Influence of concrete strength and length/diameter on the axial capacity of CFT columns

Abstract This paper presents an experimental analysis of the confinement effects in steel–concrete composite columns regarding two parameters: concrete compressive strength and column slenderness. Sixteen concrete-filled steel tubular columns with circular cross section were tested under axial loading. The tested columns were filled by concrete with compressive strengths of 30, 60, 80, and 100 MPa, and had length/diameter ratios of 3, 5, 7, and 10. The experimental values of the columns’ ultimate load were compared to the predictions of 4 code provisions: the Brazilian Code NBR 8800:2008, Eurocode 4 (EN 1994-1-1:2004), AINSI/AISC 360:2005, and CAN/CSA S16-01:2001. According to the results, the load capacity of the composite columns increased with increasing concrete strength and decreased with increasing length/diameter ratio. In general, the code provisions were highly accurate in the prediction of column capacity. Among them, the Brazilian Code was the most conservative, while Eurocode 4 presented the values closest to the experimental results.

[1]  M. S. Kumar,et al.  Experimental and computational study of concrete filled steel tubular columns under axial loads , 2007 .

[2]  K. F. Chung,et al.  Composite column design to Eurocode 4 : based on DD ENV 1994-1-1: 1994 Eurocode 4: design of composite steel and concrete structures: part 1.1: general rules and rules for buildings , 1994 .

[3]  Brian Uy,et al.  Strength of slender concrete-filled steel box columns incorporating local buckling , 2002 .

[4]  S De Nardin,et al.  Axial load behaviour of concrete-filled steel tubular columns , 2007 .

[5]  Ahmad Husseini,et al.  Canadian standards association , 1993 .

[6]  Dennis Lam,et al.  Axial capacity of circular concrete-filled tube columns , 2004 .

[7]  Hiroyuki Nakahara,et al.  Behavior of centrally loaded concrete-filled steel-tube short columns , 2004 .

[8]  Mathias Johansson,et al.  The efficiency of passive confinement in CFT columns , 2002 .

[9]  Silvana De Nardin,et al.  An experimental study of connections between I-beams and concrete filled steel tubular columns , 2004 .

[10]  Mathias Johansson,et al.  Composite Action and Confinement Effects in Tubular Steel-Concrete Columns , 2002 .

[11]  Russell Q. Bridge,et al.  DESIGN OF CIRCULAR THIN-WALLED CONCRETE FILLED STEEL TUBES , 2000 .

[12]  N. J. Gardner,et al.  Structural Behavior of Concrete Filled Steel Tubes , 1967 .

[13]  Stephen P. Schneider,et al.  Axially Loaded Concrete-Filled Steel Tubes , 1998 .

[14]  F. E. Richart,et al.  A study of the failure of concrete under combined compressive stresses , 1928 .

[15]  Kent Gylltoft,et al.  Structural behavior of slender circular steel-concrete composite columns under various means of load application , 2001 .

[16]  N. E. Shanmugam,et al.  State of the art report on steel–concrete composite columns , 2001 .

[17]  Hanbin Ge,et al.  A CAPACITY PREDICTION PROCEDURE FOR CONCRETE-FILLED STEEL COLUMNS , 2001 .

[18]  M. Ala Saadeghvaziri,et al.  State of the Art of Concrete-Filled Steel Tubular Columns , 1997 .

[19]  Kamel Chaoui,et al.  An experimental behaviour of concrete-filled steel tubular columns , 2005 .