Structural Engineering and Mechanics

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Effects of tensile softening on the cracking resistance of FRP reinforced concrete under thermal loads

  • Received : 2010.03.08
  • Accepted : 2010.07.16
  • Published : 2010.11.10
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Abstract

Fiber reinforced polymer (FRP) bars have been widely used as reinforcement for concrete structures. However, under elevated temperatures, the difference between the transverse coefficients of thermal expansion of FRP rebars and concrete may cause the splitting cracks of the concrete cover. As a result, the bonding of FRP-reinforced concrete may not sustain its function to transfer load between the FRP rebar and the surrounding concrete. The current study investigates the cracking resistance of FRP reinforced concrete against the thermal expansion based on a mechanical model that accounts for the tensile softening behavior of concrete. To evaluate the efficacy of the proposed model, the critical temperature increments at which the splitting failure of the concrete cover occurs and the internal crack radii estimated are compared with the results obtained from the previous studies. Simplified equations for estimating the critical temperature increments and the minimum concrete cover required to prevent concrete splitting failure for a designated temperature increment are also derived for design purpose.

Keywords

References

  1. Abdalla, H. (2006), "Concrete cover requirements for FRP reinforced members in hot climates", Compos. Struct., 73, 61-69. https://doi.org/10.1016/j.compstruct.2005.01.033
  2. Aiello, M.A. (1999), "Concrete cover failure in FRP reinforced beams under thermal loads", J. Compos. Construct., 3(1), 46-52. https://doi.org/10.1061/(ASCE)1090-0268(1999)3:1(46)
  3. Aiello, M.A., Focacci, F. and Nanni, A. (2001), "Effects of thermal loads on concrete cover of fiber reinforced polymer reinforced elements: Theoretical and experimental analysis", ACI Mater. J., 98(4), 332-339.
  4. American Concrete Institute (ACI) (2005), ''Building code requirements for structural concrete", 318-05, Detroit.
  5. American Concrete Institute (ACI) (2006), "Guide for the design and construction of concrete with FRP bars", 440.1R-06, Detroit.
  6. Fu, Y.F., Wong, Y.L., Tang, C.A. and Poon, C.S. (2004), "Thermal induced stress and associated cracking in cement-based composite at elevated temperatures-Part II: Thermal cracking around multiple inclusions", Cement Concrete Compos., 26, 113-126. https://doi.org/10.1016/S0958-9465(03)00087-8
  7. Gentry, T.R. and Husain, M. (1999), "Thermal compatibility of concrete and composite reinforcements", J. Compos. Constr., 3(2), 82-86. https://doi.org/10.1061/(ASCE)1090-0268(1999)3:2(82)
  8. Masmoudi, R., Zaidi, A. and Gérard, P. (2005), "Transverse thermal expansion of FRP bars embedded in Concrete", J. Compos. Constr., 9(5), 377-387. https://doi.org/10.1061/(ASCE)1090-0268(2005)9:5(377)
  9. Pantazopoulou, S.J. and Papoulia, K.D. (2001), "Modeling cover-cracking due to reinforcement corrosion in RC structures", J. Eng. Mech., 127(4), 342-351. https://doi.org/10.1061/(ASCE)0733-9399(2001)127:4(342)
  10. Rahman, H.A., Kingsley, C.Y. and Taylor, D.A. (1995), "Thermal stress in FRP reinforced concrete", Proceedings of the Annual Conference of the Canadian Society for Civil Engineering, Ottawa, June.
  11. Sakai, T., Kanakubo, T., Yonemaru, K. and Fukuyama, H. (1999), "Bond splitting behavior of continuous fiber reinforced concrete members", Proceedings of the International Symposium on Fiber-reinforced Polymer for Reinforced Concrete Structures, Baltimore, MD, ACI SP-188.
  12. Tepfers, R. (1979), "Cracking of concrete cover along anchored deformed reinforcing bars", Mag. Concrete Res., 31(106), 3-12. https://doi.org/10.1680/macr.1979.31.106.3
  13. Tepfers, R. (1982), "Lapped tensile reinforcement splices", J. Struct. Div.-ASCE, 108(1), 283-301.
  14. Tepfers, R. and De Lorenzis, L. (2003), "Bond of FRP reinforcement in concrete- a challenge", Mech. Compos. Mater., 39(4), 315-328. https://doi.org/10.1023/A:1025642411103
  15. Wang, X. and Liu, X. (2003), "A tensile-softening model for steel-concrete bond", Cement. Concrete Res., 33, 1669-1673. https://doi.org/10.1016/S0008-8846(03)00137-6
  16. Wong, Y.L., Fu, Y.F., Poon, C.S. and Tang, C.A. (2006), "Spalling of concrete cover of fiber-reinforced polymer reinforced concrete under thermal loads", Mater. Struct., 39, 991-999. https://doi.org/10.1007/s11527-005-9032-5
  17. Zaidi, A. and Masmoudi, R. (2008), "Thermal effect on fiber reinforced polymer reinforced concrete slabs", Can. J. Civil Eng., 35, 312-320. https://doi.org/10.1139/L07-110

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  1. Modeling of mechanical bond–slip for steel-reinforced concrete under thermal loads vol.48, 2013, https://doi.org/10.1016/j.engstruct.2012.10.015
  2. Modeling of bonding between steel rebar and concrete at elevated temperatures vol.27, pp.1, 2012, https://doi.org/10.1016/j.conbuildmat.2011.08.014