沥青混合料破坏阶段的黏弹性行为

采用基于连续破坏力学和功势原理的模型对沥青混合料破坏阶段的黏弹性行为进行研究.该模型中利用虚应变来描述沥青混合料的时间依赖性,利用破坏参数和虚劲度模量的关系描述沥青混合料的破坏特性.通过不同条件下的复数模量试验确定了沥青混合料的线黏弹性力学参数,进行了不同条件下的恒应变率压缩试验来确定沥青混合料的破坏特性.确定了破坏参数、应力的勒贝格范数和虚劲度模量之间的关系,进而用线性分段法计算了沥青混合料的黏弹性应变.利用该模型对不同条件下的恒应变率压缩试验结果进行了分析.结果表明:预测值和实测值吻合良好.

Viscoelastic Behavior of Asphalt Mixtures with Damage Stage

A model based on continuum damage mechanics and work potential theory was used to analyze the viscoelastic behavior of asphalt mixture with damage stage. Pseudo strain was used to account for the time-dependence of asphalt mixture, and relationship between damage parameter and pseudo stiffness was used to describe the damage characteristics of asphalt mixture. Linear viscoelastic properties and damage characteristics of asphalt mixture were determined by conducting complex modulus tests and constant strain compression tests respectively at various conditions. Relationships among damage parameter, Lebesgue norm of stress and pseudo stiffness modulus were obtained, and piecewise linear approach was used to calculate viscoelastic strain of asphalt mixture. The model was validated by comparing the predicted and measured results from constant strain compression tests at various conditions.