Strength Aspects of Concrete Filled Steel Tube Columns Through Design Codes

Abstract

Concrete filled steel tabular columns have increased huge significance in recent decades due to various structural benefits particularly in developed countries like china, Japan, U.S.A, Britain. In this paper analytical equations are put to understand the mechanism of concrete filled steel tube columns under axial loading for both greased and non-greased columns. For this purpose a comparison between designs codes such as Eurocode-4, ACI, AS, AISC-LRFD and CECS 28:90 has been made in evaluating the axial compressive strength of concrete filled steel tube columns. Eurocode-4 and CECS 28:90 incorporate confinement effect of concrete because of steel tube in evaluating the axial compressive strength of CFST columns. In Eurocode-4 the confinement effect is related to slenderness ratio (λ) and eccentricity (e) of the applied loading. In CECS 28:90 slenderness ratio and load eccentricity are taken as independent parameters governing the ultimate strength of concrete filled steel tube columns.