Chloride-induced corrosion of steel reinforcement in concrete bridge decks is a major concern for bridge owners and managers. Because early intervention, before concrete damage has occurred, is the most cost-efficient bridge deck management approach, a device for measuring the quality of protection provided to the steel reinforcement against chloride ingress on bridge decks was needed. Vertical electrical impedance (VEI) measurements have been shown to directly quantify the degree of protection provided by the concrete cover and by any rebar coatings and/or deck surface treatments. The development of a multi-channel VEI scanner is reported based on the theoretical and practical development of a large-area electrode to replace direct electrical connections to steel reinforcement. The VEI scanner is able to operate in conditions where other techniques fail or provide inadequate diagnostic capability. Specifications for use of the VEI scanner and interpretation of the data are reported to enable successful commercialization of the technology.

The final report is available.