Behaviour and Design of Steel Square Hollow Sections Filled With High Strength Concrete

Abstract Concrete filled steel columns in multistorey buildings provide outstanding constructability and economy when compared to traditional steel sections. However, minimal research work and insufficient design guidance is available throughout the world, particularly concerning slender composite columns, although they are becoming increasingly used in multistorey buildings. This paper is concerned with the behaviour and design of high strength concrete filled slender box columns. A series of tests were carried out which included four slender composite columns, four slender steel columns, four short composite columns and additional material property tests. Two different steel hollow section types were chosen for this study together with two nominal concrete strengths of 60 and 80 MPa. The columns were tested under concentric axial force and the experimental results are presented and discussed. The results of these experiments, and of experiments conducted elsewhere, have been calibrated successfully with the numerical solution developed herein. Furthermore, comparisons have been carried out between predicted column strengths, as provided by Eurocode 4, BS5400, AS4100 and experimental test results. Recommendations are then made which may be amenable for the designs of slender composite columns when using high strength concrete.