Application of reactive rejuvenator in aged SBS modified asphalt regeneration: A review

SBS modified asphalt (SBSMA) pavements have gained popularity worldwide due to their prominent performance. However, its maintenance and reconstruction projects will produce a large amount of reclaimed asphalt pavement (RAP) during the long-term service of asphalt pavement. Adding rejuvenators products is a common method to recycling RAP. However, conventional rejuvenators are typical component regulators applicable to recycling unmodified asphalt, while there is a poor regeneration effect for the aged SBS modified asphalt (ASBSMA), because it cannot repair the degraded SBS polymer. Fortunately, reactive rejuvenator (RR) has achieved this breakthrough based on the research findings in recent years. It contains special compounds that have the ability to repair the degraded SBS. The vital questions to be investigated in the present review are how the four current systems of RR (epoxy system, isocyanate system, compound system and polymer system) affect ASBSMA's properties and how well does its regeneration effect. Existing research indicated that RRs are favorable for the regeneration of A-SBSMA and have their respective characteristics. This review summaries various RR different regeneration mechanism, and analyzed its effects on physical properties, rheological properties, high and low temperature properties, and microscopic characteristics of A-SBSMA. Although research on RR is still in its infancy with a limited number of relevant studies, they show an excellent regeneration effect for A-SBSMA and hold a promising prospect. Overall, this review provides information on the feasibility of using RR as a sustainable SBSMA rejuvenator to promote conserving resources and reusing RAP.