Effects of graphene oxide size on mechanical properties of ordinary Portland cement paste

This paper reports the results of the incorporation of 0.02wt% of GO into Portland cement. The influence of different sizes of GO produced by applying various degree of sonication was investigated. It was found that medium size GO with an average diameter of around 670nm give the best results, increasing the compressive and tensile strength and fracture toughness of cement by 46.2%, 48.9% and 21.9%, respectively. The high reinforcing efficiency may be attributed to: (1) the refinement and densification of the microstructure arising from alteration of the hydration process and (2) the superior physical reinforcing effects of GO sheets.