基于DEM的沥青混合料劈裂强度尺寸效应

Size Effect of Splitting Strength of Asphalt Mixture Based on DEM

为了探究沥青混合料劈裂抗拉强度的尺寸效应,应用颗粒离散元数值模拟技术,对4种级配(AC-13、AC-16、AC-20、AC-25)不同尺寸的沥青混合料进行巴西劈裂数值试验,每组级配模型尺寸缩放系数分别为0.6、0.8、1.0、1.2、1.4,并建立尺寸缩放系数与沥青混合料抗拉强度尺寸效应的关系,得到4种级配下的沥青混合料抗拉强度的临界尺寸和临界强度。试验结果表明,4种级配的沥青混合料抗拉强度均具有明显的尺寸效应,级配越大,尺寸效应越不明显,级配AC-25的试样抗拉强度尺寸相关系数约为级配AC-13试样的94.37%。

In order to investigate the size effect of the splitting tensile strength of asphalt mixture,the Brazilian splitting numerical tests of four kinds of asphalt mixture with different sizes(AC-13,AC-16,AC-20,AC-25)were carried out by using particle discrete element numerical simulation technique.The size scaling coefficients of each group of gradation models are 0.6,0.8,1.0,1.2,1.4 respectively.The relationship between the size scaling coefficients and the size effect of tensile strength of asphalt mixture is established,and the critical size and critical strength of asphalt mixture under four gradations are obtained.The test results show that the tensile strength of the four graded asphalt mixtures has obvious size effect,and the larger the grading,the less obvious the size effect.The correlation coefficient of tensile strength of the graded AC-25 sample is about 94.37%of the graded AC-13 sample.