Abstract: In order to analyze the influence of the distribution morphology of coarse aggregates on the fatigue performance of asphalt mixtures, two meso features of coarse aggregate such as angularity and internal contact state of the mixture were selected as coarse aggregate distribution morphological parameters.The image software such as MATLAB was used to analyze and extract the microscopic features of coarse aggregates in asphalt mixtures, and the virtual two-dimensional asphalt mixture specimens were also generated at the same time.Then, the virtual test piece was imported into the discrete element PFC2D software by interactive means, and the codes for setting relevant microscopic parameters and simulating indirect stretching indoor virtual experiments were edited to complete the discrete element simulation experiment.The results show that: when the defined angularity parameter is between 110 000 and 130 000, there is a peak strength of fatigue failure resistance; within the range of contact pairs with normal grading, there is a certain positive correlation between the number of contact pairs and the fatigue failure resistance of asphalt mixtures.

Key words: highway engineering; asphalt mixture; coarse aggregate; distribution morphological parameter; discrete elements; split fatigue damage

摘要： 为分析粗集料的分布形态对沥青混合料疲劳性能的影响，选择粗集料棱角性和混合料内部接触状态2个细观特征作为粗集料分布形态参数，利用MATLAB 等图像软件分析并提取粗集料在沥青混合料中的细观特征，同时生成虚拟的二维沥青混合料试件。利用交互手段将虚拟试件导入离散元PFC2D 软件，编辑设置相关细观参数和模拟间接拉伸室内虚拟实验的代码，完成离散元模拟实验。结果表明：定义的棱角性参数在110 000~130 000之间时，存在一个抗疲劳破坏的强度峰值；在级配正常的接触对范围内，接触对数量与沥青混合料抗疲劳破坏性能呈现一定的正相关关系。

关键词: 道路工程；沥青混合料；粗集料；分布形态参数；离散元；劈裂疲劳损伤