Effect of Polymer and Oil Modification on the Aging Susceptibility of Asphalt Binders

Abstract

Oxidative aging causes hardening of asphalt binders and, consequently, contributes to the deterioration of asphalt pavements. The principal cause of asphalt aging and embrittlement in service is the atmospheric oxidation of molecules with the formation of highly polar and strongly interacting functional groups containing oxygen. Therefore, aging is a complex process in unmodified asphalt binders, and the complexity increases for modified binders. The dynamics of world resource economics suggest that the asphalt pavement industry should be exploring economically and environmentally sustainable approaches to development, such as the addition of recycled oils to the base asphalt binder, and thus research activities are noteworthy in this area. The effect of oil and polymer modification on asphalt binder rheology and oxidative aging has become a popular topic for research in recent years. However, the effects of oil and polymers are often studied independently. The objective of this study was to investigate the modification effects of bio-oil, re-refined wasted engine oil, polymers, and the interaction between polymers and oil on the aging susceptibility of asphalt binders. After laboratory accelerated aging procedures were conducted, dynamic shear rheometer and bending beam rheometer tests were used for the rheological performance evaluation. Gel permeation chromatography and Fourier transform infrared spectroscopy were used to verify the rheological results with chemical analysis tools. Results indicate that the aging susceptibility of modified asphalt binders is dependent on modification chemistry. Certain polymers and combinations of polymers with oil can reduce the base asphalt binder’s susceptibility to aging.