▎ 摘　　要

NOVELTY - Modified graphene composite material comprises a nano-silicon dioxide loaded on surface of crosslinked modified graphene framework, where the crosslinked modified graphene framework has cross-linked structure formed by polycarboxylic acid water reducing agent and graphene oxide. USE - The modified graphene composite material is useful in cement. ADVANTAGE - The material can improve the strength, fluidity and stability of cement. DETAILED DESCRIPTION - INDEPENDENT CLAIMs are also included for: (1) Preparing modified graphene composite material comprising hydrolyzing graphene oxide and silicate ester in aqueous solvent to obtain graphene oxide loaded with nano silicon dioxide, carrying out crosslinking reaction to the graphene oxide loaded with nano silicon dioxide and polycarboxylic acid water reducing agent, and loading graphene oxide with silicon dioxide and the polycarboxylic acid water reducing agent form a crosslinked structure to obtain the modified graphene composite material. (2) Cement reinforcing agent comprising modified graphene composite material. (3) Cement comprising cement base material and cement reinforcing agent. (4) Concrete comprising aggregate and cement.