沥青砂浆动态模量室内试验与数值仿真

Laboratory Test and Numerical Simulation for Dynamic Modulus of Asphalt Mortar

文章选取了4种典型矿料级配成型沥青砂浆,引入了离散单元法和Burger's自定义接触本构模型,采用室内试验与数值模拟相结合的方法,进行了不同温度与频率条件下的沥青砂浆动态模量试验。研究结果表明:离散元方法和Burger's接触模型能够较好地实现沥青砂浆动态模量虚拟试验;轴向应变幅值随荷载作用呈现增大趋势,砂浆相比混合料具有更显著黏弹性;细集料增多会提高砂浆抗变形能力,沥青用量增大则加剧砂浆蠕变变形;离散元模拟与室内试验动态模量总体匹配较好,油石比较大的砂浆模拟结果与室内试验误差更小;沥青砂浆动态模量主曲线呈现出较为均匀的变化,验证了砂浆类似均质材料的特征。

In this paper, the asphalt mortar were formed using four typical mineral aggregate gradations, the discrete element method（DEM） and the Burger＇s self-defined contact constitutive model are introduced, the dynamic modulus tests of asphalt mortar are conducted under different temperatures and frequencies combining laboratory test with numerical simulation. The results indicate that the dynamic modulus virtual test of asphalt mortar is greatly implemented using the DEM and the Burger＇s contact model; the axial strain amplitude presents an increasing tendency following load action, which shows that the mastic has more significant viscoelastic behavior than mixture, moreover, the increase of fine aggregates will enhance the resistance to deformation of mortar, and the increase of asphalt content will deteriorate the creep deformation of mastic. Totally, the results of dynamic modulus are in agreement with those of laboratory test. The less error is obtained between the simulation and the test when asphalt content is larger. Furthermore, the mortar curves of dynamic modulus show equable variation, which validate the homogeneous character of asphalt mortar.