Performance Evaluation And Rehabilitation Of Asphalt Overlaid Concrete Pavements

This research is an in-depth investigation of the performance, evaluation, and rehabilitation of asphalt-overlaid concrete (AC/PCC) pavements. It addresses a critical need to better understand this type of pavement, which is quickly becoming a major portion of the highway mileage of the United States. The analysis of AC/PCC pavement performance includes investigation of AC/PCC pavement distress types, a survival analysis of AC overlays of JRCP, and field studies of AC/PCC pavements. Performance of AC/PCC pavements could be improved by considering traffic level, existing distress, preoverlay repair, and modes of AC overlay deterioration directly in design. Key condition indicators (distress, roughness, serviceability, subjective ratings, and rutting) were investigated to assess their usefulness in AC/PCC rehabilitation project selection. Guidelines are provided for a comprehensive project-level evaluation of AC/PCC pavements, including functional evaluation, structural evaluation, drainage evaluation, and an evaluation of the AC surface mix. Detailed guidelines and procedures were developed for distress surveying, nondestructive deflection testing, coring, and materials testing. A procedure was developed for backcalculation of PCC slab and foundation moduli from AC/PCC pavement deflection data. This backcalculation procedure quickly and repeatably produces results consistent with other backcalculation methods and consistent with observed distress and the condition of cores. Guidelines are given for interpretation and practical use of backcalculation results. Rehabilitation methods for structural, functional, drainage, and AC mix deficiencies in AC/PCC pavements are described. The four structural improvement options presented are second AC overlay, unbonded PCC overlay, fracturing the PCC slab before a new AC overlay, and reconstruction. Approaches to thickness design for the overlay options are summarized. The evaluation and rehabilitation guidelines were developed and tested using case studies of in-service AC/PCC pavements on Illinois Interstates. The case studies demonstrate the collection and analysis of design, construction, traffic, performance, distress, roughness, deflection, coring, and materials data for project-level evaluation and rehabilitation planning and design.