Performance of regenerated asphalt mixture based on different sampling methods of RAP

Two sampling methods (bulk sampling method and stack sampling method) were selected to obtain the RAP samples. The Marshall method was used to design the mix proportion of regenerated asphalt mixture with different contents of RAPs. The performance and its variability of different regenerated asphalt mixtures were analyzed by the rutting test, low-temperature tensile test, immersion Marshall test and the freeze-thaw splitting test. Results show that the RAP obtained from the stack sampling method exhibits an improved effect on the low-temperature crack resistance and water stability of regenerated asphalt mixture in comparison with the RAP obtained from the bulk sampling method. The stack sampling method can reduce the performance variation of the regenerated asphalt mixture than the bulk sampling method.