Rheological Investigations of Highly Modified Asphalt HiMA Binders Across Different Temperatures and Aging Conditions

Abstract

In recent years, modified binders have become more popular than traditional newlinebituminous binders from refineries to handle increasing traffic and changing weather conditions. newlineThe modifier dosage added to the binder is crucial in controlling the pavement distresses. newlineModifiers that increase binder stiffness perform well against rutting at high temperatures in newlineunaged conditions. However, higher stiffness can also lead to more fatigue damage at lower newlinetemperatures. To better understand the binder behavior at intermediate and low temperatures, it newlineis important to study how it responds to shear, temperature, and aging. Additionally, modifiers newlinecan affect the workability of the bituminous mixtures. Understanding the Newtonian and non- newlineNewtonian behavior can help improve the bituminous mixture production process. newlineThis study involved a detailed experimental investigation across two temperature newlineranges: 0 to 30°C and 90 to 160°C. The base binder, VG10, was modified with SBS polymer at newlinetwo dosages, labeled as HiMA 4% and HiMA 8%. All three binders underwent aging through newlinetwo cycles of a pressurized aging vessel (PAV), referred to as 1PAV (one cycle) and 2PAV (two newlinecycles). For low-temperature testing, a Dynamic Shear Rheometer (DSR) was used. Tests were newlineconducted in both oscillatory shear mode and time-dependent mode. A frequency sweep test in newlinestrain-controlled mode was performed with a constant strain of 0.01% at a fixed temperature. newlineThe stress relaxation test was carried out in a time-varying mode, where relaxation behavior was newlineobserved at a non-linear strain of 2%. Additionally, a linear amplitude sweep test was conducted newlineat different temperatures to evaluate binder fatigue damage newline