行车和温度荷载作用下沥青路面的松弛响应分析

目的研究沥青混凝土路面在行车和温度荷载作用下的松弛特性，更好地做到防裂控制工作．方法确定黏弹性材料参数及能够反应温度、沥青混合料黏弹性本构关系，建立典型的路面结构三维有限元模型，模拟面层材料在不同初始变形的应力状态，分析路表弯沉、沥青面层层底和土基顶面的响应．结果沥青路面在荷栽和温度作用下，面层黏弹性材料会使路面应力减小．面层层底和基层层底应力会发生松弛，最后趋于稳定值；在行车载荷作用下弯沉会随着时间的推移发生回弹，最后逐渐趋于稳定．结论松弛是材料本身属性与其他因素无关；应力松弛模量越小，松弛性能越好，低温抗裂性越好．

Analysis of Relaxation Responses of Asphalt Pavements under Traffic Load and Temperature

This paper analyzes relaxation characteristics of asphalt pavement under traffic load and tempera- ture in order to control crack. Firstly, relaxation parameters for asphalt concrete are determined. Secondly, constitutive relations for viscoelastic materials that can reflect the effect of traffic load and temperature is put forward. Thirdly, Viscoelastic three-dimensional （3 D）finite element model for typical asphalt pavement is de- veloped. The stress and deflection relaxation responses of asphalt pavement under load are simulated under different initial deformations. Viscoelastic material for asphalt surface will make the pavement stress reduce. Normal stress on the bottom surface of the surface layer and base layer will relax and finally tends to a stable value;Resilient deflection with time is occurred and then finally tends to a stable value. Relaxation is inde- pendent of material properties without other factors. The stress relaxation modulus is smaller, the performance of relaxation property and crack resistance for low temperature is better.