Resumen
In order to significantly reduce the weight of flat monolithic reinforced concrete floors, foundations, and other slab structures, construction operations have increasingly involved effective inserts as the separate articles made from relatively light and cheap materials that are placed in the midsection and left in the slabs after concreting.The inserts made from relatively light and cheap materials, with respect to concrete, have the strength and rigidity that are orders of magnitude less and are essentially used to form hollows. The inserts considered in this paper are prismatic. When the inserts are arranged in two directions, which is typical for most slab structures, we obtain the I-sections, whose calculation involved the analysis of the impact exerted by the general and local strength factors. Under such conditions, slabs must be calculated taking into consideration the biaxial work of concrete. In this paper, we have examined the stressed-strained state of the slab reinforced concrete structures with a bidirectional location of inserts and have substantiated the estimation schemes and calculation dependences related to the procedure for calculating the floors and other slab reinforced concrete structures with a bidirectional location of inserts. The paper gives an example of the calculation of a monolithic flooring slab based on the proposed procedure, which demonstrated that accounting for the biaxial stressed-strained state of concrete significantly increases the strength of concrete and the rigidity of a flooring slab, by 19.3 %.Thus, the consideration of biaxial compression of concrete is an important factor in the design of slab structures with a bidirectional arrangement of inserts