CONCRETE : REINFORCING BARS
Deformed bars are used to limit the cracks that may develop in reinforced concrete around mild steel bars, due to the stretching of the bars and some loss of bond under load. It have projecting ribs twisted to improve the bond in concrete.
The type of deformed reinforcing bars generally used are ribbed bars that are rolled from mild steel and ribbed along length, ribbed mild steel bars that are cold drawn as high yield ribbed bars, ribbed cold drawn and twisted bars, high tensile steel bars that are rolled with projecting ribs and cold twisted square bars.
Galvanized steel reinforcing bars
Galvanized reinforcement are used where reinforced concrete is exposed externally or is expose to corrosive industrial atmosphere. It is a sound practice to use galvanized reinforcement as protection against corrosion of the steel to prevent rust staining of Fair face finishes and inhibit rusting of reinforcement that might weaken the structure. The steel reinforcing bars are cut to length, bent and then coated with zinc by the hot dip galvanizing process. The considerable increase in cost of the reinforcement is well worth while.
Stainless Steel reinforcing bars
Stainless Steel is an alloy of iron, chromium and nickel compound which an invisible corrosion resistant film forms on exposure to air. The disadvantage of Stainless Steel is that, it is ten times the cost of ordinary mild steel. It is used for reinforcing bars in concrete where the cover of the concrete for corrosion protection would be much greater than that required for fire protection and the least section of reinforced concrete is a critical consideration.