Accelerated Performance of a Failed Pavement on a Soft Clay Subgrade after Rehabilitation with High Polymer Mix at the NCAT Pavement Test Track

The Pavement Test Track is a full-scale, accelerated performance test facility for flexible pavements managed by the National Center for Asphalt Technology (NCAT) at Auburn University. Forty-six unique 60-m test sections are installed around a 2.7-km oval and subjected to accelerated damage via a fleet of tractors pulling heavy triple trailers. Methods and materials that produce better performance for research sponsors are identified so that future pavements can be constructed based on objective life cycle comparisons. In this study, a 250-mm thick, full depth asphalt pavement that failed near the end of the previous research cycle was first rehabilitated using conventional methods. When the section failed a second time after less than half the traffic that produced the original failure, it was decided to rehabilitate the section again using the same high polymer mix that had performed well in another test section. Traffic applied to the high polymer rehabilitation has now surpassed the level needed to completely fail the original conventional rehabilitation, with no indication that another failure is pending. An overview of the original construction and subsequent rehabilitation of the failed pavement on a soft clay subgrade are included in this paper, with a focus on comparing the performance of the conventional rehabilitation with the high polymer content asphalt inlay.