Physical and Antiaging Properties of Rodlike Nano-ZnO–Modified Asphalt

Abstract

Asphalt aging is the main cause of fatigue failure of asphalt pavement. The performance of rodlike nano-ZnO is better than that of nano-ZnO in all aspects, and rodlike nanomaterials can reduce the agglomeration phenomenon of powder like nanomaterials in asphalt. Therefore, in this paper, rodlike nano-ZnO particles were added to asphalt to improve its aging resistance. Asphalt was modified by adding different amounts of rodlike nano-ZnO particles. The penetration (25°C), softening point, and ductility (5°C) of rodlike nano-ZnO–modified asphalt were tested. The aging of rodlike nano-ZnO–modified asphalt was simulated by thin film oven test (TFOT) and ultraviolet (UV) aging. The dynamic shear rheological (DSR) properties of modified asphalt before and after aging were studied, and the mechanism was explained using UV-visible-infrared absorption test, Fourier transform infrared (FITR) spectroscopy, and scanning electron microscopy. Rodlike nano-ZnO particles can increase the softening point of asphalt and reduce the penetration (25°C), which has a positive effect on the ductility (5°C), but when the content is 3%, the ductility of asphalt will be affected. The complex shear modulus (G*) and phase angle (δ) of the composites can be improved using rodlike nano-ZnO. With the increase of the amount of rodlike nano-ZnO, the performance change rate of modified asphalt before and after aging decreases gradually. When the content of rodlike nano-ZnO is 3%, the modified asphalt has the best UV absorption capacity, does not affect other physical properties, and can significantly improve the drying and hardening of the microsurface after aging. Therefore, rodlike nano-ZnO can significantly improve the UV resistance of asphalt.