The epoxy resin coated steel bar is made of an epoxy resin film on the surface of the steel bar as a protective layer. The thickness of the protective layer is generally 0.15mm and 0.30mm. It has very high chemical stability and will not react with acids and bases. And steel bar surface has a very strong degree of adhesion. Epoxy coating can effectively cut off the penetration of chloride ion, prevent chloride ion from destroying the passivation film on the surface of steel bar, play an effective anti-corrosion role, and improve the service life of concrete structure.
The cost of the early coated steel bar was increased by 80-120% on the basis of the original steel. Since it was used in the 1970s, the cost of the coated steel bar has been reduced. As consumption and production continue to increase, the costs paid by users are gradually reduced. For most buildings, although all the steel bars in the components are coated steel, the total cost has only increased by about 1-3%.
As early as December 1997, the Ministry of Construction of China promulgated JG3042-1997, which provides a strict standard for the use of epoxy resin coated steel bars. In 1999, the Ministry of Communications organized the compilation of "Technical Code for anticorrosion of concrete structures in Seaport Engineering". Epoxy resin coated steel bar is listed as one of the main anticorrosion measures. After many times of careful study, the two ministries have determined the important role of epoxy resin coated steel bar as an advanced anticorrosion technology. On December 23, 2010, the General Administration of quality Supervision, Inspection and Quarantine, in conjunction with the State Standardization Management Committee of China, formally issued the Standard of Epoxy coated reinforcement for reinforced concrete (Epoxy-coated steel for reinforcement of concrete) GB/T 25826-2010, And officially implemented on September 1, 2011, It indicates that China's epoxy coated steel bar has officially entered a large area of promotion. It has been widely used in Hangzhou Bay Sea Crossing Bridge, Hong Kong-Zhuhai-Macao Bridge and high-speed rail construction.