This review article provides general information about reinforced concrete corrosion and types of corrosion. The most dangerous consequence of corrosion processes in reinforced concrete is a decrease in the load-bearing capacity of the structure. Corrosion of reinforcing steel is one of the most common damages to reinforced concrete structures. The most dangerous type of rebar corrosion is chloride corrosion, since at a certain concentration of chlorides, the concrete immediately loses its protective properties in relation to the rebar, the corrosion develops locally and deep into the rod, leading to significant losses of its cross-section, often without visible damage to the concrete surface. Types of corrosion: physical corrosion, chemical corrosion, leaching corrosion, magnesian corrosion, carbon dioxide corrosion, sulphate corrosion, hydrogen sulfide corrosion, biological corrosion, electrochemical and electroosmotic corrosion, the destruction of cement stone. The article provides an overview of the mechanism of reinforcement corrosion, its initiation, progress and factors that expedite the process of reinforcement corrosion. Once the reinforcement corrosion is initiated, it shortens the service life of the structures by cracks initiation, propagation and subsequently spalling of the cover concrete due to expansion of corrosion steel. Corrosion of the embedded reinforcing steel is the most frequent cause for degradation.

The authors of the article investigate new design solutions for the restoration of damaged masonry vaults and arches. The article presents the results of experimental studies of the deformability of reinforced and unreinforced masonry arches on lime-sand solutions during normal operation with a fracture factor (horizontal and vertical movement of the support). During the study numerical and physical experiments were carried out. The article also presents the results of observations of the basement floor of the building of the Kazan Hotel on Bauman Street, Kazan, Russia. The study allowed authors to determine the deformation and crack formation of masonry arches. The experiment included a test of an unreinforced arch, until damage was obtained when a support movement occurred. At the second stage of the experiment, the damaged arch was strengthened by the developed method, and its further testing was carried out. The study allowed authors to determine the vertical displacement of the arch before and after amplification. According to the test results, one can make an assumption about the change in the deformability and destruction of the reinforced masonry arch. The reason for this may be a halt in the development of cracks that have appeared and a change in vertical displacements.

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An improved technique for determining the strength of reinforced beams with polymer composite reinforcement based on a nonlinear deformation model using a three-line diagram of concrete deformation under uniaxial compression with an elastic, elastic-plastic zone and a concrete softening zone is considered and proposed. The features of the strength analysis of beams with fiberglass reinforcement are revealed. The calculation method presented in this article allows us to minimize the use of empirical coefficients to determine the height of the compressed zone of concrete and at the same time does not lead to labor-intensive calculated dependencies. The method is based on the use of the Euler – Bernoulli beam theory and the use of physical stress-strain relations for concrete. This calculation method allows you to set accurately the height of the compressed zone of concrete, and accordingly the strength of the beam elements in the normal section. Good results of comparison with experimental data were obtained.

The purpose of the study is to analyze previously developed structural solutions of the “slab-column” unit under various modes of static and cyclic loading using various reinforcing elements and types of concrete, to compare methods for calculating the slab for punching at the fillet places with columns according to Russian, Belarusian, and European standards. Calculations at different standards give different results, which differ significantly from each other. The main objective of the study was to develop a methodology for calculating flat reinforced concrete slabs for punching using a frame-rod model of work and models of destruction of reinforced concrete in a compressive power flow. The significance of the results obtained for the construction industry lies in the fact that the results of theoretical studies are applicable to create a methodology that allows calculating the fracture from overcoming the concrete resistance to tearing, shear and crushing when forcing flat reinforced concrete slabs at the fillet places with the columns. Flat slab contribute to the maximum use of floor height, provide an effective location below the slab of utilities.