UV Aging Assessment of Asphalt Binder: Influence of Duration and Zinc Oxide

Abstract

Bitumen Ageing is studied in the laboratory using methods, which represents thermo-oxidative ageing. In the field, bitumen undergoes photo-oxidative ageing due to the presence of ultraviolet (UV) radiations. In order to understand the effect of UV radiations, laboratory study was conducted using viscosity graded VG40 bitumen with and without zinc oxide nanoparticles (ZnO-NP), as an anti-photo-oxidative additive. Rheological and chemical investigations were carried out on the UV aged bitumen using DSR and Fourier transform infrared (FTIR) spectroscope. The results indicated that UV radiations aged the bitumen significantly and this increased with duration. The stiffness of the bitumen with ZnO-NP was relatively lower and showed significant resistance against UV ageing. The Cross model for viscosity and ageing model was fitted to quantify the effect of UV ageing. Further, carbonyl and sulfoxide indices were calculated from the FTIR spectrum, where these indices were found to be higher for bitumen without ZnO-NP.