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PROJECT DETAILS

Project Type
Emerging Investigators Program
Project Dates
09/01/2016 - 03/31/2018
Principal Investigators
Institution
Project Status
Complete

One of the primary mechanisms in which asphalt binder and asphalt pavement undergoes aging is oxidation. Oxidative aging can be categorized as either thermal oxidation, which occurs primarily during mixing, transporting, and placement, or UV-oxidation which occurs throughout the lifetime of the pavement due to solar irradiance. This project aims to further investigate the UV-oxidation of asphalt binder. Through experimental tests on thin asphalt binder specimens and an analytical investigation of actual in-field UV-irradiance measurements, a link will be made between laboratory accelerated aging due to UV-oxidation and in-service aging that occurs during the service life of a pavement. UV fluorescent lamps will be used to expose thin asphalt binder samples to UV radiation and the extent of UV-oxidation will be evaluated using a rotational viscometer. As asphalt binder oxidizes it begins to stiffen due to the formation of new functional groups including carbonyls and sulfoxides. This chemical change significantly alters the asphalt binder’s rheological properties, including an increase in the viscosity which leads to a higher susceptibility to fatigue cracks and pavement deterioration.