An experimental study of the viscoelastic characteristics and fatigue performance of asphalt binder modified by CNT nanoparticles

This study aims to investigate the effectiveness of carbon nanotubes (CNTs) and styrene-butadiene-styrene (SBS) on the fatigue performance of two types of base asphalt binders (70# and 90#). Frequency sweep and linear amplitude sweep (LAS) tests were carried out on CNT- and CNT/SBS-modified asphalt binders using a dynamic shear rheometer. The fatigue damage characteristics and fatigue failure behavior of the modified binders were analyzed using the simplified viscoelastic continuous damage theoretical model. The dynamic modulus master curve outcomes indicated that incorporating CNT and SBS enhanced the stiffness and elastic recovery of the base asphalt binder, thereby enhancing its resistance to permanent deformation. The results of the LAS tests showed that incorporating CNT nanoparticles can significantly improve the fatigue life of 70# and 90# base asphalt binders. The fatigue damage resistance of both the CNT-modified and the CNT/SBS-modified asphalt binders was also significantly improved. The fatigue life of the 90#/CNT-modified asphalt binder was greater than that of the 70#/CNT-modified asphalt binder under an unaged condition. After the short-term aging process, the fatigue life of the modified asphalt binder decreases, and the fatigue life of the modified asphalt binder after ultraviolet aging indicates an additional reduction in overall fatigue life.