한국건설순환자원학회논문집 (Journal of the Korean Recycled Construction Resources Institute)

한국건설순환자원학회 (Korean Recycled Construction Resources Institute)
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염해를 받은 콘크리트의 역학적 거동 및 수화 생성물 조사

Investigation of Mechanical Behavior and Hydrates of Concrete Exposed to Chloride Ion Penetration

  • 강윤석 (고려대학교 환경공학과) ;
  • 임귀환 ((재)한국건설생활환경시험연구원) ;
  • 박병선 (고려대학교 환경공학과)
  • Yunsuk Kang (Department of Environmental Engineering, Korea University) ;
  • Gwihwan Lim (Korea Conformity Laboratories) ;
  • Byoungsun Park (Department of Environmental Engineering, Korea University)
  • 투고 : 2023.10.23
  • 심사 : 2023.11.01
  • 발행 : 2023.12.30
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초록

본 연구에서는 염해를 받은 콘크리트의 역학적 성능 평가를 수행하고, 실험 결과를 바탕으로 염소이온 농도에 따른 압축응력변형률 모델을 제시하였다. 염해를 모사하기 위해 콘크리트 배합 시 CaCl2 용액을 첨가하였으며, 염소이온의 농도는 결합재의 중량 대비 0, 1, 2, 4 %가 되도록 하였다. 콘크리트의 최대 압축응력 이후의 응력-변형률 곡선을 조사하기 위해 변위 제어를 통해 압축강도를 측정하였다. 염소이온 농도가 1 %인 경우에는 최대 압축응력이 증가하였으나, 염소이온 농도가 2 % 이상인 경우에는 최대 압축응력이 감소하였다. 최대 압축응력에서의 변형률의 경우 재령 7일의 시편에서는 염소이온 농도에 따른 경향이 나타나지 않았다. 재령 28일의 시편에서는 염소이온 농도가 증가함에 따라 감소하였다. 재령 28일의 최대 압축응력와 변형률의 변화를 이용하여 Popovics model에 기반한 응력-변형률 곡선 모델을 제시하였다. 염소이온의 농도 증가에 따른 역학적 성능 저하의 원인을 조사하기 위해 수화생성물 분석을 수행하였다. 염소이온의 농도가 증가함에 따라 Friedel's salt가 증가하고, portlandite가 감소하는 것을 확인하였다.

In this study, the mechanical performance of concrete exposed to chloride ion penetration was investigated. And a compressive stress-strain model was presented. CaCl2 solution was added when mixing concrete to simulate long-term chloride ion penetration, and the concentration of chlorine ions was set to 0, 1, 2, and 4 % based on the weight of the binder. To investigate the compressive stress-strain curve after the peak stress of concrete, the compressive strength was measured by displacement control. When the chlorine ion concentration was 1 %, peak stress increased, but when the chlorine ion concentration was 2 % or more, peak stress decreased. In the case of peak strain, no trend according to chloride ion concentration was observed at 7 days. At 28 days, peak strain decreased as the chloride ion concentration increased. A compressive stress-strain curve model based on the Popovics model was presented using changes in peak stress and peak strain at 28 days. Microstructure analyses were performed to investigate the cause of the decrease in mechanical performance as the concentration of chlorine ions increased. It was confirmed that as the concentration of chlorine ion increased, Friedel's salt increased and portlandite decreased.

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과제정보

이 연구는 과학기술정보통신부의 재원으로 사용후핵연료관리 핵심기술개발사업단 및 한국연구재단의 지원을 받아 수행된 연구입니다(NO. 2021M2E1A1085229). 이에 감사드립니다.

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