Enhanced dynamic mechanical properties of cement paste modified with graphene oxide nanosheets and its reinforcing mechanism

The effect of graphene oxide (GO) nanosheets on the static and dynamic mechanical properties and microstructure of cement paste has been investigated. The results of dynamic mechanical testing revealed that loss factors of the pastes containing 0.05, 0.10, and 0.20 wt.% of GO were improved by 31%, 58%, and 77%, respectively. The maximum storage modulus of 52% was observed at a GO content of 0.1 wt.%, while the 28-d flexural and compressive strengths of the cement pastes with GO contents of 0.05 and 0.2 wt.% exceeded those of the control pastes by 12%-26% and 2%-21%, respectively. TGA analysis and microstructural analysis of the hardened cement pastes showed that the added GO could promote cement hydration, refine the capillary pore structure, reduce the air voids content, and improve the density of pastes. Dynamic mechanical properties reinforced mechanisms of paste incorporated with GO were also revealed based on the internal contact surfaces, porosity, and non-uniform stress distribution analysis.