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An Experimental Study on Charateristics of Autogenous Shrinkage of HPFRCC considering Early Age Coefficient of Thermal Expansion

초기재령에서 열팽창계수를 고려한 고성능 섬유보강 시멘트 복합체의 자기수축 특성에 관한 실험적 연구

  • Park, Jung-Jun (Korea Institute of Civil Engineering and Building Technology) ;
  • Moon, Jae-Heum (Korea Institute of Civil Engineering and Building Technology) ;
  • Park, Gi-Joon (Korea Institute of Civil Engineering and Building Technology) ;
  • Lee, Jang-Hwa (Korea Institute of Civil Engineering and Building Technology) ;
  • Kim, Sung-Wook (Korea Institute of Civil Engineering and Building Technology)
  • 박정준 (한국건설기술연구원 구조융합연구소) ;
  • 문재흠 (한국건설기술연구원 구조융합연구소) ;
  • 박기준 (한국건설기술연구원 구조융합연구소) ;
  • 이장화 (한국건설기술연구원 구조융합연구소) ;
  • 김성욱 (한국건설기술연구원 구조융합연구소)
  • Received : 2015.04.16
  • Accepted : 2015.05.07
  • Published : 2015.05.31

Abstract

HPFRCC is characterized by a very low water-to-binder ratio which induce extremely large autogenous shrinkage at early age. The restriction of such autogenous shrinkage through the use of forms and reinforcing bars will increase substantially the risk of excessive residual stresses and shrinkage cracking. The exact understanding of the shrinkage behavior and studies on solutions to reduce shrinkage should be imperatively undertaken for further application of HPFRCC to real structures. Therefore, this paper investigated the mechanical properties of HPFRCC with respect to the eventual introduction of expansive admixture(EA) and shrinkage reducing agent (SRA) in the mixture. Autogenous shrinkage test was conducted considering the coefficient of thermal expansion (CTE) measured at early age so as to examine the effects of EA and SRA on the autogenous shrinkage behavior of HPFRCC.

고성능 섬유보강 시멘트 복합체(HPFRCC)는 물-결합재비(W/B)가 상당히 낮기 때문에 재령초기에서 자기수축이 크게 나타나는 특성을 지니고 있다. 이러한 자기수축의 영향으로 거푸집 및 보강철근 등에 의해 HPFRCC가 구속될 경우 상당히 큰 잔류응력 발생과 수축균열 위험성이 나타나게 된다. 이러한 문제를 해결하기 위해서는 초기재령에서의 수축거동에 따른 균열거동에 대한 평가와 수축을 억제하거나 감소시키기 위한 재료적 검토 등을 포함한 HPFRCC의 수축특성에 대한 폭넓은 연구가 반드시 수행되어야 한다. 따라서, 이 논문에서는 팽창재와 수축저감제의 조합사용 여부에 따른 HPFRCC의 역학적 특성 평가와 초기 재령에서의 열팽창계수 측정 및 이를 고려한 자기수축 실험을 수행하여 팽창재와 수축저감제가 HPFRCC의 자기수축 거동에 미치는 영향을 분석하였다.

Keywords

References

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