The New Approach and Requests in Designing the Composite Steel and Concrete Grid Structures

The study of the composite steel and concrete grid structures is considered and updated. The structures are made of separate spatial units. The units have the shape of a pyramid, where a reinforced concrete slab is at the base, and the role of the pyramid's ribs is played by steel rods made of hollow tubes of a circular cross-section. The connection of a reinforced concrete slab and steel rods to each other is carried out during concreting the slab by putting the rods into the slab solid. Such structures were fairly well studied by the authors in early works, but still, the structures are not devoid of drawbacks. First of all, the disadvantage of the structures is the way of connecting the units into a roof structure. The units connecting are provided via bolted flange connections. As the practice of introducing such structures into the real sector of construction has shown, flange bolted joints in such structures are not the best solution. Since they are difficult to manufacture, they complicate the structure, make the structure vulnerable, and quite significantly increase the weight of the structure. In this regard, the current investigation is devoted to the study of such structures in the context of the search for a way that helps to avoid flange connections and indirectly increase the reliability of structures and reduce their weight.