Stochastic Viscoelastic–Viscoplastic Response of Asphalt Mixture under Uniaxial Compression

Abstract

The mechanical properties of asphalt mixture always exhibit large degrees of variability due to asphalt’s random internal structure. A stochastic constitutive model is proposed to describe the random mechanical response of an uniaxially compressed asphalt mixture. In this model, the simplified Schapery’s nonlinear viscoelastic model and the modified Swchartz’s viscoplastic model are combined to estimate the material average deformation, and a random parameter with lognormal probability distribution is introduced to reflect the specimen dispersion. Based on statistical methods, the model is calibrated by the multiple-stress repeated creep-recovery test and the 1-h creep test, and then validated by the irregular loading test and the uniform repeated creep-recovery test. It is shown that the model can predict not only the average mechanical behavior but also the scattering range of the material responses at a certain probability.