Experimental study on mechanism, aging, rheology and fatigue performance of carbon nanomaterial/SBS-modified asphalt binders

Abstract

This study employs two carbon nanomaterial (i.e., graphene oxide, GO; carbon nanotubes, CNT)/polymer (i.e., styrene-butadienestyrene, SBS) composites to modify asphalt binder for the optimal design of asphalt pavement materials. The feasibility of utilizing GO + SBS or CNT + SBS composites in asphalt binders is investigated from the perspectives of the modification mechanism, aging resistance, high- and low-temperature rheological properties, and fatigue performance. To reveal the modification mechanism, X-ray diffraction (XRD) and Raman spectroscopy were performed to detect the composition, crystal structure, and defects of the GO/CNT/SBS modifiers and the modified asphalt binders. Fourier transform infrared (FTIR) spectroscopy characterization was performed to reveal the interaction mechanism between the GO/CNT/SBS modifiers and the base binder. The variations in oxygen-containing groups were detected by FTIR to assess the aging resistance of all the modified binders. The high- and low- temperature properties were determined by multiple stress creep recovery (MSCR) tests and bending beam rheometer (BBR) tests, respectively. Moreover, the fatigue performance of the GO + SBS- and CNT + SBS-modified binder was examined by linear amplitude sweep (LAS) tests. The XRD and Raman spectroscopy results suggested that the GO/CNT/SBS modifiers were of high quality, and showed that GO was beneficial to the crystallization of SBS-modified binders, while CNT had the opposite effect. The FTIR characterization results showed that there was no chemical reaction between GO (or CNT) and SBS or the base binder. The promotion of the anti-aging resistance of the asphalt binders by GO and CNT was proven by FTIR analysis. A favorable high-temperature rheological performance was obtained for the binders with GO or CNT additives, and the low-temperature performance of the SBS-modified binders was also promoted by GO and CNT. Moreover, the nano-reinforcement effect of carbon nanomaterials can extend the asphalt binder’s fatigue life predicted under the framework of the linear viscoelastic continuum damage theory.