Steel and Composite Structures

Techno-Press (테크노프레스)
권호 표지
DOI QR코드

DOI QR Code

Retrofitting of shear damaged RC beams using CFRP strips

  • Altin, Sinan (Civil Eng. Dept., Gazi University) ;
  • Anil, Ozgur (Civil Eng. Dept., Gazi University) ;
  • Toptas, Tolga (Civil Eng. Dept., Gazi University) ;
  • Kara, M. Emin (Civil Eng. Dept., Gazi University)
  • Received : 2010.04.10
  • Accepted : 2011.03.09
  • Published : 2011.05.25
⟨ Previous Next ⟩

Abstract

The results of an experimental investigation are presented in this paper for retrofitting of shear damaged reinforced concrete beams by using U shaped CFRP strips. The experimental program is consisted of seven shear deficient T cross sectioned 1/2 scale simply supported beam specimens. One beam was used as reference specimen, and the remaining six specimens were tested in two stages. At the first stage, specimens were shear damaged severely, and then were retrofitted by using CFRP strips with or without fan type anchorages. Finally, retrofitted beams were tested up to failure. Three different CFRP strip spacing were used such as 125 mm, 150 mm, and 200 mm. The effect of anchorages on shear strength and behavior of the retrofitted specimens is investigated. CFRP strips without anchorages improved the shear strength, but no flexural failure mode was observed. Specimens showed brittle shear failure due to peeling of CFRP strip from RC beam surface. Shear damaged specimens retrofitted with anchoraged CFRP strips showed improved shear strength and ductile flexural failure. Maximum strains at anchoraged strips were approximately 68% larger than that of strips without anchorages.

Keywords

References

  1. ACI Committee 440, (1996), "State-of-the-art report on fiber reinforced plastic (FRP) Reinforcement for Concrete Structures", American Concrete Institute, Detroit, Michigan, 68.
  2. ACI Committee 318, (1995), "Building code requirements for structural concrete (ACI 318-99)", American. Concrete. Inst., Detroit, 369.
  3. Arduini, M. and Nanni, A. (1997), "Behavior of pre-cracked rc beams strengthened with carbon FRP sheets", J. Comp. Constr., 1(2), 63-70. https://doi.org/10.1061/(ASCE)1090-0268(1997)1:2(63)
  4. Anil, O., Belgin, C. and Kara, M. E. (2010), "Experimental investigation on CFRP to concrete bonded joints across crack", Struct. Eng. Mech, 35(1)., 1-18. https://doi.org/10.12989/sem.2010.35.1.001
  5. Barros, J.A.O., Dias, S.J.E. and Lima, J.L.T. (2007), "Efficacy of CFRP-based techniques for the flexural and shear strengthening of concrete beams", Cement. Concrete. Comp., 29(3), 203-217. https://doi.org/10.1016/j.cemconcomp.2006.09.001
  6. Barros, J.A.O. and Dias, S.J.E. (2006), "Near surface mounted CFRP laminates for shear strengthening of concrete beams", Cement. Concrete. Comp., 28(3), 276-292. https://doi.org/10.1016/j.cemconcomp.2005.11.003
  7. Chajes, M.J., Januska, T.F., Mertz, D.R., Thomson, T.A. and Finch, W.W. (1995), "Shear strengthening of reinforced concrete beams using externally applied composite fabrics", ACI Struct. J., 92(3), 295-303.
  8. Diagana, C., Li, A., Gedalia, B. and Dlemas, Y. (2003), "Shear strengthening effectiveness with CFF strips", Eng. Struct., 25, 507-516. https://doi.org/10.1016/S0141-0296(02)00208-0
  9. Ehsani, M., Saadatmanesh, H. and Al-Saidy, A. (1997), "Shear behavior of URM retrofitted with FRP overlays", J. Comp. Const., 1(1), 17-25. https://doi.org/10.1061/(ASCE)1090-0268(1997)1:1(17)
  10. Eurocode No. 2, (2002), "Design of concrete structures-part 1: General rules and rules for buildings", Commission of the European Communities, prEN 1992-1-1 draft, 85-89.
  11. FIB bulletin, (2001), "Externally bonded FRP requirement for RC structures", Technical Report, Federation International du Beton, France, 14, 60-63.
  12. Jayaprakash, J., Abdul Samad, A.A., Abbasovich, A.A. and Abang Ali, A.A. (2008), "Shear capacity of precracked and non-precracked reinforced concrete shear beams with externally bonded bi-directional CFRP strips", Const. Building. Materials., 22(6), 1148-1165 https://doi.org/10.1016/j.conbuildmat.2007.02.008
  13. Kachlakev, D. and McCurry, C.C. (2000), "Behavior of full scale reinforced concrete beams retrofitted for shear and flexural with FRP laminates", Composites: Part B, 31(6-7), 445-452. https://doi.org/10.1016/S1359-8368(00)00023-8
  14. Khalifa, A., Gold, W., Nanni, A. and Abel-Aziz, M. (1998), "Contribution of externally bonded FRP to the shear capacity of RC flexural members", J. Compo. Const., 2(4), 195-203. https://doi.org/10.1061/(ASCE)1090-0268(1998)2:4(195)
  15. Khalifa, A., Alkhrdaji, T., Nanni, A. and Lansburg, A. (1999), "Anchorage of surface mounted FRP reinforcement",Concrete Int., ACI Struct. J., 21(1), 49-54.
  16. Khalifa, A., and Nanni, A. (2002), "Rehabilitation of rectangular simply supported RC beams with shear deficiencies using CFRP composites", Const. Buil. Mater., 16(3), 135-146. https://doi.org/10.1016/S0950-0618(02)00002-8
  17. Khalifa, A. and Nanni, A. (2000), "Improving shear capacity of existing RC T-section beams using CFRP composites", Cement . Concr. Comp., 22(3), 165-174. https://doi.org/10.1016/S0958-9465(99)00051-7
  18. Li, A., Diagana, C. and Delmas, Y. (2001), "CFRP contribution to shear capacity of strengthened RC beams", Eng. Structures, 23, 1212-1220. https://doi.org/10.1016/S0141-0296(01)00035-9
  19. Mertoglu, C. (2009), "Behavior of strengthened RC beams with CFRP straps against shear", M. Sc. Thesis, Gazi University, 102.
  20. Norris, T., Saadatmanesh, H. and Ehsani, M. (1997), "Shear and flexural strengthening of R/C beams with carbon fiber sheets", J. Struct. Eng., 123(7), 903-911. https://doi.org/10.1061/(ASCE)0733-9445(1997)123:7(903)
  21. Ritchie, P., Thomas. D., Lu, L. and Connelley, G. (1991) "External reinforcement of concrete beams using fiber reinforced plastics", ACI Structural Journal, 88(4), 490-500.
  22. Sato, Y., Ueda, T., Kakuta, Y. and Tanaka, T. (1996), "Shear reinforcing effect of carbon fiber sheet attached to side of reinforced concrete beams", Advanced Composite Materials in Bridges and Structures, M.M. El-Badry ed., 621-627.
  23. Sharif, A., Al-Sulaimani, G., Basunbul, I., Baluch, M., Ghaleb, B. (1994), "Strengthening of initially loaded reinforced concrete beams using FRP plates", ACI Struct. J., 91(2), 160-168.
  24. Swamy, R.N., Mukhopadhyaya, P. and Lynsdale, C.J. (1999), "Strengthening for shear of RC beams by external plate bonding", J. Struct. Eng., 77(12), 19-30.
  25. Taljsten, B. and Elfgren, L. (2000), "Strengthening concrete beams for shear using CFRP materials: evaluation of different application methods", Composites: Part B, 33, 87-96.
  26. Taljsten, B. (2003), "Strengthening concrete beams for shear with CFRP sheets", Const. Build. Mater., 17, 15-26. https://doi.org/10.1016/S0950-0618(02)00088-0
  27. Triantafillou, T.C. (1998), "Shear strengthening of reinforced concrete beams using epoxy-bonded FRP composites", ACI Struct. J., 95(2), 107-115.
  28. Toptas, T. (2009), "Rehabilitation of shear damaged reinforced concrete beams with CFRP", M. Sc. Thesis, Gazi University, 107.

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. Experimental investigation on shear capacity of RC beams with GFRP rebar & stirrups vol.21, pp.6, 2016, https://doi.org/10.12989/scs.2016.21.6.1265
  3. Energy absorption of reinforced concrete deep beams strengthened with CFRP sheet vol.16, pp.5, 2014, https://doi.org/10.12989/scs.2014.16.5.481
  4. Shear Strengthening of Reinforced Concrete T-Beams by Using Fiber-Reinforced Polymer Composites: A Data Analysis vol.45, pp.5, 2011, https://doi.org/10.1007/s13369-020-04412-x
  5. Shear strengthening of RC beams with Basalt Fiber Reinforced Polymer (BFRP) composites vol.10, pp.2, 2011, https://doi.org/10.12989/acc.2020.10.2.093
  6. Experimental analysis of shear deficient reinforced concrete beams strengthened by glass fiber strip composites and mechanical stitches vol.40, pp.2, 2011, https://doi.org/10.12989/scs.2021.40.2.267