<P> 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 ) , 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 . </P>
<P> 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 ) , 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 . </P>
what type of steel is used in rebar
what type of steel is used in rebar
unfinished tempered steel
unfinished tempered steel