Structural Engineering and Mechanics

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Strength assessment of RC deep beams and corbels

  • Adrija, D. (Atkins) ;
  • Geevar, Indu (Department of Civil Engineering, Rajagiri School of Engineering and Technology) ;
  • Menon, Devdas (Department of Civil Engineering, IIT Madras) ;
  • Prasad, Meher (Department of Civil Engineering, IIT Madras)
  • Received : 2018.08.08
  • Accepted : 2020.10.23
  • Published : 2021.01.25
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Abstract

The strut-and-tie method (STM) has been widely accepted and used as a rational approach for the design of disturbed regions ('D' regions) of reinforced concrete members such as in corbels and deep beams, where traditional flexure theory does not apply. This paper evaluates the applicability of the equilibrium based STM in strength predictions of deep beams (with rectangular and circular cross-section) and corbels using the available experiments in literature. STM is found to give fairly good results for corbel and deep beams. The failure modes of these deep members are also studied, and an optimum amount of distribution reinforcement is suggested to eliminate the premature diagonal splitting failure. A comparison with existing empirical and semi empirical methods also show that STM gives more reliable results. The nonlinear finite element analysis (NLFEA) of 50 deep beams and 20 corbels could capture the complete behaviour of deep members including crack pattern, failure load and failure load accurately.

Keywords

References

  1. Balakrishnan, B., Hussain, S. and Menon, D. (2016), "Assessment of shear strength of circular reinforced concrete beams", ACI Struct. J., 113(6), 1209-1221. https://doi.org/10.14359/51689145
  2. Birrcher, D.B., Tuchscherer, R.G., Huizinga, M.R. and Bayrak, O. (2013), "Minimum web reinforcement in deep beams", ACI Struct. J., 110(2), 297-306.
  3. Brena, S.F and Roy, N.C. (2009), "Evaluation of load transfer and strut strength of deep beams with short longitudinal bar anchorages", ACI Struct. J., 106(63), 678-689.
  4. Campione, G. and Minafo, G. (2011), "Experimental investigation on compressive behavior of bottle-shaped struts", ACI Struct. J., 108(3), 294-303.
  5. Clark, A.P. (1951), "Diagonal tension in reinforced concrete beams", ACI Struct. J., 48(10), 145-156.
  6. Foster, S.J. and Gilbert, R.I. (1998), "Experimental studies on high-strength concrete deep beams", ACI Struct. J., 95(4), 382-390.
  7. Geevar, I., Menon, D. (2019), "Strength of reinforced concrete pier caps-experimental validation of strut-and-tie method", ACI Struct. J., 116(1), 261. https://doi.org/10.14359/51711138
  8. Hwang, S.J., Lu, W.Y. and Lee, H.J. (2000a), "Shear strength prediction for deep beams" ACI Struct. J., 97(3), 367-376.
  9. Hwang, S.J., Lu, W.Y. and Lee, H.J. (2000b), "Shear strength prediction for reinforced concrete corbels", ACI Struct. J., 97(4), 543-552.
  10. Kriz, L.B. and Raths, C.H. (1965), "Connections in precast concrete structures - strength of corbels", PCI J., 10(1), 16-61. https://doi.org/10.15554/pcij.02011965.16.61
  11. Lim, E. and Hwang, S.J. (2016), "Modeling of the strut-and-tie parameters of deep beams for shear strength prediction", Eng. Struct., 108, 104-112. https://doi.org/10.1016/j.engstruct.2015.11.024.
  12. Liu, J. and Mihaylov, B. (2016), "A comparative study of models for shear strength of reinforced concrete deep beams", Eng. Struct., 112, 81-89. https://doi.org/10.1016/j.engstruct.2016.01.012.
  13. Lu, W.Y. and Lin, I.J. (2009), "Behavior of reinforced concrete corbels", Struct. Eng. Mech., 33(3), 357-371. https://doi.org/10.12989/sem.2009.33.3.357.
  14. Mathey, R.G. and Watstein, D. (1963), "Shear strength of beams without web reinforcement containing deformed bars of different yield strengths", ACI J. Proceedings, 60(2), 183-208.
  15. Mattock, A.H., Chen, K.C. and Soongswang, K. (1976), "Behavior of Reinforced Concrete Corbels", PCI J., 21(2), 52-77. https://doi.org/10.15554/pcij.03011976.52.77
  16. Moody, K.G., Viest, I.M., Elstner, R.C. and Hognestad, E. (1954), "Shear strength of reinforced concrete beams part 1 -tests of simple beams", ACI J. Proceedings, 51(12), 317-332.
  17. Morrow, J. and Viest, I.M. (1957), "Shear strength of reinforced concrete frame members without web reinforcement", ACI J. Proceedings, 53(9), 833-869.
  18. Mihaylov, B.I., Bentz, E.C., Collins, M.P. (2013) "Two-parameter kinematic theory for shear behaviour of deep beams", ACI Struct. J., 110(3), 447-456.
  19. Ritter, W. (1899), Construction Method of Hennebique (Die Bauweise Hennebique), Schweizerische Bauzeitung, Zurich, Switzerland.
  20. Russo, G., Venir, R. and Pauletta, M. (2005) "Reinforced concrete deep beams - shear strength model and design formula", ACI Struct. J., 102(3), 429-437.
  21. Sahoo, D.K., Sagi, M.S.V, Singh, B. and Bhargava, P. (2010), "Effect of detailing of web reinforcement on the behavior of bottle-shaped struts", J. Adv. Concrete Technol., 8(3), 303-314. https://doi.org/10.3151/jact.8.303.
  22. Sahoo, D. K.; Singh, B.; and Bhargava, P. (2009), "Investigation of dispersion of compression in bottle-shaped struts", ACI Struct. J., 106(2), 178-186
  23. Salamy, M.R., Kobayashi, H. and Unjoh, S. (2005), "Experimental and analytical study on RC deep beams", Asian J. Civil Eng. (AJCE), 6(5), 409-422
  24. Schlaich, J., Schafer, K. and Jennewein, M. (1987), "Toward a consistent design of structural concrete", PCI J., 32(3), 74-150. https://doi.org/10.15554/pcij.05011987.74.150
  25. Smith, K.N. and Vantsiotis, A.S. (1982), "Shear strength of deep beams", ACI J. Proceedings, 79(3), 201-213.
  26. Su, R.K.L. and Looi, D.T.W. (2016), "Revisiting unreinforced strut efficiency factor", ACI Struct. J., 113(2), 301-315. https://doi.org/10.14359/51688062
  27. Tanimura, Y. and Sato, T. (2005), "Evaluation of shear strength of deep beams with stirrups", Quarterly Report RTRI, 46(1), 53-58. https://doi.org/10.2219/rtriqr.46.53
  28. Tuchscherer, R.G., Birrcher, D.B., Williams, C.S., Deschenes, D.J. and Bayrak, O. (2014), "Evaluation of existing strut-and-tie methods and recommended improvements", ACI Struct. J., 111(6), 1451-1460. https://doi.org/10.14359/516869926
  29. Tuchscherer, R.G., Birrcher, D.B. and Bayrak, O. (2016), "Reducing discrepancy between deep beam and sectional shearstrength predictions", ACI Struct. J., 111(1), 3-15.
  30. Vecchio, F.J. and Collins, M.P. (1993), "Compression response of cracked reinforced concrete", J. Struct. Eng., 119(12), 3590-3610. https://doi.org/10.1061/(ASCE)0733-9445(1993)119:12(3590)
  31. Walraven, J. and Lehwalter, N. (1994), "Size effects in short beams loaded in shear", ACI Struct. J., 91(5), 585-593.
  32. Yang, K.H., Chung, H.S., Lee, E.T. and Eun, H.C. (2003), "Shear characteristics of high-strength concrete deep beams without shear reinforcements", Eng. Struct., 25, 1343-1352. https://doi.org/10.1016/S0141-0296(03)00110-X
  33. Zhang, N. and Tan, K.H. (2007a), "Direct strut-and-tie model for single span and continuous deep beams", Eng. Struct., 29(11), 2987-3001. https://doi.org/10.1016/j.engstruct.2007.02.004
  34. Zhang, N. and Tan, K.-H. (2007b), "Size effect in RC deep beams: Experimental investigation and STM verification", Eng. Struct., 29(12), 3241-3254. https://doi.org/10.1016/j.engstruct.2007.10.005
  35. Birrcher, D.B., Tuchscherer, R.G., Huizinga, M.R., Bayrak, O., Wood, S.L. and Jirsa, J.O. (2009), "Strength and serviceability design of reinforced concrete deep beams", Report No. 0-5253-1, Center for Transportation Research, the University of Texas at Austin; Austin, TX, USA.
  36. Claus, T. (2009), "Nonlinear finite element analysis of shear critical reinforced concrete beams", M.Sc. Dissertation, Delft University of Technology, Netherlands.
  37. Hognestad, E. (1951), "A study of combined bending and axial load in reinforced concrete members", Bulletin Series, 399, University of Illinois Engineering Experiment Station, Urbana, USA.
  38. Hordijk, D.A. (1991), "Local Approach to Fatigue of Concrete", Ph.D. Dissertation, Delft University of Technology, Netherlands.
  39. ACI Committee 318 (2014), Building Code Requirements for Structural Concrete and Commentary, ACI 318-14, American Concrete Institute, Farmington Hills, USA.
  40. EN 1992-1-1(2004): Eurocode 2: Design of Concrete Structures - Part 1-1: General Rules and Rules for Buildings, European Committee for Standardization, Brussels, Belgium.
  41. fib Buttetin 66 (2010), Model Code, Vol 2, International Federation for Structural Concrete (fib), Switzerland.
  42. JSCE Concrete Committee, 2010, Standard Specifications for Concrete Structures - 2007, Tokyo, Japan.