Steel Concrete Composite Structures: Introduction

Composite structures of steel and concrete have become popular for a number of reasons. One reason is the fact that while concrete is excellent for compression, steel can carry large tensile stresses. In some sense any reinforced concrete girder is a composite structure, with re-bars in composite action with the concrete. Secondly, it is often necessary when constructing concrete structures to elevate the structure from ground level. Building composite structures is a means of circumventing this step. Indeed, the steel girders' ability to support formwork, reinforcement and the concrete deck has greatly contributed to the increasing popularity of composite structures, along with the reduced construction time compared to concrete structures. The time savings can mean that an office or flat can be taken in use earlier, bringing along better economy for the owner of the house. For the case of road bridges, every month of earlier opening of a bridge saves large money for the contractor, but also for the road user supposed to use the bridge, an effect that is often neglected when evaluating different structural solutions. A third advantage for composite structures in buildings is that a good fire protection can be achieved by concrete encased and concrete filled steel profiles. A theme of “Steel/Concrete Composite Structures” for this special issue of Structural Engineering International was initiated by the IABSE Working Commission 2, Steel, Timber and Composite Structures, in order to provide interesting reading for both researchers and designers across the world. This theme seemed to be attractive and received a huge number of abstracts. As it was not easy to select papers to accommodate in one issue, papers have been split into two issues. This issue of SEI includes papers from all around the world, covering different aspects such as developing composite action on non composite bridges, innovative floor deck systems and shear transfer between steel and concrete. The next issue (planned in May, 2010) presents composite bridges. Enjoy your reading!