ANALYSIS OF THE EFFICIENCY OF MIGRATIVE CORROSION INHIBITORS (MCI) USAGE IN ORDER TO INCREASE THE EXPLOITATION DURATION OF REINFORCED CONCRETE
Authors:   Chernihiv Polytechnic National University, Bolotov Gennady , Tsybulya Serhii ,   Chernihiv Polytechnic National University, Bolotov Maksym ,   Chernihiv Polytechnic National University, Prybytko Iryna ,   Chernihiv Polytechnic National University, Yushchenko Svitlana ,   Chernihiv Polytechnic National University
Published: August 2022

Currently, concrete and reinforced concrete structures are an indispensable component of any construction. However, during operation due to the active influence of aggressive components of the atmosphere and the environment, there is a destruction of the protective layer of concrete and corrosion of metal reinforcement.The porous structure of cement stone, which is the basis of concrete, determines the degree of its hydration and, accord-ingly, penetration into it together with moisture aggressive components of the environment (various chlorides, sulfates, carbon dioxide, etc.). The latter leads to a change in the pH of the pore fluid and the development of low destructive processes in the structure of the concrete and metal reinforcement.The detailed analysis of the situation showed that the most favorable conditions, in terms of complete coverage in scien-tific journals, have developed around primary corrosion protection of reinforced concrete structures, which consists in the use of corrosion inhibitors (substances based on various amino compounds, salts of benzoic acids and nitrites of benzoate compo-sitions) at the stage of manufacturing reinforced concrete structures and products from them. The secondary protection of reinforced concrete structures that have been in operation for some time with the use of migrating inhibitor mixtures with good passivation ability and diffusion permeability is less studied, but very relevant.However, to date, there is still no systematic material on the mechanism of their protective action and the effective ratio of molar concentrations of their individual components despite the large number of publications on thedevelopment of migrat-ing corrosion inhibitors as corrosion protection of reinforcing elements of reinforced concrete structures,.In this regard, the purpose of this work is to determine the mechanism for ensuring effective corrosion resistance of metal elements of reinforced concrete structures with the use of migrating corrosion inhibitors.It is shown that the effectiveness of migrating corrosion inhibitors will be determined not only by the nature of its com-ponents, but also by the ratio of concentrations of its passivators of anodic and cathodic reactions, as well as the adsorption component. Monoethanolamine and triethanolamine have been found to be typical surfactants with low surface tension with a satisfactory ability to passivate cathodic reactions, while NaNO2 serves as a passivator for the anodic reaction of steel ioni-zation. The results show that the most effective anticorrosive effect is provided by mixtures with equal ratio of concentrations of adsorption and corrosion inhibiting components (15TEA + 15NaNO2 and 15MEA + 15NaNO2, respectively).Thus, research in the field of corrosion protection of reinforced concrete structures that have been in operation for some time has identified promising ways to develop migratory corrosion inhibitors, mainly related to the creation of synergistic composite compounds that will contain adsorption and passivation components. The effectiveness of inhibitory compositions, which include surfactants based on amine-type compounds, which in combination with sodium nitrites are able to penetrate into the pores of cement stone, reaching the metal reinforcement to inhibit both existing corrosion centers and prevent its occurrence in the future.