Testing of selected metallic reinforcing bars for extending the service life of concrete bridges : testing in solutions.

Details

• Creators:
  Scully, John R ; Marks, Christopher A ; Hurley, Michael F
• Corporate Creators:
  Virginia Transportation Research Council (VTRC) ; Virginia. Dept. of Transportation ; United States. Federal Highway Administration
• Subject/TRT Terms:
  Building Materials--Service Life Concrete Bridges--Design And Construction Reinforced Concrete--Testing Reinforcing Bars--Testing Service Life (Engineering)
• Publication/ Report Number:
  FHWA/VTRC 03-CR11
• Resource Type:
  Tech Report
• Geographical Coverage:
  Virginia
• Edition:
  Final contract report.1/30/9911/30/02.
• Corporate Publisher:
  Virginia Transportation Research Council (VTRC)
• Abstract:
  Stainless steel-clad rebar provides an opportunity to significantly increase the Cl- threshold concentration associated with active corrosion initiation compared to plain carbon steel. However, threshold Cl- concentrations for 316L stainless steel-clad rebar are unknown. Moreover, the impact of possible galvanic corrosion between the clad layer and any exposed carbon steel core has not been investigated. The Cl- threshold concentrations for corrosion initiation on clad 316L stainless steel (with a thickness of about 1 mm over a carbon steel core), solid 316LN stainless steel, and plain carbon steel were examined in saturated Ca(OH)2 plus various concentrations of NaCl. The electrochemical properties of "intact" 316L stainless steel-clad rebar were found to be similar to those of solid 316LN stainless steel according to several electrochemical criteria. The Cl- threshold concentrations for corrosion initiation were increased to Cl-/OH- molar ratios as high as 17 to 24 even at high anodic potentials for "intact" 316L-clad and solid 316LN stainless steel, respectively. Thus, active corrosion of "intact" 316L-clad rebar could be delayed for many years due to the high Cl-/OH- molar ratios required at the stainless steel/concrete interface and the slow transport rate of chloride in concrete. In contrast, the threshold chloride concentration for corrosion initiation on carbon steel was low (Cl-/OH- molar ratio < 1.5) at all potentials. Cladding with a physical breech exhibited Cl-/OH- thresholds dominated by the exposed plain carbon steel. Galvanic coupling between exposed plain carbon steel and the stainless steel-cladding accelerated corrosion of the plain carbon steel only at and above the Cl-/OH- ratio necessary for corrosion initiation on carbon steel.
• Format:
  PDF
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:628766e686f834b0490730acfbaa9a87f2c83022c108198022b6a9603ba09f75
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/19571/dot_19571_DS1.pdf
• File Type:
  [PDF - 2.32 MB ]