Corrosion and protection in reinforced concrete

Abstract

Corrosion and protection in reinforced concrete. Pulse cathodic protection: an improved cost-effective alternative. The aim of the research project was to study the possibilities for establishing a new or improved electrochemical method for corrosion prevention/protection for reinforced concrete. The main objective was to develop an alternative for the generally applied impressed current cathodic protection (CP), based on pulse technology. The new technique, denoted as pulse CP, was proved to achieve and address the following: Pulse CP is able to achieve sufficient protection of the steel reinforcement on one hand and minimize the known side effects of the conventional CP on the other. The principles of CP are electrochemical, hence proper execution lies in the thorough understanding of the electrochemical mechanisms which cause the damage itself i.e. the corrosion process. Therefore, the performance of the pulse CP technique was evaluated after a comprehensive research on electrochemical and miscrostructural phenomena, related at first to the corrosion process in reinforced concrete. Further, elucidating the fundamental basis of CP in terms of the influence of current flow on both the steel reinforcement and the bulk concrete matrix, was essential for the evaluation of any new or improved CP technique, which is the pulse CP in this study. The main research goal, in terms of establishing an improved CP technique, was achieved by implementing a multi-disciplinary approach i.e. correlating certain fields of science (electrochemistry and concrete materials science) and engineering applications (generally accepted criteria and standards for CP monitoring and control). Finally, the pulse cathodic protection was found to be an efficient, cost-effective and superior alternative for corrosion protection in reinforced concrete structures.