Temperature related visco-elastoplastic properties of asphalt mixtures

Parameter characterization of asphalt mixtures at various test temperatures is a crux to the performance evaluation of flexible pavements using the vi sco-elastoplastic method. But the difficulty of determining the relevant pa rameters 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 t he transient and time dependent deformations in creep and recovery tests. B ased on the deformation separation, parameters of visco-elastoplastic model s of asphalt mixtures proposed by Sides et al. are evaluated. Experiments c onducted under four temperatures show that all parameters obtained in this way can be related to the temperature approximately either by a linear func tion or by a power function. Test results and parametric studies show that viscous response of asphalt mixtures to the stress is particularly strong a t high temperatures. It is postulated that the process of transition from i nitial creep to the secondary or final stage of creep will be accelerated f or the asphalt mixtures at high temperatures.