Aging degradation of asphalt binder by narrow-band UV radiations with a range of dominant wavelengths

Abstract

To investigate the aging degradations of dominant wavelength of UV radiation on asphalt binder, five narrow-band UV radiations with different dominant wavelengths, namely 300, 320, 340, 360 and 380 nm, were used to age asphalt. After the UV aging, the aging degradations of the UV radiations on the chemical compositions, physical properties, rheological properties and complex viscosities of asphalt binder were tested by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), physical property test, and dynamic shear rheometer (DSR) respectively. The results show that all UV radiations, with the dominant wavelengths from 300 nm to 380 nm, can cause the aging degradations on the neat asphalt, UV aging can change the chemical compositions of asphalt, as well as the macro-performance of asphalt, such as physical and rheological performance. While, the molecules of asphalt have different susceptibilities to different wavelengths of UV radiations, different dominant wavelengths of UV radiations have different aging degradations on asphalt, it is not that a UV radiation with shorter wavelength (higher photon energy) definitely produces more serious aging effect on asphalt. Making into comparison, under the same aging condition, the asphalt binder aged by the UV – 360 has the highest aging degree, followed with the asphalt binders aged by UV – 340, UV – 320, UV – 300 and UV – 380, respectively.