Effect of Layered Double Hydroxides (LDHs) on Aging Properties of Bitumen

Layered double hydroxide (LDH) modified bitumen was prepared via melt blending. The effects of LDHs on the physical properties and aging properties of bitumen were studied. The influence of LDHs on the chemical structure of bitumen before and after a thin film oven test (TFOT) and an ultraviolet (UV) radiation test was evaluated by means of Fourier transform infrared (FTIR) spectroscopy analysis. The results show that with increasing LDH content, the softening point and viscosity of bitumen gradually increase, whereas the ductility and penetration of bitumen decrease. LDHs can improve the ability of bitumen to resist TFOT aging and UV aging, especially when the LDH content is more than 3 wt. %. In the FTIR analysis, it is seen that LDHs can inhibit the oxidation of bitumen during TFOT and UV aging, resulting in smaller carbonyl and sulphoxide contents than in the pristine bitumen.