To mitigate the harmful chemicals ingression into cementitious materials, traditional methods often aim to densify the pore structure, posing challenges for concrete dead-load or crack control. This paper proposes a facile method to mitigate chloride attack via increasing the pore solution viscosity in cementitious material without changing the matrix density or compromising other properties. The results indicate that the addition of viscosity modifying admixtures (VMAs) to the mortar, as an equivalent mass replacement of mixing water, can mitigate chloride ingress. Although it reduces the early age hydration heat, the mechanical strength at full age (3 d–28 d) and the porosity at 28 d remain unchanged when using an effective VMA (PEG1000). In addition, the matrix resistance to leaching is improved as well. These results may be attributed to the enhanced pore solution viscosity and the coexistence of VMA and C–S–H with decreased interlayer distance and shortened mean chain length. After 28 d of exposure, the most effective experimental group (PEG1000) showed approximately a 28 % decrease in chloride diffusion coefficient compared to the control group. This paper may inspire new technology to mitigate ions diffusion and promote its practical application.

为了减少有害化学物质侵入水泥材料，传统方法通常旨在致密孔隙结构，这给混凝土恒载或裂缝控制带来了挑战。本文提出了一种简便的方法，通过增加胶凝材料中的孔隙溶液粘度来减轻氯化物侵蚀，而不改变基体密度或损害其他性能。结果表明，在砂浆中添加粘度调节剂（VMA）作为混合水的等量替代品，可以减少氯化物的进入。尽管它降低了早期水化热，但使用有效的 VMA (PEG1000) 时，全龄期（3 d-28 d）的机械强度和 28 d 的孔隙率保持不变。此外，基质的抗浸出性也得到改善。这些结果可能归因于孔隙溶液粘度的增强以及VMA和C-S-H的共存，同时层间距离，平均链长缩短。暴露 28 天后，最有效的实验组 (PEG1000) 与对照组相比，氯离子扩散系数降低了约 28%。本文可能会启发减轻离子扩散的新技术并促进其实际应用。