콘크리트학회논문집 (Journal of the Korea Concrete Institute)

  • 제21권3호
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  • Pages.337-345
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  • 2009
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  • 1229-5515(pISSN)
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  • 2234-2842(eISSN)
한국콘크리트학회 (Korea Concrete Institute)
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표면매입 및 외부부착 탄소섬유판으로 보강된 철근콘크리트 부재의 전단 거동에 관한 실험적연구

An Experimental Study on the Shear Behavior of RC Beams Strengthened with Near Surface Mounted and Externally Bonded CFRP Strips

  • 임동환 (동서대학교 건축토목공학부 토목공학) ;
  • 권영순 (재신건설(주))
  • 발행 : 2009.06.30
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초록

본 연구에서는 탄소섬유판이 외부 부착, 표면 매입 그리고 외부부착 및 표면매입이 혼합된 보강 방식의 철근콘크리트 부재의 전단 거동 및 전단 보강 효과를 구명하고자 하였다. 본 연구 결과, 표면매입 탄소섬유판 및 외부부착과 표면매입으로 혼용된 탄소섬유판으로 보강된 철근콘크리트 보의 전단 강성 및 극한 전단강도는 섬유판으로 보강되지 않은 보에 비하여 크게 증진되는 것으로 나타났다. 표면매입 탄소섬유판 및 외부부착과 표면매입으로 혼용된 탄소섬유판으로 보강된 철근콘크리트 보의 파괴는 전단균열로 시작되었으며, 하중이 증가함에 따라 하중 재하점과 가장 인접한 매입 탄소섬유판 하단 모서리에서 발생한 휨 균열은 하중재하점 방향으로 급격하게 진행되었고, 하중 재하점과 휨 균열을 연결하는 압축파괴가 발생되었다. 이러한 사실은 매입 섬유판의 전단보강 효과가 매우 우수하여 보가 전단으로 파괴되지 않고 섬유판이 매입 보강되지 않은 휨 구역에서 압축파괴가 발생하고 있음을 설명하고 있다. 매입 탄소섬유판 보강부재 및 탄소섬유판 부착 및 매입을 혼용한 부재에서는 매입 탄소섬유판의 변형률이 각각 0.45% 및 0.35%로 나타났으며, 외부 부착 탄소섬유판의 변형률이 약 0.3%로 나타났다.

The purpose of this study is to investigate the shear strengthening effectiveness of the beams strengthened with near surface mounted (NSM) and external bonded (EB) CFRP strips. A total of nine concrete beams were made and tested. From this study, it was found that the shear stiffness and strength of the beams strengthened with NSM and EB strips were significantly improved compared to the control beam. Failure of the beam strengthened with NSM and EB strips was initiated by shear cracks, propagated diagonally to the adjacent epoxy grooves without crossing the epoxy and finally sudden diagonal crack connecting the point of application of load and flexural crack was occurred. For the beam strengthened combined with NSM and EB CFRP strips, the tensile strains in the NSM CFRP strips were observed in the range of 0.35% to 0.45% and strains with EB strips were measured about 0.3%.

키워드

참고문헌

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피인용 문헌

  1. Evaluation of Structural Performance of Reinforced Concrete Beams using Hybrid Retrofitting with Groove and Embedding FRP Rod and CFRP Sheet vol.18, pp.4, 2014, https://doi.org/10.11112/jksmi.2014.18.4.041
  2. An Experimental Study on the Optimum Mix Design and Site Application Case of Soil Mixing Wall for Trench Stability vol.27, pp.4, 2015, https://doi.org/10.4334/JKCI.2015.27.4.419
  3. Evaluation of Shear Behavior of Beams Strengthened in Shear with Carbon Fiber Reinforced Polymer with Mohr's Circle vol.28, pp.5, 2016, https://doi.org/10.4334/JKCI.2016.28.5.527