Early-age behavior of concrete overlays on continuously reinforced concrete pavements

Delamination is the primary mode of distress in most bonded concrete overlay (BCO) projects. The objective of the present study was to develop and calibrate a mechanistic delamination model to properly predict the early-age behavior of concrete overlays bonded to continuously reinforced concrete pavements (CRCPs). An experimental BCO on a CRCP section was constructed to monitor its behavior, and the field data were used to calibrate the mechanistic models. Two- and three-dimensional finite element models of the BCO on CRCPs were developed and calibrated. The results from the numerical analysis matched the experimental results well. Equations to predict the interfacial stresses at the corner of the composite structure by use of the two-dimensional finite element model were also developed. A sensitivity analysis was performed to investigate the effects of overlay and CRCP parameters, such as elastic modulus, thickness, coefficient of thermal expansion, and percent reinforcement, on the shear and interfacial normal stresses. This mechanistic model has been incorporated into the HIPERBOND (High-Performance Bonded Concrete Overlays) software developed for FHWA.