开级配大粒径沥青碎石混合料劈裂试验的离散元数值分析  

Numerical Analysis on Splitting Test of Open-graded Large Stone Asphalt Mixture Using Discrete Element Method

作　　者：郭红兵[1,2] 陈拴发[3] 

机构地区：[1]陕西交通职业技术学院,陕西西安710018 [2]长安大学公路学院,陕西西安710064 [3]长安大学材料科学与工程学院,陕西西安710064

出　　处：《公路交通科技》2014年第11期22-26,40,共6页Journal of Highway and Transportation Research and Development

基　　金：交通运输部西部交通建设科技项目(200831881210);中央高校基本科研业务费专项资金项目(CHD2010JC011);陕西省教育厅专项科研计划项目(14JK1067)

摘　　要：为了弥补现有沥青路面结构设计理论中将沥青混合料当作完全弹性体进行计算分析的不足,以AC-16,AC-20,开级配大粒径沥青碎石混合料OLSM-25的劈裂强度为研究对象,采用离散元方法,运用二维颗粒流程序(PFC2D),从细观角度入手,对AC-16,AC-20,OLSM-25的劈裂(间接拉伸)试验进行数值模拟,对比分析AC-16,AC-20,OLSM-25圆柱体试件内部集料颗粒之间的接触力、位移矢量、微裂缝数量及其分布规律。结果表明:在峰值轴向力作用下,当沥青混合料圆柱体试件开裂破坏时,随着沥青混合料公称最大粒径、空隙率的增大以及油石比的减小,试件内部集料颗粒之间的接触力由基本均匀趋于相对离散分布,位移矢量存在显著差异,微裂缝数量逐渐减少。与AC-16,AC-20相比,OLSM-25的间接拉伸抗裂效果显著。In order to make up for the deficiencies of asphalt mixture taken as a perfectly elastic body to be analyzed and calculated in the existing structural design theory of asphalt pavement, we focused on the splitting strengths of AC - 16, AC - 20 and OLSM - 25 by using the discrete element method and the2D particle flow code （ PFC^2D ）, carried out the numerical simulation of splitting （ indirect tensile） test of AC - 16, AC-20 and OLSM-25 from the meso-scopic view, and comparatively analyzed the aggregate particle contact forces, the displacement vectors and the quantities of micro cracks as well as the distribution patterns of the cylinder specimens of AC - 16, AC - 20 and OLSM - 25. The result indicates that （ 1 ） under the action of the peak axial force, when the cylinder specimen of asphalt mixture is cracking, with the increase of nominal maximum size and the porosity of asphalt mixture and the decrease of asphalt-aggregate ratio of asphalt mixture, the distribution of the contact force between the aggregate particles in the specimen changes from the basic uniform distribution to the relative discrete distribution, the displacement vector varies greatly from each other, and the quantity of micro-cracks reduces gradually. Compared with AC -16 and AC -20,the anti-cracking effect of OLSM -25 in the indirect tensile test is more significant and remarkable.

关 键 词：道路工程 开级配大粒径沥青碎石混合料 二维离散元 劈裂(间接拉伸)试验 数值分析 抗裂性能 

分 类 号：U416.217[交通运输工程—道路与铁道工程]