Properties of corrosion inhibitors on reinforced concrete

Abstract

Corrosion of reinforced concrete steel is one of the main reasons for the deterioration of reinforced concrete structures all around the world and the biggest problem that civil engineers are facing today. Various methods have been developed to protect the steel reinforcement in reinforced concrete against corrosion. According to recent statistics, the global cost of corrosion is determined to be $2.5 trillion or 3.4 percent of world gross domestic product. New technologies and materials have been developed to delay, decrease or control the corrosion of concrete reinforcement and increase the durability. The most common corrosion prevention technique is the use of inhibitors. Inhibitors are chemicals that added to the concrete in small concentrations that prevent the onset of corrosion in reinforced concrete structures or extend the corrosion start time. The aim of this article is to review the recent developments in corrosion inhibitors used in reinforced concrete structures and their applications in field and laboratory conditions. This research is based on the types of inhibitors, their mechanism of action and their type of application. The main topics are; cathodic, anodic, mixed type inhibitors and their type of field applications. This research also includes: comparison the performance of admixed inhibitors, surface applied (migrating) inhibitors, electrochemical injection of corrosion inhibitors (EICI) and electrochemical chloride ion extraction (ECE) methods of corrosion inhibitors. The use of green (ecological) corrosion inhibitors (non-toxic and non-carcinogenic chemicals) becoming more popular nowadays. Studies with green inhibitors have been widely discussed in this review and we should increase their use in the next few years.