Behaviour of concrete filled steel square-tube stub column with steel-fiber reinforced high strength concrete

Abstract

The paper presents an experimental study on the behavior of axial loaded concrete-filled steel square-tube stub columns with high strength fiber reinforced concrete until failure. Four specimens were tested to investigate the effect of high strength concrete on the load carrying capacity of the concrete-filled steel square-tube stub columns. The effect of the presence of steel fiber in high strength concrete which filled in the steel tube was also investigated. The main parameters in the tests were: (1) the strength of concrete (30 Mpa and 100 Mpa), and (2) the use of reinforcing steel fiber in concrete (plain high strength concrete and steel fiber high strength concrete). The main purpose of these tests were three-step: (1) to describe a series of tests on composite stub columns, (2) to analyze the influence of several parameters, and (3) to compare the accuracy of the predictions by using the specifications in the code (ACI and EC4 etc.) for the design of high-strength composite columns. Experimental results indicate that the high strength of concrete and use of steel-fiber in concrete had significant influence on both the axial compressive load capacity and the ductile of the steel square-tube stub columns.