Evaluation of UV aging resistance of bitumen containing lignosulfonate grafted layered double hydroxides

The service life of bitumen pavement is impacted by ultraviolet (UV) light and some other conditions, which affected the physical properties and rheological behaviors of bitumen obviously. Lignosulfonate grafted layered double hydroxides modified bitumen (LS-g-LMB) was prepared, and the evaluation of UV aging resistance was investigated through Fourier Transform Infrared Spectroscopy (FTIR), aging indexes, temperature sensitivity, dynamic shear rheometer (DSR) and rheological dynamic model analyzer. The results revealed that lignosulfonate grafted layered double hydroxides (LS-g-LDHs) could alleviate bituminous oxidation reaction, variations of aging indexes and temperature susceptibility in the period of UV exposure observably. After aging, LS-g-LMB showed better low (G', G“ and tanδ) and high temperature (G*, δ and G*/sinδ) performance than pristine bitumen (PB) and layered double hydroxides modified bitumen (LMB). Meanwhile, the instantaneous elasticity, delay elasticity and viscous deformation of bitumen could be inhibited by LS-g-LDHs based on the rheological model analyses. Therefore, the introduction of LS-g-LDHs could promote the UV aging resistance of bitumen significantly according to the changes of bituminous physical properties and rheological behaviors before and after UV aging.