Post carbon road: Limits and possibilities of cyclic bitumen rejuvenation

Abstract

In road construction, the reuse of reclaimed asphalt depends on the addition of large quantities of fresh binder. Bio-based rejuvenators can represent a sustainable alternative to this, but their performance concerning multiple reuses has yet to be investigated. For this study, fresh 50/70 bitumen was subjected to up to four ageing and rejuvenation cycles using eight commercially available rejuvenators (five bio- and three petroleum-based). The rheological and chemical evaluation of the raw materials and resulting products was carried out using a dynamic shear rheometer and Fourier transform infrared spectrometer. Through examination of the infrared spectra, the rejuvenators were divided into three groups based on similar chemical composition. Further, evaluated optimum dosage quantities required to rejuvenate aged binder indicate that bio-based rejuvenators are more resource-efficient than their petrol-based counterparts. Finally, a most promising bio-based rejuvenator candidate was found, allowing up to four reuse cycles.