Rutting and fatigue performance evaluation of warm mix asphalt mastic containing high percentage of artificial RAP binder

Abstract This study investigated the rutting and fatigue performance of asphalt mastics containing high percentage of artificial reclaimed asphalt pavement (RAP) binder and two types of warm mix asphalt (WMA) additives, R and M. The filler/asphalt ratio (F/A) ranged from 0.0 to 1.5 and the recycled asphalt binder was blended with 50% artificial RAP binder. The Superpave high-temperature performance grade test and multiple stress creep recovery (MSCR) test were carried out to evaluate the rutting resistance of recycled asphalt mastic. An approach to determine the optimum filler/asphalt ratio was also proposed based on the MSCR parameter Jnr-diff. The fatigue performance under strain-controlled and stress-controlled load modes was investigated by linear amplitude sweep (LAS) test and time sweep test. It was found that artificial RAP binder, WMA additive M and mineral fillers could improve the high-temperature performance while the incorporation of WMA additive R would offset the advantage of artificial RAP binder in rutting resistance. The fatigue test results indicated that the effects of artificial RAP binder, WMA additives and mineral fillers on the fatigue cracking resistance of asphalt mastic exhibited different dependencies on the load mode. Besides, the energy-based approaches might be more acceptable for evaluating the fatigue life of asphalt materials according to time sweep test results.