Optimum design of steel and concrete composite building structures

Steel and concrete composite structures are a structurally efficient, fast-to-erect and economically competitive solution for buildings. In this paper, the general modelling principles and design criteria for these structures are discussed. A parametric study dealing with typical office buildings braced horizontally and with regularly spaced columns is presented. In a first step, two common structural arrangements for the girders are compared for material economy. In a second step, and for the most convenient girder arrangement, the type of column layout, the spans and the structural steel grade are varied. The most representative internal forces and the steel weight of the main and secondary girders, of the columns, and of the whole structure are presented and discussed, to access the most convenient choice of parameters for an optimal structural design. Mathematical functions aimed at predicting the steel weight for a tentative span and similar layout are also presented. Finally, these functions are applied to a real building design and the results are compared to verify their accuracy.