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Shear Strength of Prestressed PC-CIP Composite Beams without Vertical Shear Reinforcements

수직전단보강이 없는 PS 콘크리트와 현장타설 콘크리트 합성보의 전단강도

  • Kim, Chul-Goo (Dept. of Architecture & Architectural Engineering, Seoul National University) ;
  • Park, Hong-Gun (Dept. of Architecture & Architectural Engineering, Seoul National University) ;
  • Hong, Geon-Ho (Dept. of Architectural Engineering, Hoseo University) ;
  • Kang, Su-Min (Dept. of Architectural Engineering, Chungbuk National University) ;
  • Suh, Jung-Il (Dept. of Architecture & Architectural Engineering, Seoul National University)
  • Received : 2014.04.21
  • Accepted : 2014.06.12
  • Published : 2014.08.30

Abstract

Currently, composite construction of prestressed Precast Concrete (PC) and Cast-In-Place (CIP) concrete with different concrete strengths are frequently used in the modular construction. However, current design codes do not clearly define shear design methods for such composite beams. In this present study, simply supported prestressed PC-CIP composite beams without vertical shear reinforcement or only with horizontal shear reinforcement were tested to evaluate the effect of prestressing on the shear strength and the shear design method for such composite members. The test variables were the area ratio of PC and CIP concretes, prestressing force, shear span-to-depth ratio, and shear reinforcement ratio. The results showed that the shear strength was increased by the increase of prestressing force and prestressed PC area, and the decrease of shear span-to-depth ratio.

최근 들어, 지하주차장과 같은 모듈화 건물에 프리캐스트 콘크리트와 현장타설 콘크리트가 함께 사용되는 복합공법의 사용이 증가하고 있다. 일반적으로 프리캐스트 콘크리트는 공장에서 선 제작되기 때문에 재료의 효율성을 극대화하기 위해 프리텐션을 도입하여 사용한다. 현행 구조기준이 긴장력이 가해진 단일 단면의 전단 강도식은 제시하지만 긴장력이 가해진 프리캐스트와 현장타설 콘크리트 합성단면의 전단강도식은 제시하지 못하고 있는 실정이다. 따라서 긴장력이 가해진 합성 부재의 전단강도 실험을 통해 긴장력이 전단강도에 미치는 영향과 합성부재의 전단강도 산정시 고려해야할 사항에 대해 알아보았다. 변수로는 콘크리트의 면적비, 긴장재의 긴장력, 전단 경간비, 그리고 전단철근비를 고려하였다. 실험 결과를 분석해보면, 전단강도는 긴장력 크기와 긴장력이 가해진 단면의 면적비가 커질수록 증가하였고 전단경간비가 증가할수록 감소하였다.

Keywords

References

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  3. Evaluation of Horizontal Shear Strength for Concrete Composite Members vol.28, pp.4, 2016, https://doi.org/10.4334/JKCI.2016.28.4.407