Experimental testing of axial load capacity and stability of circular CFT columns

Abstract

The paper presents the experimental testing of the axial capacity and stability of short, moderately slender and slender circular CFT columns. For the purpose of sample testing a special set of hydraulic presses was constructed. In order to achieve centric loading of the load, a device calotte was used. With the help of the dosing and gauges placed at the top of the column, force and vertical displacement were measured continuously. The test was carried out on two short columns 0.5 m and 1.0 m long, and four moderately slender and slender columns with a length of 4.0 m with different boundary support conditions. In the short CFT columns the confinement effect was taken into account as well and loss of bearing capacity occurred due to the steel profile yield strength. In moderately slender and slender columns, the loss of stability occurs before the loss of the load capacity of the column. The obtained results of the experimental tests were then compared with the valid regulations: EC4, ACI, AS and AISC. It can be concluded that EC4 gives the most approximate results to the experiment.