从微观结构分析沥青混合料受力及破坏机理

Analysis on Force and Failure Mechanism of Asphalt Mixture from Microscopic Structure

为了从微观层面研究沥青混合料的受力及高温破坏机理,通过PFC离散元程序建立沥青混合料矿料颗粒的离散元模型,分析在外加荷载作用下,颗粒接触特性及应力传递规律,从细观角度解释混合料矿料滑移破坏机理,即粗集料的接触特性直接决定了混合料整体的强度,粗集料接触良好,能够形成较好的骨架结构,沥青混合料抵抗高温变形的能力越好,反之,越易发生车辙病害。

To study the force and high temperature failure mechanism of asphalt mixture on the micro- scopic level, discrete element model of asphalt mixture mineral aggregate had been established using PFC2D. Contact characteristics of mineral aggregate and stress-transfer law were analyzed under imposed load. Slip failure mechanism of asphalt mixture mineral aggregate was explained on the microscopic level. It was showed that the contact characteristics of coarse aggregate directly determined the overall strength of asphalt mixture, and a better skeleton structure was formed when contact characteristics of coarse aggregate was better, such the ability of resistance to high temperature deformation of asphalt mixture was better, otherwise, more prone to rutting disease.