Analysis of Formulas for Determining the Transverse Force Perceived by Concrete When Bending a Reinforced Concrete Element

Abstract

The normative methods for determining the transverse force perceived by concrete during bending of a reinforced concrete element are considered. It has been shown that the strength conditions of inclined sections proposed by SP 63.13330.2012,
formed taking into account the first theory of strength and experimental data, are empirical and do not meet the principle (postulate) of N. Bohr. A model of concrete fracture in inclined sections is proposed using the methods of classical solid mechanics, fracture mechanics (according to A. Griffith), and fractal geometry (according to B. Mandelbrot).
In the process of destruction, three limiting states are identified: the first is the formation of a defect at the microstructure level
of critical size d; the second is the formation of an inclined crack; the third is the destruction of concrete in a compressed zone.