沥青混凝土非均质性对其蠕变行为的影响  

Effect of Heterogeneity on Creep Behavior of Asphalt Concrete

作　　者：张德育[1,2] 黄晓明[3] 高英[3] 洪锦祥[1,2] 白桃[3] 

机构地区：[1]江苏省建筑科学研究院有限公司高性能土木工程材料国家重点实验室,江苏南京210008 [2]江苏博特新材料有限公司,江苏南京210008 [3]东南大学交通学院,江苏南京210096

出　　处：《建筑材料学报》2013年第4期614-620,共7页Journal of Building Materials

基　　金：国家自然科学基金资助项目(51108081)

摘　　要：为研究非均质性对沥青混凝土蠕变行为的影响,对沥青混凝土单轴蠕变试验进行了三维离散元模拟.生成了包含粗集料、沥青砂浆及空隙在内的沥青混凝土三维离散元数字试件,对数字试件微观组成材料之间的接触赋予了相应的微观接触模型,并通过室内试验对此模型进行了验证.在此基础上,假定粗集料刚度和沥青砂浆微观黏弹性参数服从Weibull分布,研究了粗集料和沥青砂浆的非均质性对沥青混凝土蠕变行为的影响.结果表明:随着粗集料和沥青砂浆均质度的增大,沥青混凝土的蠕变应变呈减小趋势,且随粗集料均质度增大而减小的幅度较沥青砂浆显著;粗集料刚度分布均匀时沥青混凝土的蠕变应变比粗集料均质度较低(均质度m=1.0)时减小49%.在沥青混凝土材料的选择中应更为重视粗集料的均质性.In order to investigate the effect of the heterogeneity on creep behavior of asphalt concrete, three-dimensional（3D） simulation of uniaxial creep test was performed using discrete element method. The 3D discrete element（DE） digital specimen composed of coarse aggregates, asphalt mastic and air voids was generated. The corresponding micromechanical models among the interactions of microscale components of digital specimen were assigned. The 3D DE model was also verified with laboratory measurements. On the basis of the 3D DE model, the Weibull distribution of coarse aggregate stiffness and the microscale viscoe- lastic parameters of asphalt mastic were assumed in DE model to investigate the effect of the heterogeneity of coarse aggregates and asphalt mastic on creep behavior of asphalt concrete（AC）. The results show that the creep strain of AC decreases with the increasing homogeneity, and decreases faster with the increasing homogeneity of coarse aggregates than with that of asphalt mastic. The creep behavior of AC is more sen- sitive to the heterogeneity of coarse aggregates. The creep strain of AC in which the aggregate stiffness distributes uniformly decreases by 49 % compared to that of AC in which the coarse aggregate homogeneity is lower （homogeneity rn= 1.0）. Therefore, more attention should be paid to the homogeneity of coarse aggregates in choosing the component materials of AC. The coarse aggregates of stable homogeneity should be used, and those from different origins should not be blended.

关 键 词：沥青混凝土 非均质性 蠕变行为 WEIBULL分布 离散元法 

分 类 号：U414[交通运输工程—道路与铁道工程]