Corrosion protection performance of epoxy-coated reinforcing bars

Abstract

The main purpose of this investigation was to conduct an in-depth study to determine the level of corrosion protection offered by epoxy-coated bars in four bridge decks in the Minneapolis/St. Paul, MN metropolitan area. The bridges studied were built between 1973 and 1978 and all decks had a top mat built with epoxy-coated bars. The bottom mat was epoxy-coated in only one deck whereas black steel was used for the bottom mat in the other bridges. These bridges had been assessed in 1996 and thus, the present study is a follow up investigation to obtain data and assess the field performance of epoxy-coated bars over a period of approximately 30 years. The investigation included field inspection and surveys of the decks, as well as laboratory tests of concrete core and bar samples. After 30 years of service, the overall condition of the epoxy-coated bars is good to very good, with no or modest levels of corrosion activity. In only one bridge, corrosion activity appears to be moderate to severe. The majority of corroded bars were found near joints or at crack locations. The amount of delamination in all decks is very low.