ПРОБЛЕМА РАСКРЫТИЯ ТРЕЩИН В ЖЕЛЕЗОБЕТОНЕ

Abstract

The article discusses various aspects of the problem of assessing crack opening in reinforced concrete based on experimental data obtained in recent studies. The author proposed a classification of crack types, introduced a number of new hypotheses, established experimentally the effects of deformation of reinforced concrete in the crack zone. The principles formulated on their basis include schemes for the distribution of force flows between cracks, the concept of progressing main cracks and the deformation effect in reinforced concrete - a special two-console element in the local region near the crack banks, new generalized hypotheses, theorems and functionals about linear and angular deformations of the compressed and tensile zones of reinforced concrete element sections at all levels of elastic-plastic deformation. The proposed model of composite rods in the form of single strips for determining the stiffness of a section of reinforced concrete with intersecting cracks has made it possible to reduce the differential equations of the theory of composite rods by an order of magnitude when solving such problems. The connection is established and analytical dependences for displacements in the crack with opening and shear of the crack banks are given. The main vector of displacements and the angle of equidirectional forces in the reinforcement crossing the crack are determined. Calculated dependences for determining the level distances between cracks and crack opening widths are constructed. Within the framework of the general methodology of the considered problem of crack opening in reinforced concrete, using the formulated principles, a general combined numerical-analytical model of the structural mechanics of reinforced concrete is constructed, which takes into account the deformation effect in the crack modeled by a double cantilever element, the types of cracks, the spatial surface of strain distribution in the cross section with the crack and other experimentally determined features of the mechanics of reinforced concrete, cracks types, spatial surface of strain distribution in the cross-section with a crack and other experimentally determined features of reinforced concrete mechanics.