Investigating the role of sulfur stabilizer in modulating aging properties of SBS-modified asphalt

Abstract

Stabilizers are commonly employed in SBS-modified asphalt, yet their specific impact on aging behavior remains ambiguous. Past studies have not agreed on their role and have primarily examined effects on the SBS polymer phase, neglecting asphalt phase influences. Understanding these interactions is essential for aging mechanisms and rejuvenation strategies. To solve this issue, this study compared three types of asphalt to analyze their properties during aging. Microscopic tests comprising morphology, chemical structure, and molecular weight analyses with nine quantitative indicators were conducted, and the distinct influences of stabilizers on asphalt and SBS polymer phases were elucidated. The results revealed that the change rate in the physical properties of SBS-modified asphalt during aging decreases with sulfur addition, rheological parameters indicated that sulfur predominantly protects the polymer network structure from degradation during short-term aging. Furthermore, stabilizers had no explicit impact on the carbonyl index but could delay the generation of asphaltene molecules during aging, the change rates of asphaltene% were 1.65% without stabilizers and 12.36% with them after TFOT (Thin film oven test) aging. Stabilizers also notably mitigated polymer degradation and exhibited beneficial effects even during PAV (Pressure aging vessel) aging. The overall findings contribute to a clearer understanding of the complex interplay among the various components of SBS-modified asphalt, such as base asphalt, SBS modifiers, and stabilizers, providing theoretical insights into aging mechanisms and rejuvenation strategies involving stabilizers.