Development of Proper Overlay Type and Designs for PCC Pavement

Project Details
STATE

TX

START DATE

01/01/16

END DATE

02/28/18

RESEARCHERS

Moon Won

SPONSORS

TX DOT

KEYWORDS

Continuously reinforced concrete pavements; Guidelines; Overlays (Pavements); Portland cement concrete; Rehabilitation (Maintenance); Reinforced concrete

Project description

Currently, guidelines on portland cement concrete (PCC) pavement overlay on PCC pavement are more focused on overlay slab thickness determination for mostly jointed concrete pavement (CPCD), but do not provide clear directions on (1) whether existing PCC pavement is a good candidate for concrete overlay, or (2) if it is, which overlay type-bonded concrete overlay (BCO) or unbonded concrete overlay (UBCO)-is appropriate. This deficiency in currently available guidelines is primarily due to insufficient information on the structural responses and performance of PCC overlays built on PCC pavements at various structural conditions. Very few existing design guidelines address continually reinforced concrete pavement (CRCP) overlays because other states have not built CRCP as much as Texas has. As of 2014, Texas Department of Transportation (TxDOT) manages a total of 17,300 lane miles of 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 rehabilitations in one form or another. This is especially true for the projects built prior to 1986, when TxDOT changed the pavement design period from 20 to 30 years. Those projects built or designed prior to 1986 have a deficiency in slab thickness from today‰Ûªs truck traffic volumes. Sound guidelines are needed for the selection of an optimum overlay type, especially for CRCP overlays, which could extend the performance period of structurally deficient PCC pavements in Texas at a reasonable cost.
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