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Title |
Chloride Extraction and Modified Structural Behavior of Concrete under Electrochemical Treatment
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Authors |
안기용(Ki-Yong Ann) ; 김기범(Ki-Beom Kim) ; 양희준(Hee-Jun Yang) |
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DOI |
https://doi.org/10.4334/JKCI.2017.29.1.109 |
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Keywords |
전기방식법 ; 구조 거동 ; 부식복원 ; 탈염 ; 재알칼리화 electrochemical treatment ; structural behavior ; repassivation ; chloride extraction ; re-alkalization |
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Abstract |
The present study concerns quantitative assessment of chloride extraction, repassivation and structural behavior of concrete. Concrete specimen (160×160×1000 mm) was fabricated with 3 steel bar located in the middle with 20 mm of the cover depth, containing 5.0% of chloride to accelerate corrosion process, then to be subjected to electrochemical treatment. The current density accounted for 750 mA/m2 at 2, 4 and 8 weeks. As a result, it was found that an increase in the duration of the treatment resulted in an increase in the chloride extraction, accounting for 64.7-83.7% for the specimen at 8 weeks treatment. It implies that a portion of bound chlorides would turn free to be removed, considering the binding capacity of cement about 50-60% to total ones. Even after the treatment, the corrosion was still active; the corrosion rate was 6.5 mA/m2 and 330 mV vs. SCE in the potential. For structural behavior, the maximum load was increased by corrosion on the steel bars, which was subsequently lowered by the treatment, but still higher than for control.
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