steel is the type of steel that is used in rebar.
what type of steel is used in rebar?
steel
common rebar is made of unfinished tempered steel, making it susceptible to rusting. normally the concrete cover is able to provide a ph value higher than 12 avoiding the corrosion reaction. too little concrete cover can compromise this guard through carbonation from the surface, and salt penetration. too much concrete cover can cause bigger crack widths which also compromises the local guard. as rust takes up greater volume than the steel from which it was formed, it causes severe internal pressure on the surrounding concrete, leading to cracking, spalling, and, ultimately, structural failure. this phenomenon is known as oxide jacking. this is a particular problem where the concrete is exposed to salt water, as in bridges where salt is applied to roadways in winter, or in marine applications. uncoated, corrosion-resistant low carbon/chromium (microcomposite), silicon bronze, epoxy-coated, galvanized, or stainless steel rebars may be employed in these situations at greater initial expense, but significantly lower expense over the service life of the project. extra care is taken during the transport, fabrication, handling, installation, and concrete placement process when working with epoxy-coated rebar, because damage will reduce the long-term corrosion resistance of these bars. even damaged bars have shown better performance than uncoated reinforcing bars, though issues from debonding of the epoxy coating from the bars and corrosion under the epoxy film have been reported. these bars are used in over 70,000 bridge decks in the usa.
rebar
in wet and cold climates, reinforced concrete for roads, bridges, parking structures and other structures that may be exposed to deicing salt may benefit from use of corrosion-resistant reinforcement such as uncoated, low carbon/chromium (micro composite), epoxy-coated, hot dip galvanised or stainless steel rebar. good design and a well-chosen concrete mix will provide additional protection for many applications. uncoated, low carbon/chromium rebar looks similar to standard carbon steel rebar due to its lack of a coating; its highly corrosion-resistant features are inherent in the steel microstructure. it can be identified by the unique astm specified mill marking on its smooth, dark charcoal finish. epoxy coated rebar can easily be identified by the light green colour of its epoxy coating. hot dip galvanized rebar may be bright or dull grey depending on length of exposure, and stainless rebar exhibits a typical white metallic sheen that is readily distinguishable from carbon steel reinforcing bar. reference astm standard specifications a1035/a1035m standard specification for deformed and plain low-carbon, chromium, steel bars for concrete reinforcement, a767 standard specification for hot dip galvanised reinforcing bars, a775 standard specification for epoxy coated steel reinforcing bars and a955 standard specification for deformed and plain stainless bars for concrete reinforcement.
reinforced concrete