Influence of Chloride-Containing Media on the Protective Properties of Concrete

Abstract

The main factor causing the destruction of reinforced concrete is the corrosion of steel reinforcement, about 80% of the damage is due to this phenomenon. Chloride-containing media are aggressive both to cement concrete and to steel reinforcement. Experimental studies of liquid corrosion of cement concretes in chloride-containing media were conducted: in 2% MgCl₂ solution and in hydrochloric acid solution with pH = 5. It is established that at the initial stage of concrete corrosion in liquid media, their strength increases due to the formation of corrosion products in the pores. The influence of the type of concrete coating on the electrochemical corrosion of steel reinforcement located in concrete is studied. In concretes containing hydrophobizing additives, the corrosion of steel reinforcement occurs much later compared to the reinforcement found in non-hydrophobized cement concretes. During 6 months of testing, changes in the surface potential of steel reinforcement in hydrophobized concretes exposed to media of various degrees of aggressiveness were not recorded. The studies and data obtained give an idea of the influence of various media on the development of the corrosion processes of reinforcement and concrete and serve as the basis for clarifying the features of corrosion and methods for its elimination in the system “steel reinforcement – concrete”.