Journal of the Korean Ceramic Society (한국세라믹학회지)

The Korean Ceramic Society (한국세라믹학회)
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Pore Structure Changes in Hardened Cement Paste Exposed to Elevated Temperature

고온 환경에 노출된 시멘트 경화체의 공극 구조 변화

  • Kang, Seung-Min (Department of Advanced Materials Engineering, Kangwon National University) ;
  • Na, Seung-Hyun (Research Center of Advanced Convergence Processing on Materials, Kangwon National University) ;
  • Kim, Kyung-Nam (Department of Advanced Materials Engineering, Kangwon National University) ;
  • Song, Myong-Shin (Research Center of Advanced Convergence Processing on Materials, Kangwon National University)
  • 강승민 (강원대학교 기능소재공학과) ;
  • 나승현 (강원대학교 재료융합공정연구소) ;
  • 김경남 (강원대학교 기능소재공학과) ;
  • 송명신 (강원대학교 재료융합공정연구소)
  • Received : 2014.10.27
  • Accepted : 2014.12.18
  • Published : 2015.01.31
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Abstract

Hardened cement-based materials exposed to the high temperatures of a fire are known to experience change in the pore structure as well as microstructural changes that affect their mechanical properties and tend to reduce their durability. In this experimental investigation, hardened Portland cement pastes were exposed to elevated temperatures of 200, 400, 600, 800, and $1000^{\circ}C$ for 60 minutes, and the resulting damage was studied by thermogravimetry (TG), mercury intrusion porosimetry (MIP) and density measurements. These results revealed that the residual compressive strength is increased at temperatures greater than $400^{\circ}C$ due to a small pore size of 3 nm and/or rehydration of the dehydrated cement paste. However, a loss of the residual strength occurs at temperatures exceeding 500 and $600^{\circ}C$. This can be attributed to the decomposition of hydrates such as portlandite and to an increase in the total porosity.

Keywords

References

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