Corrosion Performance of Concrete Cylinder Piles

Cylinder bridge piles that are produced by a centrifugally cast, vibrated, roller compacted process (also known as Raymond piles) have shown promising resistance to reinforcement corrosion in earlier Florida Department of Transportation (FDOT) surveys. This investigation examined additional FDOT bridges built with cylinder piles for evidence of similar corrosion resistance and in considering updating guidelines for corrosion performance of these piles. A survey of three 40-year-old marine bridges indicated in general minor or no corrosion distress of the spiral reinforcement in the piles, even though the concrete clear cover was on average only ~1.2 in. (~30 mm). Chloride diffusivity was small with a median value lower than the typical results obtained in modern FDOT class V concretes for aggressive marine service. Other physicochemical concrete tests were also indicative of very low permeability. Thin concrete cracks not caused by corrosion were observed in some of the piles but preferential chloride penetration along the cracks was less pronounced than noted earlier in conventional marine substructures. Investigation of a 2-year-old bridge with modern cylinder piles also showed excellent resistance of the bulk concrete to chloride penetration. Thin cracks (not caused by corrosion distress) were observed as well, with some evidence of enhanced chloride penetration. Therefore continued monitoring of these spots as the bridge ages is recommended. The chloride threshold value for corrosion initiation in the older bridges is estimated to be above ~2 pcy (1.2 kg/cu m) and possibly considerably higher. The concrete in the new bridge piles had a desirably high pore water pH despite its high pozzolanic content, suggesting that chloride threshold in the new material will be normal. Simplified corrosion damage projections suggest that if concrete quality could be sufficiently assured, moderate relaxation of present cover requirements for new construction with cylinder piles could be made without severely compromising the requirements for minimum corrosion damage within a 75-year service life goal.

Language

  • English

Media Info

  • Media Type: Print
  • Edition: Final Report
  • Features: Appendices; Figures; Photos; References; Tables;
  • Pagination: 115p

Subject/Index Terms

Filing Info

  • Accession Number: 01002002
  • Record Type: Publication
  • Contract Numbers: BC353-10
  • Files: TRIS, USDOT, STATEDOT
  • Created Date: Jul 13 2005 11:20AM