The Plastic Behaviour of Composite Floor Systems in Relation to Multi-Storey Structures

Abstract

The work described in this thesis is concerned with the ultimate load behaviour of beam and slab floor systems, using steel beams and reinforced concrete slabs, Three main areas of study have been attempted within this general heading. Firstly, upper-bound plastic solutions were developed for floor systems, involving either non-composite design or composite design, These solutions were then used to design model beam and slab floor systems to fail by a pre-chosen mode, The agreement with experimental results confirmed the validity of the theoretical methods for both composite and non-composite design. Subsequently, five different sets of assumption on degree of composite action were taken, These were shown theoretically to give very significant differences in structural and economic efficiency, An experimental program was then used to establish which of the five sets of theoretical assumptions on degree of composite action gave the best agreement with the results of the experiments. Finally, a theoretical investigation was made of the advantage to be gained by including the composite floor system, rather than just the steel beams, when designing a multi-storey steel frame, The inclusion of the floor system was found to be particularly significant as the stiffness of the beam or floor system plays a significant part in the stability criteria for a multi-storey building,