Synergistic Effects of Bio‑Derived Modifiers and Chemical Additives on the Rheological and Aging Performance of Bituminous Binders

The incorporation of bio‑derived modifiers into asphalt binders has emerged as a promising strategy to reduce environmental impacts associated with conventional petroleum‑based materials. Nevertheless, previous studies have reported that bio‑based binders may suffer from drawbacks such as reduced elasticity, increased moisture susceptibility, and inconsistent aging performance. In this study, an integrated conference‑level analysis is developed by synthesizing experimental findings from three recent peer‑reviewed investigations addressing bio‑based asphalt binders, polyphosphoric acid (PPA)–bio synergy, and polymer‑modified bio‑derived rejuvenators. The rheological behavior of the binders is evaluated using Dynamic Shear Rheometer (DSR) parameters and Multiple Stress Creep Recovery (MSCR) indices, with particular emphasis on rutting resistance, elastic recovery, and aging mitigation. The combined results demonstrate that while standalone bio‑modification can adversely affect certain high‑temperature and elastic properties, the concurrent use of PPA or polymer‑modified bio‑rejuvenators produces a clear synergistic effect. This synergy significantly enhances stiffness, elastic recovery, and resistance to permanent deformation, while partially restoring the performance losses induced by aging. The findings highlight the importance of hybrid modification strategies and provide practical insights for the design of durable and sustainable asphalt binders.

Keywords:

Bio-based asphalt , Polyphosphoric acid (PPA) , Polymer-modified bio-rejuvenator , Rheological properties , MSCR test , Rutting resistance , Jnr , Elastic recovery