한국구조물진단유지관리공학회 논문집 (Journal of the Korea institute for structural maintenance and inspection)

  • 제25권5호
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  • Pages.173-181
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  • 2021
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  • 2234-6937(pISSN)
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  • 2287-6979(eISSN)
한국구조물진단유지관리공학회 (Korea Institute for Structural Maintenance Inspection)
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FRP 보강근비에 따른 FRP 보강 콘크리트 슬래브의 파괴거동 분석

Analysis of Failure Behavior of FRP Rebar Reinforced Concrete Slab based on FRP Reinforced Ratio

  • 장낙섭 (경상국립대학교 건설환경공과대학 토목공학과) ;
  • 김영환 (경상국립대학교 건설환경공과대학 토목공학과) ;
  • 오홍섭 (경상국립대학교 건설환경공과대학 토목공학과)
  • 투고 : 2021.09.15
  • 심사 : 2021.09.30
  • 발행 : 2021.10.30
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초록

철근콘크리트 구조물은 다양한 환경에 노출되어 수분 침투로 인한 철근 부식이 발생하며, 부식으로 인한 구조물의 내구성능 저하 문제가 발생할 수 있다. 따라서 이러한 문제점을 해결하기 위해 철근에 비해 인장강도, 비부식성, 경량화 등 뛰어난 장점을 가진 FRP 보강근에 대한 연구가 활발히 진행되고 있다. FRP 보강근은 철근과 달리 항복 구간이 없으므로 파괴 시까지 선형탄성거동이 나타나고 탄성계수가 낮아 과도한 처짐이 발생할 수 있으므로 한계상태 조건에 대한 적용성 검토가 필요하다. 한계상태에서 FRP 보강 콘크리트 의 휨 설계 시 ACI 440.1R은 FRP 보강근의 재료적 불확실성을 고려하여 환경감소계수와 강도감소계수를 모두 적용하여 휨강도가 크게 낮아진다. 따라서 본 연구에서는 국내·외 다양한 문헌을 조사하여 유효단면이차모멘트 제안식의 처짐 해석 결과와 실험결과를 비교하였으며, ACI 440.1R 및 Fib bulletin 40의 설계휨강도를 분석하였다. 실험 결과에 따른 휨강도는 ACI 440.1R에 비해 Fib bulletin 40의 설계휨강도와 유사한 경향이 확인되었으며, 인장지배단면에서 ACI 440.1R은 설계휨강도를 보수적으로 평가하는 것으로 나타났다.

Reinforced concrete structures are exposed to various environments, resulting in reinforcement corrosion due to moisture and ions penetration. Reinforced concrete corrosion causes a decrease in the durability performance of reinforced concrete structures. One solution to mitigate such issues is using FRP rebars, which offer several advantages such as high tensile strength, corrosion resistance, and light-weight than conventional rebars, in reinforced concrete instead of conventional steel rebars. The FRP rebar used should be examined at the limit state because FRP reinforced concrete has linear behavior until its fracture and can generate excessive deflection due to the low elastic modulus. It should be considered while designing FRP reinforced concrete for flexure. In the ultimate limit state, the flexural strength of FRP reinforced concrete as per ACI 440.1R is significantly lower than the flexural strength by applying both the environmental reduction and strength reduction factors accounting for the material uncertainty of FRP rebar. Therefore, in this study, the experimental results were compared with the deflection of the proposed effective moment of inertia referring to the local and international standards. The experimental results of GFRP and BFRP reinforced concrete were compared with the flexural strength as determined by ACI 440.1R and Fib bulletin 40. The flexural strength obtained by the experimental results was more similar to that obtained by Fib bulletin 40 than ACI 440.1R. The flexural strength of ACI 440.1R was conservatively evaluated in the tension-controlled section.

키워드

과제정보

본 연구는 국토교통부/국토교통과학기술진흥원의 지원으로 수행되었음(과제번호21CFRP-C163381-01).

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