▎ 摘　　要

Graphene oxide (GO) nanosheets are experimentally added into cement materials to enhance the sulfate resistance, and a corresponding chemomechanical model is proposed to predict the structural life expectancy. Experimental investigations show that GO nanosheets with a dosage of 0.03% by weight of cement refine the pores, inhibit the microcracks, and improve sulfate resistance of mortars remarkably. The proposed model is designed for cement materials modified by nanosheets, including the influence of the size, concentration, arrangement, and direction of nanosheets on the tortuosity and diffusion coefficient. To explain the mechanical deterioration, the model considers the transport properties at undamaged, pore-filling, stress-generated, and crack-growing stages. Validating against the experimental data, we found the proposed model to be more suitable than the Mobasher-Tixier (MT) model in simulating the response of cement-based materials under sulfate attack, especially in the case of sheet-like nanoadditives. Numerical results infer that the addition of 0.03 wt % GO nanosheets can improve the structural life by 2.3 times as samples are immersed in 5 wt % sulfate solution.