Effect of edge oxidized graphene oxide on micro and macro mechanical properties and microstructure of cement paste

The effects of edge-oxidized graphene oxide (EOGO) on the micro-macro mechanical properties and microstructure of cement pastes were evaluated. Three different cement pastes with EOGO contents of 0 %, 0.05 %, and 0.5 % were prepared, and the compressive strengths and different ages were examined. In addition, the nanomechanical properties of the pastes were measured by nanoindentation tests, and their microstructures were assessed by scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy and mercury intrusion porosimetry. It was found that EOGO remarkably improved the compressive strength of the cement pastes by about 20 %. Nanoindentation results were also in line with the findings of compressive strength. The frequency of occurrence of indentation with modulus around 20 GPa slightly increased with the addition of EOGO. Moreover, EOGO improved the pore size distribution of the cement pastes. SEM images revealed that the EOGO-containing cement pastes were composed of similar microstructural phases.