Chapter 4 - Corrosion monitoring of reinforced concrete structures

Abstract

Corrosion is one of the most significant factors in the deterioration of the durability of civil engineering structures. Although in the past few decades, tremendous bridges, skyscrapers, super dams, and huge marine structures have been built, determining how best to deploy safety assessment, service-life prediction, maintenance and reinforcement, and even full-life design of engineering structures is still a huge challenge. A number of structural health monitoring (SHM) technologies have been developed and applied in the past 20years; however, most of these SHM techniques focus on the monitoring of macro performance of structures based on stress, strain, and acceleration parameters, etc., whereas corrosion, which is regarded as soft load compared with that of the traditional mechanical load, can affect the macro performance from materials and elements to whole structures. As far as the whole structure's performance is concerned, corrosion deterioration is not so obviously extensive as that of a typhoon, earthquake, etc. However, the accumulation effect of corrosion during the life cycle of structures is severe. Consequently, it is essential to realize accurate and reliable corrosion control based on the information extracted from the corrosion monitoring system itself. For one thing, a corrosion monitoring system can obtain the corrosion status on time; for another, a corrosion monitoring system can also help engineers to check the effects of corrosion protection, prevention, or control approaches. In this chapter, we list the main electrochemical corrosion identification methods based on the electrochemistry essence. Then, we present typical corrosion monitoring sensors. We finally summarize the current development and prospects of corrosion monitoring in civil engineering.