A comprehensive study on the rheological properties of desulfurized rubberized asphalt and establishment of micro-scale mechanical models

Recently, understanding the complex relationship between the mechanical properties and material characteristics of desulfurized rubber asphalt has received significant research attention. In this study, the rheological properties of rubber asphalt prepared by three kinds of desulfurized rubber powder are analyzed, and the mechanical response of rubber asphalt mixture is predicted using various mathematical models. Firstly, the rheological properties of desulfurized rubber asphalt are assessed through multiple stress creep recovery test, linear amplitude scanning test, and low-temperature creep test. The results indicate that the high-temperature performance index of desulfurized rubber asphalt is highly sensitive to the degree of desulfurization. As the degree of desulfurization of the rubber powder increases, the fatigue damage rate of asphalt gradually decreases, leading to an increase in the fatigue life. Notably, the difference between the m-critical temperature and stiffness-critical temperature (ΔTc) for only ML40MA does not exceed the threshold value, indicating that it has the best low-temperature cracking resistance. Additionally, the swelling capacity of desulfurized rubber powder in asphalt is better than that of ordinary rubber powder. Finally, the comprehensive performance of desulfurized rubber asphalt is characterized based on the gray correlation method. The gray correlation coefficient of ML60MA is 0.78, which is higher than that of ML40MA and ML80MA, indicating its best overall performance.