Because federally funded construction projects are now required to be designed in metric units and built with metric materials, mills are reducing and will eventually eliminate their output of inch-pound bars and produce soft metric bars instead. Fortunately, the use of soft metric rebar will not require changes in design or in fabrication and construction practices, since soft metric rebar are physically the same size as corresponding inch-pound bars. It will be important, however, for designers and contractors to become familiar with the specifications of the new metric bar sizes.
ASTM metric standards for billet-steel bars first appeared in ASTM A 615 in 1979.
Generally, epoxy-coated rebar have performed well in resisting corrosion in deicing-salt environments. But there have been isolated incidents, primarily in structures located in sea water environments, of unsatisfactory performance.
Use of epoxy-coated reinforcing bars has become widespread in recent years. A properly applied epoxy coating will provide corrosion protection for rebars in bridge decks, pavements, parking garages and other structures exposed to chlorides.
In 1984, the Concrete Reinforcing Steel Institute (CRSI) issued a set of suggested project specifications provisions for epoxy-coated reinforcing bars.