▎ 摘 要
Concrete structures constructed with cement-based materials are often at risk of chloride attack and structural damage. This project adds 0%-0.2% content of new, porous three-dimensional (3D) graphene materials into the fresh cement paste to make graphene reinforced cement-based materials. 3D graphene can be well dispersed with only a tiny amount of polycarboxylic acid water reducer. Nanoindentation tests showed that 3D graphene improved the micromechanical properties of hardened cement pastes. Just 0.1% 3D graphene can improve the microstructure and chloride diffusion resistance of hardened cement paste. Finally, a theoretical model was established to explain the barrier effect of 3D graphene on chloride diffusion and to further predict chloride diffusion coefficients in the hardened cement paste with different 3D graphene content by considering the tortuosity factor of 3D graphene. The research results can provide new ideas for applying 3D graphene reinforced cement-based materials.