Mechanical properties and microstructure of a graphene oxide–cement composite

Graphene oxide (GO) is the product of chemical exfoliation of graphite. Due to its good dispersibility in water, high aspect ratio and excellent mechanical properties, GO is a potential candidate for use as nanoreinforcements in cement-based materials. In this paper, GO was used to enhance the mechanical properties of ordinary Portland cement paste. The introduction of 0.05 wt% GO can increase the GO–cement composite compressive strength by 15–33% and the flexural strength by 41–59%, respectively. Scanning electron microscope imaging of the GO–cement composite shows the high crack tortuosity, indicating that the two-dimensional GO sheet may form a barrier to crack propagation. Consequently, the GO–cement composite shows a broader stress–strain curve within the post-peak zone, leading to a less sudden failure. The addition of GO also increases the surface area of the GO–cement composite. This is attributed to increasing the production of calcium silicate hydrate. The results obtained in this investigation suggest that GO has potential for being used as nano-reinforcements in cement-based composite materials.