Study on all-components regeneration of ultraviolet aged SBS modified asphalt for high-performance recycling

Abstract The regeneration and reusing of reclaimed asphalt mixture can promote the recycling of waste building materials and the sustainable development of asphalt pavement. To further improve the properties of rejuvenated SBS modified asphalt, the effects of structural changes of SBS, and the colloidal stability of asphalt on the properties of binder were studied. And based on the results, bio-rejuvenator and active rejuvenator were applied to rejuvenate ultraviolet aged SBS modified asphalt (USMA), the impacts of rejuvenators on the composition, structure, physical and rheological properties of USMA were systematically investigated. The results show the decrease of colloidal index and the damage of SBS structure all have a serious adverse influence on the properties of binder. Bio-rejuvenator can rebalance the colloidal stability of ultraviolet (UV) aged binders, meanwhile active rejuvenator could react with the active terminal groups of broken SBS segments and partially rebuilds its crosslinking structure. And the physical and rheological properties of UV aged asphalt can be all basically restored by adding bio-rejuvenator; however bio-rejuvenator cannot restore the properties of USMA, which can only improve the low-temperature performance of USMA. While the addition of active rejuvenator greatly enhances the high-temperature performance of rejuvenated SBS modified asphalt. Furthermore, the combination of bio-rejuvenator and active rejuvenator can both recover the colloidal structure and damaged SBS structure of USMA, which obviously improves its high- and low-temperature properties overall. This paper would contribute to the realization of high-quality regeneration of reclaimed SBS modified asphalt.