Abstract:To compare and evaluate the adhesive self-healing properties of different asphalt and explain the mechanism of asphalt self-healing from micro-level, the binder bond strength (BBS) test was conducted on seven base asphalt binders and four types of modified asphalt with different dosages (SBS, terminal blend rubber, gilsonite, and high-density polyethylene). Fourier transform infrared (FTIR) test was carried out on selected asphalt, and the mechanism of self-healing was analyzed by asphalt molecular chain structure index (methylene plus methyl hydrogen to carbon, MMHC). The correlation between viscosity of asphalt and self-healing performance was obtained. Results show that the adhesive self-healing properties of different base asphalt binders after multiple failure-healing cycles were significantly different. High-density polyethylene and gilsonite at low dosages could improve the self-healing property of asphat, whereas linear, radial SBS, and rubber powder had negative effect on the adhesive self-healing property of asphalt. There was a significant negative linear correlation between MMHC index and healing ratio of base asphalt. However, the MMHC index could not be used to predict the adhesive self-healing property of modified asphalt. The Brookfield rotary viscosity of base asphalt and modified asphalt at 135 ℃ both showed good linear correlation with their healing ratio. Compared with MMHC index, Brookfield rotary viscosity at 135 ℃ is a more suitable evaluation indicator for predicting the adhesive self-healing property of asphalt.