UV Aging Mechanism and Road Performance of Waste Vegetable Oil Recycled Asphalt
SUO Zhi1, CHEN Huan1, ZHANG Ao2, NIE Lei1
1 School of Civil Engineering and Transportation, Beijing University of Civil Engineering and Architecture, Beijing 102600, China 2 Beijing Road Engineering Quality Supervision Station, Beijing 100000, China
Abstract: Waste vegetable oil has the characteristics of low viscosity, high unsaturation and high thermal stability. It can adjust the components missing due to asphalt aging and disperse the gum in aging asphalt. The micro characteristics of asphalt were remolded from the composition and structure. Waste vegetable oil is added to the aged asphalt as a regenerant to regenerate it. However, the presence of unsaturated carbon chain in vegetable oil makes the recycled asphalt more sensitive to ultraviolet light, which affects the durability of asphalt. Therefore, this paper studies the performance of asphalt before and after UV aging from micro and macro aspects. Firstly, through four-component analysis and FTIR and other experiments, the micro changes of waste vegetable oil recycled asphalt after UV aging were revealed, and the UV aging mechanism of waste vegetable oil recycled asphalt was clarified. At the same time, the mineral oil recycled asphalt and SK-70 asphalt are introduced. The physical properties, rheological properties and road performance of the three kinds of asphalt were compared with ultraviolet aging time through DSR and BBR tests. The influence of ultraviolet aging on SK-70 asphalt and two kinds of recycled asphalt was clarified from the perspective of macro performance. The results show that compared with the other two kinds of asphalt, the dispersion of light components in waste vegetable oil recycled asphalt is more serious after UV aging, and the changes of components and functional groups are the most obvious. The change of functional groups is three times of SK-70 asphalt, and the UV aging resistance is poor. After UV aging, the indexes of three kinds of asphalt in evaluating high, medium and low temperature performance are consistent, which indicates that the changes of three kinds of asphalt after aging are consis-tent: the high temperature performance is improved, while the low and medium temperature performance is decreased, and the most obvious performance change is recycled asphalt from waste vegetable oil.