The best protection is to have impermeable dense concrete. To prevent corrosion of the reinforcing steel in a corrosive environment under certain circumstances, either the reinforcement must be made of a corrosive material, or conventional reinforcing steel must be coated to isolate the steel from contact with oxygen, moisture, arid chlorides.
Non-corrosive Steels
Natural weathering steels commonly used for structural steelworks do not perform well in concrete containing moisture and chloride and are not suitable for reinforcement. Stainless steel reinforcement has been used in special applications, especially as hardware for attaching panels in precast concrete construction, but is much too expensive to replace mild-steel reinforcement in most applications.
Epoxy Coating
The process of coating the reinforcing steel with the epoxy consists of electrostatically applying finely divided epoxy powder to thoroughly cleaned and heated bars. Integrity of the coating is monitored by a detector installed directly on the production line. The use of epoxy-coated reinforcing steel has increased substantially since it was first used in 1973. The chief difficulty in using epoxy-coated bars has been in preventing damage to the coating in transportation and handling. There may be some reduction in bond.
No comments:
Post a Comment