Steel corrosion is the main cause of deterioration of reinforced concrete (RC) structures. We provide an up-to-date review on corrosion mechanisms and recent advances in electrical methods for corrosion monitoring. When assessing corrosion mechanism, the inherent heterogeneity of RC structures and the significant effect of environmental factors remain major issues in data interpretations. The steel surface condition and local inhomogeneities at the steel–concrete interface appear to have an important effect on corrosion initiation. Considering uniform corrosion in atmospherically exposed RC structures, the two main influencing factors of the corrosion process are the water content and the pore structure at the steel–concrete interface. However, irrespective of the depassivation mechanism, i.e. carbonation or chloride-induced corrosion, non-uniform corrosion is expected to be the main process for RC structures due to local variations in environmental exposure or the presence of interconnected rebars with different properties. Future studies may then be focused on their effect on macrocell corrosion to gain further insights in the corrosion mechanisms of RC structures.

Concerning corrosion monitoring using electrical methods, the half-cell potential technique with potential mapping is accurate for locating areas with a high corrosion risk. Recent developments in the measurement of concrete resistivity have shown that the use of electrical resistivity tomography allows to consider appropriately the inherent heterogeneity of concrete and provides more insights on transport phenomena (e.g. water and salts ingress) in the material. Nevertheless, during the corrosion propagation stage, the polarization resistance remains the most important parameter to be determined as it provides quantitative information of the corrosion rate. If conventional three-electrode configuration methods can supply an accurate determination in the case of uniform corrosion, they often fail in the case of macrocell corrosion in field experiments. Recent advances have shown that a four-electrode configuration without any connection to the rebar can rather be used for the non-destructive testing and evaluation of corrosion. If studies are still required to quantify the corrosion rate, this method appears sensitive to localized corrosion and thus more suitable to field investigations. Finally, the coupling of numerical simulations with complementary electrical and other non-destructive testing methods is essential for consolidating the results to provide a better diagnosis of the service life of RC structures.

钢腐蚀是钢筋混凝土（RC）结构劣化的主要原因。我们提供有关腐蚀机理的最新评论以及用于腐蚀监测的电气方法的最新进展。在评估腐蚀机理时，RC结构固有的异质性和环境因素的重大影响仍然是数据解释中的主要问题。钢-混凝土界面处的钢表面状况和局部不均匀性似乎对腐蚀萌生具有重要影响。考虑到暴露在大气中的RC结构的均匀腐蚀，腐蚀过程的两个主要影响因素是水含量和钢-混凝土界面的孔结构。但是，无论钝化机理是什么，即碳化或氯化物引起的腐蚀，由于环境暴露的局部变化或具有不同特性的互连钢筋的存在，非均匀腐蚀有望成为RC结构的主要过程。然后，未来的研究可能会集中在它们对宏单元腐蚀的影响上，以进一步了解RC结构的腐蚀机理。

关于使用电气方法进行腐蚀监测，具有电位映射功能的半电池电位技术可准确地定位具有高腐蚀风险的区域。混凝土电阻率测量的最新进展表明，使用电阻率层析成像技术可以适当考虑混凝土固有的异质性，并提供有关材料中传输现象（例如水和盐分侵入）的更多见解。然而，在腐蚀传播阶段，抗极化强度仍然是最重要的参数，因为它提供了腐蚀速率的定量信息。如果常规的三电极配置方法可以在均匀腐蚀的情况下提供准确的确定，在现场实验中，如果发生宏电池腐蚀，它们通常会失效。最近的进展表明，与钢筋没有任何连接的四电极配置可用于无损检测和腐蚀评估。如果仍然需要研究以量化腐蚀速率，则此方法对局部腐蚀似乎很敏感，因此更适合于现场调查。最后，将数值模拟与互补的电气和其他非破坏性测试方法结合起来对于巩固结果以更好地诊断RC结构的使用寿命至关重要。如果仍然需要研究以量化腐蚀速率，则此方法对局部腐蚀似乎很敏感，因此更适合于现场调查。最后，将数值模拟与互补的电气和其他非破坏性测试方法结合起来对于巩固结果以更好地诊断RC结构的使用寿命至关重要。如果仍然需要研究以量化腐蚀速率，则此方法对局部腐蚀似乎很敏感，因此更适合于现场调查。最后，将数值模拟与互补的电气及其他非破坏性测试方法相结合对于巩固结果以更好地诊断RC结构的使用寿命至关重要。