Influence of UV aging on the rheological properties of bitumen modified with surface organic layered double hydroxides

• FTIR indicated that TEVS has been successfully grafted onto the surface of LDHs.
• The compatibility between TEVS-LDHs and bitumen has been effectively improved.
• TEVS-LDHs reduced temperature susceptibility and enhanced rutting factor of bitumen.
• TEVS-LDHs were more beneficial to enhance UV aging resistance of bitumen than LDHs.

Triethoxyvinylsilane surface organic modified layered double hydroxides (TEVS-LDHs) were prepared and applied to improve the ultraviolet aging resistance of bitumen. The effect of TEVS-LDHs and LDHs on the temperature susceptibility and rheological properties of bitumen before and after UV aging were thoroughly investigated. The storage stability test showed that the difference in the softening point (ΔS) of LDHs modified bitumen (the LDHs content at 2%) decreased from 1 °C to 0.4 °C after TEVS surface organic modification, and the descending trend was more obvious with the content of LDHs increase, which implied that TEVS-LDHs dispersed better and existed more stably in bitumen than LDHs. The introduction of TEVS-LDHs significantly alleviated the temperature susceptibility of bitumen and increased the rutting factor (G∗/sin δ) of bitumen, indicating that TEVS surface organic modification were favorable to the improvement of high-temperature performance for LDHs modified bitumen. After UV aging, bitumen became more hard and brittle, compared with LDHs, the addition of TEVS-LDHs alleviated obviously the deterioration tendency of bitumen, which suggested that LDHs surface organic modified by TEVS were far superior to unmodified LDHs in enhancing the UV aging resistance of bitumen.