Experimental and theoretical study of the strength of plates for pressure

Introduction. The issues of strength and deformability of reinforced concrete floors during punching remain insufficiently studied at present, despite the numerous publications in the technical literature. This article presents the results of experimental studies of the punching shear strength of fragments of conjugation of flat reinforced concrete monolithic slabs with a column under static loading. The purpose of these studies was to obtain experimental data on the stress-strain state of a fragment of a monolithic floor during static punching and to develop a spatial model based on the finite element method with subsequent numerical studies. Materials and methods. Experimental studies were carried out on a test bench. The characteristics of prototypes are given: dimensions, reinforcement, class of concrete and reinforcement. A test setup is described. For the numerical simulation of the slab-column interface, the ATENA software package was used, which allows for physically and geometrically nonlinear calculations of reinforced concrete structures, taking into account the real work of the materials used to create experimental models. Results. Comparison of the results for the breaking load, obtained during the experiment, with the results of numerical modeling by the finite element method and with the results of calculations using the methods of SP 63.13330.2018 and Eurocode 2. The diagrams of the distribution of deformations in reinforcement and concrete, breaking loads and patterns of distribution of cracks in the samples are obtained. Conclusions. The analysis of experimental and numerical studies made it possible to formulate the conditions for the pun­ching shear strength of flat slabs with longitudinal reinforcement and to give recommendations on the strength calculation under central loading.