No abstract

In this paper, an investigation was performed to determine the accuracy of a simplified viscoelastic back analysis to interpret dynamic loading tests on asphalt mixes (AM). First, quasi-static cyclic tension-compression lab tests were performed on different AM to fit the 3 dimensional 2S2P1D linear viscoelastic (LVE) model. Considering these tests on very different types of AM, a LVE material with "averaged" viscoelastic properties was obtained. Then, these "averaged" viscoelastic properties were considered to perform finite elements method numerical simulations of dynamic loading tests on a cylinder. The simulations were performed at ten different temperatures from − 40 to 50 • C. The longitudinal, flexural and torsional modes of vibration are studied. The complex Young's modulus and complex Poisson's ratio were first obtained using the viscoelastic 2S2P1D model at the first resonance frequency for the three studied modes of vibration. Then, a combined viscoelastic back analysis, which has the advantage of simplicity, was used to determine the elastic equivalent properties and the phase angle of the material. The results obtained directly with the 2S2P1D model and the results from the combined viscoelastic back analysis results regarding both the Young's modulus and the Poisson's ratio are discussed in the paper.

In this paper, an investigation was performed to determine if the complex modulus obtained from frequency sweeps performed with the dynamic shear rheometer (DSR) can be used to accurately predict the creep compliance obtained experimentally using the bending beam rheometer (BBR). Two sets of asphalt binders were tested at low, intermediate, and high temperatures and the results were analysed using 2S2P1D and DBN rheological models. DSR and BBR testing was performed in two different laboratories using different equipment manufacturers. It was found that significant differences are observed between the creep stiffness obtained with DSR and BBR devices, most likely due to the different preparation and conditioning of the test specimens in different cooling media.