DOI QR코드

DOI QR Code

Stiffness modeling of RC columns reinforced with plain rebars

  • Ozcan, Okan (Department of Civil Engineering, Akdeniz University)
  • Received : 2012.06.15
  • Accepted : 2014.02.25
  • Published : 2014.04.25

Abstract

Inaccurate predictions of effective stiffness for reinforced concrete (RC) columns having plain (undeformed) longitudinal rebars may lead to unsafe performance assessment and strengthening of existing deficient frames. Currently utilized effective stiffness models cover RC columns reinforced with deformed longitudinal rebars. A database of 47 RC columns (33 columns had continuous rebars and the remaining had spliced reinforcement) that were longitudinally reinforced with plain rebars was compiled from literature. The existing effective stiffness equations were found to overestimate the effective stiffness of columns with plain rebars for all levels of axial loads. A new approach that considers the contributions of flexure, shear and bond slip to column deflections prior to yielding was proposed. The new effective stiffness formulations were simplified without loss of generality for columns with and without lap-spliced plain rebars. In addition, the existing stiffness models for the columns with deformed rebars were improved while taking poor bond characteristics of plain rebars into account.

Keywords

References

  1. ACI Committee 318 (2008), Building Code Requirements for Structural Concrete and Commentary, American Concrete Institute, Farmington Hills, MI.
  2. Acun, B. (2010), "Energy based seismic performance assessment of reinforced concrete columns", PhD Dissertation, Middle East Tech. Univ., Turkey.
  3. Arani, K.K., Marefat, M.S., Biucky, A.A. and Khanmohammadi, M. (2013), "Experimental seismic evaluation of old concrete columns reinforced by plain bars", Struct. Des. Tall Spec. Build., 22(3), 267-90. https://doi.org/10.1002/tal.686
  4. ASCE (2007b), Seismic Rehabilitation of Existing Buildings, ASCE/SEI 41, Supplement I, American Society of Civil Engineers, Reston, VA.
  5. Binici, B. and Mosalam, K.M. (2007), "Analysis of reinforced concrete columns retrofitted with fiber reinforced polymer lamina", Compos. Part B: Eng., 38(2), 265-276.
  6. Biskinis, D.E. and Fardis, M.N. (2010), "Deformations at flexural yielding of members with continuous or lap-spliced bars", Struct. Concrete, 11(3), 127-138. https://doi.org/10.1680/stco.2010.11.3.127
  7. Bournas, D.A., Triantafillou, T.C. and Papanicolau, C.G. (2009), "Retrofit of seismically deficient RC columns with Textile-Reinforced Mortar (TRM) jackets", 4th Colloquium on Textile Reinforced Structures (CTRS4), Dresden, Einverlag.
  8. Bousias, S., Spathis, A.L. and Fardis, M.N. (2007), "Seismic retrofitting of columns with lap spliced smooth bars through FRP or concrete jackets", J. Earthq. Eng., 11(5), 653-674. https://doi.org/10.1080/13632460601125714
  9. Cosenza, E., Manfredi, G. and Verderame, G.M. (2006), "A fibre model for push-over analysis of underdesigned reinforced concrete frames", Comput. Struct., 84(13-14), 904-916. https://doi.org/10.1016/j.compstruc.2006.02.003
  10. Eligehausen, R., Popov, E.P. and Bertero, V.V. (1983), Local Bond Stress-Slip Relationships of Deformed Bars under Generalized Excitations, Tests and Analytical Model, UCB/EERC-83/23, Univ. of Calif., Berkeley, CA.
  11. Elwood, K.J. and Eberhard, M.O. (2006), Effective Stiffness of Reinforced Concrete Columns, PEER Research Digest No: 2006-1, PEER, University of California, Berkeley, CA.
  12. Elwood, K.J., Matamoros, A., Wallace, J.W., Lehman, D., Heintz, J., Mitchell, A., Moore, M., Valley, M., Lowes, L.N., Comartin, C. and Moehle, J.P. (2007), "Update to ASCE/SEI 41 concrete provisions", Earthq. Spec., 23(3), 493-523. https://doi.org/10.1193/1.2757714
  13. Elwood, K.J. and Eberhard, M.O. (2009), "Effective stiffness of reinforced concrete columns", ACI Struct. J., 106(4), 476-483.
  14. Eurocode 8: Design Provisions for Earthquake Resistance of Structures - Part 3: Assessment and Retrofitting of Buildings (2005), European Committee for Standardization, Brussels.
  15. Fardis, M.N. (2009), Seismic Design, Assessment and Retrofitting of Concrete Buildings Based on ENEurocode8, Springer Geotechnical, Geological and Earthquake Engineering, Volume 8.
  16. Fardis, M.N. (2013), "Performance and displacement based seismic design and assessment of concrete structures in the model code 2010", Struct. Concrete, 14(3), 215-229. https://doi.org/10.1002/suco.201300001
  17. FEMA 356 (2000), Prestandard and Commentary for Seismic Rehabilitation of Buildings, Federal Emergency Management Agency, Washington, DC.
  18. Hage, S.E. and MacGregor, J.G. (1974), Second Order Analysis of Reinforced Concrete Frames, Structural Engineering Report No 9, Dept. of Civil Eng. Univ. of Alberta, Edmonton, Canada.
  19. Hassan, M.N. (2011), "Splice tests of plain steel bars in concrete", PhD Dissertation, Uni.of Saskatchewan, Saskatoon.
  20. Ilki, A., Tezcan, A., Koç, V. and Kumbasar, N. (2004), "Seismic Retrofit of Non-ductile Rectangular Reinforced Concrete Columns By CFRP Jacketing", 13th World Conf. on Eq. Eng. (13WCEE), Vancouver, Canada.
  21. Khuntia, M. and Ghosh, S.K. (2004), "Flexural stiffness of reinforced concrete columns and beams: analytical approach", ACI Struct. J., 101(3), 351-363.
  22. Kumar, R. and Singh, Y. (2010), "Stiffness for reinforced concrete members for seismic analysis", ACI Struct. J., 107(5), 607-615.
  23. Lampropoulos, A.P. and Dritsos, S.E. (2011), "Concrete shrinkage effect on the behavior of RC columns under monotonic and cyclic loading", Constr. Build. Mater., 25, 1596-1602. https://doi.org/10.1016/j.conbuildmat.2010.10.001
  24. Lehman, D.E. and Moehle, J.P. (1998), Seismic Performance of Well Confined Concrete Bridge Columns, PEER Report 1998/01, PEER, University of California, Berkeley, CA.
  25. Ludovico M.D., Verderame G.M. and Prota A. (2009), "Experimental investigation on non-conforming full scale RC columns", XIII Convegno ANIDIS L Ingegneria Sismica in Italia (ANIDIS 2009), Bologna, Italy.
  26. Mander, J.B., Priestley, M.J.N. and Park, R. (1988), "Theoretical stress-strain model for confined concrete", J. Struct. Eng., 114(8), 1804-1826. https://doi.org/10.1061/(ASCE)0733-9445(1988)114:8(1804)
  27. Marefat, M.S., Masood, S., Shirazi, H., Rostamshirazi, R. and Khanmohammadi, M. (2009), "Cyclic response of concrete beams reinforced by plain bars", J. Earthq. Eng., 13(4), 463-481. https://doi.org/10.1080/13632460902837769
  28. Mehanny, S.S.F., Kuramoto, H. and Deierlein, G.G. (2001), "Stiffness modeling of reinforced concrete beam-columns for frame analysis", ACI Struct. J., 98(2), 215-225.
  29. Mirza, S.A. (1990), "Flexural stiffness of rectangular RC columns", ACI Struct. J., 87(4),425-435.
  30. Ozcan, O., Binici, B. and Ozcebe, G. (2008), "Improving seismic performance of deficient reinforced concrete columns using carbon fiber reinforced polymers", Eng. Struct., 30(6), 1632-1646. https://doi.org/10.1016/j.engstruct.2007.10.013
  31. Ozcan, O. (2009), "Improving ductility and shear capacity of reinforced concrete columns with Carbon Fiber Reinforced Polymer (CFRP)", PhD Dissertation, Middle East Tech. Univ., Turkey.
  32. Ozcan, O., Binici, B. and Ozcebe, G. (2010), "Seismic strengthening of rectangular reinforced concrete columns using fiber reinforced polymers", Eng. Struct., 32(4), 964-973. https://doi.org/10.1016/j.engstruct.2009.12.021
  33. Ozcan, O., Binici, B., Canbay, E. and Ozcebe, G. (2010), "Repair and strengthening of reinforced concrete columns with CFRPs", J. Reinf. Plast. Comp., 29(22), 3411-3424. https://doi.org/10.1177/0731684410376332
  34. Paulay, P. and Priestley, M.J.N. (1992), Seismic Design of Reinforced Concrete and Masonry Buildings, John Wiley & Sons, NY.
  35. Priestley, M.J.N. (2003), Myths and Fallacies in Earthquake Eng., Rev. 9th M.Milne Lect., Pavia, Italy.
  36. Sezen, H. (2002), "Seismic behavior and modeling of reinforced concrete building columns", PhD Thesis, Univ. of California, Berkeley.
  37. Sozen, M.A. (1974), "Hysteresis in structural elements", Appl. Mech. Earthq. Eng., 8, 63-98.
  38. Talaat, M.M. (2007), "Computational modeling of progressive collapse in reinforced concrete frame structures", PhD Dissertation, Univ. of California, Berkeley.
  39. Turkish Earthquake Code (TEC-07) (2007), Regulations on Structures Constructed in Disaster Regions, Ministry of Public Works and Settlement, Ankara.
  40. Verderame, G.M., Fabbracino, G. and Manfredi, G. (2008), "Seismic response of RC columns with smooth reinforcement, Part I: monotonic tests", Eng. Struct., 30(9), 2277-2288. https://doi.org/10.1016/j.engstruct.2008.01.025
  41. Verderame, G.M., Fabbracino, G. and Manfredi, G. (2008), "Seismic response of RC columns with smooth reinforcement, Part II: cyclic tests", Eng. Struct., 30(9), 2289-2300. https://doi.org/10.1016/j.engstruct.2008.01.024
  42. Xiao, Y. and Ma, R. (1997), "Seismic retrofit of RC circular columns using prefabricated composite jacketing", ASCE J. Struct. Eng., 123(10), 1357-1364. https://doi.org/10.1061/(ASCE)0733-9445(1997)123:10(1357)
  43. Yalcin, C., Kaya, O. and Sinangil, M. (2008), "Seismic retrofitting of RC columns having plain rebars using CFRP sheets for improved strength and ductility", Constr. Build. Mater., 22(3), 295-307. https://doi.org/10.1016/j.conbuildmat.2006.08.017
  44. Zuo, J. and Darwin, D. (2000), "Splice strength of conventional and high relative rib area bars in normal and high strength concrete", ACI Struct. J., 97(4), 630-641.

Cited by

  1. Rotation Capacities of RC Columns Reinforced with Plain Rebars pp.1559-808X, 2018, https://doi.org/10.1080/13632469.2018.1509809
  2. Seismic Performance Assessment of RC Buildings Reinforced with Plain Rebars vol.36, pp.2, 2014, https://doi.org/10.1061/(asce)cf.1943-5509.0001702