Evaluation of Aging Resistance of Asphalt Binder Modified with Graphene Oxide and Carbon Nanotubes

Graphene oxide (GO) and carbon nanotubes (CNTs) hold the potential to improve antiaging properties of construction material such as asphalt binders and mixtures. To prolong the service life of asphalt pavement, the aging resistance of 70# base asphalt binder, GO-modified asphalt binder, and CNT-modified asphalt binder was evaluated. Aged asphalt binders were obtained by the rolling thin-film oven test (RTFOT) and ultraviolet (UV) aging test. The high-speed shear mixing method combined with ultrasonic dispersion technology was adopted to solve the problem of dispersion of nanomaterials in asphalt binder and the asphalt samples were prepared by the melt-blending method. The surface morphology of GO and CNTs was analyzed with a focused ion beam scanning electron microscope (FIB-SEM). The residual penetration ratio (PRR), softening point increment (SPI), residual ductility ratio (DRR), and viscosity aging index (VAI) were employed to assess physical performance attenuation amplitude of asphalt binder samples after RTFOT and UV aging. The rheological properties of GO-modified asphalt binder and CNT-modified asphalt binder were investigated with a hybrid rheometer, and complex modulus (G*) ratio and phase angle (delta) ratio were selected as antiaging indexes. The ICO increments were tested by Fourier-transform infrared spectroscopy (FTIR) to identify the chemical structure changes during aging process, and the FTIR of the pure GO (or pure CNT) was also conducted. The physical performance testing results illustrated that both GO and CNT could decrease the physical performance attenuation amplitude. Values of G* ratio and delta ratio from rheological testing revealed that the addition of GO (or CNT) could effectively suppress the growth of G* and the attenuation of delta. The FTIR results indicated that the lower the ICO value, the better was the antiaging performance. All phenomena indicated that both GO and CNT can help improve the aging resistance of 70# base asphalt binder. This research provides good inspiration for exploring the excellent performance of nanoparticles modified asphalt binder, which can help broaden the application of nanomodification in asphalt materials.