The purpose of this study was to evaluate the thermal (glass transition temperature), transport (self-diffusion), and rheological (viscosity, storage and loss modulus) properties of asphalt via laboratory experiments and molecular dynamics simulations. A 12-component asphalt model was employed in the molecular dynamics simulations with the modified Amber-Cornell force field. The asphalt model with the specific force field was validated against experimental and literature density data at various temperatures. The transition from the glassy state to the viscoelastic regime was explored by calculating the glass transition temperature. The results were compared with results from the differential scanning calorimeter (DSC) experiments. The self-diffusivity was calculated at a broad temperature range. The viscosity at the viscoelastic liquid regime was measured in the laboratory and calculated with reverse non-equilibrium molecular dynamic (rNEMD) simulations at various temperatures. Laboratory dynamic shear rheological testing was conducted for a wide frequency range at 70 °C. Oscillatory shear was applied in the asphalt model for calculating the storage and loss moduli within the experimental frequency range.
Experimental and Molecular Dynamics Simulation Study on Thermal, Transport, and Rheological Properties of Asphalt
Lingyun You, Theodora Spyriouni, Qingli Dai, Zhanping You, Ashok Khanal
Construction and Building Materials 2020, 265, 120358