Behaviour of composite steel-concrete T-shaped floor members cast on thin-walled steel elements

Abstract

Composite steel-concrete floors represent an efficient and economical solution for building applications. This form of construction is usually built by supporting the composite slabs on either steel members for steel framed construction or on reinforced or prestressed concrete band beams for concrete buildings. This thesis focuses on the development of a new composite floor arrangement entirely cast on thin-walled members and suitable for prefabricated construction. In particular, the aim of the thesis is to experimentally and numerically evaluate the structural performance of a potential T-shaped member cast on different configurations of thin-walled steel sections that can be integrated into the new composite floor arrangement. An experimental program consisting in six full-scale tests of composite floor members was conducted. The simply-supported composite T-shaped members were loaded and taken to failure and suitable instrumentation was installed to monitor the structural response during testing. Variations to the geometry of the steel profiles and the introduction of different degrees of shear connection between steel and concrete were tested. Components tests were carried out to determine the material properties of steel and concrete. Three-dimensional finite element models were implemented using ABAQUS. Data gathered from the experimental tests were used to define the geometry, boundary conditions, load arrangement and material properties of the models. The interface bond between the steel profile and the concrete was modelled using surface-based cohesive behaviour. A quasi-static analysis was performed and the numerical results were compared to experimental data. Good agreement was found between experimental and numerical load-deflection curves, thus confirming the accuracy of the proposed finite element modelling technique to predict the structural performance of the T-shaped composite members.