Galvanised Steel Reinforcement.
Hot-dip galvanised (HDG) reinforcing steel is bare reinforcing steel coated with a protective layer of zinc metal. The zinc coating serves as a barrier to corrosive elements that the rebar is exposed to when embedded in concrete. In addition to the barrier protection that the zinc provides, it also provides a level of cathodic protection where the zinc will preferentially corrode when in contact with bare steel (e.g. a void or holiday on the surface of the galvanized rebar will be protected by the surrounding zinc.) Zinc (galvanized) also possesses other favorable corrosion characteristics when embedded in concrete which make it an effective coating material for corrosion resistance.