Viscoelastic-Plastic Damage Constitutive Model of Asphalt Mixture Under Cyclic Loading

In order to better describe the viscoelastic-plastic stress-strain relationship of asphalt mixture during damage process, and to clarify the effect of dynamic cyclic loading on the damage constitutive relation of the mixture, a viscoplastic element was connected in series to the Burgers viscoelastic model based on the classical viscoelastic plastic rheological theory. According to the strain equivalent principle of damage mechanics, a viscoelastic-plastic damage constitutive model of the asphalt mixture was established, which can reflect the dynamic cyclic loading characteristics and consider the influence of loading frequency. Then the indirect tensile fatigue tests were carried out to study the effects of loading frequency, ambient temperature, stress level, asphalt dosage and asphalt type on the stress-strain relationship of the mixture, and to calibrate the model parameters in order to verify the validity of the model. The results show that the model can not only better describe the damage constitutive relationship of asphalt mixture under dynamic cyclic loading, but also can reflect the influence of loading frequency, ambient temperature and load level on the stress-strain relationship of the mixture. Because the meaning of the parameters in the model is clear and regular, it deserves further research and promotion. © 2019, Editorial Department of Journal of Northeastern University. All right reserved.