Strength and Behavior of Composite Steel Tube Concrete Beam

Abstract

This paper deals with an experimental and analytical study to investigate the structural behavior of simply supported composite steel-concrete tube beams with external load, in which a concrete is connected together with steel circular tube by means of headed stud shear connectors. This type of structure not only inherits the characteristics of traditional concrete tube beams but also possesses its own unique attributes, such as advantageous mechanical performances, facilitating construction process, and low maintenance cost etc. Seven composite steel-concrete tube beams were tested to their ultimate strength. The effect of thickness and diameter of steel tube on structural performance of composite beams were investigated. Experimental results proved that, due to increase tube thickness from (2mm to 6mm), the strength increased by (63.5%) and the ultimate deflection increased by (75%). While the strength increased by (190.3%) and the ultimate deflection decreased by (47%) when the tube diameter increased from (75mm to 200mm). Based on the experimental results, a theoretical model for predicating the flexural resistance of composite steel- concrete tube beam is proposed. ANSYS computer program (version 13.0) has been used. The calculated flexural resistance based on proposed model has a high level of accuracy when compared with test results.