Model Prediction of Rutting in Asphalt Concrete

Abstract

A new elastoplastic model is presented for predicting the stress/strain response of asphalt concrete under cyclic loading. The model utilizes multiyield surfaces and isotropic hardening. Rowe's stress dilatancy theory is used to obtain the relationship between the permanent volumetric and vertical strains as well as the hardening law for the changes in the sizes of the plastic moduli caused by cyclic loading. These relationships considerably simplify the task of predicting the plastic deformation under cyclic loading of both triaxial compression and extension tests. A complete description of the plastic deformation of asphalt concrete under cyclic loading is treated, including the elastic, viscoelastic, and plastic components as well as the relationship between rutting and cracking. A computer program, called Rutting in Asphalt Concrete, RUT, determines the plastic deformation under cyclic loading. There is good agreement between the model predictions and experimental data that includes data published by other researchers.