Assessment of the flexural continuity of predalle concrete slabs through structural steel beam shelf angle systems

Abstract

Shallow floor construction systems are nowadays one of the most popular structural designer's choice in steel framed structural systems due to their benefits of reducing the structural floor depth. However, the concept of achieving flexural continuity in slim floor construction has not yet been resolved. It is therefore, the aim of this dissertation to be able to utilise the benefits of continuity in slim floor slab design with the objective of reducing the thickness of slabs, and thus having a consequent reduction in floor loads and savings in the sizing of beams, columns and foundations. Previous work has already been made regarding this concept, however from the results obtained, this system failed in a brittle manner. This study therefore continues on such research, with the aim of achieving continuity in slim floor construction which exhibits ductile behaviour. In light of this, a total of ten specimens were designed and produced, with additions introduced in several groups of specimens, to determine whether any improvement with respect to behaviour is achieved and to be able to compare and determine which additions showed potential effective benefits. These specimens were then tested under a three-point loading arrangement to achieve the bending moments required to test flexural continuity across the steel beam web. During the testing process the load applied, vertical deflection, and strains were measured and recorded for every specimen. The results obtained indicated that the most effective sample which achieved flexural continuity with significant increase in strength and demonstrated ductile bending behaviour, was the sample which contained both vertical shear reinforcement and compression reinforcement incorporated in it. It was therefore concluded from this study, that the inclusion of compression and vertical shear reinforcement provided the most effective results with respect to ductile bending behaviour however, horizontal shear reinforcement provided no benefit with respect lo the composite slab and steel beam joint.