Fatigue properties of bituminous binders reinforced with carbon nanotubes

The study presented in this paper investigated the fatigue properties of bituminous binders reinforced with carbon nanotubes (CNTs). Commercially available CNTs were used in combination with a standard base bitumen at two dosages. Different procedures were used to incorporate CNTs in bitumen, including simple shear mixing and sonication, in order to evaluate the effects of CNT dispersion on the final properties of composite materials. Fatigue analysis of bituminous binders was carried out by subjecting them to oscillatory loading in the stress-controlled mode with a dynamic shear rheometer. Experimental results were analysed with the specific goal of highlighting the performance-related potential of such innovative materials, of discussing CNT reinforcement mechanisms and of identifying critical issues which should be taken into account in design and production. It was shown that CNTs can significantly improve fatigue properties of bituminous binders if adequately dispersed in base bitumen.