Steel and Composite Structures

  • 제47권3호
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  • Pages.383-393
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  • 2023
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  • 1229-9367(pISSN)
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  • 1598-6233(eISSN)
테크노프레스 (Techno-Press)
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Strain interaction of steel stirrup and EB-FRP web strip in shear-strengthened semi-deep concrete beams

  • Javad Mokari Rahmdel (Faculty of Civil Engineering, Urmia University of Technology) ;
  • Erfan Shafei (Faculty of Civil Engineering, Urmia University of Technology)
  • 투고 : 2022.10.25
  • 심사 : 2023.04.13
  • 발행 : 2023.05.10
⟨ 이전 논문 다음 논문 ⟩

초록

Conventional reinforced concrete design codes assume ideal strain evolution in semi-deep beams with externally bonded fiber-reinforced polymer (EB-FRP) web strips. However, there is a strain interaction between internal stirrups and web strips, leading to a notable difference between code-based and experimental shear strengths. Current study provides an experiment-verified detailed numerical framework to assess the potential strain interaction under quasi-static monotonic load. Based on the observations, steel stirrups are effective only for low EB-FRP amounts and the over-strengthening of semi-deep beams prevents the stirrups from yielding, reducing its shear strength contribution. A notable difference is detected between the code-based and the study-based EB-FRP strain values, which is a function of the normalized FRP stress parameter. Semi-analytical relations are proposed to estimate the effective strain and stress of the components considering the potential strain interaction. For the sake of simplification, a linearized correction factor is proposed for the EB-FRP web strip strain, assuming its restraining effect as constant for all steel stirrup amounts.

키워드

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