Application of the Repeated Simple Shear Test at Constant Height in the Prediction of Permanent Deformation Performance of Asphalt Mixes in Pakistan

The national Highway Authority in Pakistan faced with premature and extensive failures in the highway pavement network decided to evaluate the Performance Based mix design concepts that emerged from the Strategic Highway Research Program. The high traffic, high tyre pressure, high temperature conditions prevailing in Pakistan are outside the range of most empirical mix design criteria developed elsewhere. The repeated simple shear test at constant height together with the SHRP-A-698 Performance Based mix design concepts were used to successfully predict rutting occurring at Mansor Bend. Furthermore, the analysis indicated that changes in binder requirements and aggregate gradations might be needed to insure stable mixes.