Viscoplastic behaviour of asphalt mixture in compression

Abstract

Compressive behaviour of asphalt mixture is studied in creep and strain recovery tests observing large irreversible viscoplasticity strains. The viscoplastic material model for asphalt mixture is presented, based on a modified version of Schapery’s constitutive relationship where a viscoplastic term is added. For the description of the non‐linear viscoplastic behaviour of the material, repeated creep and recovery strain tests at a fixed stress level and a fixed loading time were conducted. The viscoplastic strain is described by the strain hardening model. Constant stress creep testing was also performed to validate the developed material model. The model successfully describes the main features for asphalt mixture and shows good agreement with test data within the considered stress range.