Model for Shear Response of Asphaltic Concrete at Different Shear Rates and Temperatures

This paper presents a model for shear response of asphaltic concrete, taking into account of strain-rate and temperature effects. The model employs rate-dependent hyperplasticity theory, which is based on a thermomechanical framework. A principle of the theory is that the entire constitutive behavior can be defined by two scalar potentials: an energy potential and a flow potential. The viscous behavior of the model corresponds to the results of rate process theory and defines the strain-rate and time dependent behavior. The initial modulus and shear strength are each assumed to be exponential functions of the inverse of temperature. The model is verified and calibrated against the unconfined compression test data for asphaltic concrete at different strain rates and temperatures. A viscoelastic damage model is also addressed to make a comparison with the model developed here. Comparison between the test data, the predictions of the new model, and the predictions of the viscoelastic damage model are discussed. © 2009 ASCE