Evaluation of corrosion resistance of various concrete reinforcing materials.

PDFTech Report2013-07Reinforcing barsCorrosion resistanceConcrete bridgesSodium chlorideLife cycle analysisReinforced concreteVermontVermont. Agency of Transportation. Materials and Research SectionTremblay, Jason P.Colgrove, George W.Vermont. Agency of Transportation. Materials and Research SectionUnited States. Federal Highway AdministrationUS Transportation CollectionThe Vermont Agency of Transportation undertook a simple experiment to determine the corrosionresistance ability of various reinforcing steels (rebar) that may be used in bridges and other concretestructures. Eight types of rebar were used in the study,including: black, MMFX2, epoxy coated, Z-Bar,stainless clad, high nickel stainless steel, high manganese stainless steel, and a duplex stainless steel.Rebar samples were subjected to a 3% sodium chloride salt water solution bath three days a week foreight hours. When not submerged, samples were left to dry under standard temperature andpressures. Samples went through this procedure for a total of 260 cycles, which was equated to anapproximately 10 year outdoor lifecycle under Vermont\u2019s climatic conditions. Samples were measuredfor mass, diameter, and coating thicknesses prior to, periodically during, and at the completion of theirexposure testing.Results prove that each type of rebar show varying degrees of corrosion resistance to sodiumchloride.Black bar showed not only extensive corrosion, but it also began rapidly from the onset of theimmersions, while epoxy coated bars (ECR) showed adequate resistance to corrosion. Some ECRbars were intentionally cut and not repaired for the study showed a considerable increase in corrosionover intact bars. Bars that are designed to further combat construction damage, Z-Bar, stainless-clad,and solid stainless steels, exhibited far greater corrosion resistanc