Iowa State University
Concrete pavements, Curling, Fatigue (Mechanics), Measurement, Pavement performance, Performance measurement, Quality assurance, Quality control, Traffic loads
The 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.