基于离散元方法的排水沥青混凝土黏结失效行为研究  

Investigation of bond failure behavior of porous asphalt concrete using discrete element method

作　　者：马翔[1] 袁则瑜 周培圣 李强[1] MA Xiang;YUAN Zeyu;ZHOU Peisheng;LI Qiang(College of Civil Engineering,Nanjing Forestry University,Nanjing 210037,China)

机构地区：[1]南京林业大学土木工程学院,江苏南京210037

出　　处：《铁道科学与工程学报》2020年第12期3097-3103,共7页Journal of Railway Science and Engineering

基　　金：国家自然科学基金资助项目(60472120);河北省交通运输厅科技项目(TH1-202013);苏州市科技计划项目(SS202032)。

摘　　要：为了揭示排水沥青混凝土的黏结失效机理,构建排水沥青混凝土的离散元模型,通过虚拟力学试验分析半正弦波荷载加载过程中排水沥青混凝土的黏结失效演化历程。研究结果表明:在荷载作用下,排水沥青混凝土的主力链分布于砂浆较薄的集料周边,其黏结失效单元个数增长会经历低速、快速、减速及无增长4个发展阶段;高温条件下黏结失效存在2种破坏模式,分别为砂浆内部的黏聚破坏和砂浆−集料间的黏附破坏,主要表现为黏聚破坏,水、冻融等自然条件使黏结失效加剧,对砂浆−集料界面的影响更大,黏附破坏增幅更显著;加载阶段黏结失效不断发生,失效界面颗粒滑动摩擦加剧,接触力不断做功使得摩擦功增大,摩擦功与黏结失效单元个数之间存在良好的线性相关性。To reveal the bond failure mechanism of porous asphalt concrete(PAC),the discrete element model of the PAC was developed.Under half sine wave loading,the bond failure evolution process of PAC was analyzed by virtual mechanical test.The results show that the main force chain of PAC is distributed around the aggregate with thin mortar,and the growth of the quality of adhesive failure can be divided into four periods,including low speed,fast speed,slow speed and no growth.Under high temperature conditions,there are two kinds of bond failure models including adhesive failure and cohesive failure,and cohesive failure is the main failure type.The curing conditions such as water and freeze-thaw make the bond failure more serious,which has a greater impact on the mortar aggregate interface and a more significant increase in the bond failure.During the loading stage,the bond failure occurs continuously,and the slip friction of the particles at the failure interface increases.The contact force made the friction energy increase continuously,and there is a good linear correlation between the friction energy and the quality of bond failures.

关 键 词：道路工程 黏结失效 离散元 排水沥青混凝土 主力链 

分 类 号：TU43[建筑科学—岩土工程]