Study on Dynamic Repeated Creep Tests for Viscoelastic Property of Asphalt Mixtures with Varying Air Voids Content

Abstract

Dynamic repeated creep test which accords with the response relationship of pavement load and deformation has been readily proposed to evaluate the rutting resistance of asphalt pavements. Air void content is one of the most important factors affecting the rutting resistance of asphalt pavements. AH-70# base asphalt, SBS modified asphalt, AH-70# base asphalt mixture and SBS modified asphalt mixture at 40°C and 60°C were investigated using the dynamic shear rheometer AR-2000. The objective was to study the effect of temperature, materials, applied stress levels and air voids content on the mixtures high temperature creep properties by varying air voids content from 1.99 to 6.59%. Burgers viscoelastic model for description of dynamic creep of asphalt mixtures were discussed and analyzed. Analysis of test data indicates that the effect of temperature and air voids content to the accumulated strain(or compliance) of asphalt mixtures is larger, and that asphalt mixtures at 4% air voids content have excellent anti-deformation property. Furthermore, the Burgers viscoelastic model can effectively describe and explain the creep performance at high temperature and viscoelastic properties.