细观因素对密级配沥青混合料低温断裂试验的影响仿真模拟研究（英文）
发布时间：2019-02-19 12:59
【摘要】：为了研究关键因素对密级配沥青混凝土低温断裂性能的影响,采用离散单元法(DEM)和三维颗粒流程序PFC3D模拟弯曲断裂试验.基于随机生成算法和虚拟不规则粗集料库模拟集料级配和不规则形状、沥青砂浆以及空隙率的生成过程.然后,在虚拟试件中添加细观力学接触本构模型进行虚拟断裂试验,虚拟试验结果与室内试验结果对比验证了虚拟试验结果的有效性.此外,基于虚拟仿真采用正交试验研究集料和空隙的体积分数、集料和沥青砂浆的刚度、沥青砂浆内部粘结强度以及集料和空隙的分布对虚拟断裂试验的影响.研究表明,上述因素对断裂性能都有不同程度的影响,其中对弯拉强度和弯曲应变能密度影响最大的是沥青砂浆的粘结强度,对弯拉应变影响最大的是粗集料的体积分数.为了得到较好的密级配沥青混合料低温断裂性能,考虑沥青砂浆和集料的细观结构非常重要.
[Abstract]:In order to study the influence of key factors on the low-temperature fracture behavior of dense graded asphalt concrete, the bending fracture test was simulated by discrete element method (DEM) and three-dimensional particle flow program (PFC3D). Based on random generation algorithm and virtual irregular coarse aggregate library, the formation process of aggregate gradation and irregular shape, asphalt mortar and voids are simulated. Then, the virtual fracture test is carried out by adding the meso-mechanical contact constitutive model to the virtual specimen. The virtual test results are compared with the results of the laboratory test to verify the validity of the virtual test results. In addition, the effects of volume fraction of aggregate and void, stiffness of aggregate and asphalt mortar, internal bond strength of asphalt mortar and distribution of aggregate and void on virtual fracture test were studied by orthogonal test based on virtual simulation. The results show that the above factors have different effects on the fracture properties, among which the binder strength of asphalt mortar and the volume fraction of coarse aggregate have the greatest influence on flexural tensile strength and flexural strain energy density. It is very important to consider the meso-structure of asphalt mortar and aggregate in order to obtain better low-temperature fracture performance of dense gradation asphalt mixture.
【作者单位】： 东南大学交通学院;南京工程学院建筑工程学院;
【基金】：The National Natural Science Foundation of China(No.51378006,51378121)
【分类号】：U414
，
本文编号：2426522
[Abstract]:In order to study the influence of key factors on the low-temperature fracture behavior of dense graded asphalt concrete, the bending fracture test was simulated by discrete element method (DEM) and three-dimensional particle flow program (PFC3D). Based on random generation algorithm and virtual irregular coarse aggregate library, the formation process of aggregate gradation and irregular shape, asphalt mortar and voids are simulated. Then, the virtual fracture test is carried out by adding the meso-mechanical contact constitutive model to the virtual specimen. The virtual test results are compared with the results of the laboratory test to verify the validity of the virtual test results. In addition, the effects of volume fraction of aggregate and void, stiffness of aggregate and asphalt mortar, internal bond strength of asphalt mortar and distribution of aggregate and void on virtual fracture test were studied by orthogonal test based on virtual simulation. The results show that the above factors have different effects on the fracture properties, among which the binder strength of asphalt mortar and the volume fraction of coarse aggregate have the greatest influence on flexural tensile strength and flexural strain energy density. It is very important to consider the meso-structure of asphalt mortar and aggregate in order to obtain better low-temperature fracture performance of dense gradation asphalt mixture.
【作者单位】： 东南大学交通学院;南京工程学院建筑工程学院;
【基金】：The National Natural Science Foundation of China(No.51378006,51378121)
【分类号】：U414
，
本文编号：2426522
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