Diagnostika korozního napadení oceli v betonu

Abstract

During service life time of reinforced concrete construction is rebar in concrete exposed to many factorss, which increase the primary low corrosion aggressiveness of the environment and leads to corrosion attack. The development of corrosion attack of mild steel rebars is one of the causes of the most serious failures of operational reliability of reinforced concrete structures and most often limits their total service life. The corrosion processes of the steel of the embedded reinforcement are influenced by many factors. With the increasing operating time of the structure, these effects become more and more intense and often also amplify other negative factors, such as some design and design defects. The transport and infrastructure sectors in various countries are associated with significantly higher corrosion costs than other economic sectors. The way to reduce of costs is continually improve of non-destructive methods for detecting corrosion attack of embedded steel in concrete. Based on data from the literature, an overview of the current knowledge of the corrosion attack of embedded reinforcement and its non-destructive monitoring is prepared. The characteristics of the corrosive environment of concrete (pore solution) are described, the influence of initiation factors of the corrosion process is described, ie the influence of cement, aggregates and water, chlorides, carbonation, stray currents and positive factors – use of inhibitors and careful maintenance of reinforced concrete. Methods used to monitoring of corrosion attack and their advantages or disadvantages for use in operating conditions are described. Another part of thesis is devoted to the possibilities of improving the interpretation of data measured by the half-cell method and factors that are important for correct measurement procedures. An overview of recommendations for the application of the method of measuring half-cell potentials in practice was drawn up and the direction of further research into the conditions of corrosion attack initiation in alkaline environment in the presence of chlorides was outlined.