Temperature Related Visco-Elastoplastic Properties of Asphalt Mixtures

Abstract

Parameter characterization of asphalt mixtures at various test temperatures is a crux to the performance evaluation of flexible pavements using the visco-elastoplastic method. But the difficulty of determining the relevant parameters experimentally is that deformations of time independent components and viscous components occur simultaneously in the tested sample. To solve this problem, a measuring system of two loggers was introduced to record the transient and time dependent deformations in creep and recovery tests. Based on the deformation separation, parameters of visco-elastoplastic models of asphalt mixtures proposed by Sides et al. are evaluated. Experiments conducted under four temperatures show that all parameters obtained in this way can be related to the temperature approximately either by a linear function or by a power function. Test results and parametric studies show that viscous response of asphalt mixtures to the stress is particularly strong at high temperatures. It is postulated that the process of transition from initial creep to the secondary or final stage of creep will be accelerated for the asphalt mixtures at high temperatures.