Application of Surface-Modified Nanosilica for Performance Enhancement of Asphalt Pavement

Abstract

AbstractThe fatigue performance of asphalt binder can be significantly increased by incorporating nanosilica, but due to the poor dispersion of nanosilica in asphalt, high mechanical energy is required to achieve good homogeneity. The viscosity of asphalt is nearly double when 3% nanosilica is added. Consequently, the mixing temperature of asphalt with aggregate is dozens of degrees higher to compensate for its high viscosity. To solve this problem, modification of nanosilica was introduced and the effects of its performance on asphalt are reported here. Several types of nanosilica at various dosages were modified and characterized by Fourier-transform infrared spectroscopy (FT-IR) and thermogravimetric analysis (TGA). The properties of asphalt, such as viscosity, rutting, fatigue, softening point, penetration and ductility were investigated. The viscosity of asphalt with 3% modified nanosilica was 80% lower than that of the asphalt with unmodified nanosilica and a 20 °C reduction in temperature for mixing the asphalt binder with aggregate was achieved. Moreover, the rutting and fatigue performance of asphalt with modified nanosilica were significantly enhanced. The asphalt with modified nanosilica not only had lower viscosity but also has similar performance to asphalt with unmodified nanosilica. The asphalt with modified nanosilica had excellent performance and thus good practical application potential.