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고온가열 및 하중재하에 따른 80, 130, 180 MPa 초고강도콘크리트의 역학적특성평가

Evaluation of Properties of 80, 130, 180 MPa High Strength Concrete at High Temperature with Heating and Loading

  • Choe, Gyeong-Cheol (Dept. of Architectural Engineering, Chungnam National University) ;
  • Yoon, Min-Ho (Dept. of Architectural Engineering, Chungnam National University) ;
  • Lee, Tae-Gyu (Dept. of Architectural Engineering, Chungnam National University) ;
  • Lee, Seong-Hun (Samsung C&T Corporation) ;
  • Kim, Gyu-Yong (Dept. of Architectural Engineering, Chungnam National University)
  • 투고 : 2013.05.02
  • 심사 : 2013.09.23
  • 발행 : 2013.12.31

초록

콘크리트는 고온에 강한재료로 인식되어 왔으나, 화재 등의 고온에 의해 내부조직의 물리 화학적 변화가 발생해 역학적 특성이 저하하게 된다. 이에, 고온시 콘크리트의 역학적 특성의 저하에 관한 연구보고 및 기준이 제시되고 있다. 그러나 고강도 콘크리트 및 하중을 재하한 상태에 관한 연구데이터는 적다. 따라서 이 연구에서는 고온 및 하중재하에 따른 고강도 콘크리트의 고온특성을 평가하였다. W/B 12.5%, 14.5%, 20%의 고강도 콘크리트를 대상으로 비재하상태 및 $0.25f_{cu}$의 하중조건을 설정하여, 고온시의 응력-변형, 최대하중에서의 변형, 압축강도, 탄성계수, 열팽창변형, 단기 고온크리프을 평가하였다. 실험 결과, 압축강도가 높아질수록 가열에 의한 압축강도의 저하가 크게 나타났고, $500^{\circ}C$이상의 온도에서 고온에 의한 열팽창변형과 하중재하에 의한 수축변형이 상쇄되어 압축강도 및 탄성계수의 잔존율이 높아지는 것을 확인할 수 있었다.

Concrete has been recognized as a material which is resistant to high temperatures, but chemicophysical property of concrete is changed by the high temperature. So, mechanical properties of concrete may be reduced. Because of this, standards and researches on the degradation of the mechanical properties of concrete at high temperatures have been presented. However, research data about the state that considering the loading condition and high-strength concrete is not much. Therefore, this study evaluated the high-temperature properties of high-strength concrete by loading condition and elevated temperature. The stress-strain, strain at peak stress, compressive strength, elastic modulus, thermal strain and the transient creep are evaluated under the non-loading and $0.25f_{cu}$ loading conditions on high strength concrete of W/B 12.5%, 14.5% and 20%. Result of the experiment, decrease in compressive strength due to high temperature becomes larger as the compressive strength increases, and residual rate of elastic modulus and compressive strength is high by the shrinkage caused by loading and thermal expansion due to high temperature are offset from each other, at a temperature above $500^{\circ}C$.

키워드

참고문헌

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피인용 문헌

  1. A Study on Economically-Efficient Binder Combination of 80MPa Ultra High Strength Concrete vol.3, pp.1, 2015, https://doi.org/10.14190/JRCR.2015.3.1.064