The rheological property of asphalt is an important factor affecting the pavement performance of asphalt binder, and the fundamental reason for the change of asphalt rheological property is the strong evolution of asphalt material meso structure. However, the internal mechanism of rejuvenated asphalt mastic system is complex and its rules are difficult to grasp. Aiming to study the relationship between meso mechanical parameters and rheological parameters of rejuvenated asphalt mastic, the meso structure model of rejuvenated asphalt mastic was established and improved based on the discrete element method. Moreover, the meso parameters of the model were obtained by the objective function method, and then the influences of various factorswere studied to construct the mathematical constitutive model of rheological parameter modulus and meso mechanical parameters. Combing with the reliability of the improved Burgers model was verified based on the rheological test results of rejuvenated asphalt mastic. In addition, the virtual test of dynamic shear rheological dynamic frequency scanning was carried out on the asphalt mastic sample by particle flow software. By adjusting the mesomechanical parameters, the simulation results (complex shear modulus and phase angle)were consistent with the test results. This study clarified the relationship between mesomechanics and macro performance, and this model could be used to obtain the complex shear modulus of rejuvenated asphalt mastic under different types, filler-asphalt ratio and external force environments by adjusting particle flow, wall boundary and other conditions, which can greatly save the workload for the later research and provide a theoretical basis for production experiments.

This article discusses the rheological tests and analyses based on the Schapery non-linear viscoelasticity model that were performed to study asphalt mastic behaviour under high shear stresses. Seven mineral filler types were applied in this study, including a mixed filler with hydrated lime and fillers derived from dust extraction systems. Determination of basic properties of the fillers was followed by creep and recovery tests (DSR) at different levels of shear stress conducted in accordance with a modified MSCR procedure. The first stage in the analysis was the identification of linear viscoelastic region and the non-linear viscoelasticity model parameters such as the length of the loading period, the temperature and the stress level using TTSSP (Time-Temperature- Stress Superposition Principle). Subsequent numerical simulations of strain variation with respect to stress confirmed a high degree of agreement between the non-linear viscoelasticity model and mastic sample behaviour. A strong correlation was found between the non-linear viscoelasticity parameters and mastic properties. The proposed methodology is able to quickly identify and eliminate the fillers that may contribute to HMA deformations.