This paper describes an innovative experiment to construct and evaluate the performance of a thin concrete overlay placed on an existing asphalt pavement. While concrete overlays on asphalt (whitetopping) is an accepted pavement rehabilitation method, most whitetopping projects range in thickness from 100 mm to 250 mm. Little research and documentation exists on whitetopping projects less than 100 mm thick. To investigate the feasibility constructing thin whitetopping and to investigate the performance of such pavement, an experimental project was built in Louisville, Kentucky in September 1991. The project included a number of innovative features: 1) Two thin sections of concrete overlay (50 mm and 90 mm); 2) High-early concrete overlay (50 mm and 90 mm); 2) High-early strength concrete mixture; 3) Fast-Track paving techniques; 4) Polypropylene fibers. The project was constructed on the entrance road to a waste disposal facility. The roadway carries a high number of heavy trucks (400-600 per day). Several years of typical residential and low-volume road traffic were simulated in a few weeks. Therefore, the accelerated pavement performance evaluations were made. This paper documents the experiment's construction, material evaluation, instrumentation, and pavement performance. A correlation with observed pavement distress and applied traffic loading is made. Theoretical pavement stress calculations are presented. Reasons for the pavement's unexpectedly good performance are discussed. Possible applications for this innovative product and directions for future research are suggested. (A)
Abstract