• Title/Summary/Keyword: 재알칼리화

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Chloride Extraction and Modified Structural Behavior of Concrete under Electrochemical Treatment (전기방식에 따른 콘크리트 중의 탈염효과 및 구조거동)

  • Ann, Ki-Yong;Kim, Ki-Beom;Yang, Hee-Jun
    • Journal of the Korea Concrete Institute
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    • v.29 no.1
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    • pp.109-116
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    • 2017
  • The present study concerns quantitative assessment of chloride extraction, repassivation and structural behavior of concrete. Concrete specimen ($160{\times}160{\times}1000mm$) 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 $750mA/m^2$ 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 $6.5mA/m^2$ 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.