RESEARCHES ON VISCOELASTIC MECHANICS BEHAVIOR OF ASPHALT SAND MIXTURE

Uniaxial compression tests were performed under the controlled-stress state with five different stress amplitudes(0.1MPa, 0.15MPa, 0.2MPa, 0.25MPa and 0.3MPa). A visco-elastoplastic mechanical model of asphalt sand is presented, which can describe its total creep behavior. The model is composed of two submodels in series, which describe viscoelastic and viscoplastic characterizations respectively. Through modifying the viscosity coefficient of a viscoplastic submodel, a creep constitutive equation of the model is established, a creep representation is obtained and the relationship of model parameter values with loading stresses are also detremined. The resulting visco-elastoplastic model successfully predicts the experimental results under various loading stress amplitudes, and reflects the visco-elastoplastic deformation characterization of asphalt sands.