ABSTRACT

Long life bituminous pavement is widely pursed. The change of bitumen properties after long term field aging, however, often receives little attention. Particularly missing are oxidative aging mechanisms and oxidation products generated in sufficient long term field aging conditions. Bitumen binders studied in this paper were extracted from Hong Kong field pavement which has served for 36 years. In addition, four strategic highway research program (SHRP) bitumen binders were artificially aged to simulate long term oxidative aging. The bitumen binders extracted from field as well as their asphaltene components were examined by using Fourier Transform Infrared spectroscopy (FTIR) and X-ray Photoelectron Spectroscopy (XPS). The artificially aged bitumen binders were subject to analysis by using FTIR. Main oxidation products in different bitumen components were analyzed. The relationships between ketone, alcohol and the corresponding dynamic viscosity were investigated. Alcohol was proven to be a significant long term aging product but not seriously affect the dynamic viscosity of field-aged bitumen.