Simulating the Visco- Elasto Plastic Behavior of Glasphalt Mixtures by Using of Modified Burgers Model

Analogous to most visco-elastoplastic materials, the creep curve of asphalt mixture can be generally divided into three-stages: decelerated creep, equi-velocity creep and accelerated creep. The Burgers model which can exhibit linear visco-elastic behavior is suitable to describe the first two stages of creep process and is not enough to represent the third stage. The aim of this study is simulating the visco- elastoplastic behavior of glasphalt mixtures under dynamic loading conditions by using the modified Burgers model. In this model a viscoplastic string is added to the Burgers model to predict visco-elastoplastic behavior of glasphalt mixtures at higher strain and high temperature. In this research the creep constitutive equation of the modified Burgers model is established for test conditions. Then the model parameters are solved by mathematical methods and also, predictions from the proposed model are compared with the experimental results. The results show that the modified Burgers model constitutes a very good fitting with the experimental data for each of the separately analyzed level of applied stress and testing temperature.