Effect of multiple freeze-thaw on rheological properties and chemical composition of asphalt binders

Perennial freeze-thaw cycles have caused frequent disasters on asphalt pavements. To investigate the effect of four types of freeze-thaw cycles on asphalt binders, the DSR and FTIR test results of #70 Jinlin base asphalt binder (J binder) and SBS modified asphalt binder (S binder) were studied. The rutting factor, creep compliance and fatigue life of binders after freeze-thaw cycles were evaluated first, and then the chemical composition was analyzed. The results show that multiple freeze-thaw cycles lead to a growth in the complex modulus of asphalt binders, but the phase angle of S binder did not decrease significantly. The attenuation of fatigue life of S binder was significantly higher than that of J binder, and there was a certain dependency on fatigue parameters and freeze-thaw damage based on the S-VECD model. Furthermore, after the freeze-thaw cycle, the creep recovery of S binder decreased, while that of J binder increased, due to the increased elasticity by the oxidation of J binder. Carbonyl index (CI) and sulfoxide index (SI) of binders gradually grew with the number of freeze-thaw cycles, and butadiene index (BI) of S binder also slightly decreased. In general, during repeated freezing and thawing, low temperature had a certain adverse influence on the binders, but it is lower than that caused by high temperature.