Investigation of Anti-UV Aging of Bitumen Modified with Layered Double Hydroxides

Abstract

Layered double hydroxides (LDHs) were used to modify bitumen. Effect of LDHs on physical properties and chemical compositions of bitumen was investigated. Fourier transform infrared (FTIR) spectroscopy was carried out to analyze the structural change of LDHs modified bitumen after UV aging. The results show that LDHs is effective in improving the UV aging resistance of bitumen since the viscosity aging index (VAI) and softening point increment (SPI) of bitumen decrease while the retained penetration ratio (RPR) increases with increasing LDHs contents. The carbonyl and sulfoxide of LDHs modified bitumen presented a smaller increase after UV aging in comparison with unmodified bitumen according to FTIR analysis, and the changing rate of carbonyl and sulfoxide index of aromatics and asphaltenes reduced obviously compared with the slight changes of saturates and resins after the introduction of LDHs during UV aging, which demonstrated that LDHs mainly inhibit the oxidation of aromatics and asphaltenes during the UV aging.