Rutting investigation of asphalt pavement subjected to moving cyclic loads: an implicit viscoelastic–viscoplastic–viscodamage FE framework

Abstract

ABSTRACT In this study, rutting due to factors such as damage and permanent deformation and different types of moving cyclic loads are investigated. For this purpose, prediction of rutting and life estimation of asphalt pavement life are made possible by 3D simulation of pavement under realistic moving, equivalent and pulsatile loads at high cycle numbers. A thermodynamically consistent viscoelastic–viscoplastic–viscodamage model is implicitly discretised and user material subroutine implemented in the FEM software to predict asphalt pavement behaviour. All the discretised equations in the numerical procedure are obtained and the material consistent tangent matrix is presented. Additionally, the Newton–Raphson method is employed to calculate internal variables including internal variables of damage and viscoplastic strain components. In addition, the discretisation flowchart and respective algorithms are presented. Simulation results indicate the impact of factors such as mean load, applied stress level and loading time on rutting and damage. Furthermore, the rutting due to equivalent and pulsatile loadings have about 40% difference from the value corresponding to the realistic moving load obtained by the simulation of the tire as a hyper-viscoelastic material on the asphalt pavement. This difference leads to the inaccurate estimation of asphalt pavement’s service life by pulsatile and equivalent loading types.