Thermal aging behavior characteristics of asphalt binder modified by nano-stabilizer based on DSR and AFM

In order to clarify the effect of thermal aging on the nano-stabilized modified asphalt binder, TINUVIN 770 (T770) hindered amine light stabilizer of nanoscale was selected as aging modifying agent to prepare modi-fied asphalt. The impact of thermal aging on the rheo-logical properties of T770-modified asphalt was investigated using dynamic shear rheological test of frequency sweep and multiple stress creep recovery test. The surface rough-ness variation of T770-modified asphalt was characterized by using atomic force microscope throughout the thermal aging process. Furthermore, the typical morphology and parameter features of T770-modified asphalt were identi-fied. The results showed that with the extension of thermal aging time, the high temperature rutting resistance of T770-modified asphalt was improved, while the unrecover-able creep compliance was degraded. When the thermal aging time exceeded 6 h, the bee structure appeared on the surface of T770-modified asphalt. Meanwhile, with the increase in thermal aging time, the special structure formed on the surface of asphalt gradually became smaller. The surface fluctuation difference of T770-modified asphalt reflected the better thermal aging resistance property of T770-modified asphalt than 70# asphalt.

Automated summary

The study found that the high temperature rutting resistance of T770-modified asphalt improved with the extension of thermal aging time, while the unrecoverable creep compliance decreased. Additionally, a honeycomb structure appeared on the surface of the asphalt after thermal aging for more than 6 hours, and the special structure gradually decreased in size with increasing thermal aging time.