Corrosion of Steel Reinforcement in Hydrophobized Concrete Under the Influence of Aggressive Chloride-Containing Medium

The study of the reasons for shortening the period of concrete protection of steel reinforcement and the development of ways to increase its duration are the basis for increasing the durability of reinforced concrete products and structures. To increase the durability of reinforced concrete products, calcium stearate in an amount of 0.7 wt. % was introduced into the cement paste at the preparation stage to ensure volumetric hydrophobization. Corrosion studies of steel reinforcement in cement stone were carried out under the conditions of exposure to a 2% MgCl2 solution. Breaking of the passivity of reinforcement in cement stone without the addition of calcium stearate occurs after about 6 months of exposure to an aggressive environment, in hydrophobized cement stone after 9 months of liquid corrosion. The electrochemical behavior of steel reinforcement in conventional and hydrophobized concrete was evaluated using polarization measurements. The calculated corrosion rates of steel reinforcement in cement stone have small values, but over time aggressive particles will accumulate near the surface of the reinforcement, which will contribute to the intensive development of corrosion processes. Corrosion of reinforcement in cement concrete without the addition of a hydrophobizer proceeds 1.3 times faster than reinforcement in hydrophobized concrete. However, it takes much longer to reach the maximum concentration of chloride ions at the surface of steel reinforcement in concrete with a hydrophobizer, therefore, corrosion processes will begin to develop later.