Journal of the Korea Academia-Industrial cooperation Society (한국산학기술학회논문지)

The Korea Academia-Industrial cooperation Society (한국산학기술학회)
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Characteristics of Flexural Cracking Widths in FRP-Reinforced Concrete Beams Subjected to Short-Term Loads

단기하중을 받는 FRP-보강근 콘크리트 보의 휨균열폭 특성

  • Choi, Bong-Seob (Department of Architectural Engineering, Chungwoon University)
  • 최봉섭 (청운대학교 건축공학과)
  • Received : 2015.08.03
  • Accepted : 2015.10.08
  • Published : 2015.10.31
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Abstract

The use of FRP(Fiber-reinforced polymer) bars results in larger crack widths under service load due to the generally low elastic modulus and poor bond characteristics of FRP as compared with steel reinforcing bars. The work presented herein includes the results from 12 beams composed of nine rectangular beams and three T-beams reinforced with FRP bars tested under four-point bending. It was investigated that the bond coefficient, $k_b$ in ACI 440.1R-06 equation had high variability which the coefficient of variation was 40% in the range of 0.6 to 1.88 with average 1.05.

콘크리트 부재에서 FRP-보강근의 사용은 철근의 사용에 비해서 일반적으로 낮은 탄성계수와 부착성능으로 인하여 보다 넓은 균열폭을 초래 할 수 있다. 따라서 본 연구에서는 9개의 장방형보와 3개의 T형보로 구성된 총 12개의 시험체들로부터 4점가력 휨실험을 통하여 얻어진 균열폭 결과들과 기존 ACI 440.1R-06 제안식으로 계산된 결과들을 비교 분석하여 설계변수들이 균열폭에 미치는 영향과 적용 범위에 대한 문제점들을 파악하였다. 결과로서 주요 설계변수의 하나인 변동계수, $k_b$ 값은 0.6~1.88 범위에서 1.05의 평균값과 약 40%의 높은 변동계수를 나타냈다.

Keywords

References

  1. ACI Committee 440, "Guide for the Design and Construction of Concrete Reinforced with FRP Bar (ACI 440.1R-06)". American Concrete Institute, Farmington Hills, Michigan, 44pp., 2006.
  2. ACI Committee 318-05, "Building Code Requirements for Structural Concrete (ACI 318M-05) and Commentary (ACI 318M-05)". American Concrete Institute, Farmington Hills, Michigan, 430pp., 2005.
  3. El-Nemr, A., Ahmed E. A. and Benmokrane B., "Flexural Behavior and Serviceability of Normal-and High-Strength Concrete Beams Reinforced with Glass Fiber-Reinforced Polymer Bars", ACI Structural Journal, V. 110, No. 6, pp.1077-1087, 2013.
  4. Bouguerra, K., Ahmed, E. A., El-Gamal, S., and Benmokrane, B., "Testing of Full-Scale Concrete Bridge Deck Slabs Reinforced with Fiber Reinforced Polymer (FRP) Bars", Construction and Building Materials, V. 25, No. 10, pp. 3956-3965, 2011. DOI: http://dx.doi.org/10.1016/j.conbuildmat.2011.04.028
  5. Lee, W. K., Jansen, D. C., Berlin, K. B. and Cohen, I. E., "Flexural Cracks in Fiber-Reinforced Concrete Beams with Fiber-Reinforced Polymer Reinforcing Bars", ACI Structural Journal, V. 107, No. 3, pp. 321-329, 2010.
  6. Gergely, P. and Lutz, L., "Maximum Crack Width in Reinforced Concrete Flexural Members", Causes, Mechanism and Control of Cracking in Concrete, ACI SP-20, pp. 87-117, 1968.
  7. ACI Committee 440, "Guide for the Design and Construction of Concrete Reinforced with FRP Bar (ACI 440.1R-01)", American Concrete Institute, Farmington Hills, Michigan, 41pp., 2001.
  8. Frosch, R. J., "Another Look at Cracking and Crack Control in Reinforced Concrete", ACI Structural Journal, V. 96, No. 3, pp. 437-442, 1999.
  9. Veysey, S. and Bischoff, P. H., "Designing FRP Reinforced Concrete for Deflection Control", Fiber-Reinforced Polymer Reinforcement for Concrete Structures, ACI SP-275, pp. 3.1-3.23, 2011.