DETERIORATION OF CONCRETE BRIDGE DECKS FROM CORROSION OF REINFORCING STEEL

Twenty-two bridge decks were examined to determine the extent of deterioration of the concrete resulting from corrosion of the reinforcing steel. Visual inspection indicated that about 40 percent of the decks containing bare reinforcing steel were in the initial stage of deterioration, but none of the decks containing epoxy-coated reinforcing steel were deteriorating because of corrosion of the steel. An in-depth study of 4 of the decks revealed more extensive deterioration of those containing bare steel, but no deterioration in those containing epoxy-coated steel. The in-depth study also indicated that the diffusion of chloride ions through concrete bridge decks obeys Fick's law and an effective diffusion constant exists which can be used for planning maintenance and rehabilitation.