沥青混合料劈裂试验的颗粒流程序模拟研究  

Splitting Test Modeling of Asphalt Mixture Using Particle Flow Code

作　　者：于大超 王江洋[2,3] 

机构地区：[1]中交一航局第三工程有限公司,天津300461 [2]苏州市一级公路建设指挥部,江苏苏州215144 [3]东南大学智能运输系统研究中心,江苏南京210018

出　　处：《现代交通技术》2015年第2期1-4,共4页Modern Transportation Technology

基　　金：国家自然科学基金资助项目(项目编号:51308116)

摘　　要：为了从细观角度模拟分析沥青混合料的低温开裂行为,选取了4种集料类型、4种矿料级配类型,运用颗粒流程序PFC2D内置"Fish"语言,重构了包含沥青砂浆和粗集料在内的沥青混合料细观数字试件,采用离散元方法实施了虚拟劈裂试验。研究结果表明:离散元模拟得到的劈裂抗拉强度与室内试验结果的匹配程度较好;试件在加载至峰值荷载前,内部已萌生一定数量微观裂纹,极值点荷载后微观裂纹数量大幅增加;高强度集料组成的混合料基本沿着集料与砂浆的界面发生破坏,低强度集料则部分会被裂纹贯穿;基于颗粒流程序的虚拟劈裂试验可以作为研究沥青混合料断裂特征的辅助手段。In order to describe the crack behavior at low temperature of asphah mixture from the micro-scale perspective, firstly, four different aggregates and four different gradations were selected. Secondly, a microstruetural digital sample of asphalt mixture including asphalt mastic and coarse aggregates was reconstructed using the Fish language provided in the particle flow code in two-dimensional （PFC2D）. Finally, a virtual splitting test was implemented using the discrete element method （DEM）. The results indicated that the macro splitting strength of virtual test showed generally good agreement with the experimental results. Furthermore, a number of microeracks occurred in the internal structure of asphalt mixture before peak loads, and a lot of microcraeks appeared after peak loads. Additionally, the crack deflection around aggregates appeared to be a consequence of the high strength aggregates, while the crack path might traverse through aggregates due to the weak aggregates. It was found that the method based on PFC2D, which was used to illustrate the development of splitting test, could be used as a supplemental tool to investigate the crack behavior of asphalt mixture.

关 键 词：沥青混合料 颗粒流程序 离散元模型 虚拟劈裂试验 裂纹路径 

分 类 号：U414[交通运输工程—道路与铁道工程]