Deterioration of Concrete Bridge Decks and Review of the WSDOT Bridge Deck Program

This report reviews the program developed by the Washington State Department of Transportation (WSDOT) to minimize premature deterioration of concrete bridge decks subject to chloride deicing chemicals. The review includes WSDOT's deck rehabilitation strategy, deck protective systems, deck evaluation techniques, and research and special investigations. The report includes a number of recommendations based on information obtained from previous research relative to the WSDOT program. Among protective systems used or proposed for use, cathodic protection appeared to be the most promising approach, short of removal of all chloride-contaminated concrete, that will stop active corrosion of steel in bridge decks. Information evolving from the study also pointed to waterproofing membrane and asphalt concrete overlay as a relatively inexpensive approach to protect existing bridge decks against corrosion. However, there appears to be a lack of hard data to support the effectiveness of this system. It is recommended that half-cell corrosion detection be included in the evaluation of bridge decks in combination with other techniques such as chloride analysis and chain dragging delamination detection.