Behaviour of the Tubular Columns Filled by Concrete Subjected to Buckling Compression

Abstract

The paper deals with the possibility of using high strength concrete in case of steel tubular columns filled by concrete subjected to compression. Especially the effect of the concrete strength on buckling resistance of the composite columns is investigated. The focus of the resolution is the experimental verification of working whereas the behaviour of the compressed tubes filled by high strength concrete is compared with that filled by normal strength concrete. The combination of circular tubes and high-strength concrete seems to be one of the most effective ways to use the high-strength concrete because of eliminating the lack of tensile strength. In the case of high-strength concrete the tensile strength is growing not in proportion to compressive strength, but more slowly. This means that a large increase in compressive strength is not accompanied by a corresponding increase in tensile and shear strength in comparison with normal strength concrete. Confinement of concrete core by steel shell leads to prevention of shear or tension failure whereas high compressive strength can be activated.This paper includes interpretation and evaluation of the results of experimental analysis. A part of the paper is introduction of the results of numerical model which has been developed in order to ensure consistency of the output of the numerical calculation and the data obtained at the test specimens.