Experimental investigation on uniaxial compressive behaviour of square concrete filled steel tubular columns

Abstract

This paper presents a brief review of previous research work done on uniaxial compressive behavior of concrete filled steel tubular (CFT) columns and the resultsof experimental study conducted on twenty four number of cold-formed steel square sections filled with conventional concretes of grade M30 and M60 tested under uniaxial compression. The effect of length to breadth (L/B) ratio of square steel tubes and concrete core strength of CFTs on axial compressive strength and behavior of CFT columnswas studied. The experimental strength values were compared with predictions using Eurocode 4-1994, ACI 1999, AS 3600-1994, AISC-LRFD-1999, AISC 2005, GJB 4142-2000 an BS5400-1979 and from equation suggested by previous researcher. The effect of breadthtothickness (B/t) ratio, % steel area contribution and constraining factor on axial compressive strength was also examined. The results showed that the axial compressiv strength of CFTs increases due to confinement effect of concrete core on steel tubes andthe estimation of axial compressive strength using all methods is conservative. modified equation is also suggested.