The effect of graphene oxide grafted carbon fiber on mechanical properties of class G Portland cement

As described in the research, CFs were reinforced by graphene oxide (GO) and prepared by grafting-to technology and this new graphene oxide modified carbon fiber (GO-CF) showed excellent adhesion properties to cement material, which was with excellent mechanical properties and analyzed by infrared spectroscopy (FTIR), scanning electron microscope (SEM), X-ray diffraction analysis (XRD), and X-ray photoelectron spectroscopy (XPS). To deeply explore the reinforcement mechanism of graphene oxide to CFs, not only were scanning electron microscopy analysis and X-ray diffraction (XRD) analysis conducted, but triaxial strain-stress mechanical performance tests, a dynamic simulation to subsurface operation environment, were also utilized to confirm the mechanical effect of GO-CFs to cement. The results showed that GO-CF reinforced cement (GOCFRC) exhibited excellent compressive strength performance with GO of only 0.4% BWOC content. And cement compressive strength increased to over 1.18 times that of pure cement after 14-day curing period. Above all, the new kind of reinforced cement material showed superior toughness compared to pure cement. Its flexural tensile strength increased by 38.81% in 3-day curing period, 38.65% in 7-day curing period, and 41.76% in 14-day curing period. Furthermore, it displayed excellent triaxial stress-strain toughness compared to pure cement: Young’s modulus increased to 150.9%, ultimate stress increased to over 121%, and ultimate strain increased to about 267%. Excellent compatible interface adhesion performance of new carbon fiber was detected through SEM analysis. Via this research, the application mechanism of GO reinforced cement material was improved, and a new type of carbon fiber reinforced cement (CFRC) with higher mechanical performance was developed.HighlightsGraphene oxide (GO) was used for the surface properties modification of carbon fiber.Graphene oxide (GO) can significantly increase the mechanical behaviors of carbon fiber.Graphene oxide-carbon fibers (GO-CFs) can significantly increase the mechanical behaviors of cement.The influence that GO-CF had on the mechanical integrity of the cement was discovered (SEM).The reinforcing mechanism that GO-CF had on the oil-well cement was discussed in detail.