Comparison of dynamic mechanical properties of carbon fiber and graphene oxide grafted carbon fiber modified concrete

Graphene oxide grafted carbon fiber (CF-GO) is successfully prepared by the chemical grafting method of "grafting to". The physical properties, mechanical properties and dispersion effects of carbon fiber and graphene oxide are comparatively studied. Carbon fiber modified concrete (CFMC) and graphene oxide grafted carbon fiber modified concrete (CF-GOMC) are prepared, and the dynamic mechanical properties and fiber/concrete matrix interfaces of CFMC and CF-GOMC are comparatively studied. The results show that the physical and mechanical properties of CF-GO are improved compared with carbon fiber, and the dispersion effect of CF-GO in concrete matrix is better than that of carbon fiber. When the fiber content is the same, the dynamic mechanical properties of CF-GOMC are better than that of CFMC, and the strain rate effect of dynamic mechanical properties indicatoes is stronger than that of CFMC. The strengthening and toughening effect of CF-GO on concrete is better than that of carbon fiber. The carbon fiber/concrete matrix interface exhibits a relatively large porosity, while the CF-GO/concrete matrix interface is well bonded. The graphene oxide on the surface of CF-GO exerts an "expansion bolt" effect, attracting the deposition of hydration product crystals and regulating their crystal structure.