Experimental and numerical study on the structural behaviour of HST, RCC and CFST stub columns under pure axial compression

摘要

The use of hollow steel tubes (HST) as structural members is gaining in popularity due to their excellent properties regarding loading in compression, torsion and bending in all directions. Also, concrete-filled steel tubes (CFST) as compression members is widely used in construction industries due to the enhanced structural properties and economic advantages it provides. Compared to reinforced cement concrete (RCC) columns, CFST delivers the economies of an RCC column, resulting in significant economies in the overall structure of a building project. This paper presents a comparison study through an experimental and a finite element (FE) study of HST, CFST and RCC stub columns, for which there are currently little research data, which are the focus of the present study. A total of six specimens was tested under uniform axial compression, and the test observations are fully reported. The ultimate loads, load-displacement curves and failure modes from the tests were used for the validation of finite element (FE) models developed through FE software package Abaqus. Parametric finite element analyses were then performed. The results showed that filling the HST columns with concrete infill increases the strength capacity of the CFST columns by 2 times for slender sections and 2.9 and 2.4 times for stocky sections of square and circular sections, respectively. It was also observed that the strength capacity of the HST columns is about 0.45 times of RCC columns for slender sections and 1.35 times of RCC columns for stocky sections. And the strength capacity of the CFST columns is about on an average 1.3 times of RCC columns for slender sections of steel tubes and 2.8 times of RCC columns for stocky sections of steel tubes.