Synergetic effect of multi-dimensional nanomaterials for anti-aging properties of SBS modified bitumen

Styrene-butadiene-styrene copolymers (SBS) modified bitumen has been extensively applied to high grade pavement due to its excellent high and low temperature performance, however, degradation of its performance is inevitable as service time of road pavement goes on. Aging occurred in SBS modified bitumen is primary responsible for the performance deterioration. This research focuses on improvement of multi-dimensional nanomaterials containing surface modified nano-zinc oxide (nano-ZnO) and organic expanded vermiculite (OEVMT) on performances of SBS modified bitumen during different aging modes. Various ratios multi-dimensional nanomaterials were used for preparing compound SBS modified bitumen, all prepared adhesives suffered from rolling thin film oven test (RTFOT), pressure aging vessel (PAV) and accelerated ultraviolet (UV) aging. Conventional physical property tests and rheological property tests were carried out on all samples, as well as their chemical structures were revealed by Fourier transform infrared (FTIR) spectroscopy test. Results show that the addition of multi-dimensional nanomaterials slows down significantly deterioration of physical and rheological performances of SBS modified bitumen during thermal oxidative and photo oxidative aging process. Overall considering the results from physical and rheological performances analysis before and after different aging modes, the recommended ratio is 1%OEVMT + 2%nano-ZnO. Meanwhile, OEVMT and nano-ZnO compound have synergetic effect in enhancing SBS modified bitumen aging resistance. FTIR spectroscopy test result manifests that multi-dimensional nanomaterials remarkably prevent carbonyl formation in SBS modified bitumen in the process of RTFOT, UV and PAV aging.