Effect of graphene nano-sheets on the chloride penetration and microstructure of the cement based composite

In this work, the effects of the non covalent surface modification method on the dispersion of graphene nano-sheets (GNS) in water and chloride diffusion of the cement paste incorporating these dispersions were investigated. Results showed that stable and homogeneous suspensions of graphene nano-sheets were prepared using polyoxyethylene (40) nonylphenylether (CO890) as a dispersant. In this research, water to cement ration is kept 0.30, the addition of GNS is ranging from 0.02% to 0.15% by weight of cement. It is found that introduction small quantities of GNS as little as 0.02% can decrease the chloride penetration depth and coefficient by as much as ∼37% and ∼42%, respectively. This improvement could be attributed to the enhanced degree of cement hydration, filling effect, barrier effect and crack-arresting effect of GNS in cement matrix. This work provides a new way to further understand the improvement of GNS in cement composites.