Abstract:The resource utilization of waste oil provides a sustainable source for asphalt rejuvenators. However, the components of oil-based rejuvenators from different sources and processing paths vary significantly, and the understanding of their regeneration effects and mechanisms still needs to be improved. This paper selects two types of waste cooking oil products obtained at different stages of the biodiesel industrial production chain as rejuvenators. The rheological properties of the recycled asphalt at varying dosages were assessed using a dynamic shear rheometer (DSR) and a bending beam rheometer (BBR).The diffusibility of the rejuvenator and the adhesion of the recycled asphalt were evaluated by infrared spectroscopy and photoelectric colorimetry. Additionally, the microscopic mechanisms were analyzed using Fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), and gel chromatography(GPC). The results indicate that at a 6% dosage, the complex modulus and phase angle of the two recycled asphalts closely resemble those of the base asphalt, demonstrating optimal high-temperature resistance to permanent deformation and low-temperature crack resistance. An increase in the small molecule content of the rejuvenator enhances the low-temperature performance, adhesion, and diffusibility of the recycled asphalt, while a higher concentration of large molecules improves its high-temperature performance. The rejuvenator promotes the formation of honeycomb-like structures in aged asphalt while reducing their area. A physical blend occurs between the rejuvenator and the aged asphalt, enabling the replenishment of small molecules in the aged asphalt and inhibiting the formation of large molecules.
