Full range temperature susceptibility of aged bitumen rejuvenated by polymer modified bio-derived rejuvenator

In this work, a polymer modified bio-derived rejuvenator consisting of bio-oil, polymer modifier, and other additives (plasticizer, cross-linking agent) was developed. Commercial rejuvenator (CR), bio-based rejuvenator (BR), and polymer modified bio-derived rejuvenator (PMBR) were applied to rejuvenate the aged base bitumen and styrene–butadiene–styrene (SBS) modified bitumen. The relationships between temperatures and properties of rejuvenated aged bitumen gained from Bending Beam Rheometer test (BBR), Dynamic Shear Rheometer test (DSR), and Rotational Viscosity test (RV) were utilized to evaluate the temperature susceptibility under full temperature range corresponding to various circumstances like preparation, construction, and service processes. Subsequently, the chemical fractioning of aged bitumen before and after rejuvenation were characterized via Saturates Aromatics Resins and Asphaltenes Analysis (SARA). The results showed that PMBR at proper dosages performed satisfactorily in rejuvenating the aged bitumen. However, PMBR presented better long-term performance on rejuvenating SBS modified and base bitumen compared with conventional rejuvenators. Moreover, the temperature susceptibility of PMBR rejuvenated bitumen was preferable to that of CR and BR rejuvenated bitumen in full temperature range. Finally, the SARA results showed that PMBR could readjust polar and non-polar fractions to make rejuvenated bitumen more like gel structure. This can explain the temperature susceptibility of PMBR rejuvenated bitumen.