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The aim of this paper was to investigate the passive corrosion control and active corrosion protective effect of the reinforced concrete structures by electrochemical chloride removal (ECR) method and inhibitors approach, respectively.

The concentration of aggressive chloride ion distributed from the reinforcing steel to the surface of the concrete cover was analyzed during the ECR processes. Besides, the half-cell potential, the concrete resistance R _c , the polarization resistance R _p and the capacitance of double layer C _dl of the steel/concrete system were used to characterize the electrochemical performance of the concrete prisms.

The effectiveness of ECR could be enhanced by increasing the amplitude of potential or prolonging the time. Inhibitor SBT-ZX(I) could successfully prevent the corrosion development of the reinforcing steel in concrete.

The research provides the scientific basis for the practical application of ECR and inhibitors in the field.

Corrosion sensors and networks are the most effective techniques to obtain the corrosion information and recognize the corrosion status of reinforced concrete structures. However, reference electrode is the key element to provide the baseline for potential control of the corrosion monitoring sensors during corrosion measurement process. Therefore, the purpose of this paper is to provide the novel solid‐state reference electrode for the corrosion sensors.

A solid‐state Ag/AgCl reference electrode has been prepared. Furthermore, the performance of the reference electrode, such as stability, temperature response, anti‐polarization and influence of the concrete admixture, has been investigated.

The results indicate that the balance potential and the temperature coefficient of the reference electrode are 3.64±1mv (vs. SCE) at 25°C and −0.51 mv/°C±0.03 mv/°C, respectively. Furthermore, the polarization curve exhibits characteristics of three stages as the polarization current is in (−10μA/cm2,+10μA/cm2). Additionally, the reference electrode is insensitive to the concrete admixtures which include Na2SO4, NaCl, NaNO3 and NaNO2.

The research provides the key element for the corrosion monitoring sensors to integrate structural health monitoring system in future.

The purpose of this paper is to present a novel five‐electrode electrochemical corrosion sensor. Health degradation by the corrosion of steel in civil engineering is a persistent problem. Structural health monitoring (SHM) techniques, including embedded sensors, can greatly improve the quantification of the steel corrosion information, which can lead to promote assessments of structural safety and serviceability. To integrate the corrosion monitoring system in future, the corrosion sensor and the monitoring methods have been explored here in advance. Also, the corrosion monitoring system has been applied preliminarily in the investigation of reinforcing concrete (RC) beams.

First, a novel five‐electrode electrochemical corrosion sensor has been developed as the hardware to provide the platform for corrosion monitoring methods. Second, half‐cell potential of the RC beams has been measured before and after corrosion. Third, galvanostatic step method has been used to excite the steel‐concrete system, and the transient response of the system has been obtained and analyzed. Finally, wavelet transform algorithm has been established to analyze the electrochemical noise (EN) data of the steel bars in RC beams.

The results show that the corrosion sensor can be used effectively as the hardware to support the electrochemical measuring techniques. Much valuable information which is extracted by analyzing the potential response to the galvanostatic pulse excitation can be applied to determine the general corrosion state of the reinforcing steel. For pitting corrosion, the energy distribution plot of EN can be adopted as a benchmark method to identify the presence of the corrosion pit.

The paper provides the key techniques for a SHM system to realize corrosion monitoring of large‐scale RC structures in the future.