Reinforcing steel is used extensively in buildings to provide strength and integrity to the concrete structure. This material is, however, highly susceptible to corrosion in chloride-contaminated environments, which increases the risk of structural instability and failure. This work characterises the mechanisms and efficiency of corrosion protection offered by sodium nitrate, casein, and two amino acids (11–aminoundecanoic acid, and p–aminobenzoic acid) in simulated concrete pore solutions with different contents of chloride ions. The performance of each inhibitor in the critical chloride concentration (C_cirt) was investigated using electrochemical techniques. Open circuit potential and linear polarisation were used to identify the C_crit in synthetic pore solutions. Potentiodynamic polarisation and electrochemical impedance spectroscopy were performed to evaluate the corrosion activities and the passivation mechanism of inhibitors in C_crit. Results indicate that reinforcing steel can be protected through an appropriate selection of corrosion inhibitors. Among of the inhibitors studied here, casein demonstrated the highest corrosion inhibition efficiency with minimum current density of 9.19 × 10⁻⁸ μA/cm² and inhibitor efficiency of more than 80%. Casein provides passivity to the reinforcing steel in the presence of the C_cirt in the pore solution.

钢筋广泛用于建筑物中，以为混凝土结构提供强度和完整性。但是，这种材料在氯化物污染的环境中极易受到腐蚀，从而增加了结构不稳定和失效的风险。这项工作表征了硝酸钠，酪蛋白和两种氨基酸（11-氨基十一烷酸和对氨基苯甲酸）在具有不同氯离子含量的模拟混凝土孔隙溶液中提供的腐蚀防护机理和效率。使用电化学技术研究了每种抑制剂在临界氯化物浓度（C _cirt）下的性能。使用开路电势和线性极化来识别C_临界在合成孔溶液中。进行了电位极化和电化学阻抗谱评价碳_临界腐蚀抑制剂的腐蚀活性和钝化机理。结果表明，钢筋可以通过腐蚀抑制剂的合适的选择来保护。其中这里所研究的抑制剂，酪蛋白演示了的9.19×10最小电流密度最高的缓蚀率^-8  μA/厘米²和超过80％的抑制剂的效率。酪蛋白在孔溶液中存在C _cirt时可为增强钢提供钝化作用。