The effect of filling materials on the behaviour of filled steel tube composite beam

Abstract

This study is concerned with investigating the performance of filled steel tube composite beams, the composite beam consisting of a filled steel tube and reinforced concrete slab connected by perfobond connector. Six composite beams were tested; the main parameter in this investigation was the type of filling materials used to fill the steel tube. All specimens were simply supported, the specimens tested using a four-point load. The deflection at mid-span and slips were recorded with loads. All specimens failed by the flexural and the specimens show similar behaviour during the test, the first crack of the concrete slab appears in the final stages of loading. It is found that the highest ultimate strength of the composite beam obtained when using normal concrete as a filling material. The other filling material (wood, aggregate, and lightweight concrete) were less density and ultimate load. Wood is the best filling material as an alternative to normal concrete. All these filling material gives higher ultimate strength of the composite beam compared with a hollow steel tube composite beam. The test demonstrated that the gypsum is unuseful as a filling material.