Tang Wei, Yu Xin, Li Ning, Dong Fuqiang, Wang Zhongyuan, Zhang Yu
College of Civil and Transportation Engineering, Hohai University, Nanjing 210098, China.
School of Traffic and Transportation Engineering, Changsha University of Science and Technology, Changsha 410114, China.
Materials (Basel). 2021 Oct 25;14(21):6385. doi: 10.3390/ma14216385.
The use of rejuvenators has enhanced the workability of asphalt mixtures containing the reclaimed asphalt pavement (RAP). This conclusion is based on the determination of viscosity of asphalt binders, while not validated from reclaimed asphalt mixtures. In this study, the effect of two rejuvenators (ordinary and emulsified rejuvenator) on the workability of reclaimed asphalt mixtures was evaluated by measuring the mixing torque and determining the air void content of reclaimed mixtures. In addition, their effects on the performances of reclaimed mixture were studied via the three indexes tests, rutting test and freeze-thaw splitting tests. The experimental results show that mixing torque and air void content of reclaimed mixtures with the emulsified rejuvenator is 4% and 6% lower than that with the ordinary rejuvenator, respectively. This indicates that improvement of the workability of reclaimed mixtures can be achieved by using an emulsified rejuvenator, but not by an ordinary rejuvenator. That is also the reason that at least 20% greater high-temperature stability is found for reclaimed mixtures by using the emulsified rejuvenator than using the ordinary rejuvenator. In addition, reclaimed mixtures with the emulsified rejuvenator show similar moisture susceptibility to that with the ordinary rejuvenator. This study provides a feasible method to assess the workability effect of rejuvenators on reclaimed mixtures directly and recommends the use of an emulsified rejuvenator to improve the workability and high-temperature stability of reclaimed mixtures.
再生剂的使用提高了含有再生沥青路面（RAP）的沥青混合料的工作性能。这一结论是基于对沥青结合料粘度的测定得出的，而未从再生沥青混合料中得到验证。在本研究中，通过测量搅拌扭矩和测定再生混合料的空隙率，评估了两种再生剂（普通再生剂和乳化再生剂）对再生沥青混合料工作性能的影响。此外，通过三项指标试验、车辙试验和冻融劈裂试验研究了它们对再生混合料性能的影响。试验结果表明，使用乳化再生剂的再生混合料的搅拌扭矩和空隙率分别比使用普通再生剂的低4%和6%。这表明使用乳化再生剂可以提高再生混合料的工作性能，而普通再生剂则不能。这也是使用乳化再生剂的再生混合料比使用普通再生剂的再生混合料高温稳定性至少高20%的原因。此外，使用乳化再生剂的再生混合料与使用普通再生剂的再生混合料表现出相似的水敏感性。本研究提供了一种直接评估再生剂对再生混合料工作性能影响的可行方法，并建议使用乳化再生剂来提高再生混合料的工作性能和高温稳定性。
