Effect of Short- and Long-Term Aging on the Rheological and Chemical Properties of Asphalt Binders Modified with Different Technologies

Abstract

This research aims to investigate the impact of short- and long-term aging on the chemo-physical properties of various conventional and modified asphalt binders. The study incorporates different technologies, namely, polymers, rubber, nano, and antiaging modifiers with a combination of 11 original (unaged) asphalt binders, which were short-term aged in the rolling thin film oven, and then long-term aged in the pressure aging vessel (PAV). A comparison between the set of unaged and the two sets of aged asphalt binders was carried out using series of physical and rheological laboratory tests as well as two chemical analyses. Measured laboratory data for the three sets (33 asphalt binders) was used to study the interrelationships between the selected aging indices (AIs) using regression analysis. Results showed that styrene butadiene styrene polymer modified asphalt was one of the best asphalt binders to resist physical changes but fell in the middle range when tested chemically. The carbon nano tubes modified asphalt binder showed great resistance to aging physically and chemically. Although most antioxidant modified binders generally perform better than conventional ones in terms of aging resistance, furfural antioxidant modified asphalt showed poor resistance to rheological changes after aging, while it was superior to resist PAV aging by means of chemical analysis. According to the relationships for long-term aging indices, complex shear moduli at high and intermediate temperatures correlated the most with other physical and rheological parameters. Nonetheless, rotational viscosity and creep compliance (Jnr) correlated the most with other parameters for short-term aging. Finally, the AI of carbonyl chemical group (IC═O) from the Fourier infrared spectrometry had poor correlations with most rheological indices at all aging levels. IC═O was found to have fair to good correlations with Jnr and linear amplitude sweep test parameters after PAV aging.