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

发布时间：2018-01-29 00:03

本文关键词： 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　出处：《公路交通科技》2014年11期 　论文类型：期刊论文

【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。
[Abstract]:In order to make up for the deficiency of existing asphalt pavement structural design theory that the asphalt mixture is regarded as a complete elastomer, AC-16AC-20 is used to calculate and analyze the asphalt mixture. The split strength of open-gradation and large-size asphalt macadam mixture (OLSM-25) is studied. The discrete element method and two-dimensional particle flow program are used to study the splitting strength of OLSM-25 from a meso point of view. The splitting (indirect tensile) test of AC-16 / AC-20 / OLSM-25 was simulated and compared with that of AC-16AC-20. The contact force, displacement vector, number and distribution of micro-cracks between aggregate particles in OLSM-25 cylinder specimen are discussed. The results show that the contact force, displacement vector, and the distribution of micro-cracks are affected by the peak axial force. When the cylinder specimen of asphalt mixture is cracked and destroyed, with the maximum nominal particle size of asphalt mixture, the increase of porosity and the decrease of the ratio of stone to stone. The contact force between the aggregate particles in the specimen tends to be relatively discrete from basic uniformity, the displacement vector is significantly different, and the number of micro-cracks decreases gradually, compared with AC-16 and AC-20. The indirect tensile crack resistance of OLSM-25 is remarkable.
【作者单位】：陕西交通职业技术学院;长安大学公路学院;长安大学材料科学与工程学院;
【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)
【分类号】：U414
【正文快照】： 0引言沥青混合料是由沥青和粗细集料等粒状单元共同组成的多相复合材料,其工程性质相当复杂。在荷载作用下,组成沥青混合料的各颗粒体材料呈现出相对离散的运动状态。目前现有的沥青路面结构设计理论均将路面结构当作均匀连续、各向同性的弹性体进行计算分析,这与沥青混合料自

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