Behaviour of multi-span composite steel-concrete beams subjected to combined flexure and torsion

This paper utilised experimental tests to provide further information and conclusions regarding composite steel-concrete beam specimens by examining the behaviour of multi-span composite steel-concrete beams which are subjected to combined actions of torsion and flexure for both full and partial shear connection and comparing the disparity in the varying degrees of shear connection. Generally, it was found that in the presence of torsion, there is no increase in the flexural capacity of a multi-span composite steel-concrete beam regardless of the degree of shear connection. Furthermore, there was no increase in the torsional capacity when flexure was present. In regards to shear connection, partial shear connection multi-span composite steel concrete beam specimens attained nearly the same capacities in terms of both flexure and torsion as the full shear connection multi-span composite steel-concrete beam specimens. Additionally, it was discovered that the multi-span composite steel-concrete beam specimens achieved almost double the flexural capacities of similar single span composite steel-concrete beams. However, in terms of torsional capacity, there is a larger difference between multi-span composite steel-concrete beam specimens and single span composite steel-concrete beam specimens with multi-span composite steel-concrete beam specimens achieving more than three times the capacities of the single span specimens in certain cases.