Effect of Three-Dimensional Porous Graphene on Chloride Diffusion and Sulfate Attack of Cement Mortar

In this study, the barrier mechanism of cement mortar reinforced by three-dimensional porous graphene (3DPG) with unique structure was investigated. Various sizes of cement mortar samples were prepared, and the basic mechanical properties, chloride ion diffusion test and sulfate attack test were carried out for these samples. The mechanism of 3DPG reinforced cement mortar was analyzed by MIP, TGA, XRD, and SEM. The results demonstrate that compared with the cement mortar without 3DPG, the compressive and flexural strength of cement mortar which add 0.1% 3DPG at 28-day curing age are increased by 14.6% and 20.9%, the chloride diffusion coefficient and the surface chloride ion concentration are reduced by 48.54% and 40.40%. In addition, after 90 days of sulfate attack, the weight loss rate of cement mortar with 0.1% 3DPG added is 0.36%, and the sulfate resistance coefficient is 4.55% higher than that of the sample without 3DPG added. Adding 3DPG to cement mortar can improve the pore structure and microstructure of the cement mortar through methods such as local solidification, nucleation, and bridging. This enhancement leads to improved mechanical properties, resistance to chloride ion penetration, and resistance to sulfate ion erosion of the cement mortar.