Journal of the Korea institute for structural maintenance and inspection (한국구조물진단유지관리공학회 논문집)

Korea Institute for Structural Maintenance Inspection (한국구조물진단유지관리공학회)
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Experimental Study for Evaluation of Chloride Ion Diffusion Characteristics of Concrete Mix for Nuclear Power Plant Water Distribution Structures

원전 취배수 구조물 콘크리트 배합의 염소이온 확산특성 평가를 위한 실험적 연구

  • 이호재 (한국건설기술연구원 구조연구본부) ;
  • 서은아 (한국건설기술연구원 구조연구본부)
  • Received : 2022.09.12
  • Accepted : 2022.09.26
  • Published : 2022.10.30
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Abstract

In this study, the diffusion characteristics were evaluated using the concrete mix design of nuclear safety-related structures. Among the concrete structures related to nuclear power safety, we selected the composition of intake and drainage structures that are immersed in seawater or located on the tidal platform and evaluated the chloride ion permeation resistance by compressive strength and electrical conductivity and the diffusion characteristics by immersion in salt water. analyzed. Compressive strength was measured on the 1st, 7th, 14th, 28th, 56th, and 91st days until the 91st day, which is the design standard strength of the nuclear power plant concrete structure, and chloride ion permeation resistance was evaluated on the 28th and 91st. After immersing the 28-day concrete specimens in salt water for 28 days, the diffusion coefficient was derived by collecting samples at different depths and analyzing the amount of chloride. As a result, it was found that after 28 days, the long-term strength enhancement effect of the nuclear power plant concrete mix with 20% fly ash replacement was higher than that of concrete using 100% ordinary Portland cement. It was also found that the nuclear power plant concrete mix has higher chloride ion permeation resistance, lower diffusion coefficient, and higher resistance to salt damage than the concrete mix using 100% ordinary Portland cement.

이 연구는 원전 안전성 관련 구조물의 콘크리트 배합설계를 이용하여 확산특성을 평가하였다. 원전안전성관련 콘크리트 구조물 중 해수에 침지되거나 간만대에 위치하는 취배수구조물의 배합을 선정하여 압축강도, 전기전도도에 의한 염소이온 침투저항성 평가, 염수침지를 통한 확산특성을 분석하였다. 원전 콘크리트 구조물의 설계기준강도인 91일까지 재령에 따라 1, 7, 14, 28, 56, 91일에 압축강도를 측정했으며, 재령 28, 91일에 염소이온 침투저항성 평가를 실시했다. 재령 28일 콘크리트 시험체를 28일간 염수에 침지한 뒤 깊이별 시료를 채취하여 염화물량을 분석함으로써 확산계수를 도출하였다. 결과적으로 보통포틀랜드시멘트를 100% 사용한 콘크리트보다 플라이애시가 20% 치환된 원전 콘크리트 배합이 28일 이후 장기적인 강도증진 효과가 더 높게 나타났다. 또한 원전콘크리트 배합이 보통포틀랜드시멘트를 100% 사용한 배합보다 염소이온 침투저항성이 높고 확산계수도 더 낮게 나타나 염해에 대한 저항성이 더 높은 것으로 나타났다.

Keywords

Acknowledgement

본 연구는 원자력안전위원회의 재원으로 한국원자력안전재단의 지원을 받아 수행한 원자력안전연구사업의 연구결과입니다(No. 2203025).

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