An experimental study on elliptical concrete filled columns under axial compression

This paper presents the experimental results and observation of elliptical concrete filled tube (CFT) columns subjected to axial compressive load. A total of twenty-six elliptical CFT specimens including both stub and slender composite columns are tested to failure to investigate the axial compressive behaviour. Various column lengths, sectional sizes and infill concrete strength are used to quantify the influence of member geometry and constituent material properties on the structural behaviour of elliptical CFT columns. As there is no design guidance currently available in any Code of Practice, this study provides a review of the current design rules for concrete filled circular hollow sections in Eurocode 4 (EC4). New equations based on the Eurocode 4 provisions for concrete filled circular hollow sections were proposed and used to predict the capacities of elliptical CFT columns. •Structural behaviour of concrete filled elliptical composite columns.•Experimental studies on concrete filled elliptical composite columns.•Parameters affect the behaviour of concrete filled elliptical composite columns.•Proposed equation to evaluate the axial capacity of elliptical composite columns.