矿物性质对沥青黏附性影响的分子模拟研究

Study on Molecular Simulation of Effect of Mineral Properties on Adhesion of Asphalt

摘要:

现有基于分子模拟的沥青-集料黏附性研究通常忽略了矿物表面性质对沥青-集料黏附性的影响。针对这一问题，基于两种不同的表面悬键补偿方式构建了具有不同表面性质的SiO2及Al2O3矿物模型，从矿物表面电荷和矿物表面基团两个角度探究矿物表面性质对沥青-集料黏附性的影响。分子模拟结果表明，矿物表面原子及其电荷决定了沥青与矿物间的静电相互作用，同时影响沥青分子的分布及空间构型。此外，矿物表面羟基化对沥青-矿物模型的总结合能影响较小，但能够显著提高沥青与矿物模型间的范德华相互作用，同时显著降低二者间的静电相互作用。

Abstract:

The existing studies on asphalt-aggregate adhesion based on molecular simulations usually ignore the influence of mineral surface properties on asphalt-aggregate adhesion. Aiming at this problem, SiO2 and Al2O3 mineral models with the different surface properties are constructed according to two different surface suspension compensation methods to investigate the influence of mineral surface properties on asphalt-aggregate adhesion from two perspectives of mineral surface charge and mineral surface group. The results of the molecular simulations show that the mineral surface atom and its charge determine the electrostatic interaction between the bitumen and the mineral, and also affect the distribution and spatial configuration of the bitumen molecules. In addition, the mineral surface hydroxylation has a small effect on the total binding energy of the bitumen-mineral model, but can significantly increase the van der Waals interaction between the bitumen and mineral model, while significantly reduce the electrostatic interaction between the both.