Nghiên cứu chế tạo cảm biến điện hóa galvanic giám sát trạng thái ăn mòn cốt thép trong môi trường xâm thực bởi ion clorua

Abstract

This paper presents the results of a study on the corrosion of steel reinforcement in concrete pore solutions contaminated with chloride ions. With increasing chloride concentration, the open-circuit potential and the anodic polarization curve shift towards more negative potential values, the passive potential region of the anodic polarization curve decreases. The corrosion rate of reinforcement was evaluated according to the linear polarisation resistance technique. Accordingly, the corrosion rate of steel reinforcement is 4.53 µA/cm2 in the solution containing 1 M Cl-. In this study, galvanic electrochemical sensors with low carbon steel anodes and copper cathodes were developed. In an environment with no or low Cl- concentration, where the reinforcement is passivated, the corrosion current density of the sensor does not exceed 10.0 µA/cm2. The corrosion current of the sensor increases sharply under cathodic control with increasing chloride content. Thus, the developed sensor has a high sensitivity to chloride corrosion and is capable of detecting pitting corrosion caused by chlorides at an early stage.