基于颗粒堆积理论的沥青混合料细观结构特性研究

发布时间：2018-09-06 13:21

【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。
[Abstract]:In order to study the effect of particle gradation on the meso-structure of asphalt mixture, the interference coefficient of particle gradation evaluation index was established by particle stacking theory, and the different gradation was evaluated by computer tomography (CT) technique. Different compaction times and different molding methods (Marshall compaction, rotary compaction) of the asphalt mixture specimen scanning and three-dimensional reconstruction, combined with digital image processing technology, The pore space distribution and the contact relation between particles in asphalt mixture are obtained. The fractal dimension of three-dimensional void volume distribution and spatial location distribution is calculated by fractal theory. Finally, the relationship between the interference coefficient and the fractal dimension of three dimensional voids and the contact relation of particles is analyzed. The results show that with the increase of compaction times, the number of pores increases first and then decreases, and the average void volume decreases continuously, and the average void volume of mesopore increases with the increase of compaction times. For micropores and micropores, the number of voids increases with the increase of compaction times, but the average void volume does not change obviously, and the continuity of void volume distribution decreases with the increase of interference coefficient. The uniformity of space position distribution increases with the increase of interference coefficient, and the volume distribution of void volume of asphalt mixture formed by rotary compaction is poor, and the uniformity of space position distribution is better. The number of contact points of main skeleton particles will increase with the increase of compaction times. The number of (OGFC) contact points of open graded asphalt mixture is the most, the (AC) of continuous graded asphalt mixture is the least, and the (SMA) of asphalt mastic macadam is the middle. The number of contact points decreases with the increase of interference coefficient.
【作者单位】：哈尔滨工业大学交通科学与工程学院;辽宁省交通科学研究院;
【基金】：国家杰出青年科学基金项目(51225803)
【分类号】：U414

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