Structural Engineering and Mechanics

Techno-Press (테크노프레스)
권호 표지
DOI QR코드

DOI QR Code

Experimental and analytical investigations for behaviors of RC beams strengthened with tapered CFRPs

  • Kim, Naeun (Department of Architectural Engineering, Ewha Womans University) ;
  • Kim, Young Hee (Department of Architectural Engineering, Ewha Womans University) ;
  • Kim, Hee Sun (Department of Architectural Engineering, Ewha Womans University)
  • Received : 2013.09.08
  • Accepted : 2014.10.09
  • Published : 2015.03.25
⟨ Previous Next ⟩

Abstract

This study investigates structural and mechanical behaviors of RC (Reinforced concrete) beams strengthened with tapered CFRP (Carbon fiber reinforced polymer) sheets having various configurations. Toward this goal, experiments are performed on RC beams strengthened with four layers of CFRP sheets and each layer of the CFRP is prepared to have different length. Experimental results show that tapered CFRPs have better strengthening effect than non-tapered CFRP sheets and maximum loads of the beams with tapered CFRPs are governed by the length of first CFRP layer rather than total length of CFRP layers. In addition, analyses are performed using FE (Finite Element) models including cohesive elements to predict debonding behaviors between FRP and concrete elements. The predicted results from the FE models show good agreement with the experimental results.

Keywords

Acknowledgement

Supported by : National Research Foundation of Korea (NRF)

References

  1. ABAQUS (2010), Theory Manual Version 6.10-3, Dassault Systems Simulia Corp., Providence, RI, USA.
  2. ACI committee 440 (2008), Guide for the Design and Construction of Externally Bonded FRP Systems for Strengthening Concrete Structures, American Concrete Institute, ACI 440, 2R-08.
  3. Al-Tamimi, A., Hawileh, R., Abdalla, J.A. and Rasheed, H. (2011), "Effects of ratio of CFRP plate length to shear span and end anchorage on flexural behavior of SCC R/C beams", J. Compos. Constr., ASCE, 15(6), 908-919. https://doi.org/10.1061/(ASCE)CC.1943-5614.0000221
  4. Brena, S.F. and Marcri, B.M. (2004), "Effect of carbon-fiber-reinforced polymer laminate configuration on the behavior of strengthened reinforced concrete beams", J. Compos. Constr., ASCE, 8(3), 229-240. https://doi.org/10.1061/(ASCE)1090-0268(2004)8:3(229)
  5. Camata, G., Spacone, E. and Zarnic, R. (2007), "Experimental and nonlinear finite element studies of RC beams strengthened with FRP plates", Compos. Part B, 38, 277-288. https://doi.org/10.1016/j.compositesb.2005.12.003
  6. Choi, E.S., Utui, N. and Kim, H.S. (2013), "Experimental and analytical investigations on debonding of hybrid FRPs for flexural strengthening of RC beams", Compos. Part B, 45(1), 248-256. https://doi.org/10.1016/j.compositesb.2012.06.022
  7. Gao, B., Kim, J.K. and Leung, C.K.Y. (2006), "Effect of tapered FRP sheets on interlaminar fracture behavior of FRP concrete interface", Compos. Part A, 37(10), 1605 -1612. https://doi.org/10.1016/j.compositesa.2005.10.010
  8. Hawileh, R., Naser, M. and Abdalla, J.A. (2013), "Finite Element Simulation of Reinforced Concrete Beams Externally Strengthened with Short-Length CFRP Plates", Compos. Part B, 45(1), 1722-1730. https://doi.org/10.1016/j.compositesb.2012.09.032
  9. Kang, T.H.K., Howell, J., Kim, S. and Lee, D.J. (2012), "A State-of-the-Art review on debonding failures of FRP laminates externally adhered to concrete", Int. J. Concrete Struct. Mater., 6(2), 123-134. https://doi.org/10.1007/s40069-012-0012-1
  10. Kim, H.S. and Shin, Y.S. (2011), "Flexural behavior of RC (RC) beams retrofitted with hybrid fiber reinforced polymers (FRPs) under sustaining loads", Compos. Struct., 93(2), 802-811. https://doi.org/10.1016/j.compstruct.2010.07.013
  11. Kadhim, M.M.A. (2011), "Effect of CFRP sheet length on the behavior of HSC continuous Beam", J. Therm. Compos. Mater., 25(1), 33-44. https://doi.org/10.1177/0892705711401847
  12. Leung, C.K.Y. (2006), "FRP debonding from a concrete substrate: Some recent findings against conventional belief", Cement Concrete Compos., 2, 742-748.
  13. Maalej, M. and Leong, K.S. (2005), "Effect of beam size and FRP thickness on interfacial shear stress concentration and failure mode of FRP-strengthened beams", Compos. Sci. Tech., 65(7-8), 1148-1158. https://doi.org/10.1016/j.compscitech.2004.11.010
  14. Mongi, B.O., Abdeldjeliln, B. and Bae, S.W. (2009), "Effective bond length of FRP sheets externally bonded to concrete", Int. J. Concrete Struct. Mater., 3(2), 127-131. https://doi.org/10.4334/IJCSM.2009.3.2.127
  15. Obaidat, Y., Heyden, S. and Dahlblom, O. (2010), "The effect of CFRP and CFRP/Concrete interface models when modelling retrofitted RC beams with FEM", Compos. Struct., 92(6), 1391-1398. https://doi.org/10.1016/j.compstruct.2009.11.008
  16. Smith, S.T. and Teng, J.G. (2002), "FRP-strengthened RC beams. II: assessment of debonding strength models", Eng. Struct., 24, 397-417. https://doi.org/10.1016/S0141-0296(01)00106-7
  17. Teng, J.G., Yuan, H. and Chen, J.F. (2006), "FRP-to-concrete interfaces between two adjacent cracks:Theoretical model for debonding failure", Int. J. Solid. Struct., 43(18-19), 5750-5778. https://doi.org/10.1016/j.ijsolstr.2005.07.023
  18. Teng, J.G., Chen, J.F., Smith, S.T. and Lam, L. (2011), FRP Retrofitted RC Structures, John Wiley & Sons, Inc.
  19. Yang, Q., Qin, Q. and Zheng, D. (2002), "Analytical and numerical investigation of interfacial stresses of FRP-concrete hybrid structure", Compos. Struct., 57(1-4), 221-226. https://doi.org/10.1016/S0263-8223(02)00088-0

Cited by

  1. The effects of CFRP orientation on the strengthening of reinforced concrete structures vol.25, pp.15, 2016, https://doi.org/10.1002/tal.1282
  2. Retrofitting of RC girders using pre-stressed CFRP sheets vol.20, pp.4, 2016, https://doi.org/10.12989/scs.2016.20.4.833
  3. Absolute effective elastic constants of composite materials vol.57, pp.5, 2016, https://doi.org/10.12989/sem.2016.57.5.897
  4. Minimum cost design of overhead crane beam with box section strengthened by CFRP laminates vol.61, pp.4, 2015, https://doi.org/10.12989/sem.2017.61.4.475
  5. Modified DEBA for determining size dependent shear fracture energy of laminates vol.28, pp.1, 2018, https://doi.org/10.12989/scs.2018.28.1.111