Calculation of the strength of multilayer floor slabs supported on three sides

Abstract

The article considers the calculation of the ultimate rupture load of multilayer floor slabs supported on three sides (two short and one long). The calculation is carried out taking into account three fracture schemes: the first scheme consists of three main destructive cracks that converge at one point, forming an "envelope"; the second scheme consists of two main inclined cracks passing from the corners towards the non-supported side and not converging on the plate field; the third scheme consists of a horizontal crack forming trapezoid in combination with angular cracks, which is the case when testing prototypes. The reduction of a three-layer section to a single-layer section is carried out according to the elasticity modules of the concretes that make up the section. The value of the rupture load is determined from the condition of equilibrium of external and internal forces. The results of the VAT analysis of multilayer reinforced concrete structures according to the proposed schemes were carried out by the authors on the basis of static tests of prototypes of flat reinforced concrete three-layer slabs. The obtained research results allow us to determine rational parameters for the design of multilayer slab structures with reinforced concrete layers of various strength.