▎ 摘　　要

Graphene oxide (GO) nanosheets are prepared by oxidation of graphite followed by sonication exfoliation. FTIR and AFM results indicate that the GO nanosheets have a thickness of about 6 nm, and that the GO surface is covered with oxygenated groups (-OH, -O-, -COOH and -SO3H). Hardened cement pastes containing different proportions of the GO nanosheets are prepared, and it is found that the GO formed both flower-like and polyhedron-like crystals, with these effects increasing as the GO content increases from 0.01% to 0.06% by weight of the cement. The compressive strength and toughness of the corresponding hardened cement paste are found to be markedly increased compared to a control sample. The results suggest that the GO nanosheets can control the crystalline form and assembly of the cement hydration products. A formation mechanism for regular hydration crystals is proposed, based on the experimental results. This research indicates significant potential for the practical application of GO nanosheets in the preparation of cement-based materials of high strength and durability.