Fire Science and Engineering (한국화재소방학회논문지)

Korean Institute of Fire Science and Engineering (한국화재소방학회)
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Review of Spatting Effect on Concrete Element in Fire

화재시 콘크리트 요소 폭렬영향성 고찰

  • 김형준 (한국건설기술연구원 화재 및 설비연구부) ;
  • 한상훈 (한국건설기술연구원 화재 및 설비연구부) ;
  • 최승관 (한국건설기술연구원 화재 및 설비연구부)
  • Published : 2007.06.30
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Abstract

Concrete is generally accepted to have good inherent fire resistance. It mainly relies on the assumption that concrete has low heat-transfer characteristic and spatting does not occur during the course of a fire. However, the significant numbers of fire accidents have shown in recent years that incidence of spatting has caused sever damages to many structures. This review has systematically investigated the behaviour of concrete in fire, including phenomenon of spatting, with respect to the theorical consideration and experimental results. Explosive spatting is caused by the build-up of water vapor pressure in concrete subjected to increasing temperatures. When this pressure exceeds the tensile strength of the concrete over a fire-exposed area, explosive spatting can result in a typical temperature range between $200^{\circ}C\;and\;400^{\circ}C$. The major functions are known to be moisture content, pore pressure, load ratio, and heating regime.

콘크리트는 일반적으로 내화성능이 내재되어 있다고 여겨지나, 이것은 화재시 콘크리트의 낮은 열전달 특성으로 인해 폭렬이 일어나지 않는다는 것을 전제한 것이다. 그러나, 최근의 화재사고사례를 분석한 결과 콘크리트 폭렬이 구조물에 미치는 영향은 심대한 것을 알 수 있다. 따라서, 본 연구는 콘크리트 폭렬에 관한 선진 연구 성과의 이론적 고찰 및 실험결과의 분석 검토를 토대로 국내에 상대적으로 미흡한 화재시 콘크리트의 거동특성 및 폭렬현상을 체계적으로 규명하였다. 또한, 본 연구를 통해 화재조건에서의 성능 설계법을 제시할 수 있는 콘크리트 폭렬 기초연구자료를 제시하고자 한다. 폭발성 폭렬현상은 고온 영역 하에서 공극압력이 상승하게 되어 단면을 감싸는 인장응력보다 박리되고자 하는 압력이 커지게 되어 $200^{\circ}C{\sim}400^{\circ}C$에서 발생하게 된다. 폭렬에 직접적인 원인이 되는 요소는 수분함유량, 공극(수증기에 의한) 압력, 변형에 의한 응력변화(하중비), 가열비(화재강도) 등으로 할 수 있다.

Keywords

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