Structural Engineering and Mechanics

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Experimental study on long-term behaviour of CFRP strengthened RC beams under sustained load

  • Ahmed, Ehsan (Department of Civil Engineering, Faculty of Engineering, Universiti Malaysia Sarawak) ;
  • Sobuz, Habibur Rahman (Department of Civil Engineering, Faculty of Engineering, Universiti Malaysia Sarawak)
  • Received : 2010.12.23
  • Accepted : 2011.06.24
  • Published : 2011.10.10
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Abstract

The strengthening and rehabilitation of reinforced concrete structures with externally bonded carbon fibre reinforced polymer (FRP) laminates has shown excellent performance and, as a result, this technology is rapidly replacing steel plate bonding techniques. This paper addresses this issue, and presents results deals with the influence of external bonded CFRP-reinforcement on the time-dependent behavior of reinforced concrete beams. A total of eight reinforced concrete beams with cracked and un-cracked section, with and without externally bonded CFRP laminates, were investigated for their creep and shrinkage behavior. All the beams considered in this paper were simply supported and subjected to a uniform sustained loading for the period of six months. The main parameters of this study are two types of sustained load and different degrees of strengthening scheme for both cracked and un-cracked sections of beams. Both analytical and experimental work has been carried out on strengthened beams to investigate the cracking and deflection performance. The applied sustained load was 56% and 38% of the ultimate static capacities of the un-strengthened beams for cracked and un-cracked section respectively. The analytical values based on effective modulus method (EMM) are compared to the experimental results and it is found that the analytical values are in general give conservative estimates of the experimental results. It was concluded that the attachment of CFRP composite laminates has a positive influence on the long term performance of strengthened beams.

Keywords

References

  1. ACI Committee 435R-95 (2003), "Control of deflection in concrete structures", American Concrete Institute, Redford Station, Detroit, Michigan.
  2. Annual Book of ASTM Standards, Section 4: Construction (1990), Standard Test Method for Creep of Concrete in Compression, ASTM C-512, ASTM.
  3. Annual Book of ASTM Standards, Section 4: Construction (1990), Standard Test Method for Length Change of Hardened Hydraulic-Cement Mortar and Concrete, ASTM C-157, ASTM.
  4. Alsaycd, S.H. (1993), "Flexural deflection of reinforced fibrous concrete beams", ACI Struct. J., 90(1), 72-76.
  5. Arockiasamya, M., Chidambarama, S., Amera, A. and Shahawy, M. (2000), "Time-dependent deformations of concrete beams reinforced with CFRP bars", Compos. Part B, 31, 577-592. https://doi.org/10.1016/S1359-8368(99)00045-1
  6. Al Chami, G., Theriault, M. and Neale, K.W. (2009), "Creep behavior of CFRP-strengthened reinforced concrete beams", Constr. Build. Mater., 23, 1640-1652. https://doi.org/10.1016/j.conbuildmat.2007.09.006
  7. Al-Mahaidi, R. and Kalfat, R. (2011), "Investigation into CFRP laminate anchorage systems utilizing bidirectional fabric wrap", Compos. Struct., 93, 821-830. https://doi.org/10.1016/j.compstruct.2010.07.012
  8. BS 8110-1 (1997), "Structural use of concrete- Part 1: Code of practice for design and construction", British Standards Institute, London.
  9. Branson, D.E. (1977), Deformation of Concrete Structures, McGraw-Hill, New Work.
  10. Chajes, M.J., Thomson, T.A., Jr., Januszka, T.F. and Finch, W.W., Jr. (1994), "Flexural strengthening of concrete beams using externally bonded composite materials", Constr. Build. Mater., 8(3), 191-201. https://doi.org/10.1016/S0950-0618(09)90034-4
  11. Ezeldin, A.S. and Shiah, T.W. (1995), "Analytical instantaneous and long-term deflections of fiber-reinforced concrete beams", J. Struct. Eng., 12(4), 727-738.
  12. Gilbert, R.I. (2006), "Instantaneous and time-dependent deflection of reinforced concrete flexural members", Concrete Forum, 1(1), 7-17.
  13. Ghali, A., Favre, R. and Elbadry, M. (2002), Concrete Structures: Stress and Deformation, 3rd Edition, Spon press, London and New York.
  14. Gilbert, R.I. (2001), "Shrinkage, cracking and deflection the serviceability of concrete structures", Electronic J. Struct. Eng., 1, 15-37.
  15. Hamoush, S.A. and Ahmed, S.H. (1990), "De-bonding of steel plate-strengthened concrete beams", J. Struct. Eng., 116(2), 356-371. https://doi.org/10.1061/(ASCE)0733-9445(1990)116:2(356)
  16. Meir, U. and Kaiser, H. (1991), "Strengthening of structures with CFRP laminates", Adv. Compos. Mater., 224-232.
  17. Muller, M., Toussaint, E., Destrebecq, J.F. and Grediac, M. (2007), "Investigation into the time-dependent behavior of reinforced concrete specimens strengthened with externally bonded CFRP-plates", Compos. Part B, 38, 417-428. https://doi.org/10.1016/j.compositesb.2006.10.001
  18. Plevris, N. and Triantafillou, T.C. (1984), "Time-dependent behavior of RC members strengthened with FRP laminates", J. Struct. Eng., 120(3), 1016-1045.
  19. Paulson, K.A., Nilson, A.H. and Hover, K.C. (1991), "Long-term deflection of high strength concrete beams", ACI Mater J., 88(2), 197-206.
  20. Product Data Sheet Edition 0308/2 (2008), Sika Carbudur Plates, Sika Kimia Sdn. Bhd., Malaysia.
  21. Ross, A., David, M.J., Joseph, W.T. and Mary, L.H. (1999), "Strengthening of reinforced concrete beams with externally bonded composites laminates", ACI Struct. J., 96(2), 212-220.
  22. Swamy, R.N., Jones, R. and Bloxham, J.W. (1987), "Structural behavior of reinforced concrete beams strengthened byepoxy-bonded steel plates", Struct. Eng. Part A, 65(2), 59-68.
  23. Sommerard, T. (1977), Swanley's Steel Plate Patch Up, New Civ. Engr., Mag. of the Inst. of Civ. Engrs., London, 18.
  24. Saadatmanesh, K. and Ehsani, M.R. (1991), "R/C beam strengthened with GFRP Plates 1: experimental study", J. Struct. Eng., 3434-3455.
  25. Saha, M.K. and Tan, K.H. (2005), "Long-term deflections of FRP-strengthened beams under sustained loads", FRP Composites in Civil Engineering-CICE 2004-Seracino (ed) @ 2005 Taylor and Francis Group, London, ISBN 90 5809 638 6.
  26. Triantafillou, T.C. (1998), "Strengthening of structures with advanced FRPs", Prog. Struct. Eng. Mater., 1, 126-134. https://doi.org/10.1002/pse.2260010204
  27. Tan, K.H. and Saha, M.K. (2006), "Long-term deflection of reinforced concrete beams externally bonded with FRP system", J. Compos. Constr., 10(6), 474-482. https://doi.org/10.1061/(ASCE)1090-0268(2006)10:6(474)
  28. Zou, P.X.W. (2003), "Theoretical study on short-term and long-term deflections of fiber reinforced polymer prestressed concrete beams", J. Compos. Const., 7(4), 285-291. https://doi.org/10.1061/(ASCE)1090-0268(2003)7:4(285)

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