Journal of the Korea Concrete Institute (콘크리트학회논문집)

Korea Concrete Institute (한국콘크리트학회)
권호 표지
DOI QR코드

DOI QR Code

Shear Behavior of Reinforced Concrete Beams Strengthened with CFRP Strips

탄소섬유판 (CFRP Strip)으로 보강된 철근콘크리트 부재의 전단거동

  • 임동환 (동서대학교 건축토목공학부 토목공학) ;
  • 남민희 (동서대학교 건축토목공학부 토목공학)
  • Published : 2008.06.30
Download PDF
⟨ Previous Next ⟩

Abstract

The main goal of this study was to examine the shear behavior of reinforced concrete beams strengthened with CFRP strups. Seven rectangular beams were tested. The test variables were the configuration types, spacing length of CFRP strips and the amount of reinforced stirrups bars. From this experimental study, the shear capacity of beams strengthened with CFRP increased significantly compared to the beam without CFRP strip. Maximum increase of ultimate shear strength was found about 100% more than that of the beam without a CFRP strip and the CFRP strips attached in the shear region can resist the occurrence of the initial shear cracks and the propagation of major shear cracks. In this test, most of the shear strengthened beams failed suddenly due to the debonding of CFRP strips. A calculation of the shear strength of reinforced beams strengthened with CFRP strips based on the effective stresses was conducted and the comparisons were made with the test results.

본 연구는 탄소섬유판으로 보강된 철근콘크리트 부재의 전단거동 특성 및 파괴형상을 구명함에 그 목적이 있다. 이를 위하여 탄소섬유판의 형상, 섬유판 부착 간격 및 전단보강 철근량 등의 변수를 포함하는 실험 연구가 수행되었다. 본 실험 결과 탄소섬유판으로 보강된 철근콘크리트 부재의 전단 강성은 보강되지 않은 보에 비해 현저하게 개선되며 최대 전단강도 증진율은 100% 이상인 것으로 나타났다. 또한 탄소섬유판은 전단균열의 발생 및 진전을 억제하며, 적은 량의 탄소섬유판으로 보강했을 경우에도 전단강도의 증진 효과는 매우 좋은 것으로 나타났다. 본 연구에서는 탄소섬유판에 발생하는 변형률을 기본으로 하여 유효응력을 도출하였으며, 탄소섬유판으로 보강된 철근콘크리트 부재의 전단강도를 계산하였다. 이는 실험 결과와 잘 일치하는 것으로 나타났다.

Keywords

References

  1. Lim, D. H. and Oh, B. H., "Experimental and Theoretical Investigation on the Shear of Steel Fiber Reinforced Concrete Beams," Engineering Structures, Vol. 21, 1999, pp. 937-944 https://doi.org/10.1016/S0141-0296(98)00049-2
  2. 심종성, 오홍섭, 문도영, 박경동, "FRP로 전단보강된 철근콘크리트 보의 전단강도 예측(I)-전단강도 예측 모델제안 및 검증-," 콘크리트학회 논문집, 17권, 3호, 2005, pp. 343-351
  3. 심종성, 박철우, 문도영, 심제원, "FRP로 전단보강된 철근콘크리트 보의 전단강도 예측(II)-모델검증 및 변수연구-," 콘크리트학회 논문집, 17권, 3호, 2005, pp. 353-359
  4. Chen, J. F. and Teng, J. G., "Shear Capacity of Fiber-Reinforced Polymer-Strengthened Reinforced Concrete Beams: Fiber Reinforced Polymer Rupture," Journal of Structural Engineering, Vol. 129, No. 5, 2003, pp. 615-625 https://doi.org/10.1061/(ASCE)0733-9445(2003)129:5(615)
  5. Bousselham, A. and Chaallal, O., "Shear Streng-Thening Reinforced Concrete Beams with Fiber-Reinforced Polymer: Assessment of Influencing Parameters and Required Research," ACI Structural Journal, Vol. 101, No. 2, 2004, pp. 219-227
  6. Colotti, V. and Spadea, G., "Shear Strengthened with Bonded Steel or FRP Plates," Journal of Structural Engineering, Vol. 127, No. 4, 2001, pp. 367-373 https://doi.org/10.1061/(ASCE)0733-9445(2001)127:4(367)
  7. Diagana, C., Li, A., Gedalia, B., and Delmas, Y., "Shear Strengthening Effectiveness with CFF Strips," Engineering Structures, Vol. 25, 2003, pp. 507-516 https://doi.org/10.1016/S0141-0296(02)00208-0
  8. Colotti, V. and Spadea, G., "Shear Strength of RC Beams Strengthened with Bonded Steel or FRP Plates," Journal of Structural Engineering, Vol. 127, No. 4, 2001, pp. 367-380 https://doi.org/10.1061/(ASCE)0733-9445(2001)127:4(367)
  9. Whitehead, P. A. and Ibell, T. J., "Novel Shear Reinforcement for Fiber-Reinforced Polymer-Reinforced and Prestressed Concrete," ACI Structural Journal, Vol. 102, No. 2, 2005, pp. 286-294
  10. Zhang, Z. and Hsu, C. T. T., "Shear Strengthening of Reinforced Concrete Beams Using Carbon-Fiber-Reinforced Polymer laminates," Journal of Composites for Construction, Vol. 9, No. 2, 2005, pp. 158-169 https://doi.org/10.1061/(ASCE)1090-0268(2005)9:2(158)
  11. Zhang, Z., Shear Strengthening Carbon Fiber Reinforced Polymer Laminates, PhD Dissertation, Dept. of Civil and Env. Engineering, NJIT, Newark, N.J., 2003
  12. WhiteHead, P. A. and Ibell, T. J., "Rational Approach to Shear Design in Fiber Reinforced Polymer-Prestressed Concrete Structures," Journal of Composite for Construction, Vol. 9, No. 1, 2005, pp. 90-100 https://doi.org/10.1061/(ASCE)1090-0268(2005)9:1(90)
  13. Zhang, Z. and Hsu, C. T. T., "Shear Strengthening of Reinforced Concrete Deep Beams Using Carbon Fiber Reinforced Polymer Laminates," Journal of Composite for Construction, Vol. 8, No. 5, 2004, pp. 403-414 https://doi.org/10.1061/(ASCE)1090-0268(2004)8:5(403)

Cited by

  1. Evaluation of Shear Behavior of Beams Strengthened in Shear with Carbon Fiber Reinforced Polymer with Mohr's Circle vol.28, pp.5, 2016, https://doi.org/10.4334/JKCI.2016.28.5.527