Research on viscosity and rheological properties of asphalt in aging process

To analyze viscosity and rheological properties of asphalt in the process of aging, five types of asphalt were aged for different time by rolling thin film oven test (RTFOT). According to the viscosities under different temperatures, the visco-flow activation energy (Eη) of asphalt was calculated using Arrhenius equations. And then, the relationship between viscosity of asphalt under different temperature and aging time was analyzed, and change regularity of Eη was discussed. The results and analysis indicate that there was very important influence of aging on rheological index of asphalt. The viscosities of asphalt less than 135°C increase by exponential relationship with aging time, but those greater than 135°C increase by linear relationship. With aging degree deepening, Eη of asphalt all increase continuously. The molecule structure of aged asphalt will change which cause high-temperature flow energy increase and low-temperature flexibility decay. That is the reason of performance change of asphalt. Because of differences of anti-aging performance and aging mechanism, there were different rheological behaviors for different asphalt in different aging stage.