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Epoxy Coating of Steel ReinforcementIt is important to use epoxy coated rebar to protect steel from corrosion. Using certain types of epoxies yielded positive results, especially in steel exposed to seawater while evaluating the use of epoxy to coat steel reinforcements exposed to chloride attack. Epoxies have been used in painting reinforced steel for bridges and offshore structures since 1970. Some shortcomings have been found using this method. Precautions must be taken during the manufacturing and operation of painting the steel, such as avoiding the absence of any friction between the bars, which would affect the result of the erosion of the coating layer due to friction. Also, it is difficult to use methods for measuring the corrosion rate such as polarization or half-cell, so it is not easy to predict the steel corrosion performance or measure the corrosion rate. Painting steel-reinforced bars has been used extensively in the United States and Canada for 25 years. More than 100,000 buildings use coated bars, which is equal to 2 million tons of epoxy-coated bars. The coated steel bar must follow ASTM A 775M/77M-93, which sets allowable limits as the following:
- Coating thickness should be in the range of 130–300 ?m.
- Bending of the coated bar around a standard mandrel should not lead to formation of cracks in the epoxy coating.
- The number of pinhole defects should not be more than six per meter.
- The damage area on the bar should not exceed 2%.