Magnesium phosphate cement (MPC) is a cementitious material formed by an acid-base reaction, which has usually developed as repair material for rehabilitation engineering. It also has the potential as coating materials for fire-resistance and for corrosion protection. In this study, the effect of magnesium phosphate cement as an inorganic coating on the water permeability of cement-based material is studied. X-ray computed tomography (XCT) was used to track the capillary adsorption process of hardened cement non-destructively. The results showed that magnesium phosphate cement as the coating of cement-based materials has an excellent resistance to water penetration, and the quantitative and qualitative analysis of XCT water penetration was conducted. The microstructure analysis showed that the MPC matrix has much smaller porosity and pore sizes than the OPC matrix, and the interphase of OPC and MPC is dense and continuous, which may provide a remarkable effect on the capillary absorption blocking process. According to the Lucas-Washburn equation, a linear relationship between water absorption height and the square root of time was established to verify the experimental results measured/calculated by XCT.

磷酸镁水泥（MPC）是通过酸碱反应形成的胶结材料，通常已开发为修复工程的修复材料。它也有潜力用作耐火和防腐的涂料。在这项研究中，研究了磷酸镁水泥作为无机涂料对水泥基材料透水性的影响。X射线计算机断层扫描（XCT）用于无损跟踪硬化水泥的毛细管吸附过程。结果表明，磷酸镁水泥作为水泥基材料的涂料具有优异的耐水渗透性，并对XCT的水渗透性进行了定量和定性分析。显微组织分析表明，MPC基体的孔隙度和孔径比OPC基体小得多，并且OPC和MPC的相间致密且连续，这可能对毛细管吸收阻塞过程产生显着影响。根据Lucas-Washburn方程，建立了吸水高度与时间平方根之间的线性关系，以验证XCT测量/计算的实验结果。