基于离散元法的排水沥青混合料空隙特征分析

Analysis of Air Voids Characteristics of Drainage Asphalt Mixture Based on Discrete Element Method

摘要: 为研究不同级配的排水沥青混合料内部的空隙特征，基于离散元法模拟沥青混合料试件的生成。首先利用中心球扩散法模拟粗集料的形态特征，生成特殊算法有效地表征不同矿料级配，然后对试件进行“虚拟”的横向切片并通过图像处理获取断面空隙特征参数，探究排水沥青混合料的空隙特征的影响规律。仿真结果表明：空隙数量主要分布在空隙等效直径为0 mm~6 mm的范围内。随着空隙率的增大，空隙数量逐渐减小，但空隙等效直径增大；空隙数量随着9.5 mm~16 mm集料含量的增加而减少。可见离散元法描述沥青混合料空隙特征具有实际意义。

Abstract: In order to study the air voids characteristics of drainage asphalt mixture with different gradations, the asphalt mixture specimen was generated based on discrete element method. Firstly, the central sphere diffusion method was used to simulate the morphological characteristics of coarse aggregates, and a special algorithm was generated to effectively characterize different aggregate gradations. Then, the cross-section void characteristic parameters were obtained by “virtual” cross-section slicing through image processing, and the influence of void characteristics of drainage asphalt mixture was explored. The simulation results show that the voids number is mainly distrib-uted in the range of the void equivalent diameter of 0 mm - 6 mm. As the void ratio increases, the number of voids gradually decreases, but the equivalent diameter of the void increases. The num-ber of voids decreases with the increase of 9.5 mm - 16 mm aggregate content. It is of practical sig-nificance to describe the void characteristics of asphalt mixture by discrete element method.