Investigation of Ultraviolet Ageing on Rheological Characteristics of Bitumen

The influence of ultraviolet (UV) ageing on complex modulus, phase angle and low-temperature fatigue factor was studied by dynamic shear rheometer test. The ageing degree of the bitumen was evaluated by the rheological parameters. The results show that UV ageing causes an increase in complex modulus and fatigue factor, as well as a decrease in phase angle, indicating that the bitumen becomes more elastic after UV ageing process and is apt to crack at low temperatures. Different bitumen exhibits diverse changes in the rheological parameters after UV ageing, which is much dependent on the sources of bitumen.