Influence of thermo-rheological complex behavior on thermal stress calculation of asphalt binder

Abstract:

For improving the existing thermal stress calculation methods of asphalt binders, the bending beam rheological (BBR) test was performed to obtain the creep compliance of asphalt material, and the strain-stress relationship of the linear viscoelastic Burgers model was introduced to obtain the rheological parameters at different temperatures. The analytical solution of the constitutive equation of state of the Burgers model was used to calculate the numerical solution of the thermal stress under the asphalt layer (incremental method), and the calculation results were compared with the results of the traditional Hopkins and Hamming′s algorithm. Results show that the two methods were basically consistent, but at a lower temperature (around -30 ℃) the results of the Hopkins and Hamming′s algorithm were smaller than those of the incremental method, underestimating the effect of thermally reversible aging. The hardening effect of low-temperature curing on asphalt was related to the rheological properties of asphalt. The more complex the rheological properties of asphalt were, the more obvious the hardening effect of low-temperature curing was. When under low temperature or long-term loading, the rigidity master curve of the thermo-rheological complicated asphalt deviated from the timek-temperature superposition principle.