Finite Element Modeling of Permanent Deformation in the Loaded Wheel Tracker Test

Rutting distress is one of the most common modes of failure in flexible pavements and is caused by cumulative permanent deformations in the wheelpath under repeated axle loads. Rutting can occur largely in the asphalt layer or in both asphalt and the other pavement layers. Permanent deformation is commonly characterized by the uniaxial static or dynamic creep test or triaxle repeated loading creep test in addition to the wheel tracker test. The uniaxial and triaxle creep tests provide fundamental information about creep compliance and number of cycles or time that will yield important information about viscoelastic parameters that can be used to develop permanent deformation models. In the research presented in this paper, both the creep and the Burgers model were used in finite element modeling with Abaqus to model the permanent deformation behavior of dense graded asphalt concrete mix loaded in the wheel tracker test. Uniaxial creep test data were used to determine the viscoelastic parameters required for the Abaqus creep model and Burgers model. The wheel tracker test was conducted on the modeled mix, and the experimental data output was used to validate the finite element model. Both the creep and the Burgers model reasonably modeled the permanent deformation behavior, but neither model provided perfect predictions of the measured data.