Laboratory Investigation on the Short-term Aging Behavior of Various Highly Modified Asphalt Binders

Highly modified asphalt binders have become the preferred choice for high-grade flexible pavements; however, current research lacks clarity on the mechanisms of short-term oxidation and degradation among different modifiers. In response, this study investigates the short-term aging of various modified asphalt binders, including SBS, crumb rubber, PPA, and gilsonite. The study utilizes a PG 58-22 neat asphalt and eight modified binders, examining their aging behavior at temperatures of 163°C, 178°C, and 193°C. The study utilizes FTIR, oscillation tests, Multiple Stress Creep Recovery (MSCR), and master curve techniques to analyze the binders post-aging. Results show that PPA reduces aging by preventing asphaltenes micelle agglomeration, whereas other modifiers show increased aging and carbonyl formation. Gilsonite-modified binders exhibit the least aging resistance, while CR and SBS display softening effects with stable modulus post-aging. Higher modifier dosages (20% CR, 24% Gilso, 7.5% SBS) reduce aging severity by increasing viscosity, which limits the flow and reduces oxidation and volatilization within the RTFOT.