基于离散元法的多孔沥青混合料空隙衰变研究

发布时间：2018-04-02 20:26

本文选题：多孔沥青混合料　切入点：离散元法　出处：《建筑材料学报》2017年05期

【摘要】：为了研究加载后多孔沥青混合料的空隙衰变规律,使用离散元软件PFC2D生成了多孔沥青混合料的二维车辙板虚拟试件并模拟了车辙试验.在虚拟试件生成过程中采用了新的空隙生成算法,即按照空隙级配来模拟不规则多边形,将其投放在沥青砂浆内并删除后形成空隙.通过室内静态蠕变试验获取多孔沥青混合料的微观参数值,以此来设计虚拟车辙试验的加载方式、空隙信息提取算法,并将虚拟车辙试验结果与室内车辙试验结果进行对比,验证了虚拟车辙试验的可行性.虚拟试验结果表明:荷载越大,试件空隙衰变越明显;随着荷载作用时间的增长,试件空隙率持续衰减,但速率变缓,在混合料结构破坏之前存在趋于稳定的状态;环境温度对试件空隙率影响明显,随环境温度升高,空隙率的衰减呈现3阶段变化;试件初始空隙率为20%(体积分数)时,加载后其空隙率衰变值最小.
[Abstract]:In order to study the void decay law of porous asphalt mixture after loading, the two-dimensional rutting plate virtual specimen of porous asphalt mixture was generated by using discrete element software PFC2D and the rutting test was simulated.A new voidage generation algorithm is adopted in the process of virtual specimen generation, that is, the irregular polygon is simulated according to the void gradation, which is placed in the asphalt mortar and deleted to form the void.The microscopic parameters of porous asphalt mixture are obtained by static creep test in laboratory to design the loading mode of virtual rutting test and the algorithm of extracting void information. The results of virtual rutting test are compared with the results of indoor rutting test.The feasibility of virtual rutting test is verified.The results of virtual test show that the larger the load is, the more obvious the void decay of the specimen is, and with the increase of loading time, the void rate of the specimen continues to decline, but the rate becomes slower, and the void rate tends to be stable before the structure of the mixture is destroyed.The effect of ambient temperature on the voidage of the specimen is obvious. With the increase of ambient temperature, the decay of voidage presents three stages, and when the initial porosity of the specimen is 20 (volume fraction), the decay value of voidage is the smallest after loading.
【作者单位】：东南大学交通学院;
【基金】：国家自然科学基金资助项目(51378006) 江苏省自然科学基金资助项目(BK20161421)
【分类号】：U414

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