沥青混合料永久变形过程中粗集料空间运动分析

编写了三维不规则多面体粗集料的随机生成程序,重构了包含粗集料、沥青砂浆及空隙的沥青混合料车辙试件的三维离散元模型.通过对三维离散元模型进行数字切割获取了沥青混合料车辙试件的二维离散元模型,对沥青混合料车辙试件二维离散元模型中微观组成结构之间的接触赋予了相应的微观接触模型及模型参数.进行了沥青混合料车辙试验的二维离散元模拟,分析了沥青混合料永久变形过程中粗集料的平动和转动.结果表明:二维离散元模型能够较为精确地描述粗集料在沥青混合料永久变形过程中的空间运动情况,从而为今后沥青混合料车辙形成机理的探讨提供新的研究方式.

Analysis of Space Movement of Coarse Aggregates during Permanent Deformation of Asphalt Mixture

A three dimensional(3D) generation procedure for randomly created irregular polyhedron coarse aggregates was developed, and a 3D discrete element(DE) model of asphalt mixture(composed of coarse aggregates, asphalt mastic and air voids) specimen in rutting test was reconstructed. The two dimensional(2D) DE model of asphalt mixture specimen in rutting test was constructed by cutting numerically the 3D DE model. The corresponding micro contact models and parameters were given for the interactions of microscale components of 2D DE model of asphalt mixture specimen in rutting test. The rutting test of asphalt mixture was simulated using the 2D DE model. Finally, the translation and rotation of coarse aggregates during permanent deformation of asphalt mixture were analyzed. It is found that the 2D DE model can more accurately describe the space movement of coarse aggregates during permanent deformation of asphalt mixture, and provide a new research method for investigating the rutting mechanism of asphalt mixture.