基于分子动力学的沥青自愈合行为研究

选取12种沥青分子及1种SBS分子分别建立了基质沥青与SBS改性沥青的分子结构模型,并利用分子动力学研究了沥青自愈合过程中沥青分子的运动规律及扩散行为。结果表明,沥青自愈合过程按沥青分子的运动特征可分为自由运动、互相渗透及无序化运动3个阶段;沥青不同组分的扩散系数存在显著差异且SBS的添加能显著增大沥青质的扩散系数;在中低温条件下,SBS改性沥青整体扩散系数较大,自愈合性能较基质沥青更佳,但高温时情况则相反。

Study on self-healing behavior of asphalt binder based on molecular dynamics

The molecular structure models of base and SBS modified asphalt were established by 12 asphalt molecules and 1 SBS molecule, and then the motion and diffusion behavior of asphalt molecules during self-healing process was investigated by molecular dynamics. The results show that, according to motion features of asphalt molecules, the self-healing process can be divided into 3 stages:free movement, interpenetration and disordered movement. The diffusion coefficients of different components are significantly different, and diffusion coefficients of asphaltenes remarkably increase with the incorporation of SBS. The self-healing performance of SBS modified asphalt is better than that of the base asphalt at low and moderate temperatures, but the result is opposite at high temperatures.