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Effects of Shrinkage Reducing Agent (SRA) Type and Content on Mechanical Properties of Strain Hardening Cement Composite (SHCC)

수축저감제의 종류 및 혼입률에 따른 변형경화형 시멘트복합체의 역학적 특성

  • Han, Seung-Ju (Korea Hydro & Nuclear Power Co., Ltd. Central Research Institute) ;
  • Jang, Seok-Joon (Dept. of Architectural Engineering, Chungnam National University) ;
  • Khil, Bae-Su (Tripod Co., Inc.) ;
  • Choi, Mu-Jin (Dept. of Architectural Engineering, Chungnam National University) ;
  • Yun, Hyun-Do (Dept. of Architectural Engineering, Chungnam National University)
  • Received : 2015.05.29
  • Accepted : 2015.09.14
  • Published : 2016.02.29

Abstract

This research investigates the effects of shrinkage reducing agent (SRA) on the mechanical behavior of strain-hardening cement composite (SHCC). SHCC material with specified compressive strength of 50 MPa was mixed and tested in this study. All SHCC mixes reinforced with volume fraction of 2.2% polyvinyl alcohol (PVA) fiber and test variables are type and dosage of shrinkage reducing agents. The shrinkage reducing materials used in this study are phase change material as the thermal stress reducing materials that have the ability to absorb or release the heat. The effect of SRA was examined based on the change in length caused by shrinkage and hardened mechanical properties, specially compressive, tensile and flexural behaviors, of SHCC material. It was noted that SRA reduces change in length caused by shrinkage at early age. SRA can also improve the tensile and flexural strengths and toughness of SHCC material used in this study.

본 연구는 두 종류의 수축저감제를 혼입한 변형경화형 시멘트 복합체(SHCC)의 압축, 인장 및 휨 특성을 평가하기 위하여 계획되었으며, 재령과 수축저감제의 종류 및 혼입률을 변수로 진행되었다. SHCC는 설계기준압축강도 50 MPa이며, 섬유는 PVA 섬유를 2.2% 혼입하였다. 배합에 혼입된 수축저감제는 상변이 물질로 수화현상으로 발생되는 열을 흡수 또는 방출하여 급격한 수축 및 팽창을 제어하는 물질이다. 수축저감제의 혼입에 대한 영향은 선변형 길이변화 실험과 압축, 인장 및 휨 성능의 측면에서 평가되었으며, 수축저감제를 혼입할 경우 초기 재령에서의 수축량이 감소되었다. 또한 수축저감제를 혼입함에 따라 균열 분산 성능과 인장 및 휨 성능이 개선되었다.

Keywords

References

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