ULTIMATE BEHAVIOUR OF COMPOSITE STEEL-CONCRETE FLOOR MEMBERS

Composite floor systems are a well-established form of construction used for buildings throughout the world. They combine the advantages of two flooring systems that are commonly used, i.e. composite slabs in steel structures and post-tensioned composite slabs in concrete structures. The uniqueness of composite slabs rests on the ability of the profiled steel sheeting to act as permanent formwork and, once the concrete has hardened, as external reinforcement. This paper presents the experimental results of a series of tests aimed at the development of an effective composite thin-walled beam for building floor applications. With this approach the composite beam is formed by a thin-walled section, here considered as being either a C-section or a combined steel section, on which the concrete is cast and it is assumed to support the composite floor slab. The vision at the basis of this approach is to develop a composite thin-walled floor system that does not require hot-rolled members or prestressing. Different typologies of shear connection have been considered and their performance has been discussed based on the reported experimental results.