Influence of rejuvenator preheating temperature and recycled mixture’s curing time on performance of hot recycled mixtures

Abstract

The recycled hot mix asphalt mixture performance is improved by a rejuvenator with good diffusion ability. This paper investigates the rejuvenator-aged asphalt diffusion and its influencing factors, including the rejuvenator's preheating temperature and curing process of recycled mixtures. A molecular dynamic simulation of the diffusion process between rejuvenator and aged asphalt is performed. Its results are then validated by a gel permeation chromatography test. Laboratory tests are also employed to evaluate these two factors' influence on the recycled mixture's performance on a macroscale. Simulated and experimental results strongly indicate that a proper combination of rejuvenator preheating and recycled mixture curing improves the rejuvenator diffusion ability and the recycled mixture performance. Following this, the 110℃ preheating temperature of rejuvenator and the 3-hour curing time after completing the mixing process of the hot plant-mix asphalt mixture are recommended based on the above results.