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

• Published in: Construction & building materials Vol. 295; p. 123616
• Main Authors: Li, Mingchen, Liu, Liping, Xing, Chengwei, Liu, Lingxiao, Wang, Huayu
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 09-08-2021
• Subjects: Curing time; Diffusion; Hot recycled asphalt mixture; Mixing method; Molecular dynamics; Preheating temperature; Molecular dynamics; Curing time; Preheating temperature; Hot recycled asphalt mixture; Diffusion; Mixing method
• ISSN: 0950-0618; 1879-0526
• DOI: 10.1016/j.conbuildmat.2021.123616

•Increasing the preheating temperature and diffusion time of rejuvenator can enhance its diffusion.•The 110℃ rejuvenator preheating temperature is recommended to improve diffusion effect.•The 3-hour recycled mixture’s curing time is recommended to improve its performance.
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.