A multiphysics evaluation of the rejuvenator effects on aged asphalt using molecular dynamics simulations
A multiphysics evaluation of the rejuvenator effects on aged asphalt using molecular dynamics simulations
复制标题
使用分子动力学模拟对再生剂对老化沥青的影响进行多物理场评估
DOI：
10.1016/j.jclepro.2020.120629
复制
发表时间：
2020-06-20
影响因子：
11.1
通讯作者：
Dong, Qiao
中科院分区：
文献类型：
--
作者：
Cui, Bingyan;Gu, Xingyu;Dong, Qiao
老化沥青的返老剂效果容易受到紫外线照射、过热和水暴露等多种物理条件的影响。在这项研究中，使用分子动力学(MD)模拟对老化沥青的再生剂效果进行了多物理评价。在老化沥青模型中加入不同剂量的再生剂，观察其微观性能的变化。然后，在模拟中考虑了水和温度场，考察了它们对返老剂的单独和耦合影响。结果表明，在老化沥青中加入再生剂对降低车辙性能的作用大于对提高抗裂性的作用。就沥青的微观结构而言，尽管加入再生剂有助于缓解沥青质的自聚集，但胶体结构仍不能完全恢复。此外，还发现随着再生剂用量的增加，老化沥青的抗水毁性能有所提高，与Al_2O_3的粘附性要好于SiO_2。返老剂在热混合温度下的扩散速度是热混合温度下的2-3倍。此外，在高温下，与高剂量的嫩肤剂相比，低剂量的嫩肤剂具有更高的扩散系数。在温度和水的多物理耦合作用下，水和高温都对沥青与集料之间的粘结功有负面影响，其中水的影响比高温的影响更显著。(C)2020年由爱思唯尔有限公司出版。
The rejuvenator effects on aged asphalt are easily influenced by multiple physical conditions such as ultraviolet irradiation, overheating and water exposure. In this study, a multiphysics evaluation of the rejuvenator effects on aged asphalt was conducted using molecular dynamics (MD) simulations. Different rejuvenator dosages were added to the aged asphalt model to observe the changes in the microscopic properties. Then, water and temperature fields were considered in the simulation to investigate their individual and coupled effects on rejuvenators. The results showed that the effect of rejuvenators in aged asphalt on weakening the rutting resistance was greater than that of improving the cracking resistance. Regarding the microstructure of asphalt, the colloidal structure still could not be fully restored, although adding rejuvenators could help mitigate the self-aggregation of asphaltenes. In addition, it was discovered that the increase in rejuvenators improved the moisture damage resistance of aged asphalt, which had better adhesion with Al2O3 than SiO2. The rejuvenators could diffuse 2-3 times faster at hot-mix temperatures than warm-mix temperatures. Additionally, under high temperatures, rejuvenators with low dosages had higher diffusion coefficients compared to that of high dosages of rejuvenators. For the multiphysics coupled effects of temperature and water, both water and high temperatures were found to have negative effects on the work of adhesion between the asphalt and aggregates, where the effect of the water was more significant compared with that of high temperatures. (C) 2020 Published by Elsevier Ltd.