Computers and Concrete

  • 제8권2호
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  • Pages.207-227
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  • 2011
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  • 1598-8198(pISSN)
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  • 1598-818X(eISSN)
테크노프레스 (Techno-Press)
권호 표지
DOI QR코드

DOI QR Code

Maximum concrete stress developed in unconfined flexural RC members

  • Ho, J.C.M. (Department of Civil Engineering, The University of Hong Kong) ;
  • Pam, H.J. (Department of Civil Engineering, The University of Hong Kong) ;
  • Peng, J. (Department of Civil Engineering, The University of Hong Kong) ;
  • Wong, Y.L. (Department of Civil and Structural Engineering, The Hong Kong Polytechnic University)
  • 투고 : 2009.07.23
  • 심사 : 2010.06.17
  • 발행 : 2011.04.25
⟨ 이전 논문 다음 논문 ⟩

초록

In flexural strength design of unconfined reinforced concrete (RC) members, the concrete compressive stress-strain curve is scaled down from the uni-axial stress-strain curve such that the maximum concrete stress adopted in design is less than the uni-axial strength to account for the strain gradient effect. It has been found that the use of this smaller maximum concrete stress will underestimate the flexural strength of unconfined RC members although the safety factors for materials are taken as unity. Herein, in order to investigate the effect of strain gradient on the maximum concrete stress that can be developed in unconfined flexural RC members, several pairs of plain concrete (PC) and RC inverted T-shaped specimens were fabricated and tested under concentric and eccentric loads. From the test results, the maximum concrete stress developed in the eccentric specimens under strain gradient is determined by the modified concrete stress-strain curve obtained from the counterpart concentric specimens based on axial load and moment equilibriums. Based on that, a pair of equivalent rectangular concrete stress block parameters for the purpose of flexural strength design of unconfined RC members is determined.

키워드

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피인용 문헌

  1. Improving design limits of strength and ductility of NSC beam by considering strain gradient effect vol.47, pp.2, 2013, https://doi.org/10.12989/sem.2013.47.2.185
  2. Combined strain gradient and concrete strength effects on flexural strength and ductility design of RC columns vol.15, pp.4, 2015, https://doi.org/10.12989/cac.2015.15.4.607
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  4. Concurrent flexural strength and ductility design of RC beams via strain-gradient-dependent concrete stress-strain curve vol.24, pp.9, 2015, https://doi.org/10.1002/tal.1203