Effects of coupling graft graphene fluid on modifying asphalt binders: Preparation, characterization and performance validation

Inorganic nanomaterials are widely studied to modify asphalt binder. However, the problems caused by poor compatibility and high viscosity have not been well resolved, and hence their further application is still limited. In order to break the limitation, this study proposes a new grafting method to optimize the surface characteristics of graphene oxide (GO), and finds that the upgraded GO when used as a modifier can significantly improve above mentioned problems. Specifically, coupling graft graphene fluid (CG-GF) was successfully synthesized via a two-step grafting method, and then properties of CG-GF were studied through Fourier infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), thermogravimetric analysis (TG), dispersion and fluidity tests. Thirdly, the prepared CG-GF was used to modify the pure asphalt binder (A-90), and the comprehensive performance of CG-GF modified asphalt binder (CMAB) was validated. Results show the modified binder doesn’t see a significant increase in viscosity above 135 °C and compatibility is not weakened. The significance of this paper is to propose a feasible method to modify the performance of inorganic nanomaterials, and this method widens the application of inorganic nanomaterial modified asphalt binders (INMAB) in pavement engineering.