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Title |
The Inhibitive Effect of Electrochemical Treatment Applied to Fresh/hardened Concrete
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Keywords |
전기방식 ; 철근 부식 ; 염화물 이온 ; BSE 이미지 분석 ; 콘크리트 ; Ca(OH)2 Electrochemical treatment ; Steel corrosion ; Chloride ions ; BSE image analysis ; Concrete ; Ca(OH)2 |
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Abstract |
In this study, the inhibitive effect of electrochemical treatment subjected to fresh and hardened concrete and literature reviews in terms of the treatment were performed. In hardened concrete, chloride ions are mixed during casting to destroy the passivity of steel, and then the current was provided for 2 weeks with 250, 500 and 750 mA/m2. After completion of electrochemical treatment, the extraction of chloride ions was quantified and repassivation of steel was observed. Simultaneously, the equated levels of current density for 2 weeks were applied to fresh concrete. Steel-concrete interface in concrete was observed by BSE image analysis and the concrete properties in terms of the diffusivity of chloride ions and the resistance of steel corrosion was measured. As the result, electrochemical treatment is very effectiveness to rehabilitate the passive film on the steel surface and 63-73% of chloride ions in concrete were extracted by the treatment. As the treatment was applied to fresh concrete, the resistance of steel corrosion was improved due to the densification of Ca(OH)2 layers in the vicinity of steel. However, an increase in the current density resulted in an increase in surface chloride content of concrete.
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