Temperature dependence of the cohesive strength of asphalt binder in low- and medium-temperature zone and its mechanism

This study studied the changes in the bond strength of asphalt binders in medium and low temperature areas, focusing on the temperature-dependent mechanism that affects the bond strength of asphalt. The quantitative testing technology independently developed by the team was used to accurately measure the bond strength of three representative asphalt types (Type I, Type II, and Type III), and their change curves in the temperature range of 25 to − 35 °C were plotted. The experimental results show that within this temperature range, the bond strength of the three asphalts all showed significant peaks, and there were significant differences in the temperature and change rate when they appeared. These differences are mainly related to the differences in the asphalt component ratio and brittle temperature. The study also revealed the key influence of the asphalt brittle temperature on its low-temperature performance. The results show that by adjusting the asphalt composition to reduce the brittle temperature, its low-temperature bonding performance can be significantly improved. This study provides a theoretical basis for the selection of asphalt binders in road construction in cold areas, and proposes the importance of using brittle temperature as a screening indicator.