Rheological evaluation of asphalt binder modified with zinc oxide nanoparticles

The use of asphalt binders modified by nanomaterials has been studied to minimize premature deterioration of the surface layer of pavements also caused by increases in traffic volume without adequate control of axle load and tire pressure. Whereas usual modifiers, such as polymers, rubber, and fillers, may provide limited improvement of service life and resistance to rutting of asphalt mixtures. Zinc oxide (ZnO) is an activator of chemical accelerations and UV absorbers. Its properties depend on its microstructure and are mainly determined by its morphology and material size. Therefore, its addition in asphalt mixtures has been assessed in recent researches. The present work added zinc oxide nanoparticles (nano ZnO) in the asphalt binder (50/70 penetration index) at the contents of 0%, 3%, 5%, and 7% of the binder weight. The tests of penetration, softening point, rotational viscosity, Rolling Thin-Film Oven (RTFO), Performance Grade (PG), Multiple Stress Creep Recovery (MSCR), Linear Amplitude Sweep (LAS), and master curve were conducted to evaluate the effect of these modifications. The results indicated that the nano ZnO addition, especially at 7%, increased the base binder's PG, fatigue life, and rutting resistance. Therefore, the nano ZnO is considered technically feasible as a modifier of the asphalt binder studied.