Behavior of epoxy-coated reinforcement concrete beams with sodium chloride contamination

Premature corrosion of reinforcing steel has caused many concrete structures to deteriorate before their design life was attained. So, the effectiveness of reinforced concrete structural elements is how to protect the reinforcement from severe environment and weathering condition. This paper presents an experimental study on the strength and behavior of concrete beams with plain and epoxy-coated reinforcing steel. This study had two main objectives: 1) to develop and evaluate effective and economical methodologies for arresting or reducing the extent of steel corrosion due to chloride-contamination of concrete structures, thereby reducing maintenance costs and minimizing interruption to users. 2) to develop sound design and construction practices for preventing corrosion of reinforcement, hence minimizing future deterioration. To meet these objectives, 7-year research program in this study was carried out. In this study, 14-concrete beams were cast in concrete with 5\% sodium chloride to simulate the severe environment, where the deterioration of concrete structures due to salt content can be considered as one of the major problems in the Middle East. The beams were tested after 28, 365, day and 7 years. The parameters of this study were the effectiveness of partial and full coating for long-term protection of steel against corrosion, effectiveness of type of steel grade in corroded environment and corrosion rates after long-term exposure as a function of time and environment. Effect of corrosion on mechanical properties of reinforcement is studied. A 7-year program indicated that, the rate of corrosion could be decreased significantly by using epoxy coating, which can give good long-term performance under severe conditions. Rate of corrosion in plain mild steel is double that of high-grade deformed steel. Pitting corrosion severely affected the load carrying capacity of beams. The beams were tested up to failure and the influence of variable factors on the structural behavior is reported.