Abstract The low pH of magnesium potassium phosphate (MKPC) has raised concerns over its capability to protect reinforcing steel. The passivation of mild steel in MKPC pore solutions was investigated in this study via electrochemical measurements, XPS and Raman spectroscopy. Results show that the passivity of mild steel in MKPC was comparable or even better than that in Portland cement. Although the passivity was dominated by the pH of MKPC, it also increases with increasing magnesium-to-phosphate (M/P) ratios. The formation of iron phosphate in the low pH MKPC (such as M/P 7) also made additional contributions to the passivity of steel.

中文翻译：

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镁磷比对磷酸镁钾水泥软钢钝化的影响

摘要 磷酸镁钾 (MKPC) 的低 pH 值引起了对其保护钢筋的能力的担忧。本研究通过电化学测量、XPS 和拉曼光谱研究了 MKPC 孔溶液中低碳钢的钝化。结果表明，MKPC 中低碳钢的钝化率与硅酸盐水泥相当甚至更好。尽管钝化受 MKPC 的 pH 值支配，但它也随着镁与磷酸盐 (M/P) 比率的增加而增加。在低 pH 值 MKPC（如 M/P 7）中形成磷酸铁也对钢的钝化做出了额外的贡献。