Aging Resistances Evaluation of Multi-dimensional Nanomaterials Modified Asphalt by Characterizing Binders Recovered from Aged Asphalt Mixtures

Abstract

Abstract In terms of the aging susceptibility of asphalt, the multi-dimensional nanomaterials (MDNMs) have been developed to improve the aging resistance of asphalt. In comparison with most of previous studies that are only based on asphalt binder aging simulation methods to evaluate anti-aging properties of MDNMs modified asphalt, aging resistances of MDNM-modified asphalt were evaluated in this research by extracting and recovering binders from their aged asphalt mixtures and then characterizing the aging degree of the extracted binders in terms of physical, rheological, and chemical properties. Organic expanded vermiculite (OEVMT) and nanoparticles (nano zinc oxide [ZnO], nano titanium dioxide [TiO2], and nano silica [SiO2]) were chosen to compose three kinds of MDNMs. And six types of aging patterns (including mixing aging [MA], short-term aging [STA], compacted and loose long-term aging [CLTA and LLTA], and compacted and loose ultraviolet (UV) aging [CUVA and LUVA]) for asphalt mixtures were conducted. The results indicate that the ranking of aging degree for the six types of aging patterns is LUVA > LLTA > CUVA > CLTA > STA > MA. Regardless of the types of asphalt mixture aging patterns, the aging resistances of extracted MDNM-modified asphalt binders are all better than extracted pure asphalt binder, and the composite form of OEVMT combined with ZnO presents more significant improvements on asphalt aging resistance than the other two composite forms (OEVMT + SiO2 and OEVMT + TiO2).