Mechanical properties of concrete modified by graphene oxide grafted carbon fiber reinforcement

In order to enhance the interface properties of carbon fiber/concrete matrix, and investigate the effects of graphene oxide grafted carbon fiber reinforcement (CF-GO) on the mechanical properties of concrete, by using amino silane as bridge material, carbon fiber and graphene oxide were tightly bonded through chemical bonds and CF-GO was prepared. The microstructure and functional groups of CF-GO were characterized by scanning electron microscopy and infrared spectroscopy. Graphene oxide was successfully grafted to the surface of carbon fiber and the interfacial shear strength of CF-GO was tested. CF-GO modified concrete (CF-GO/C) was prepared, its mechanical properties were tested and compared with those of carbon fiber modified concrete. In addition, the modification mechanism of CF-GO on the mechanical properties of concrete was analyzed. The results show that the interfacial shear strength of CF-GO increases by 25.37% compared with that of carbon fiber. With the increase of CF-GO content, the flexural and compressive strength of CF-GO/C first increase and then decrease. The optimal content of CF-GO is 0.3vol%, and the optimal content of carbon fiber is 0.2vol%. The flexural and compressive strength of CF-GO/C increase by 33.21% and 24.63% respectively with the optimal CF-GO content. Graphene oxide on the surface of CF-GO enhances the interface of CF-GO/concrete matrix physically and chemically by improving the mechanical bite between CF-GO and concrete matrix and promoting the formation of hydration products on the surface of CF-GO.