Physical and chemical evaluation of adhesion recovery property of aged high-viscosity asphalt based on specialized composite rejuvenators

Abstract

With the wide application of porous asphalt pavement, the techniques for recycling aged porous asphalt mixture have attracted more attention for facilitating its sustainable development. One of the most critical issues is how to recover the adhesion properties of aged high-viscosity asphalt (HVA). In this study, different specialized composite rejuvenators types on the adhesive properties of aged asphalt binder were designed and evaluated for the goal of adhesion recovery. A bond strength test was used to evaluate the macroscale adhesion properties between the regenerated asphalt and aggregate. Micro-scale chemical and physical tests were utilized to discover the regeneration mechanism of specialized composite rejuvenators on asphalt adhesion. The results showed that the proposed three kinds of composite rejuvenators can effectively restore and improve the adhesive properties of aged HVA. The results of differential scanning calorimetry (DSC) represented that recycled HVA with smaller Tg and total heat absorption showed better adhesion properties. The FT-IR and AFM test results showed that the adhesion of recycled HVA is highly correlated with the C–O functional group index and micro adhesion. In addition, the concave structure in the asphalt surface is more beneficial to improve the asphalt-aggregate interface bonding, and the scheme of adding 8% optimized rejuvenator based on graft co-polymerization had the best effect, which could be promoted for the future application in the recycling of HVA in porous asphalt pavement.