EXPERIMENTAL RESEARCHES ON A VISCO-ELASTOPLASTIC CREEP DAMAGE CONSTITUTIVE MODEL OF ASPHALT MASTIC

Considering the nonlinear characteristics of asphalt mastic and coupling continuum damage mechanics, this paper proposed a visco-elastoplastic damage constitutive model of asphalt mastic by modifying Burgers model. Based on a series of uniaxial compression creep tests which were performed under different stress levels and temperatures, a nonlinear fitting program was developed for determining model parameters. The proposed visco-elastoplastic model was used for analysis and prediction. The curves of predicted creep strain versus damage evolutional rate under different stresses and temperatures were plotted. It is shown the proposed model can be used to predict the accelerated creep behavior of asphalt mastic. In addition, the damage evolutional rate is found to be influenced distinctly by creep time, stress level and condition temperature.