Evaluation of Regeneration Effects of Different Rejuvenators on Aged Asphalt

As a polymer-like organic material, asphalt often undergoes aging during service life. Regeneration technology is the main approach to achieve its recycling; therefore, the rejuvenator is an important factor affecting the regeneration effect. In order to evaluate the rejuvenation effects of rejuvenators on aged asphalt, fluid catalytic cracking (FCC) slurry and a penetrant containing epoxy functional groups were used to prepare conventional rejuvenators (CR1 and CR2) and a penetrable rejuvenator (PR). The impact of the penetrant on the physical properties of the rejuvenator was investigated, and the rejuvenation effects of different rejuvenators on mild and severe aged asphalt were evaluated through physical and rheological tests. Results show that the penetrant effectively lubricates the movement of rejuvenator molecules, improving the high temperature stability and aging resistance of the rejuvenator. CR1 and CR2 are more suitable for mild aged asphalt, as mild aging has a relatively minimal effect on the chemical composition and colloidal structure of asphalt. At a 25% dosage, the PR significantly restores the physical properties of severe aged asphalt, while CR1 and CR2 still fail to meet specifications. The PR is more effective for severe aged asphalt because it not only dissolves and disperses asphaltenes but also weakens interactions between asphaltenes, which facilitates a more effective restoration of the colloidal structure and significantly enhances the rejuvenation effect. The findings of this study provide insights into the design of penetrable rejuvenators for a more efficient utilization of reclaimed asphalt pavement (RAP).