The parallel rheological framework constitutive model based on the Arruda-Boyce theory for large strain behavior of asphalt mortar

The large deformations of the asphalt pavement are primarily caused by the large strain in the asphalt mortar, while the high-hardness asphalt aggregates undergo relatively small deformations. To study the large deformations of pavement, it is essential to first investigate the large deformation theory of asphalt mortar. However, there is almost no constitutive theory available for large strains (strain values 0.1-0.6) in asphalt mortar. This study develops a parallel rheological framework (PRF) constitutive model based on the Arruda-Boyce theory that expresses the large strain behavior of asphalt mortar. The model is based on the Arruda-Boyce theory, which has been effectively applied to describe the large deformation behavior of polymer-like materials. A comprehensive experimental program was designed, encompassing specimen preparation and a wide temperature range testing system. Uniaxial tensile tests were conducted on asphalt mortar specimens at various temperatures and tensile rates, and a genetic simulated annealing algorithm was used to fit the model to the experimental data, to accurately determine the theoretical parameters of the constitutive model, these parameters were subsequently validated through finite element simulations, ensuring the reliability of the model's predictions. The integration of experimental data, theoretical modeling, and finite element analysis confirmed the accuracy of the PRF constitutive model based on the Arruda-Boyce theory for describing large strain behavior of asphalt mortar. The model demonstrated broad applicability across a wide temperature range from medium-low to high temperatures. The consistency between the theoretical model and simulation results underscores the robustness of the proposed approach.