Tensile Deformations of “Mild” Reinforcing Steels for Reinforced Concrete Structures

Reinforced concrete structures are widely used in all areas of modern construction, which is explained by their durability, the possibility of using local building materials, low consumption of steel, and a variety of forms. The increasing requirements for ensuring the reliability of reinforced concrete structures makes it necessary to improve the calculation of bent elements. The main difficulty of the calculation is that “mild” steels, like all real structural materials, are deformed under force loading non-equilibrium and non-linear, while the desired physical relationship “stress – deformation” is usually reflected by analytical dependencies of high degrees (5 and higher). The authors consider the nature of the “stress – deformation” curves taking into account the heterogeneity of the physical properties of various steel components, the elastic limits on the tensile curve, the nature of steel deformation, the transition sections of the experimental tensile curves of reinforcing bars from the elastic limits and proportionality to the yield point determined by the results of experimental data from various devices, and the expression of the secant modulus of deformation of mild” steels is developed, which allows not only to calculate accurately reinforced concrete bending elements, but it also allows getting the elastic coefficients of individual sections of reinforcing steel when they are stretched.