콘크리트학회논문집 (Journal of the Korea Concrete Institute)

  • 제15권1호
  • /
  • Pages.143-153
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  • 2003
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  • 1229-5515(pISSN)
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  • 2234-2842(eISSN)
한국콘크리트학회 (Korea Concrete Institute)
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부분 비부착 NSM Hybrid FRP 보강근에 의한 철근콘크리트보의 연성보강

Ductile Strengthening of Reinforced Concrete Beams by Partially Unbonded NSM Hybrid FRP Rebars

  • 이차돈 (중앙대학교 건축공학과) ;
  • 정상모 (한동대학교 토목공학과) ;
  • 원종필 (건국대학교 지역건설환경공학과) ;
  • 이승환 (중앙대학교 건축공학과)
  • Lee, Cha-Don (Dept. of Architectural Engiveering, Chung-Ang University) ;
  • Chung, Sang-Mo (Dept. of Civil Engineering, Han-Dong. University) ;
  • Won, Jong-Pil (Dept. of Rural Engineering, Kon-Kuk. University) ;
  • Lee, Sng-Whan (Dept. of Architectural Engiveering, Chung-Ang University)
  • 발행 : 2003.02.01
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초록

철근콘크리트를 FRP 복합재로 보강할 경우, 취성파괴를 방지하고 연성파괴를 확보할 수 있는 새로운 기법을 표면매립공법(Near Surface Mounted technique: 이하 NSM 공법)에 근거하여 제시하였다. 제안된 기법은 Hybrid FRP rebar를 부분적으로 비부착 시킴으로서 보강된 보의 연성을 확보한다. Hybrid FRP rebar의 일부를 비부착으로 한 경우와 전부를 부착으로 한 경우의 NSM 공법에 의한 FRP 보강된 철근 콘크리트보의 거동을 비교하기 위한 실험을 실시하였다. 실험 결과, 부분 비부착 NSM 공법으로 보강된 철근 콘크리트보만이 연성거동을 함이 관찰되었다. 부분 비부착 보강된 보의 극한 시 내력을 확보하기 위한 최소한의 FRP의 부분 비부착길이를 이론적으로 산정하여 제시하였다. 제시된 부분 비부착 NSM 공법은 FRP 복합재로 보강된 철근 콘크리트 부재의 구조적 거동을 크게 향상시킬 수 있으리라 기대된다.

New strengthening method based on Near Surface Mounted technique (NSM) is suggested, which can overcome the brittle nature of failure inherent to those reinforced concrete beams strengthened with FRP composite materials. The suggested technique secures ductile failure of reinforced concrete beams by having the strengthening Hybrid FRP rebars unbonded in parts. Experiments were performed in order to compare structural behaviors of strengthened beams with and without unbending along the Hybrid FRP rebars. Test results showed that only those beams strengthened by partially unbonded NSM failed in ductile manner. Theoretical expressions were derived for the minimum unbonded length of Hybrid FRP rebars with which ultimate strength of the reinforced concrete beam with partially unbonded NSM could be reached. The suggested partially unbonded NSM technique is expected to significantly improve the structural behavior of the strengthened beam with FRP composite materials.

키워드

참고문헌

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