Viscoelastic parametric conversions and mechanical response analysis of asphalt mixtures

Abstract

In this study, dynamic modulus, dynamic resilience modulus, and creep compliance tests were conducted to characterize and quantify the effects of viscoelastic parameters of asphalt mixtures on the mechanical response of pavement structures. From the laboratory testing under different loading waveforms, master curves were generated to computed the viscoelastic parameters that were used as input for ANSYS modeling. In general, the corresponding results indicated that the stress magnitude had a significant influence on the evolution of master curves for the viscoelastic parametric conversions from creep compliance and that all the mechanical responses (namely stress, strains, and deformations) tended to increase with temperature. For the asphalt mixtures evaluated, the relaxation modulus transformed from the creep compliance was largely indifferent whilst those converted from the dynamic modulus did not exceed 15% from the actual values. In terms of the loading mode, the highest fitting accuracy for the viscoelastic parameters and master curves was obtained for the half-sine waveform. Overall, the study results indicated that ensuring good interlayer bonding is imperative for minimizing the compressive/shear stresses and strains in pavement structures to mitigate shear failure, debonding, delamination, etc. Additionally, the study also demonstrated that use of modified asphalt mixtures was critical to mitigate high compressive and shear strains arising for heavy traffic loading in high temperature climatic conditions.