The Vermont Agency of Transportation Bridge Deck Membrane Evaluation Program begun in 1971 is reviewed, and the field performance of 33 membrane systems over exposure periods of up to 11 years is discussed. Applications of deicing chemicals (sodium chloride) during the evaluation period have averaged 29.5 tons per two-lane mile per year, with accumulations totaling up to 123 lb of chloride (Cl-) per linear foot of structure. Performance results are based on the presence or absence of Cl- above base levels as determined by chemical analysis of more than 1,600 recovered concrete samples. The results indicate that, almost without exception, the experimental systems have outperformed the Agency's original standard treatment of tar emulsion. When grouped by general type, the best performance has been provided by the standard preformed sheet membranes and thermoplastic systems. Although somewhat less successful, satisfactory performance has been provided by the polyurethanes, the NCHRP Project 12-11 recommended systems, and miscellaneous preformed systems. In general, the epoxy and tar emulsion systems were not considered successful, although they have allowed only an average of 0.35 lb of Cl- per cubic yard of concrete more than base levels in the top inch of concrete as compared to an average of 6.97 lb/yd3 on exposed bridge decks over a similar evaluation period. Chloride contamination was detected in one sample or less on 33 percent of the 63 bridge decks under evaluation. Projections based on performance results to date suggest a significant number of the membrane systems will provide protection from serious Cl- contamination for 50 years or longer.

Media Info

  • Media Type: Print
  • Features: Figures; References; Tables;
  • Pagination: pp 57-65
  • Monograph Title: Bridge maintenance management, corrosion control, heating, and deicing chemicals
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00394970
  • Record Type: Publication
  • ISBN: 0309037182
  • Files: TRIS, TRB
  • Created Date: Jan 31 1986 12:00AM