Theoretical and experimental studies of steel-reinforced concrete structures that have bent steel sections

Introduction. The main problem of the behaviour of composite structures is the method of combining materials that have different qualitative characteristics. In the case of collaboration of concrete and steel, the load-bearing capacity of the structure increases, while the consumption of materials decreases. Thanks to these advantages, the use of steel-reinforced concrete floor slabs is more and more popular. A theoretical study has made it possible to assess the load-bearing capacity of a floor slab. Materials and methods. A theoretical analysis of the bearing capacity of a composite floor slab is proposed. Four samples, that consisted of a galvanized steel plate embedded in a concrete parallelepiped, were used to conduct experimental studies. Rectangular plates had different types of surface: smooth, perforated with holes, with stamped “pins”, and with bolted connecting elements. Results. The analysis of the bearing capacity of a steel-reinforced concrete floor slab, that has bent profiles, was performed. The deformation dependences of the experimental samples were obtained; the graphs describing the dependence of displacement on the load for the four types of surfaces are made; the values of the load at which samples fail, and the dependence of the breaking load on the structure of the embedded part of the plate are identified. Conclusions. The analysis of the bearing capacity of a steel-reinforced concrete floor slab, that has bent steel sections, has shown that the use of light steel thin-walled beams is possible if spans correspond to residential and public buildings. The results of the experiment allow to conclude that the collaboration of concrete and a steel beam is possible without any additional elements in the composite structures that have bent sections. Adhesive properties of materials and the stamped part of the section can take the shear forces arising in structures.