Steel and Composite Structures

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Experimental study on circular CFST short columns with intermittently welded stiffeners

  • Thomas, Job (Department of Civil Engineering, School of Engineering, Cochin University of Science & Technology) ;
  • Sandeep, T.N. (Department of Civil Engineering, School of Engineering, Cochin University of Science & Technology)
  • Received : 2017.12.29
  • Accepted : 2018.11.28
  • Published : 2018.12.10
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Abstract

This paper deals with the experimental study on strength the strength and deformation characteristics of short circular Concrete Filled Steel Tube (CFST) columns. Effect of vertical stiffeners on the behavior of the column is studied under axial compressive loading. Intermittently welded vertical stiffeners are used to strengthen the tubes. Stiffeners are attached to the inner surface of tube by welding through pre drilled holes on the tube. The variable of the study is the spacing of the weld between stiffeners and circular tube. A total of 5 specimens with different weld spacing (60 mm, 75 mm, 100 mm, 150 mm and 350 mm) were prepared and tested. Short CFST columns of height 350 mm, outer tube diameter of 165 mm and thickness of 4.5 mm were used in the study. Concrete of cube compressive strength $41N/mm^2$ and steel tubes with yield strength $310N/mm^2$ are adopted. The test results indicate that the strength and deformation of the circular CFST column is found to be significantly influenced by the weld spacing. The ultimate axial load carrying capacity was found to increase by 11% when the spacing of weld is reduced from 350 mm to 60 mm. The vertical stiffeners are found to effective in enhancing the initial stiffness and ductility of CFST columns. The prediction models were developed for strength and deformation of CFST columns. The prediction is found to be in good agreement with the corresponding test data.

Keywords

References

  1. ACI-318 (2011), Building Code Requirements for Structural Concrete and Commentary, American Concrete Institute.
  2. Che, Y., Wang, Q.L. and Shao, Y.B. (2012), "Compressive performances of the concrete filled circular CFRP-steel tube (CCFRP- CFST)", Adv. Steel Constr., 8(4), 311-338.
  3. Chen, S.M. and Zhang, H.F. (2012), "Numerical analysis of the axially loaded concrete filled steel tube columns with debonding separation at the steel concrete interface", Steel Compos. Struct., Int. J., 13(3), 277-293. https://doi.org/10.12989/scs.2012.13.3.277
  4. Dabaon, M.A., El-Boghdadi, M.H. and Hassanein, M.F. (2009), "Experimental investigation on concrete filled stainless steel stiffened tubular stub columns", Eng. Struct., 31(2), 300-307. https://doi.org/10.1016/j.engstruct.2008.08.017
  5. Dong, C.X. and Ho, J.C.M. (2012), "Uni-axial behaviour of normal-strength CFDST columns with external steel rings", Steel Compos. Struct., Int. J., 13(6), 587-606. https://doi.org/10.12989/scs.2012.13.6.587
  6. Eurocode 4, BS EN 1994-1-1 (2004), Design of composite steel and concrete structures. Part 1-1: General rules and rules for buildings, British Standards Institution.
  7. Han, L.H. (2002), "Tests on stub columns of concrete-filled RHS sections", J. Constr. Steel Res., 58(3), 353-372. https://doi.org/10.1016/S0143-974X(01)00059-1
  8. Han, L.H., Zhao, X.L. and Tao, Z. (2001), "Tests and mechanics model of concrete-filled SHS stub columns, columns and beam-columns", Steel Compos. Struct., Int. J., 1(1), 51-74. https://doi.org/10.12989/scs.2001.1.1.051
  9. Ho, J.C.M. and Lai, M.H. (2013), "Behavior of uni-axially loaded CFST columns confined by tie bars", J. Constr. Steel Res., 83, 37-50. https://doi.org/10.1016/j.jcsr.2012.12.014
  10. Hu, Y.M., Yu, T. and Teng, J.G. (2011), "FRP-confined circular concrete-filled thin steel tubes under axial compression", ASCE, J. Compos. Const., 15(5), 850-860. https://doi.org/10.1061/(ASCE)CC.1943-5614.0000217
  11. Lai, M.H. and Ho, J.C.M. (2014), "Confinement effect of ring confined concrete filled steel tube columns under uni-axial load", Eng. Struct., 67, 123-141. https://doi.org/10.1016/j.engstruct.2014.02.013
  12. Lai, M.H. and Ho, J.C.M. (2015a), "Axial strengthening of thin-walled concrete filled steel tube columns by circular steel jackets", Thin-Wall. Struct., 97, 11-21. https://doi.org/10.1016/j.tws.2015.09.002
  13. Lai, M.H. and Ho, J.C.M. (2015b), "Effect of continuous spirals on uni-axial strength and ductility of CFST columns", J. Constr. Steel Res., 104, 235-249. https://doi.org/10.1016/j.jcsr.2014.10.007
  14. Li, G., Yang, Z., Lang, Y. and Fang, C. (2016), "Behavior of CFST columns with inner CFRP tube under biaxial eccentric loading", Steel Compos. Struct., Int. J., 22(6), 1487-1505. https://doi.org/10.12989/scs.2016.22.6.1487
  15. Park, J.W. and Choi, S.M. (2013), "Structural behavior of CFRP strengthened concrete-filled steel tubes columns under axial compression loads", Steel Compos. Struct., Int. J., 14(1), 453-472. https://doi.org/10.12989/scs.2013.14.5.453
  16. Park, J.W., Hong, Y.K., Hong, G.S., Kim, J.H. and Choi, S.M. (2011), "Design Formulas of Concrete filled circular steel tubes reinforced by carbon fiber reinforced plastic sheets", Procedia Eng., 14, 2916-2922. https://doi.org/10.1016/j.proeng.2011.07.367
  17. Patel, V.I., Uy, B., Prajwal, K.A. and Aslani, F. (2016), "Confined concrete model of circular, elliptical and octagonal CFST short columns", Steel Compos. Struct., Int. J., 22(3), 497-520. https://doi.org/10.12989/scs.2016.22.3.497
  18. Petrus, C., Hamida, H.A., Ibrahim, A. and Parke, G. (2010), "Experimental behavior of concrete filled thin walled steel tubes with tab stiffeners", J. Constr. Steel Res., 66(7), 915-922. https://doi.org/10.1016/j.jcsr.2010.02.006
  19. Prabhu, G.G. and Sundarraja, M.C. (2013), "Behavior of concrete filled steel tubular (CFST) short columns externally reinforced using CFRP strips composite", J. Constr. and Build. Mater., 47, 1362-1371. https://doi.org/10.1016/j.conbuildmat.2013.06.038
  20. Prabhu, G., Sundarraja, M.C. and Kim, Y.Y. (2015), "Compressive behavior of circular CFST columns externally reinforced using CFRP composites", Thin-Wall. Struct., 87, 139-148. https://doi.org/10.1016/j.tws.2014.11.005
  21. Schneider, S.P. (1998), "Axially loaded concrete filled steel tubes", ASCE J. Struct. Eng., 124(10), 1125-1138. https://doi.org/10.1061/(ASCE)0733-9445(1998)124:10(1125)
  22. Sulong, N.H.R. and Shafigh, P. (2016), "Pitch spacing effect on the axial compressive behavior of spirally reinforced concrete-filled steel tube (SRCFT)", Thin-Wall. Struct., 100, 213-223. https://doi.org/10.1016/j.tws.2015.12.011
  23. Tao, Z., Han, L.H. and Wang, D.Y. (2007a), "Experimental behaviour of concrete-filled stiffened thin-walled steel tubular columns", Thin-Wall. Struct., 45(5), 517-527. https://doi.org/10.1016/j.tws.2007.04.003
  24. Tao, Z., Han, L.H. and Zhuang, J.P. (2007b), "Axial loading behavior of CFRP strengthened concrete filled steel tubular stub columns", Adv. Struct. Eng., 10(1), 37-46. https://doi.org/10.1260/136943307780150814
  25. Tao, Z., Han, L.H. and Wang, D.Y. (2008), "Strength and ductility of stiffened thin-walled hollow steel structural stub columns filled with concrete", Thin-Wall. Struct., 46(10), 1113-1128. https://doi.org/10.1016/j.tws.2008.01.007
  26. Tao, Z., Uy, B., Han, L.H. and Wang, Z.B. (2009), "Analysis and design of concrete-filled stiffened thin-walled steel tubular Columns under axial compression", Thin-Wall. Struct., 47(12), 1544-1556. https://doi.org/10.1016/j.tws.2009.05.006
  27. Tao, Z., Song, T.Y., Uy, B. and Han, L.H. (2016), "Bond behavior in concrete-filled steel tubes", J. Constr. Steel Res., 120, 81-93. https://doi.org/10.1016/j.jcsr.2015.12.030
  28. Uy, B. (2000), "Strength of concrete-filled steel box columns incorporating local buckling", J. Struct. Eng. ASCE, 126(3), 341-352. https://doi.org/10.1061/(ASCE)0733-9445(2000)126:3(341)
  29. Wang, Q.L. and Shao, Y. (2013), "Compressive performances of concrete filled Square CFRP-Steel Tubes (S-CFRP-CFST)", Steel Compos. Struct., Int. J., 16(5), 455-480.
  30. Wang, Q.L. and Shao, Y.B. (2015), "Flexural performance of circular concrete filled CFRP-steel tubes", Adv. Steel Constr., 11(2), 127-149.
  31. Wang, Q.L., Guan, C.W. and Zhao, Y.H. (2004), "Theoretical Analysis about Concentrically Compressed Concrete Filled Hollow CFRP-Steel Stub Columns with Circular Crosssection", Proceeding of the 2nd International Conference on Steel and Composite Structures, Seoul, Korea, pp. 684-695.
  32. Wang, Z.B., Tao, Z. and Yu, Q. (2017), "Axial compressive behavior of concrete filled double tube stub columns with stiffeners", Thin-Wall. Struct., 120, 91-104. https://doi.org/10.1016/j.tws.2017.08.025
  33. Xiao, Y., He, W. and Choi, K. (2005), "Confined concrete-filled tubular columns", J. Struct. Eng., ASCE, 131(3), 488-497. https://doi.org/10.1061/(ASCE)0733-9445(2005)131:3(488)
  34. Zhang, J., Denavit, M.D., Hajjar, J.F. and Lu, X. (2012), "Bond behavior of concrete-filled steel tube (CFT) structures", Eng. J.-Am. Inst. Steel Constr., 49(4), 169-185.
  35. Zhang, Y., Yu, C.J., Fu, G.Y., Chen, B., Zhao, S.X. and Li, S.P. (2016), "Study on rectangular concrete-filled steel tubes with unequal wall thickness", Steel Compos. Struct., Int. J., 22(5), 1073-1084. https://doi.org/10.12989/scs.2016.22.5.1073
  36. Zhong, S.T. (2006), "Application and research achievement of concrete filled steel tubular (CFST) structures in China", Proceeding of the 8th International Conference on Steel-Concrete Composite and Hybrid Structures, Harbin, China, August.
  37. Zhu, A., Zhang, X., Zhua, H., Zhu, J. and Lu, Y. (2017), "Experimental study of concrete filled cold-formed steel tubular stub columns", J. Constr. Steel Res., 134, 17-27. https://doi.org/10.1016/j.jcsr.2017.03.003

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