Effects of partial shear connection on composite steel-concrete beam behaviour under combined flexure and torsion

Acceptable methods of ultimate load analysis and design for composite steel-concrete beams are readily available. However for the case when a beam is curved in plan under vertical loading or for edge beam, it is subjected to combined flexure and torsion. Previous studies have shown that current methods of assessing flexure-torsion interaction equations for reinforced concrete beams cannot be directly applied to composite beams. In addition, partial shear connection has been commonly used in floor systems in composite construction. Therefore, this paper outlines the behaviour of six straight simply-supported composite beams under combined flexure and torsion. Each set of three test specimens were designed with full and partial shear connection respectively. The experimental results support the view that there is an increase in the torsional moment capacity in the presence of flexure for composite beams. However, the flexural capacity does not increase in the presence of torsional moment. Flexure-torsion interaction diagrams were plotted to be compared with other diagrams as well