CALCULATED DETERMINATION OF CHARACTERISTICS OF SHRINKAGE AND TOUCH OF CONCRETE

Abstract

Raising of problem. When calculating concrete and reinforced concrete structures, it is necessary to take into account the shrinkage and creep of concrete, which are not a minor factor. Because during long-term operation of such structures, these factors can significantly change the stress-strain state of structures over time and lead to the appearance of extreme deformations, cracks and their destruction. Therefore, when designing concrete and reinforced concrete structures, it is necessary to take into account the influence of shrinkage and creep of concrete. To do this, the designer must have the parameters included in the equations and calculation formulas. There are numerous of parameters and they are determined experimentally and depend on many factors. However, the designer must have these parameters even when there is no experimental data on the material and design, but when the material (strength class) has already been specified. Thus, there is a need to calculate the required parameters based on the main factors. The simplest computational determination of the creep characteristics of concrete is possible using the theory of aging at a constant modulus of elasticity of concrete, which partially takes into account the aftereffect (reversibility) of creep deformations. We will call such a theory the technical theory of aging and it operates with the smallest number of parameters (2 in total) and only one creep curve at the initial load age t0, and not with a family of these curves. Purpose. Development of theoretical solutions and practical methods for taking into account the design characteristics of shrinkage and creep of concrete in building design standards. Conclusion. The work resulted in the development of a convenient for practical use linear theory of concrete creep − the technical theory of aging and the development on its basis of theoretical solutions and practical methods for taking into account the calculated characteristics of shrinkage and creep of concrete in building design standards.