrete Material Characterization for Pavement ME Design Implementation in Idahohttps://cptechcenter.org/ncc-projects/portland-cement-concrete-material-characterization-for-pavement-me-design-implementation-in-idaho-2/AASHTOWare, Concrete, Idaho Transportation Department, Pavement-ME, Rigid pavementThe objective of this research project was to develop a concrete material database as the first step towards the implementation of Pavement ME for rigid pavement design in the state of Idaho. Eight concrete mixtures from five of Idaho Transportation Department (ITD) districts were reproduced at Washington State University’s laboratory using the local aggregates and based on the corresponding field test results obtained from the respective district. Cast portland cement concrete (PCC) specimens were tested for compressive strength (f’c ), modulus of elasticity (Ec ), Poisson’s ratio (μ), modulus of rupture (MR), splitting tensile strength (f’t ), coefficient of thermal expansion (CTE) and ultimate drying shrinkage (ε∞). All mechanical tests were repeated on 7- , 14-, 28- and 90-day ages. Based on the laboratory test results, proper values for all PCC Pavement ME material inputs at Levels 1 and 2 were recommended, wherever available. In other cases, Level 3 values were suggested for a few material inputs that were not the characterized in this project. Two case studies were developed for the rigid pavement highway sections in Idaho that are also part of the Long term Pavement Performance (LTPP) database. Pavement structure, general design inputs and traffic inputs were defined based on the LTPP data. In terms of material parameters, experimental data obtained as part of this study was utilized at input Levels 1 and 2 and compared to the default values at input Level 3. The case studies revealed that the usage of experimental data at Levels 1 and 2 results in lower distress predications and more economic design compared to Level 3. Beyond the mixtures tested in this project, tests of f’c at all four required ages, CTE, and ε∞ are recommended at minimum.Milena Rangelov, Somayeh Nassiri, Ahmed Ibrahim, Fouad Bayomy, Ahmed Muftah, Bikash Sidgel
12/01/15December 2015Laboratory Study of Optimized Concrete Pavement Mixtureshttps://cptechcenter.org/ncc-projects/laboratory-study-of-optimized-concrete-pavement-mixtures-2/Admixtures, Aggregates, air-void analysis, Compressive strength, Durability, low cement concrete, Optimization, superplasticizer, Supplementary cementitious materialsRecent research supported by the Wisconsin Department of Transportation (WisDOT) concluded that concrete produced with reduced cementitious materials content had an adequate durability; however, tested mixes frequently demonstrated poor workability. As a result, a need was identified for a multi-faceted approach to optimize the mixture proportions for low-slump concrete in pavements in order to realize the benefits related to reduced cementitious material content. The reported approach includes the use of supplementary cementitious materials (SCMs), optimized aggregate gradations, and the use of superplasticizers (high-range water reducing admixtures). Current WisDOT practice minimizes the use of portland cement through replacement with SCMs, but does not address the use optimized aggregate gradation or superplasticizers. Therefore, additional research was conducted to support the development of specifications inclusive of these factors to improve the performance and sustainability of concrete paving mixtures used in Wisconsin. This research project evaluated the feasibility of expanding current specifications to incorporate the optimized superplasticized concrete in sustainable concrete paving applications. Furthermore, the goal of the reported study was to produce the guidelines for optimizing concrete mix design by evaluating the performance of a range of concrete mixtures. The performance evaluation of optimized concrete included the workability (slump), air content, compressive and flexural strength, freeze-thaw resistance, and rapid chloride permeability in accordance with the relevant AASHTO or ASTM standards. Finally, the reported research recommended the selection of aggregate gradations and superplasticizing admixtures in low-slump concrete with reduced cementitious materials intended for paving applications.Konstantin Sobolev, Mohamadreza Moini, Rani Pradoto, Marina Kozhukhova, Ismael Flores-Vivian, Scott Muzenski, Steve Cramer, Ahmed Fahim, Le Pham
01/01/17January 2017Class F Fly Ash Assessment for Use in Concrete Pavementshttps://cptechcenter.org/ncc-projects/class-f-fly-ash-assessment-for-use-in-concrete-pavements/Admixtures, Compressive strength, Durability, Fly ash, low cement concrete, superplasticizer, Supplementary cementitious materialsThe Wisconsin Department of Transportation (WisDOT) currently specifies Class C fly ash for use as a partial replacement for portland cement in concrete pavements. Class F fly ash sources were eliminated from WisDOT specifications in the 1990’s due to high values of loss on ignition (LOI) which led to difficulties in establishing and maintaining a proper entrained air void system in the concrete used in paving applications. A recent study that looked at the use of Class F fly ash demonstrated its potential usage in WisDOT specifications. However, WisDOT needs more evaluation with regard to durability testing. Specifically, research is needed to evaluate the feasibility of expanding current specifications to allow for use of Class F fly ash in concrete paving applications with southern Wisconsin aggregates. In order for Class F fly ash to be a viable alternative as a supplemental cementitious material, its use must produce mixes that meet current performance standards with respect to strength (including early strength) and durability, when compared with a commonly used Class C fly ash. The main objective of this study is to evaluate whether the locally available Class F fly ash from Elm Road Generating Station, operated by WE Energies and located in Oak Creek, Wisconsin, will provide satisfactory performance in concrete pavement, in comparison with a Class C fly ash from Columbia Energy Center currently in use. The study will also provide mix design guidance related to acceptable proportions of Class F fly ash that can be used in paving applications without negatively impacting performance. The performance evaluation of optimized concrete included workability (slump), air content, compressive strength, freezethaw and salt scaling resistance in accordance with the relevant AASHTO or ASTM standards. Finally, the reported research recommended the selection of fly ash for low-slump concrete with reduced cementitious material content intended for paving applications.Konstantin Sobolev, Mohamadreza Moini, Rani Pradoto, Marina Kozhukhova, Ismael Flores-Vivian, Scott Muzenski, Habib Tabatabai, Hani H. Titi
04/01/17April 2017Better Concrete Mixes for Rapid Repair in Wisconsinhttps://cptechcenter.org/ncc-projects/better-concrete-mixes-for-rapid-repair-in-wisconsin-2/Calcium chloride, Concrete, high early strength, Life cycle analysis, Mix design, Portland cement, rapid repair, Rigid pavementWith the increasing demands on the highway system and increasing costs of user delay, the use and development of rapid-repair techniques are expected to grow rapidly. High early strength (HES) portland cement concrete can help reduce the duration of traffic closures while being cost-competitive with other solutions such as concrete using proprietary cements and precast concrete. This research investigated the performance of HES portland cement concrete used for pavement repairs through multiple approaches. Thirteen mixtures were made and tested in the laboratory for strength, drying shrinkage, and scaling resistance. A field review of 12 recent rapid-repair pavement projects in Wisconsin was conducted to evaluate field performance of the pavements. An informal survey of Wisconsin concrete suppliers was conducted to obtain information on mix design, challenges, and approaches to rapid repair of pavement. Life-cycle cost analysis was conducted for pavement repairs using cost data assumed to be representative of the lab tested mixtures and precast concrete. The field review showed no significant durability issues except for one project where severe scaling occurred. Concrete using portland cement with calcium chloride accelerator can surpass WisDOT compressive strength requirements of 3000 psi in 8 hours and have satisfactory scaling resistance. Concrete using a nonchloride accelerator had excellent scaling resistance, slightly higher shrinkage than non-accelerator concrete, and may be a good alternative to calcium chloride when the strength requirement of 3000 psi can be extended to within 10 hours. Overall it appears that durability issues that occurred in rapid-repair pavements are more likely due to difficulties associated with construction or mix procedures than the WisDOT specifications. To ease these difficulties, the use of dry calcium chloride may be considered if it can be mixed uniformly with the concrete. An upper slump limit specifically for rapid-repair concrete would provide flexibility and may be higher than that for conventional concrete.Steven M. Cramer, Le T. Pham, Mark B. Snyder
08/01/18August 2018Joint Sawing Practices and Effects on Durabilityhttps://cptechcenter.org/ncc-projects/joint-sawing-practices-and-effects-on-durability/Absorption, Conventional joint sawing, early entry joint sawing, Freeze thaw durability, joint durabilityJoint deterioration has become a renewed concern for concrete pavements in Northern climates. Recently, a large number of relatively young pavements (less than 20 years) have experienced premature joint deterioration requiring disproportionately high amounts of maintenance. While specifications and testing help to identify dcracking aggregates, optimize mixtures for low shrinkage and permeability, utilize advanced air testing techniques, and help determine potential deicer issues; the current joint deterioration problem spans many states and concrete mixtures and has the potential, if left unchecked, to seriously damage the reputation of concrete pavements as durable, low maintenance options. This research report presents findings from joint durability studies conducted on test specimens extracted from two research test sections specifically built with southern limestone and northern igneous gravel as the predominant coarse aggregates. Transverse saw cuts were made with conventional and early entry saws using a variety of blade types and post-construction timing intervals. Sections sawn early in the timing window exhibited physical damage to the aggregate and concrete. Sections sawn with old/worn saw blades were more absorptive to water and exhibited more variability. Silane treatment of the joints provided significant reduction in water absorption. The concrete mixtures were freeze-thaw durable to 300 cycles and had acceptable performance to 600 cycles. Surface deicer scaling was not influenced by sawing factors. The application of silane did not reduce chloride penetration for the limestone mixture but did reduce penetration by 50% for the gravel mixture.James A. Crovetti, John T. Kevern
07/01/21July 2021Evaluation of Roadway Concrete Barriers and Materialshttps://cptechcenter.org/ncc-projects/evaluation-of-roadway-concrete-barriers-and-materials/Distress, Mechanical Testing, Non-Destructive Evaluation, Single-slope BarriersThe research objective was to investigate the causes and sources of distress observed in single-slope slip-formed roadway concrete barriers with the goal of developing strategies to ensure the long-term performance of these barriers in Wisconsin. To that end, barriers built between 2012 and 2015 and located in three different regions of WI were studied. The research approach included a state-wide survey, field inspection of the barriers, as well as laboratory tests of concrete cores and powder samples. Data analysis was performed to distinguish between observed types and the extent of distress. Based on the findings, several recommendations are presented which include improving construction practices, inspection, and quality control during construction, following concrete specification, improving data collection during barrier construction, limiting the size of aggregates, modifications to the amount of horizontal reinforcement, and heat of hydration of cement.Vista Shahriari, Pavana Prabhakar, Jose A. Pincheira
02/20/22February 2022Evaluation of Concrete Pavement Buckling in Wisconsinhttps://cptechcenter.org/ncc-projects/evaluation-of-concrete-pavement-buckling-in-wisconsin-2/Buckling, Concrete pavements, Field tests, Literature reviews, Pavement joints, Thermal expansionBuckling of concrete pavements is a serious problem in many states, but even more so in Wisconsin due to a combination of factors including climate, construction practices, maintenance practices, materials, and design. Although the incidences of buckling in concrete are fewer than other distresses such as cracking and spalling, they disproportionately affect the traveling public due to potential safety concerns requiring immediate repair, which is expensive and can be difficult. The research team investigated buckling in Wisconsin by conducting a thorough literature review, interviewing agency and industry representatives from other states and countries, reviewing neighboring agency standards and specifications, performing field investigations of eight buckling sites and three control sites in Wisconsin, analyzing the field data, and simulating the risk of buckling using analytical modeling. Based on the research activities, the research team noted factors that increase the risk of buckling and provided recommendations to reduce the occurrences of buckling in Wisconsin. Specific recommendations include considering single cut sawed joints filled with low modulus sealant to reduce amount of incompressibles and water infiltrating through the joints, reviewing and making changes to cold weather concreting practices to reduce likelihood of low neutral temperature thus effectively increasing the concrete temperature at which buckling happens, specifying strong and more durable concrete to increase concrete’s resistance to compressive stresses, using concrete with lower coefficient of thermal expansion when possible to reduce expansion and associated compressive stresses, repairing spalled joints with concrete full- or partial depth patches as soon as practical to improve joint integrity, providing positive drainage in areas susceptible to moisture to reduce concrete damage, using a stabilized base course to increase friction and reduce compressive stresses, and using wider paved shoulders and vegetation beyond shoulders to help reduce the availability of incompressibles to the mainline joint and crack. Wisconsin Department of Transportation should also experiment with forcing joints to activate to reduce the number of dominant joints and consider using pressure relief expansion joints as a last resort when other options have been exhausted. Shreenath Rao, Hesham Abdualla, Hyung Lee, Michael Darter
05/01/19May 2019Rapid Concrete Repairhttps://cptechcenter.org/ncc-projects/rapid-concrete-repair/autogenous, calcium sulfoaluminate, Concrete, Creep, Drying, Internal curing, pavement, rapid, repair, ShrinkageInvestigations to develop a full depth durable concrete mixture (15 year life) to be used for pavement with four hour cure time and 4000 psi compressive strength that will minimize cracking were carried out. Current high early strength concrete mixtures have natural cracking and shrinkage problems due to the high content of cementitious material or their chemical components. Using IC allows for early strength, enhanced durability, reduced shrinkage and a better curing by providing water that can be absorbed by the cement past after the final set. Different OPC and CSA mixtures were prepared, with and without IC. Mixtures with IC had reduced early strength and delayed hydration, however, when combined with CSA cement, were able to obtain about 4000 psi strength and delayed hydration, however, when combined with CSA cement, were able to obtain about 4000 psi of compressive strength in 4 hours of curing. Significant improvements in volume stability were also noted in the IC mixtures. Drying and creep shrinkage were reduced by factors of up to 15% and 30%, respectively. A CSA mixture with IC is recommended by the authors.Ivan Quezada, Robert J. Thomas, Marc Maguire
03/01/17March 2017Strategies to Increase the Service Life of Concrete Bridge Deckshttps://cptechcenter.org/ncc-projects/strategies-to-increase-the-service-life-of-concrete-bridge-decks/Corrosion of the steel in reinforced concrete bridge decks is a critical issue for structures that are exposed to chloridecontaining de-icing chemicals or marine salts. Oregon Department of Transportation (ODOT) has a large number of bridges that are vulnerable to this form of deterioration. An obvious indicator of a corrosion problem is visible damage; unfortunately, if corrosion damage is visible, the window for preventive action is likely closed. Pre-emptive actions and early detection of potential problems are more cost effective than repair or replacement of bridge decks that have already experienced corrosion. In recent years, electrical-based methods have emerged as durability-related performance indicators for reinforced concrete structures. Several investigations have shown the existence of relationships between electrical resistivity (or formation factor) of concrete and other durability-related parameters such as corrosion rate of steel reinforcement and transport properties of concrete. The main motivation of this research is to provide ODOT with a protocol to select bridges for its ongoing bridge deck treatment operations using quantitative tools that are practical and quick. Although rapid surface resistivity measurements are highly correlated with water and chloride transport properties of concrete, they do not directly provide the actual chloride depth profiling. However, transport properties that are revealed by surface resistivity measurements can be used in chloride ingress models that can be used to predict chloride profiles in concrete. The accuracy of the predictions improves with additional easily accessible quantitative information such as concrete mixture design properties (e.g. water-to-cement ratio), environmental data (e.g. temperature and relative humidity), and salt exposure histories. Most of these additional quantitative data are readily available for most locations in Oregon. These predictions, coupled with surface resistivity data, will also indicate if additional chloride profiling is necessary, and if so, at which locations on the deck it should be conducted. To achieve the project goals, the following tasks have been performed: (1) An experimental investigation was conducted to establish the relationship between electrical properties of concrete (e.g. SR or formation factor), environmental data (e.g. temperature and relative humidity), and chloride ingress in reduced-size reinforced concrete slabs simulating bridge decks commonly used in Oregon. (2) The effect of freeze-and-thaw action on the observed relationship was investigated. (3) A comprehensive modeling framework that relates the electrical properties of concrete, environmental data and chloride ingress was developed, verified, and validated. (4) A virtual test bed using the validated modeling framework was developed to conduct statistically significant number of virtual experiments to obtain closed-form relationships between electrical properties of concrete, environmental data and chloride ingress for bridge decks in different geographical areas in Oregon. (5) A demonstration case study was performed to show the development of a closed-form equation and how it can be used in a bridge-deck evaluation-protocol that can be used by ODOT in practice.O. Burkan Isgor, Jason H. Ideker, David Trejo, Vahid Jafari-Azad, David A. Rodriguez, Silas Shields, Parnian Husseini
01/01/22January 2022Constructability and Durability of Concrete Pavementshttps://cptechcenter.org/ncc-projects/constructability-and-durability-of-concrete-pavements/aggregate void, Concrete, mixture proportioning, paste volume, Pavements, resilience, sustainabilityConcrete for pavements must be proportioned so that the concrete is economical and durable. Because ordinary Portland cement (OPC) is the most costly component and is generally less durable than the aggregates, the OPC should be minimized. OPC significantly contributes to CO2 during manufacturing. Therefore, minimizing the OPC will also make the concrete greener. This research developed a mixture proportioning method to minimize the OPC content. This is achieved by characterizing the aggregates that will be use in the concrete to minimize the voids in the aggregates (fine and coarse). This will result in lower OPC requirements. This research assessed concretes proportioned with the new method. All concretes met edge slump and surface void requirements. All concretes met compressive and flexural strength requirements. Most concretes met formation factor requirements. Select testing indicates that shrinkage, as measured with shrinkage rings, is likely dependent on paste content; lower paste contents lead to lower shrinkage, but more research is needed. Select concretes did not perform well in freeze-thaw testing, however void spacing and size were not assessed.David Trejo, Naga Pavan Vaddey, Gokul Dev Vasudevan, O. Burkan Isgor, Armen Amirkhanian
05/01/15May 2015The Behavior and Durability of Self-Consolidating Concretehttps://cptechcenter.org/ncc-projects/the-behavior-and-durability-of-self-consolidating-concrete/This report focuses on the production of self-consolidating concrete using local materials from Las Vegas, Nevada. Tests were conducted on eight self-consolidating concrete mixtures having two different percentages of fly-ash replacement (25% and 35%) as well as the inclusion of the superplasticizer ADVA 195 and the viscosity modifying admixture V-MAR 3. The fresh properties tested were flowability, passing ability, and stability. Mechanical properties evaluated were compressive strength, splitting tensile strength, and the modulus of elasticity. The durability of specimens produced from the mixtures was tested for chloride ion resistance, sulfate resistance, and salt scaling. A key outcome of these tests for both fresh and hardened properties was that the mix design of self-consolidating concrete should be tailored according to the planned application (drilled shafts, precast products, repair concrete, etc…). Another key outcome was the importance mix design to accommodate the hauling time while maintaining consistent fresh properties of self-consolidating concrete at the delivery site. Recommendations for applications for self-consolidating concrete include using additional parameters to assess the suitability of the mixture to the designated application such as (T50, Jring), especially in critical applications where complications occur. And while additional testing may become a burden on the overall operation, it can be performed in trial batches and selectively during delivery. Another recommendation is to further investigate the use of techniques to control bleeding in large volume self-consolidating concrete casts.Aly Said, Pramen P. Shrestha, Kojo Nkuako
01/01/17January 2017High-Early-Strength High-Performance Concrete for Rapid Pavement Repairhttps://cptechcenter.org/ncc-projects/high-early-strength-high-performance-concrete-for-rapid-pavement-repair-2/In the construction industry, High Early-Age Strength (HES) concrete was traditionally regarded as a concrete that achieves a loading strength in matter of days rather than weeks. However, in the last 10-15 years, this time has been reduced down to a matter of hours. The required minimum compressive strength is determined on a caseby-case basis depending on the project. In construction applications for structures and dwellings the minimum allowed by the International Building Code is 2500 psi (IBC 2012), while in road and bridge construction the minimum requirement is typically 3000 psi, and for airport construction is typically 4000 psi. Due to the accelerated strength gain of HES provided by chemical admixtures, the minimum opening strengths are often reduced since it is expected that the concrete continues to gain strength after the traffic load is introduced. Since the target of this investigation is high early-age strength concrete for the purposes of road and bridge deck repairs, this will be the main focus from this point on.Nader Ghafoori, Meysam Najimi, Matthew Maler
06/30/18June 2018Improving the Long-Term Performance of Concrete Bridge Decks using Deck and Crack Sealershttps://cptechcenter.org/ncc-projects/improving-the-long-term-performance-of-concrete-bridge-decks-using-deck-and-crack-sealers/Bridge, Concrete, SealersMaintaining bridge decks is a huge issue. It is critical to extend the life of a bridge deck as long as possible since bridge deck replacement is difficult, expensive, and it significantly disrupts the traveling public. For example, NDOT currently utilizes overlays, but effective use of sealants and deck treatments could delay overlays, save costs, and extend bridge deck life. The primary objective of the project will be to develop a bridge deck maintenance guide that focuses on weather conditions that are common in the desert southwest. This includes areas of extreme dry heat to mountainous regions with snow and deicing salts. The primary focus of this research is to take the best practice from other states and determine the best implementation plan for the SOLARIS members. Therefore, the research will focus on reviewing the literature for current best practices. After collecting the literature, comparisons will be made between states in terms of bridge maintenance, construction practice, and deck conditions. An experimental phase will test these materials under accelerated conditions and then use test bridges to apply the knowledge in the field. The final step will be a comprehensive report that describes the work and provides recommendations for bridge deck maintenance.Devin Sanders, Karim Mostafa
01/01/16January 2016Pavement Surface Characteristics Concrete New Construction (MnROAD Study)https://cptechcenter.org/ncc-projects/pavement-surface-characteristics-concrete-new-construction-mnroad-study/Friction, hysteresis, Mann—Whitney Wilcoxon, Ride quality, Texture, time series, Tire/pavement noiseIn pavement infrastructure, functional characteristics are mainly preponderant over structural characteristics as the former typically govern pavement rehabilitation, maintenance and reconstruction decisions. Evidently, agencies invest in provision or restoration of friction (skid resistance) and make policies to minimize traffic noise. Most agencies accept (or reject) construction projects based mainly on initial ride quality. Consequently, this study examined various concrete textures imparted on new pavements in the 2007, 2010 and 2011 MnROAD test cell construction and monitored their ride quality, friction, tire pavement noise, visual conditions and acoustic impedance over time. The study successfully developed an in-situ impedance tube evaluation method for pervious concrete for a proxy to material and hydraulic conductivity condition. It also created tenable time-series equations for the progression of the various texture characteristics and developed a friction degradation model based on traffic and texture type. Advanced data analysis showed that longitudinal texturing and negative textures were strongly associated with pavement quietness. Investment analysis revealed that certain surfaces produced noise reduction of 6 decibels over the transverse time. Those textures including pervious concrete and diamond grinding were found to be cost-beneficial for noise abatement consideration. This research also associated rectangular texturing with anomalous laser-induced ride-quality measurements. Further analysis also accentuated a correlation of pavement condition to surface acoustics thus recommending the development of impedance tube for pavement joint condition monitoring. Additionally, This research recommended drag pre-textured longitudinal-tining as the optimal texture for durability, quietness and skid resistance based on the overall research results.Bernard Igbafen Izevbekhai
12/31/20December 2020Effects of Concrete Cure Time on Epoxy Overlay and Sealant Performancehttps://cptechcenter.org/ncc-projects/effects-of-concrete-cure-time-on-epoxy-overlay-and-sealant-performance-2/Applying flood coats (thin epoxy overlays and healer sealers) improves bridge deck condition and extends service life. The current Michigan Department of Transportation (MDOT) policy is to maintain a total curing period comprising 28 days of wet and dry curing before applying a flood coat on bridge decks with new concrete for patches and repairs. Consequently, the contractors must wait 28 days to start surface preparation for a flood coat application, which increases project completion time, traffic management, and user costs. Therefore, there is an interest to evaluate the possibility of applying a flood coat during the dry curing period. Hence, two performance-based procedures were developed to identify the minimum concrete age to receive a thin epoxy overlay or a healer sealer. Two epoxy overlays and two healer sealers were identified from MDOT approved product lists to evaluate their performance on the standard bridge deck joint repair (BDJR) and Grade DM concrete mixes. The overlay performance was evaluated under standard laboratory conditions, simulated summer exposure conditions, wet and dry conditions, and the outdoor conditions representing southwest Michigan exposure. The performance under outdoor conditions was evaluated during the fall, winter, and summer seasons. The overlay performance was assessed primarily by conducting the tensile bond pull-off strength test. Also, the effectiveness of the overlay against chloride ingress was evaluated. The performance of healer sealers was assessed by evaluating the effectiveness of sealers to prevent chloride ingress through sealed cracks. The experimental results support applying overlays and healer sealers during the dry curing period. The rational and implementable procedures developed through this research evaluate the minimum age of concrete to receive epoxy overlays or healer sealers without compromising concrete durability and overlay/healer sealer performance. Even though the process requires evaluating several parameters, this process needs to be implemented only once per each standard or approved mix resulting in significant savings from project and road user costs.Upul Attanayake, Neil Berke, Abul Fazal Mazumder
06/15/21June 2021Review of Improved Subgrade and Stabilized Subbases to Evaluate Performance of Concrete Pavementshttps://cptechcenter.org/ncc-projects/review-of-improved-subgrade-and-stabilized-subbases-to-evaluate-performance-of-concrete-pavements/Aggregate Quality, Concrete pavements, Daylighted Subbase, Drainability, Durability, Filtration, Geotextile, Granular Subbase, Separation, StabilityThis report presents findings on the evaluation of foundation layers under concrete pavements in the state of Illinois. It also provides recommendations and scenarios where unbound granular layers can be safely used under concrete pavements as economical and well-performing subbase layers. The current practice and mechanistic design methods for constructing concrete pavements in Illinois was first evaluated, including historical studies that led to the current design procedures and policies. The performance of concrete pavements with unbound granular layers in Illinois were then evaluated, and several case studies of well-performing concrete pavements with granular subbases, high traffic levels, and low distress levels and severity were realized. Next, the practices of surrounding states were evaluated, and several Midwest states, i.e., Wisconsin, Minnesota, Iowa, and Michigan, were found to regularly use unbound granular layers under concrete pavements with no issues. A literature review on the most recent requirements and recommendations for designing granular subbases under concrete pavements was then presented. It is concluded that subbase layers under concrete pavements are mainly used to provide uniform support and prevent pumping. Based on the case study evaluations and literature, a stable, drainable, and durable daylighted granular subbase design is recommended for traffic factors up to 10.0. Stability is ensured by limiting the ratio of gravel-to-sand fractions in the aggregate mix between 1.3 and 1.9. Drainability requirements can be met by limiting the percentage of fines passing the No. 200 sieve (0.075 mm) to 4% and by checking the quality of drainage is at least fair based on the time required to drain 50% of the water. Lastly, a geotextile fabric is recommended for use below the granular subbase for separation to ensure drainability throughout design life.Issam I. Qamhia, Erol Tutumluer
11/01/15November 2015Mechanical Properties of Portland Cement Concrete With Recycled Asphalt Pavement as Partial Replacement for Coarse Aggregatehttps://cptechcenter.org/ncc-projects/mechanical-properties-of-portland-cement-concrete-with-recycled-asphalt-pavement-as-partial-replacement-for-coarse-aggregate/Mechanical Properties of Concrete, Recycled AsphaltFinding constructive uses for construction waste byproducts contributes to green engineering principles. One such plentiful material is recycled asphalt pavement (RAP). This report looks at the mechanical viability of including RAP in a high strength concrete mix. The mechanical behaviors studied are: freeze-thaw durability, chloride ion penetration, bond strength, ductility, strain-rate, coefficient of thermal expansion and modulus of elasticity. The tests conducted follow ASTM and AASHTO standards where possible. A few variations to the standards are made to accommodate the limitations of the Idaho State University Laboratory. In each of the tests conducted the RAP mix performed as well or better than the control mix, except for the strain rate tests where the results were inconclusive These results show that the inclusion of RAP coarse aggregate in a high strength mix is a viable solution to achieve a “green” alternative to normal concrete mixes.Andrew D. Sorenson
04/30/17April 2017 Concrete Overlay Performance on Iowa’s Roadwayshttps://cptechcenter.org/ncc-projects/concrete-overlay-performance-on-iowas-roadways/bonded concrete overlays, concrete overlay performance, international roughness index, pavement condition index, Pavement cracking, Pavement preservation, pavement rehabilitation, unbonded concrete overlays, Whitetopping Pavement preservation and rehabilitation have been growing in importance nationwide, which has led to increased interest in concrete overlays. The objective of this study was to develop a report on the performance of concrete overlays in Iowa. Pavement condition data such as the international roughness index (IRI), transverse cracking, longitudinal cracking, D-cracking, spalled joints, and faulting has been collected on Iowa roadways since 2002. From this data, a determination of the pavement condition index (PCI) is made. By comparing key concrete overlay parameters, such as overlay type, thickness, age, and joint spacing, with IRI and PCI performance data, long-term performance trends can be established to complete the first major concrete overlay performance study of its kind. A summary of results showed that Iowa’s overlays performed very well, with service life trends exceeding previously defined expectations for concrete overlays. Further investigation of outlying data from poorly performing projects showed distress tended to be based on a combination of project-specific material- and construction-related issues rather than inherent overlay design issues. Addressing the causes of these issues may further improve the performance life of concrete overlays. Jerod Gross, Dan King, Dale Harrington, Halil Ceylan, Yu-An Chen, Sunghwan Kim, Peter Taylor, Orhan Kaya
09/01/20September 2020 Construction of Low-Cracking High-Performance Bridge Decks Incorporating New Technologyhttps://cptechcenter.org/ncc-projects/construction-of-low-cracking-high-performance-bridge-decks-incorporating-new-technology/Bridge construction, Bridge decks, Condition surveys, Cracking, Fly ash, high performance concrete, Lightweight aggregates, Mix design, Slag cement Construction and early-age crack evaluations of four bridge decks in Minnesota placed from 2016 to 2018 that incorporate specifications for Internally-Cured Low-Cracking High-Performance Concrete (IC-LC-HPC) are documented in this study. Two additional decks followed specifications for high-performance concrete and served as controls paired with IC-LC-HPC decks. Pre-wetted fine lightweight aggregate (FLWA) was used to provide a targeted internal curing water content of 8% by total weight of binder. The IC-LC-HPC mixtures included 27 to 30% slag cement by total binder weight while the control mixtures included 25 or 35% Class F fly ash by total weight of binder. For one IC-LC-HPC deck, mixture proportions were modified based on a higher FLWA absorption than originally used to design the mixture. One IC-LC-HPC placement failed due to errors in FLWA moisture corrections and concrete batching that led to rejections of batches, leaving an inadequate supply of material to complete the deck. Crack surveys were completed for the IC-LC-HPC and control decks placed in 2016 and 2017. Crack densities at these ages were low compared to most Low-Cracking High-Performance Concrete decks in Kansas and Internally-Cured High-Performance Concrete decks in Indiana. The only exception was one IC-LC-HPC deck that exhibited extensive cracking within one year after placement, which had an overlay with a high cement paste content and no internal curing. This project serves as a foundation for implementing IC-LC-HPC in upcoming bridge decks in Kansas and Minnesota. David Behzadpour, Alireza Bahadori, David Darwin, Matthew O'Reilly, Mohsen Salavati Khoshghalb
12/31/23December 2023 Construction of Low-Cracking High-Performance Bridge Decks Incorporating New Technology: Phase IIhttps://cptechcenter.org/ncc-projects/construction-of-low-cracking-high-performance-bridge-decks-incorporating-new-technology-phase-ii/Bridge decks, Construction management, Cracking, Fracture mechanics, high performance concrete, Internal curing, Internally Cured Low-Cracking High-Performance Concrete, Lightweight Aggregate The construction, crack surveys, and evaluation of 12 bridge decks with internal curing provided by prewetted fine lightweight aggregate and supplementary cementitious materials following internally cured low-cracking highperformance concrete (IC-LC-HPC) specifications of Minnesota or Kansas are described, as well as those from two associated Control decks without IC (MN-Control). Nine IC-LC-HPC decks and one Control deck were monolithic, while three IC-LC-HPC decks and one Control deck had an overlay. The internally cured low-cracking high-performance concrete had paste contents between 23.8 and 25.8 percent by volume. Of the 12 IC-LC-HPC decks, nine were constructed in Minnesota between 2016 and 2020, and three were constructed in Kansas between 2019 and 2021. The performance of the decks is compared with that of earlier IC-LC-HPC bridge decks and low-cracking high-performance concrete (LC-HPC) bridge decks without internal curing. The effects of construction practices on cracking are addressed. The results indicate that the use of overlays on bridge decks is not beneficial in mitigating cracking. The IC-LC-HPC decks constructed exhibited lower average crack densities than those without internal curing. Good construction practices are needed for low-cracking decks. If poor construction practices, which may include poor consolidation and disturbance of concrete after consolidation, over-finishing, delayed application of wet curing, are employed, even decks with low paste contents and internal curing can exhibit high cracking. Delayed curing and over-finishing can also result in scaling damage to bridge decks. David Behzadpour, Alireza Bahadori, David Darwin, Matthew O'Reilly, Mohsen Salavati Khoshghalb
05/01/22May 2022 Establishing Fresh Properties of Fiber Reinforced Concrete for Performance Engineered Mixture (PEM)https://cptechcenter.org/ncc-projects/establishing-fresh-properties-of-fiber-reinforced-concrete-for-performance-engineered-mixture-pem/Admixtures, Concrete pavements, Concrete tests, fiber reinforced concrete, Fresh concrete, Mix design The addition of macro or structural fibers into concrete enhances its post-cracking performance. The objective of this study was to conduct a laboratory investigation to determine the influence of structural fibers on the fresh concrete test parameters (Super air meter (SAM) number, V-Kelly index, and Box test rating) recommended for the performance engineered mixture (PEM) procedure. As many as fifty-seven different concrete mixes were designed and prepared, varying fiber types and dosages, aggregate types, and air contents of the concrete. Various fresh and hardened concrete tests were conducted on each of the mixes, and the results were used to determine the influence of the structural fibers on the fresh and hardened concrete properties. The study recommended the allowable range of the SAM number and provided necessary guidance on the box test rating and V-Kelly index for the fiber-reinforced concrete mixtures to be designed as per the PEM procedure. Manik Barman, Alieu Kamara, Austin Janson
01/01/18January 2018 Evaluating the Effectiveness of Fly Ashes to Mitigate ASR and Using Recycled Concrete Aggregate as an Aggregate Sourcehttps://cptechcenter.org/ncc-projects/evaluating-the-effectiveness-of-fly-ashes-to-mitigate-asr-and-using-recycled-concrete-aggregate-as-an-aggregate-source/aggregate, Alkali silica reaction, Concrete, Durability, Expansion, Wyoming A comprehensive study was performed to evaluate mitigation options to reduce premature expansion due to alkali-silica reaction (ASR) for selected Wyoming aggregates. State-of-the-art and standardized test methods were performed and results were used to compare expansion levels. Four different fly-ash sources were tested. All of the sources mitigated the moderately reactive aggregates; the most highly expansive aggregate was mitigated by two out of the four fly ash sources. An exploratory test, the Autoclave Concrete Prism Test (ACPT) was evaluated by comparing results with the University of Wyoming and the University of Alabama. Test data shows agreement between two independent laboratories. Bryce Fiore, Md Tarik Hossain, Margaret Kimble, Fayez AlMutawa, Jennifer Eisenhauer Tanner
08/31/19August 2019 SPR-4003: Improving the Quality of Concrete for INDOT Projectshttps://cptechcenter.org/ncc-projects/spr-4003-improving-the-quality-of-concrete-for-indot-projects/Concrete structures, Infrastructure, Project management, Quality controlThe project will be conducted at Oregon State University and includes two components: (1) Implementing rapid durability measure on concrete (resistivity; formation factor), and (2) Evaluating internal curing for other PCC beyond High PerformanceOregon State University
08/15/23August 2023 Measuring Transport Properties of Portland Cement Concrete Using Electrical Resistivityhttps://cptechcenter.org/ncc-projects/measuring-transport-properties-of-portland-cement-concrete-using-electrical-resistivity/Corrosion, Electrical resistivity, Freeze thaw durability, Portland cement concrete, Transport properties (Physics) Although classification tables based on susceptibility to chloride ion permeability are recommended in AASHTO T 358, the classification levels with respect to durability parameters may or may not be adequate. Of interest for concrete pavement performance, this study verifies the recommended classification levels against standard durability testing such as corrosion, salt scaling, and freeze-thaw. The researchers conducted corrosion, salt scaling, and freeze-thaw durability tests in parallel with electrical surface resistivity testing to compare performance classifications for each method. Twenty-four mixture designs were evaluated. The designs vary in water-to-cementitious material ratio (0.4, 0.45, and 0.5 w/cm ratio), supplementary cementitious material type (100% ordinary Portland cement, 20% Class C fly ash, 40% Grade 100 slag cement, and 8% silica fume replacements), and air content (air entrained and non-air entrained). The results of the experimental study indicate that there is no clear relationship between concrete electrical conductivity and durability performance based on standard methods of testing. It may not be appropriate for the determination of durability performance of a concrete mixture for concrete pavement construction. However, the test method does present advantages, as mixtures of similar composition and design can yield the same results over time under standardized curing. Here, resistivity-time curves could be a useful tool as part of a quality control and quality assurance program to ensure consistency in concrete delivery during construction. Julie Ann Hartell, Hang Zeng, Matthew O'Reilly
09/30/24September 2024 “Closing the Loop” for More Sustainable Transportation Infrastructure Materials: A Framework for Maximizing Mineral Resource Usage to Advance More Sustainable Cement-Based Materialshttps://cptechcenter.org/ncc-projects/closing-the-loop-for-more-sustainable-transportation-infrastructure-materials-a-framework-for-maximizing-mineral-resource-usage-to-advance-more-sustainable-cement-based-materials/Cement, Climate change mitigation, Concrete, Environmental impacts, Equity, Greenhouse gases, Life cycle analysis, Recycled materials, Resource utilization, Sustainable transportation Concrete is integral to building and maintaining transportation infrastructure, but it is also responsible for nearly 10% of human-caused greenhouse gas (GHG) emissions. Most of these emissions are from cement production (70-90%). As 30% of cement consumption is for transportation infrastructure, the impacts of concrete need to be reduced to develop enable sustainable transportation systems. Typically, replace cement with supplementary cementitious materials (SCMs) (e.g., fly ash from coal combustion or slag from pig iron production) is used to reduce GHG emissions. However, the supply of conventional SCMs is restricted. Society needs additional SCM resources to meet the demand for concrete materials while also complying with legislative requirements to reach net-zero cement GHG emissions by 2045. This work concurrently evaluates unconventional SCMs using industrial ecology techniques (i.e., life cycle assessment and material flow analysis) and experimentally determined mechanical performance metrics. This dissertation will present an evaluation framework, using material from California as a case study, to prioritize the adoption of SCM by concurrently considering (1) material performance, (2) resource availability, and (3) environmental impact reduction. Environmental impacts and global warming disproportionally affect historically marginalized and low-income communities. Thus, by enabling more sustainable concretes, this dissertation aligns with NCST and PSR UTC goals to develop more equitable and more sustainable transportation systems. Lauren Iacobucci, Patrick Cunningham, Sabbie Miller
09/01/25September 2025 Research on Local Aggregates: Recycled Concrete Aggregate (RCA)https://cptechcenter.org/ncc-projects/research-on-local-aggregates-recycled-concrete-aggregate-rca/Recycled concrete aggregate (RCA) One of the main factors for the low usage of Recycled Concrete Aggregate (RCAs) in concrete construction in the United States is the absence of reliable methods to characterize the quality level of these materials. The goal of this research is to develop a new petrographic method to characterize, evaluate the quality and variability of RCAs from single or multiple sources. This research will be performed to create method that correlates the physical properties of the concrete paste microstructure with quantitative data of bulk paste microstructure obtained by image analysis of fluorescent images of thin sections. Standard petrographic methods including microscopic examination, water-drop absorption test, qualitative paste hardness scratch test, stereomicroscopic examination, transmitted, Polarized Light Microscopy (PLM), Fluorescent Light Microscopy (FLM), and Image Analysis (IA) will be used during the petrographic evaluation of these four types of RCAs. Jack Youtcheff
09/30/23September 2023 Reducing Concrete Cure Times for Bridge Substructure Components and Box Culvertshttps://cptechcenter.org/ncc-projects/reducing-concrete-cure-times-for-bridge-substructure-components-and-box-culverts/Acceleration, C-S-H Seeds, Compressive strength, Concrete, Electrical resistivity, Fly ash, Formation Factor, Open Porosity This report investigated pathways to reduce concrete curing time while maintaining mechanical and durability performance. Among several options such as admixtures, supplementary cementitious materials, and low water-to-cement ratio, researchers explored two mix designs in a field demonstration project. For Stage I of the project, a low water-to-cement ratio concrete mixture was used. For Stage II, the use of calcium-silicate-hydrate (C-S-H) based seeds was explored. Concrete laboratory mixtures containing C-S-H seeds X1 and X2 exhibited increased early-age strength and reduced permeability. Based on these findings and the Illinois Department of Transportation acceptance of X2 as a Type S admixture, a field demonstration project was conducted on a box culvert near Armstrong, Illinois. The X2 concrete mix design was compared to a low water-to-cement ratio concrete mix design. Results showed that the X2 mixture with C-S-H seeds consistently demonstrated higher strength than the low water-to-cement concrete mixture, suggesting that seed-based admixtures can provide additional benefits for reducing curing times. The recommended dosage of X2 is 5 fl oz/cwt for optimal performance in reducing cure time. Nishant Garg, Faisal Qadri
05/31/24May 2024 A Sustainable Snow-Free Pavement to Mitigate the Negative Effect of Road Salts on Soil and Water Environmenthttps://cptechcenter.org/ncc-projects/a-sustainable-snow-free-pavement-to-mitigate-the-negative-effect-of-road-salts-on-soil-and-water-environment/Alternatives analysis, Deicing, Deicing chemicals, Environmental impacts, Geothermal resources, Heat exchangers, Runoff Extreme weather in winter, characterized by prolonged and severe conditions, is anticipated soon due to climate change. Consequently, the utilization of deicing chemicals such as salts (including Chloride-based, Formate-based, and Acetate solutions) is inevitable. These chemicals are employed to ensure driving safety and minimize fatal accidents, particularly on critical infrastructure like bridges, highway ramps, and transportation corridors. However, the introduction of chemical solutions into surface runoff, with subsequent infiltration into groundwater, poses significant environmental challenges. This phenomenon can have adverse effects on both soil and water ecosystems, potentially accelerating water eutrophication. Long-term road salt application leads to elevated chloride concentration in groundwater, rivers, lakes, and freshwater bodies, which disrupts aquatic ecosystems. Additionally, sodium chloride (NaCl) impacts abiotic processes in soil and water. A recent study conducted in New York highlighted the impacts of road salts on private wells in the Town of Orleans, New York State. Moreover, road salts can alter soil structures and influence biotic communities. Therefore, it is imperative to explore alternative pavement de-icing methods to mitigate soil and water contamination. This project aims to reduce chloride pollution in soil and water ecosystem with the use of active (circulating heat carrier fluid) or passive (use of higher thermal conductive elements) geothermal system. Shallow geothermal energy presents a viable solution for pavement de-icing, promoting safety while eliminating the environmental concerns associated with chemical deicers. In the case of active geothermal systems, heat exchanger tubes can be embedded within the concrete pavement to effectively de-ice the surface. Additionally, the project will investigate an innovative passive system that leverages geothermal energy to prevent ice accumulation on the pavement surface. The passive approach involves the installation of solid heat exchangers composed of materials with high thermal conductivity, deep within the soil (20 to 30 feet) to transfer geothermal heat to the surface. Both active and passive geothermal systems offer alternatives to chemical usage, particularly road salts, thus preventing soil and water contamination. By embracing these geothermal solutions, the project aims to revolutionize pavement de-icing practices while safeguarding the environment. Robin Kline, Omid Ghasemi-Fare
12/31/25December 2025 SPR-4860: Environmental Product Declaration (EPD) Benchmark Project for Indiana Asphalt and Concrete Pavementshttps://cptechcenter.org/ncc-projects/spr-4860-environmental-product-declaration-epd-benchmark-project-for-indiana-asphalt-and-concrete-pavements/Environmental impacts, Materials selection, Mix design, Pavements Environmental product declarations (EPD), in conjunction with mixture and pavement testing will provide data and a framework for guidance to make decisions for a high-quality and more sustainable asphalt and concrete mixtures. The data will be used to create benchmarks for Indiana asphalt and concrete mixtures and their environmental impact using EPD reports. John Haddock
12/31/24January 2024 Exploring Fungal-Induced Carbonate Precipitation (FICP) for Healing Concrete Crackshttps://cptechcenter.org/ncc-projects/exploring-fungal-induced-carbonate-precipitation-ficp-for-healing-concrete-cracks/Calcium carbonate, Concrete, Cracking, Durability, Fungi, Precipitation (Chemistry) Concrete structures can develop cracks during early-stage curing and long-term aging processes, reducing load-bearing capacity and affecting the service life of concrete structures. This research aims to explore fungal-induced carbonate precipitation (FICP) to heal cracks and improve the durability of concrete. FICP is a natural biomineralization process involving calcifying fungi's metabolic activities to induce CaCO3 precipitation. This research investigates the performance of several fungal strains (e.g., their growth behavior and efficiencies of FICP versus time) on the surface of cement mortar. The optimal fungal strain will be used to assess its healing capability on concrete cracks. Hai Lin
09/30/24September 2024 Advanced Environment-Friendly Concrete Materials for Rapid Infrastructure Repair and Rehabilitationhttps://cptechcenter.org/ncc-projects/advanced-environment-friendly-concrete-materials-for-rapid-infrastructure-repair-and-rehabilitation/Cement, Ductility, Engineered materials, Mechanical properties, Mix design, Repairing The United States has many infrastructure challenges in terms of maintaining and repairing an extensive network of aging roads and bridges. Additionally, an increased focus on environmentally friendly processes and materials means that there is an urgent need to develop and evaluate alternative cementitious materials and novel portland cement-based solutions to infrastructure maintenance issues. One promising technology is the utilization of calcium sulfoaluminate (CSA) cements in the production of concrete materials. CSA cements offer several advantages, including lower carbon intensity (compared to portland cement), rapid setting, and low shrinkage. These properties make them an ideal candidate for rapidly replacing or repairing critical transportation infrastructure. In addition, Engineered Cementitious Composites (ECCs) with superior ductility and mechanical strength have been proposed as a promising material alternative to extend the durability and service life of infrastructure. However, ECC typically requires a high cement content, leading to challenges such as increased hydration heat, autogenous shrinkage, and higher carbon dioxide emissions. To address these challenges, this project aims to investigate the feasibility of using CSA as a partial or complete replacement for cement in ECC without sacrificing its mechanical properties, specifically tensile ductility. The addition of CSA in concrete and ECC materials will be tested separately at the participating institutions. The Principal Investigators have planned activities to enhance collaborations between the University of Arkansas and Louisiana State University by sharing research findings, which include pursuing future collaborations and strengthening the connections between the researchers. The objectives of this study will be met through two primary tasks, one at UARK and one at LSU. The UARK researchers will examine the durability properties of belitic calcium sulfoaluminate (BCSA) cement through the following sub-tasks: (1) reviewing existing literature and preparing a test matrix including mixture designs, cement types, and curing conditions; (2) conducting experimental testing to determine carbonation and chloride penetration depths; and (3) analyzing results and preparing the final report. The LSU researchers will investigate the mechanical properties of CSA-based ECC through the following sub-tasks: (1) characterizing CSA cement to determine chemical composition, surface condition, and particle size distribution and then using that information to develop ECC mix designs; (2) investigating compression and tension behavior of developed mix designs; (3) examining adaptation of developed ECC mixes for 3D concrete printing; and (4) working with the UARK team, develop the final project report. Deliverables include the following: (1) Comprehensive reports documenting the corrosion performance of CSA cement concrete; (2) Prototypes demonstrating the effectiveness of CSA-based ECC in infrastructure repair. The outcome of this research project will be several successful CSA-based ECC mix designs that will be readily available to the state DOTs for implementation in the transportation infrastructure as well as for further evaluation in future research projects. Denise Dunn, Cameron Murray, Hassan Noorvand
12/31/24December 2024 Recycling Portland Cement Concrete Pavements using Rubblization and Fractured Slab Techniqueshttps://cptechcenter.org/ncc-projects/recycling-portland-cement-concrete-pavements-using-rubblization-and-fractured-slab-techniques/hot mix asphalt, Pavement design, Portland cement concrete, Recycled materials, Rubble This study will investigate the material properties of rubblized concrete under HMA layers for design purposes. The project recently done on I-55 in Pike County, as well as the project yet to be done on I-59 in Forrest and Jones Counties, will be used for the research on rubblization. A break-and-seat project is to be done on I-55 in Tate County, which will be investigated as part of this study.
06/30/24June 2024 MDOT Implementation of Pavement ME Phase IV Study 1 of 2: Update Plan of Implementation of AASHTOWare PMED based on MDOT-Funded Researchhttps://cptechcenter.org/ncc-projects/mdot-implementation-of-pavement-me-phase-iv-study-1-of-2-update-plan-of-implementation-of-aashtoware-pmed-based-on-mdot-funded-research/Data collection, Implementation, Pavement design, Stone matrix asphalt, Test sections In this study a review of the final report for multiple Mississippi Department of Transportation (MDOT) research studies and the engineering site report for each of 64 pavement test sections field sampled/tested in MDOT SS No. 263, “Data Collection for Local Calibration of the AASHTOWare Pavement ME Design Performance Models for Mississippi” will be conducted. The information from these sources will be synthesized and the plan of implementation of AASHTOWare PMED for Mississippi will be updated. This study will also produce a list of recommended stone matrix asphalt (SMA) test sections for a future field sampling/testing study, similar to the one conducted for MDOT SS No. 263.
05/31/24May 2024 Retrofit, Self-Contained, and Smart Solar Ice Control System for Resilient Infrastructurehttps://cptechcenter.org/ncc-projects/retrofit-self-contained-and-smart-solar-ice-control-system-for-resilient-infrastructure/Concrete pavements, Heat transfer, Heating systems, Pavement design, Phase transitions, Snow and ice control, Solar energy The proposed project will implement a micro-radiant heating system (MRHS) as a retrofit layer on the surface of existing concrete pavement. The technology will utilize a combination solar photovoltaic/thermal (PV/T) system and novel thermally active materials to keep surfaces free of snow and ice. The self-contained system will effectively provide heating, improve safety, reduce winter maintenance, while reducing carbon emissions to the environment compared to existing technologies, and eliminating the usage of deicing salt for the control of ice/snow during cold seasons. To enhance the performance, the system will incorporate low operating temperature phase change material (PCMs) based heat transfer fluid (HTF) and surface composition to circulate/store the energy in the system. The latent heat release from the PCMs provide backup source of energy during days when little-to-no-sun is available. As an additional benefit, the system will reduce the number of freeze-thaw cycles experienced by the pavement, improving long-term durability. Robin Kline, Sarvenaz Sobhansarbandi, John Kevern
Extend Service Life of Concrete Bridges Decks with Internal Curinghttps://cptechcenter.org/ncc-projects/extend-service-life-of-concrete-bridges-decks-with-internal-curing/Bridge decks, Concrete bridges, Concrete curing, Life cycle costing, Lightweight aggregates, Service life Proper curing of the concrete during the hydration process plays a vital role in the durability and longevity of the service life of concrete structures. Conventional curing techniques adopted for bridge decks are applied externally through wet-burlaps, thermal insulators, or membranes. Due to the large surface areas of bridge decks and pavement concrete, these external methods are not always effective in providing sufficient moisture to support the long-term hydration of the concrete cementitious matrix. This leads to plastic shrinkage cracks, a considerable loss of strength, and abrasion resistance. Even though strength development on the concrete surface is adversely affected by improper external curing, long-term durability is a much more significant concern. IC-HPC offers a unique approach to more durable and sustainable concrete. IC-HPC is produced by incorporating highly absorptive materials such as pre-wetted lightweight aggregate (LWA), super absorbent polymers, or chemical admixtures. These materials readily desorb water into the cementitious matrix during hydration, promoting internal humidity and boosting concrete to offer its maximum potential, especially with the loss of external curing efficiency. To evaluate the efficiency of internally cured concrete for New Jersey bridge structures, the framework of this research proposes two main phases. Phase I consist of an extensive review of other neighboring states’ DOT’s specifications, lessons learned, and challenges of the current practices for IC-HPC in the US. Afterward, Phase II is aimed to; (1) conduct a laboratory testing program tailored to evaluate the use of LWA to produce more durable concrete, (2) assess the technical feasibility of implementation of IC-HPC, and (3) perform LCCA for the benefits expected. This research is devoted to promoting the application and production of IC-HPC in NJ. Priscilla Ukpah, Hani Nassif
09/30/24September 2024 Bond Performance of Advanced Environmentally Friendly Concrete Materials for Rapid Infrastructure Repair and Rehabilitationhttps://cptechcenter.org/ncc-projects/bond-performance-of-advanced-environmentally-friendly-concrete-materials-for-rapid-infrastructure-repair-and-rehabilitation/Admixtures, Bond strength (Materials), Cement, Concrete bridges, Freeze thaw tests, Mix design, Repairing Portland cement production results in approximately 2.5 gigatons of direct CO2 emissions per year, or between 5% and 10% of CO2 emissions produced by humans. Calcium sulfoaluminate (CSA) cements are a promising alternative to hydraulic cements because of the significant reduction (nearly half) in CO2 emissions during production and high early strength (rapid setting) or controlled expansion (shrinkage compensating). These properties make CSA cement attractive and effective for transportation infrastructure, including accelerated repair of pavement and/or mitigation of shrinkage cracking. Half of the bridges in the United States already have or will reach their anticipated design life in the next 10 years. Many of these bridges can have their service life safely extended – with reduced environmental impact – by targeted repair and rehabilitation using CSA cement. Using concrete mix designs developed at the University of Oklahoma (OU), the University of Arkansas, and Louisiana State University, the proposed research will evaluate the ability of CSA cement to bond to traditional concrete substrates and the durability of those bonds over time. The objectives of the proposed study are to (1) Evaluate the bond performance of CSA cement concrete for varying substrate conditions; (2) Evaluate the freeze-thaw durability of CSA cement concrete repairs; and (3) Develop and communicate recommendations for CSA cement concrete repairs. These objectives will be achieved by experimental evaluation of CSA cement concrete mix designs developed at OU and SPTC partner institutions through six specific tasks. Task 1 will involve identifying CSA cement concrete mix designs for use in further testing. Task 2 will examine the bond of the CSA cement concrete repair materials to conventional concrete substrates with different surface preparations, using direct pull-off testing. In Task 3 freeze-thaw resistance of the repair interface will be evaluated using rapid freeze-thaw cycles. Repaired interfaces for both newly cast specimens and concrete from in-service bridges will be tested for freeze-thaw resistance. In Task 4 bond and freeze-thaw results will be compared with the results for other advanced concrete materials. Task 5 will involve the construction of a large-scale repair demonstration for DOT officials that will then be used for long-term performance evaluation. Task 6 will include the development of educational materials including a prerecorded training module, a live workshop, and a demonstration for high school outreach events. This project will provide mix designs and data on the bond behavior of CSA cement-based repair materials to concrete substrates of varying conditions and surface preparations, as well as recommendations for mix designs and surface preparations for repair using CSA cement concrete. CSA cement concrete for repair of existing transportation structures will allow more rapid repairs/rehabilitations that reduce the impact on the traveling public while extending the life of existing structures. Denise Dunn, Floyd Royce, Jeffery Volz, Shreya Vemuganti
09/30/25September 2025 SPR-2297: Updating Pavement ME Climate Module for Efficient Design, Management of Oklahoma Pavementshttps://cptechcenter.org/ncc-projects/spr-2297-updating-pavement-me-climate-module-for-efficient-design-management-of-oklahoma-pavements/Climate, Mechanistic-empirical pavement design, Pavement design This project will explore the design of climate-resilient pavements utilizing the global climate models (GCMs), and appropriate maintenance and rehabilitation measures will be also be selected. The GCMs will be evaluated and the most relevant models will be selected, and appropriate downscaling techniques that are suitable for the conditions of Oklahoma will be utilized. The selected model(s) will be used for prediction of future climate conditions and generation of synthetic data. The suitability of Oklahoma Mesonet climate data will be evaluated, as well as suitability of extracting historical climate data from other sources, for evaluation and use as a database for predicting distresses in selected pavement sections in Oklahoma. Pavement distresses will be analyzed using projected future climate data. Historical Oklahoma Mesonet data, and data from other sources including existing climate data files, will be used to create virtual weather stations in the current AASHTOWare Pavement ME software. Performance of the virtual weather stations will be analyzed and compared with those from the existing stations. Software simulation results will be analyzed to establish a regionwide climate data source for improved design of pavements in Oklahoma. Amanda Warren, Jerry Rice, Rifat Bulut
02/06/25February 2025 Development of a Pavement Repair Guide and Training Toolshttps://cptechcenter.org/ncc-projects/development-of-a-pavement-repair-guide-and-training-tools/Detection and identification, Handbooks, Pavement distress, Pavement maintenance, Repairing, Technology transfer, Training Currently ODOT's pavement repair strategies can vary widely based on the knowledge of the person directing the work. Engineers, inspectors and maintenance staff determine repair needs based on visual inspection and then repair types are determined by their experience. This project would develop both a printed and digital pocket guides that could be utilized on PCs or mobile devices allowing the user to find examples of the distresses they are seeing, provide the distress classification, proper repair type, and or any investigation that should be performed. This tool could be utilized by design staff scoping projects, construction staff marking repairs, and maintenance staff planning repairs. Additionally, this project would develop training materials that can be utilized for in-person or online training courses to provide the foundation for staff utilizing the pocket guide. Ultimately, with better training and identification tools, staff should be equipped to make better decisions. This should result in less waste by eliminating improper scoping of repairs, unnecessary repairs in construction, and eliminating other ineffective repairs. The goal of this research is to improve pavement repairs through the develop of technology transfer aids. Project objectives include the develop classroom training materials, for use by ODOT instructors, to provide training and professional development on pavement distress identification and proper repair techniques, the development "pocket guides" for in-field use by ODOT staff to assist in the identification of pavement distresses and proper repair techniques and development recommendations for electronic aids of the pocket guide for in-field use by ODOT staff on Internal Operating System (IOS) and Android mobile devices. Jennifer Spriggs, Shreenath Rao
09/30/24September 2024 Sustainable Concrete Using Native Materials from the Navajo Nationhttps://cptechcenter.org/ncc-projects/sustainable-concrete-using-native-materials-from-the-navajo-nation/Concrete pavements, Environmental impacts, Local materials, Mechanical properties, Mix design, Volcanic rock Using the Navajo Nation’s volcanic rocks and sands in concrete promotes sustainability and preserves natural resources in this culturally rich community. This study aims to use local volcanic materials from the El Malpais area for Jointed Plain Concrete Pavements (JPCP), reducing reliance on conventional aggregates and minimizing environmental impact. Therefore, the goal of this study is to reduce reliance on conventional aggregates, minimize environmental impact, empower the community, and promote economic development within the Navajo Nation. Specifically, this research will evaluate the mechanical properties of concrete containing fine aggregates of various particle size distributions, available locally. The proposed study includes the following seven tasks. Task 1: A targeted literature review will be conducted focused on the geology of the region, El Malpais, for collecting materials for this study. In addition to reviewing any use of the local materials, their properties reported in the literature will be documented. Task 2: Local volcanic aggregates and available cement materials will be collected. Task 3: Collected aggregates will be tested for their suitability for incorporation in concrete, including sieve analysis, specific gravity, water absorption, and moisture. Task 4: The mix design protocols commonly used by the Navajo Nation for JPCP mixes will be followed and tailored to the project needs, including the development of mix designs and associated material property testing. Task 5: Laboratory testing of properties required for JPCP will be conducted. Task 6: Life cycle cost analysis and carbon footprint calculations will be used to assess the economic and environmental benefits. Task 7: A comparison between the carbon footprint of the proposed mixes and typical concrete mixes will be conducted. This project seeks to empower the Navajo Nation, enhance sustainability, and promote DEIA through education and the use of local materials in infrastructure construction. This project will provide recommendations and guidelines for incorporating native aggregates in concrete construction, promoting sustainable and culturally sensitive building practices. The mix designs, test data, and recommendations will be used by the local companies and the Navajo Nation to promote the use of local materials to construct infrastructure and, thereby, enhance sustainability and economic benefits. Empowering the Navajo Nation’s aggregate industry can address the USDOT strategic goal of Economic Strength and Global Competitiveness. Denise Dunn, Anusuya Vellingiri
09/30/24September 2024 Development and Deployment of Titanium Alloy Bars for Strengthening and Cathodic Protection of Corrosion Damaged Transportation Infrastructurehttps://cptechcenter.org/ncc-projects/development-and-deployment-of-titanium-alloy-bars-for-strengthening-and-cathodic-protection-of-corrosion-damaged-transportation-infrastructure/Cathodic protection, Coastal engineering, Concrete structures, Corrosion, Reinforced concrete, Titanium alloys This project will develop and demonstrate a new concept for strengthening and preserving corrosion-damaged coastal transportation infrastructure. A system of titanium alloy bars (TiABs) combined with a surface coating and bonding system will be developed. The TiABs provide immediate strengthening and then are integrated into an impressed current cathodic protection system to provide long-term durability of corrosion-damaged reinforced concrete structures. This multi-functional material application is novel for civil infrastructure applications. The research will develop a mixed metal oxide (MMO) coating for the TiABs that will enable them to be used effectively in an ICCP system over long timescales. No prior MMO system has been used at the scale required for civil infrastructure. The system will be demonstrated on conventional reinforced concrete beams and on AASHTO Type III prestressed concrete girders that were widely used in past bridge applications. These members, when located in environments subjected to salt intrusion such as in coastal environments are susceptible to corrosion and resulting loss of strength. Results will be a field applicable system with design guidelines for allowing implementation into rehabilitation and preservation practices. Britain Bruner, Stacey Kulesza, Christopher Higgins
08/31/24August 2024 Integration and Deployment of Novel Tools for Rapid Assessment of Pavement Conditions and Remaining Lifehttps://cptechcenter.org/ncc-projects/integration-and-deployment-of-novel-tools-for-rapid-assessment-of-pavement-conditions-and-remaining-life/Climate change, Condition surveys, Data analysis, Falling weight deflectometers, Ground penetrating radar, Pavement management systems, Service life Extreme heat events from climate change are expected to expose pavements to more intense and prolonged stress. These events, coupled with soil movement from heavy rainfall and drought are also expected to threaten their functional and structural life. State and local agencies have benefited from innovative technologies and tools developed to rapidly assess pavement conditions, but data has not yet been widely implemented into pavement management systems that provide cohesive and holistic assessments of state roadways. A hybrid approach combining traffic speed deflectometer (TSD) and air-coupled ground penetrating radar (GPR) data is proposed that will allow for large-scale data collection and analysis for use in state-level pavement management systems. In this study, researchers will coordinate with Texas Department of Transportation (TxDOT) district offices to collect TSD and GPR data from roadways that are representative of different structural and functional conditions. The research team will work with the TxDOT districts to identify project sections of interest for closer evaluation. These sections may need maintenance or structural repair, have been recently constructed, or be in good condition. Collected data may be used to assist the district in pavement management activities and/or assess district priorities. In addition, Oklahoma recently collected TSD data from about 250 miles of interstate pavements. The Texas Transportation Institute (TTI) team will conduct GPR and fast-falling weight deflectometer (FFWD) testing at locations of interest identified by the Oklahoma team, based on the analysis of the collected TSD data. The TTI team may then assist in data analysis and relay the collected data to the Oklahoma team. Furthermore, the research team will develop a program for TxDOT to integrate the collected TSD and GPR data within a widely used existing program to analyze GPR data. This will allow the participating districts to gain a more holistic understanding of pavement structural data and better understand the impact of structural anomalies/deficiencies on functional pavement metrics. Increased understanding from this project will lead to more informed decisions within pavement management decision trees. In addition, researchers will utilize the collected data, along with new and existing mechanics-based modeling tools to develop a process for prediction of pavement structural condition and prediction of remaining life that will aid in pavement management decisions. Researchers may utilize AI/ML-based tools to optimize the proposed process. The results may be shared with local state and government agencies for verification and development of maintenance/repair strategies, should they be necessary. The findings will assist in incorporating resiliency within pavement management programs by producing accurate pavement structural data and remaining life estimations, with consideration of increasingly harsh environmental conditions due to accelerated climate change and increased frequency and intensity of extreme weather events. Denise Dunn, Garrett Dorsett, Tom Scullion
05/31/24May 2024 Nanotechnology-Enabled Sustainable and Cement-Free Pervious Concrete Pavementhttps://cptechcenter.org/ncc-projects/nanotechnology-enabled-sustainable-and-cement-free-pervious-concrete-pavement/Concrete pavements, Durability, Fly ash, Geopolymer concrete, Infiltration, Mix design, Nanostructured materials, Sealing compounds, Water quality management The project will take the advantage of two WSU-patented technologies (US Patent 10647612 on geopolymer binder and a provisional patent on nano-engineered penetrating sealer) to develop a sustainable pervious concrete technology. Different from conventional pervious concrete, this technology will feature: (1) 100% replacement of cement by a cement-free and biochar-amended geopolymer binder with less than 0.05 wt.% graphene oxide (a novel nano-material); (2) greatly improved durability of the pervious concrete pavement by customized design of initial water infiltration rate and treatment of hardened concrete by a nano-engineered waterproofing sealer. It is expected that the use of fly ash and biochar in place of portland cement and the extended service life of pervious concrete will both contribute to great reduction in the life-cycle footprint of the pavement. This proposed work fits well under the ERTC3 thrust area of “Sustainable construction materials and practices”. This research consists of three main tasks. Task 1 will focus on optimizing the type and dosage of nanomaterials used for the siliconate-based penetrating sealer, the mix design of biochar/fly ash geopolymer pervious concrete customized to feature infiltration rates consistent with the local rainfall rates, and the timing and procedure to apply the sealer onto the pervious concrete pavement. The objective is to achieve a reasonable balance between mechanical properties, infiltration performance, and water absorptivity. Task 2 will focus on the evaluation and potential improvement of the performance of sealer-treated geopolymer pervious concrete, in terms of: freeze/thaw resistance, salt scaling resistance, abrasion resistance, and sulfate resistance. The objective is to achieve an acceptable level of durability in aggressive environments of concern. Advanced microscopic investigations will be conducted to shed light on the roles played by selected nanomaterials in both the sealer and the geopolymer pervious concrete. Task 3 will evaluate the environmental benefits of the sealer-treated geopolymer pervious concrete pavement, starting with its ability to treat typical pollutants-laden stormwater from roadways. Portland cement pervious concrete will be used as control to compare with this “greener” pervious concrete. The simulated stormwater will include pollutants such as copper, zinc, sulfate, ammonia, nitrate, total phosphate, petroleum hydrocarbons and sodium chlorideRobin Kline, Xianming Shi
08/31/24August 2024 Bio-waste Materials as Supplementary Cementitious Materials for Coastal Concrete Applicationshttps://cptechcenter.org/ncc-projects/bio-waste-materials-as-supplementary-cementitious-materials-for-coastal-concrete-applications/Biological materials, Portland cement concrete, Waste products (Materials) The cement industry releases approximately 8% of world’s CO2 - a significant source that induces climate change. To curb the carbon emissions from the cement and concrete industry, utilization of supplementary cementitious materials (SCMs) to replace a portion of portland cement in concrete is considered one of the most effective approaches. In the U.S., coal fly ash is by far the most used SCM. Despite being used every day, the supply of coal fly ash in the U.S. has lately become a matter of concern due to the promotion of renewable energy sources and blending of different coals that produce less amount of Class F fly ash – a type of fly ash that is preferred by the concrete industry. Therefore, it is critical to identify and evaluate alternative supplementary cementitious materials that can offer concrete equivalent or better strength and durability characteristics to Class F fly ash. One area that is being overlooked by the concrete industry for alternative SCMs is bio-waste materials, which include agricultural wastes, eggshells, burnt oyster shell, etc. In this project, the feasibility of using two bio-waste materials, i.e., sugarcane bagasse ashes and ground waste eggshells, as alternative SCMs in portland cement concrete for coastal applications is investigated. Britain Bruner, Stacey Kulesza, Xijun Shi
07/31/24July 2024 Enhancing the Resiliency of Pavement Infrastructure Built on Sulfate-Rich Expansive Soil Subjected to Climate Changehttps://cptechcenter.org/ncc-projects/enhancing-the-resiliency-of-pavement-infrastructure-built-on-sulfate-rich-expansive-soil-subjected-to-climate-change/Climate change, disaster resilience, Flexible pavements, Modulus of resilience, Pavement distress, Soil stabilization, Subgrade (Pavements), Sulfates, swelling soils, Triaxial shear tests The resilient modulus of bases and subgrade is one of the most important parameters used in the design of flexible pavement. In Region 8, there is an abundance of expansive soil from the Pierre Shale formation, which is known to be often rich in gypsum which is a major source of sulfate in soils. Traditional soil treatment methods like chemical stabilization using lime or cement may not work in such soils due to sulfate-induced heave. Very limited research has been conducted on the studying the variation of resilient modulus of such sulfate-rich expansive soils. The effects of climate change may induce additional distress on the pavement infrastructure including embankments on which they are built which needs to be analyzed to ascertain the resiliency of the pavement infrastructure in the region. In the proposed study, a series of repeated load triaxial tests and suction-controlled triaxial tests will be conducted on a newly fabricated advanced triaxial setup to study the response of such problematic soils before and after treatment to evaluate the resiliency of such materials to potential cycles of extreme precipitation and drought-like conditions. Additional studies will be conducted to investigate the volume change during the wetting and drying cycles. Aritra Banerjee
08/01/22August 2022 Optimizing Reinforcing Steel in 12-inch and 13-inch Continuously Reinforced Concrete Pavement (CRCP)https://cptechcenter.org/ncc-projects/optimizing-reinforcing-steel-in-12-inch-and-13-inch-continuously-reinforced-concrete-pavement-crcp/CRCP, Horizontal Cracking, Punchout The performance of continuously reinforced concrete pavement (CRCP) in Texas has been excellent. However, truck traffic in Texas has been increasing, which required thicker slabs. Since TxDOT placed steel at the mid-depth of the slab, the use of thicker slabs increased the distance between top of the slab and longitudinal steel. This increase resulted in larger crack spacing and occasional horizontal cracking. Continued wheel loading applications degrade the top half of the concrete and partial depth distress. Traditionally, punchout has been reported as a major and only structural distress in CRCP. However, it has been observed that different types of cracking and resulting distresses have taken place in CRCP that has had improved design features such as thicker slabs, stabilized bases, and tied concrete shoulders. These cracks, which cannot be explained by traditional theories related to punchout and spalling, are normally associated with horizontal cracking at approximately mid-depth of the slab. This horizontal cracking has been observed in CRCP with thicker slabs, thickness of 12 inches or larger. It was also observed that horizontal cracks occurred at early ages before the pavement was open to traffic. These findings strongly indicate that horizontal cracks are not due to structural deficiencies of CRCP. Rather, concrete material properties, environmental conditions during and right after concrete placement, and most importantly longitudinal steel placement layouts must play a significant role in the development of horizontal cracking. The primary objective of this study is to identify the mechanisms and associated variables of horizontal cracking in CRCP and to develop mitigation methodologies. To this end, theoretical analyses of early-age CRCP behavior were conducted using 3- dimensional CRCP modeling, and field testing was conducted at 4 different CRCP construction projects. The behavior of CRCP at early ages under environmental loading (temperature and moisture variations) obtained from the field testing was compared with numerical analysis results and the model was calibrated. The effect of each variable related to design, material, and construction on the horizontal cracking potential was evaluated through comprehensive numerical analysis with a calibrated model. One of the major findings is that steel depth has significant effects on CRCP behavior and a modest decrease in the distance between slab surface and steel depth reduces horizontal cracking potential substantially. It is expected that the implementation of the findings from this study is expected to improve CRCP performance substantially for thicker CRCP. Heejun Lee, Niwesh Koirala, Fouzieh Rouzmehr, Christopher Jabonero, Moon C. Won
11/01/20November 2020 Evaluation of Use of Crushed Hydraulic Cement Concrete (CHCC) as an Additive to Base Course/Subbase Materialhttps://cptechcenter.org/ncc-projects/evaluation-of-use-of-crushed-hydraulic-cement-concrete-chcc-as-an-additive-to-base-course-subbase-material/Crushed Hydraulic Cement Concrete, Filtration Test, Geochemical Modeling, Nonwoven Geotextile, Precipitation, Tufa All new pavement systems constructed under the jurisdiction of the Virginia Department of Transportation (VDOT) require drainage systems. These drainage systems are constructed with perforated pipe and coarse aggregate that surrounds the pipe. Additionally, to separate the coarse aggregate from the base course and to create a filter, the drainage system also contains nonwoven geotextile that surrounds the coarse aggregate. Currently, the use of crushed hydraulic cement concrete (CHCC) as base course in new pavement systems is not allowed in VDOT projects because of the concerns associated with CHCC potentially clogging the geotextile of the drainage system to an extent that the serviceability of the filtration system is compromised. The basis of this concern is primarily due to the limited literature from the research conducted around the late 1990s. However, these studies are often inadequate in details and also present results that are contradictory and more importantly are not based on the specific geotextile used by VDOT. Recently due to the awareness of sustainable practices, there is interest throughout the U.S. to recycle CHCC and use it as base course aggregate. If allowed, this practice would result in the CHCC or blends of CHCC/virgin aggregate (V.A.) to be in direct contact with the geotextile. Several of the VDOT district material engineers developed a research needs statement (RNS) to investigate the VDOT provision that limits the use of CHCC. The research described in this report was conducted based on that RNS to evaluate the suitability of placing CHCC produced with a gradation similar to the Virginia 21 base course aggregate against the specific nonwoven geotextile allowed in Virginia roadways for the underdrain systems. The research described herein was primarily performed by George Mason University’s Sustainable Geotransportation Infrastructure research group. The reduction in serviceability of geotextile, when placed adjacent to CHCC and blends of CHCC and V.A., were evaluated based on the gradient ratio (GR) test. The effects of the stockpiling of CHCC before used as base course in a pavement system as it relates to changing the chemistry of CHCC were also evaluated. The results of this study show that stockpiling CHCC does not appear to create adverse effects as it relates to using CHCC as base course adjacent to geotextile. The chemical activity of CHCC stabilizes and the potential for leaching of calcareous constituents that may precipitate in the underdrain structure appears to decrease with increasing age of stockpiled CHCC. The precipitation of calcareous tufa from CHCC leachate due to the high release of alkali metals under favorable conditions is always a possibility. As such, the potential for precipitation is also shown and characterized using geochemical analyses in this study. Based on the findings, the calcareous precipitate potential appears to be significantly reduced by blending CHCC with V.A. When tested with base material having 9% fines or less, the serviceability of the geotextile used in this study did not decrease to levels such that the system flow was impacted. However, when the fines content exceeded 9%, major reductions in aggregate/geotextile system permeabilities were observed. Therefore, the fines content of the material placed over the geotextile used in the edgedrain should be limited to 9% as determined from the particles passing No. 200 U.S. sieve size. It is recommended that the findings of this study be evaluated in the field before implementing in highway construction. Burak F. Tanyu, Aiyoub Abbaspour
12/31/27December 2027 Concrete Bridge Deck Research for West Davis Corridorhttps://cptechcenter.org/ncc-projects/concrete-bridge-deck-research-for-west-davis-corridor/Bridge construction, Bridge decks, Concrete bridges, Cracking, Monitoring The objective of this research is to support new bridge deck research associated with construction of the West Davis Corridor highway project in northern Utah, where minimizing cracking of new concrete bridge decks is a high priority. Specifically, the work will complement and extend research activities already underway by the team of national experts. The main research will occur in two phases, one involving coring and analysis of existing bridge decks (not on the WDC project) and the other involving construction monitoring and inspection of new bridge decks on the WDC project. An additional research phase was added to monitor deck cracking for selected bridges on the WDC project after construction for a period of three years. David Stevens, W. Guthrie, Robert Stevens
02/29/24February 2024 Evaluation of Early Degradation in Bridge Deck Concrete: Not Fiber Reinforcedhttps://cptechcenter.org/ncc-projects/evaluation-of-early-degradation-in-bridge-deck-concrete-not-fiber-reinforced/Bridge decks, Concrete bridges, Deterioration, Mix design The primary objective of this research project is to investigate bridge deck concrete (without fiber) used on Utah Department of Transportation (UDOT) bridges in approximately the last 5-10 years for issues that have led to premature degradation, and recommend improvements for mix design and placement. The secondary objective of this research project is to better understand the cause of early degradation in bridge deck concrete used for UDOT projects. David Stevens, Andrew Sorensen
10/31/24October 2024 Developing and Characterizing Self-Healing Concrete for Bridge Deckshttps://cptechcenter.org/ncc-projects/developing-and-characterizing-self-healing-concrete-for-bridge-decks/Bridge decks, Concrete, Cracking, Deicing chemicals, Repairing This research will minimize cracking of concrete components, such as the ones observed in new bridge decks, by developing self-healing concrete (quicklime-based) suitable for applications in Utah, and quantifying the extent of crack-healing under service conditions as well as after exposure to salt-based deicing solutions. Brad Loveless, Srishti Banerji
06/30/24June 2024 Freeze-Thaw Durability of Rapid-Setting Concretehttps://cptechcenter.org/ncc-projects/freeze-thaw-durability-of-rapid-setting-concrete/Bridge decks, Cement, Concrete, Concrete pavements, Freeze thaw durability Given the regular wintertime freeze-thaw cycling that occurs in Utah and the extensive exposure of concrete utility collars, concrete pavements, and bridge decks to deicing salt, Utah Department of Transportation (UDOT) has requested this new research on the durability of a rapid-setting calcium sulfoaluminate cement (CSAC). In particular, the objective of this research is to evaluate aspects of a typical CSAC mixture (CTS Rapid Set cement) that relate to freeze-thaw durability. The scope includes field sampling of previously placed CSAC, lab testing, and analysis. David Stevens, W. Guthrie
12/31/24December 2024 Investigating the Performance of Concrete Incorporating Utah-recycled Glass Pozzolanhttps://cptechcenter.org/ncc-projects/investigating-the-performance-of-concrete-incorporating-utah-recycled-glass-pozzolan/Concrete, Glass, Pozzolan, Recycled materials This research will evaluate the performance of concrete containing pozzolan derived from local waste glass as partial cement replacement. Brad Loveless, Srishti Banerji
10/31/24October 2024 Laboratory Evaluation of Fresh and Hardened Concrete Comprising Type IP Portland-Pozzolan Cementhttps://cptechcenter.org/ncc-projects/laboratory-evaluation-of-fresh-and-hardened-concrete-comprising-type-ip-portland-pozzolan-cement/Barriers (Roads), Cast in place concrete, Fresh concrete, Portland cement concrete, Pozzolan, Specifications, Water cement ratio The objective of this project is to evaluate properties of fresh and hardened concrete comprising portland-pozzolan cement with respect to current Utah Department of Transportation (UDOT) specifications for cast-in-place concrete barriers. Specifically, the effects of a potentially higher water-cementitious materials ratio on the performance of the concrete in fresh and hardened states will be investigated, as well as methods of lowering the water-cementitious materials ratio to increase compliance with specifications. David Stevens, Taylor J. Sorensen, W. Guthrie
05/31/24May 2024 Long-Term Performance of Low Permeable Concrete for Structureshttps://cptechcenter.org/ncc-projects/long-term-performance-of-low-permeable-concrete-for-structures/Concrete structures, Corrosion, Nondestructive tests (NDT), Parking garages, Permeability, Pozzolan, ramps, Service life The primary objective of this research project is to perform non-destructive testing to evaluate the condition of a low-permeable concrete structure decks and ramp (the old SLC Int'l Airport parking structure). Secondary objectives of this research project are to validate the service life prediction for the structure using Life-365 corrosion prediction software and evaluate pozzolans (specifically silica fume) as additives in concrete for achieving similar low-permeable concrete mixtures in future structures. David Stevens, Amanda Bordelon
05/31/24May 2024 Parametric Analysis of the Durability and Chloride Penetrability of Fiber Reinforced Concrete Bridge Deckshttps://cptechcenter.org/ncc-projects/parametric-analysis-of-the-durability-and-chloride-penetrability-of-fiber-reinforced-concrete-bridge-decks/Bridge construction, Bridge decks, Chlorides, Durability, fiber reinforced concrete, Mix design, Parametric analysis, Strength of materials, Workability The primary objective of this research project is to reduce the uncertainty related to the fiber dosage rate and fiber dosage-to-paste volume ratio in fiber reinforced concrete mixes used in UDOT construction. By parametrically studying the effects of different fiber dosage rates on specific performance criteria, an ideal fiber dosage amount can be determined. The main performance criteria for optimization include strength, workability (ease of placement), long term durability (as a function of freeze/thaw and chloride penetration resistivity), and toughness (ability to flex with minimal cracking). David Stevens, Andrew Sorensen
11/30/27November 2027 Limiting the Total Cementitious Materials Content in Concreteshttps://cptechcenter.org/ncc-projects/limiting-the-total-cementitious-materials-content-in-concretes/Admixtures, Cement, Durability, Mix design, Sustainable transportation Current Virginia Department of Transportation (VDOT) specifications require minimum total cementitious materials content in all concretes except for the low shrinkage A4 modified concretes for bridge decks. Concrete mixtures with lower than the conventional or specified amount of total cementitious materials can lead to savings in cost and improvement in durability by reducing the occurrence and width of cracks, and thus contribute to sustainability. Through prior experience and references in literature, there are several potential options to achieve the required properties with reduction in cementitious materials. In this study the potential of using a maximum limit on the total cementitious material content to ensure a reduction in the amount required in the current specifications for different classes of concretes will be investigated. Celik Ozyildirim, Mary Sharifi
05/31/28May 2028 Performance of Portland Limestone Cement and Supplementary Cementitious Materials in VDOT Concreteshttps://cptechcenter.org/ncc-projects/performance-of-portland-limestone-cement-and-supplementary-cementitious-materials-in-vdot-concretes/Limestone, Portland cement, Sustainable transportation One major change in the cement industry is the introduction of the portland-limestone cements (PLC or Type IL) to reduce carbon footprint and to address concerns with sustainability. The only cement plant in Virginia has stopped producing the commonly used Type I/II cements. The new Type IL contains up to 15% limestone whereas the maximum limestone in Type I/II is 5%. Increase in the limestone amount in Type IL cement provides reduced carbon footprint but is expected to attain similar properties as the Type I/II cements mainly due to the nucleation sites created by the fine limestone particles. Supplementary cementitious materials (SCMs) are used to supplement the use of portland cement. Their use reduces the cost, improves the properties of concrete especially the durability of concrete, and contributes to sustainability. In this study existing and new SCMs will be investigated in the laboratory with the new Type IL cements to ensure quality and cost-effective concretes are achieved. Celik Ozyildirim, Mary Sharifi
06/30/28June 2028 Reducing Carbon Foot-Print in Concrete Applicationhttps://cptechcenter.org/ncc-projects/reducing-carbon-foot-print-in-concrete-application/Concrete, Environmental impacts, Hydraulic cement, Pastes, Pollutants, Sustainable transportation Hydraulic cement concrete (HCC) is the most widely used construction material worldwide. The production of portland cement, which is the main binder of HCC, is a large contributor of carbon emission. However, HCC, in general, has a low energy and carbon footprint compared to most other construction materials and has the potential of becoming even more sustainable. It is also possible to improve the properties of the concrete while making them more sustainable. Concretes with low paste contents have less shrinkage and temperature rise reducing the cracking potential and lead to improved durability. There are several effective measures, which can be applied to achieve emissions reduction in concrete materials, thus resulting in environmental benefits. In this research study, measures for CO2 emissions reduction will be analyzed for cement and concrete to identify their environmental effectiveness. It will include the past and present efforts of the Virginia Department of Transportation that result in carbon reduction and the future possibilities for further reduction without compromising the quality of concretes. Celik Ozyildirim, Mary Sharifi
11/01/23November 2023 Application of Engineered Cementitious Composites (ECCs) for Jointless Ultrathin Whitetopping Overlayhttps://cptechcenter.org/ncc-projects/application-of-engineered-cementitious-composites-eccs-for-jointless-ultrathin-whitetopping-overlay/Cement, Durability, Engineered materials, Fatigue tests, Fiber composites, Finite element method, Overlays (Pavements), Pavement joints, Whitetopping Engineered Cementitious Composites (ECC), which are a special type of high-performance fiber reinforced cementitious composite (HPFRCC), are proposed as a novel alternative for overlay applications since its outstanding mechanical properties (extreme ductility and superior flexural strength) have the potential to allow for jointless (or significantly large joint spacing) overlay systems at reduced thicknesses. The objective of this project is to evaluate ECCs for Jointless Ultrathin Whitetopping (UTW) overlay applications. To achieve this objective, ECC materials will be specifically designed for UTW application based on locally available materials. Fatigue evaluation of the UTW-ECC material will be performed to produce a σ-N relation (flexural stress vs. cycles to failure). Moreover, finite element analysis (FEA) and fatigue performance data of the UTW-ECC material (σ-N relation) will be integrated to produce a UTW-ECC overlay performance prediction model (overlay thickness vs. cycles to failure, H-N relation). To validate the developed model, a full-scale experiment of a UTW-ECC overlay system will be performed at the Louisiana Transportation Research Center (LTRC) Pavement Research Facility. Finally, a cost-analysis of the construction of jointless UTW-ECC compared to traditional jointed UTW overlays will be conducted. Marwa Hassan, Susan Bogus, Gabriel Arce, Tyson Rupnow
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