COMPARISON OF DIAGRAMS OF CONCRETE DEFORMATION FROM THE POINT OF VIEW OF SPECIFIC POTENTIAL ENERGY COSTS

Abstract

One of the most important problems in the theory of calculations of building structures made of reinforced concrete remains the task of fully studying and describing the process of the nonlinear nature of the deformation of concrete under load. Solving this problem opens up real possibilities for building a model of the stress-strain state of a reinforced concrete element, which will fully and objectively reproduce the picture of its operation at any stage of loading.

The deformation calculation method is based on the use of real deformation diagrams of concrete and reinforcement. At the same time, the criterion for the appearance of the limit state in the cross-section is the achievement of the limit values by the deformations of the compressed concrete.

Currently, the deformation calculation method (or nonlinear deformation model) of a reinforced concrete cross-section has firmly entered the use of design engineers due to its relative simplicity, versatility and the ability to independently automate calculations using it.

According to current regulations, the elements of concrete and reinforced concrete structures are calculated by strength based on a nonlinear deformation model. At the same time, both valid and simplified diagrams of concrete deformation can be used in strength calculations of reinforced concrete elements according to various standards.

From the point of view of strength calculations, it is convenient to describe the work of concrete under load with «s–e» diagrams in uniaxial tension and compression. At the same time, the final result of the strength calculation depends on the form of the corresponding diagram and the mathematical expression on the basis of which it is built, and other factors.

The most universal criterion for evaluating the resistance of concrete to force impact can be taken as energy consumption for deformation and destruction of the material. This criterion is calculated through the definite integral of the function . The results of the value of the bearing capacity of the reinforced concrete section depends on the shape of the corresponding diagram.