基于颗粒堆积理论的沥青混合料细观结构特性研究  

Research on Mesostructured Characteristics of Asphalt Mixture Based on Particle Packing Theory

作　　者：谭忆秋[1] 邢超[1] 任俊达[2] 张磊[1] TAN Yi-qiu XING Chao REN Jun-da ZHANG Lei(School of Transportation Science and Engineering, Harbin Institute of Technology, Harbin 150090, Heilongjiang, China Communications Research Institute of Liaoning Province, Shenyang 110015, Liaoning, China)

机构地区：[1]哈尔滨工业大学交通科学与工程学院,黑龙江哈尔滨150090 [2]辽宁省交通科学研究院,辽宁沈阳110015

出　　处：《中国公路学报》2017年第7期1-8,共8页China Journal of Highway and Transport

基　　金：国家杰出青年科学基金项目(51225803)

摘　　要：为研究颗粒级配对沥青混合料细观结构的影响,通过颗粒堆积理论建立颗粒级配评价指标干涉系数,采用计算机断层扫描(CT)技术对不同级配、不同压实次数和不同成型方式(马歇尔击实、旋转压实)的沥青混合料试件进行扫描并三维重构,结合数字图像处理技术,获取沥青混合料内部空隙空间分布和颗粒之间接触关系,采用分形理论计算三维空隙体积分布和空间位置分布分形维数,最后分析干涉系数与三维空隙分形维数和颗粒接触关系之间的联系。结果表明:在2种成型方式下,对于大孔和中孔,随着压实次数的增加,空隙数量呈现先增加后减少的趋势,并且大孔的平均空隙体积不断减小,中孔平均空隙体积不断增大;对于小孔和微孔,随着压实次数增加,空隙数量不断增加,平均空隙体积没有明显变化;空隙体积分布连续性随着干涉系数增加而降低,空间位置分布均匀性随干涉系数增加而增强,旋转压实成型沥青混合料空隙体积分布连续性较差,空间位置分布均匀性较好;主骨架颗粒接触点数量会随着压实次数增加而增加,开级配沥青混合料(OGFC)接触点数量最多,连续级配沥青混合料(AC)最少,沥青玛蹄脂碎石(SMA)居中,接触点数量随干涉系数增加而减小。In order to investigate the influence of particle grading on the mesostructure of asphalt mixtures,particle packing theory was utilized to propose interference parameter for particle grading evaluation.Based on the X-ray CT,the asphalt mixture with different grading,compaction times and compaction modes（i.e.Marshell and Gyratory methods）was scanned and three-dimensionally reconstructed.Combined with digital image processing technique,void distribution of the asphalt mixture and contact relations of particles were extracted.Fractal theory was applied to calculate the fractal dimension of void volume and position.Finally,relations between interference parameter and 3D void fractal dimension,interference parameter and particle contact were analyzed.The results show that with the increase of compaction times,the number of large voids and middle voids increases first and then decreases in two specific compaction modes.The average volume of large void decreases with the increase of average volume of middle void.For small voids and micro voids,the number of voids increases continuously with the increase of compaction times but the average void volume does not change obviously.The continuity of void volume distribution decreases with the increase of interference parameters,while the homogeneity of spatial location distribution increases with the increase of interference parameters.The continuity of asphalt mixture with gyratory compaction is poorer than that of mixture with Marshall compaction,however,the homogeneity of asphalt mixture with gyratory compaction is better.The number of contact points of dominant aggregate increases with the increase of compaction times,with the descending order being OGFC,SMA and AC.The number of contact points declines with the increase of interference parameters.

关 键 词：道路工程 沥青混合料 颗粒堆积理论 细观结构 CT 空隙分布 分形维数 

分 类 号：U414.1[交通运输工程—道路与铁道工程]