Durability assessment of bio oil rejuvenated asphalt based on rheology and fracture testing

Bio oil rejuvenators can restore properties of aged asphalt, but the durability of this effect during further aging requires evaluation. This study compared soybean oil residue (SOR), castor oil residue (COR), and petroleum-derived aromatic oil (ARO), each added at 3 wt% of a common laboratory-aged binder. The dosage was fixed for screening and was not optimized for each product. Rheological master curves were evaluated through PAV100, while double-edge-notched tension (DENT) testing covered the initial state, RTFO, PAV20, and PAV40. Aging indices were calculated relative to the unaged base binder or each rejuvenated binder before secondary aging; differences in these reference states limit direct base-versus-rejuvenated comparisons. Among the rejuvenated formulations, SOR showed the smallest modulus-based aging-index evolution, whereas COR showed the largest phase-angle aging response. Through PAV40, approximate critical crack-tip opening displacement (CTOD) decreased for all binders. SOR had the smallest relative CTOD loss among the rejuvenated binders, COR the largest, and ARO the lowest absolute CTOD at PAV40. Overall, the complementary rheological and fracture results demonstrate that secondary-aging durability depends strongly on rejuvenator type and support the use of multi-parameter screening for rejuvenator selection.