基于分子动力学模拟的老化沥青再生机理与评价

Study on Self-healing Property of Recycled Asphalt Based on Molecular Dynamics Simulation

采用分子动力学方法模拟了基质沥青、老化沥青以及再生沥青的自愈合过程,并通过均方位移和扩散系数对三者自愈合能力进行了评价。同时,通过径向分布函数分析了三种沥青各个组分间的聚集状态。研究结果表明,再生剂对老化沥青具有活化润滑作用;融合温度越高的再生剂在老化沥青中的扩散速率越快;沥青老化将会改变沥青质与树脂之间的聚集状态,而添加再生剂将破坏这种聚集状态,使老化沥青性能逐步恢复并接近基质沥青水平。

The molecular dynamics method was used to simulate the self-healing process of original asphalt,aged asphalt and recycled asphalt. In addition,the self-healing ability of the three was evaluated by mean square displacement and diffusion coefficient. Furthermore,the aggregation state of each component of three kinds of asphalt was analyzed by radial distribution function. The results show that the rejuvenator can activate and lubricate the aged asphalt. The higher the diffusion temperature is,the higher the diffusion rate of the rejuvenator in the aged asphalt is. The aging of asphalt will change the aggregation state between asphaltene and resin,and the addition of rejuvenator will compromise the aggregation state,and make the performance of aging asphalt gradually recover and approach the level of original asphalt.