This study field tests and evaluates conditions of five bridge decks in Washington rehabilitated and waterproofed by WSDOT System "C" membrane and paved with asphalt concrete overlay. The study also reviews and evaluates the WSDOT's selection criteria. Based on the results obtained, the membrane system was generally effective in preventing chloride intrusion into concrete decks. Deterioration in concrete and corrosion in rebar, however, was detected. The deterioration was concentrated around, in the boundary, and within the rehabilitated areas. Those test sections which satisfied the WSDOT selection criteria for protection of existing bridge decks showed minimum levels of concrete deterioration.
Included in the study are also recommendations regarding rehabilitating, waterproofing, and testing bridge decks as well as selecting bridge decks for membrane waterproofing.