The extent of corrosion of epoxy coated rebar, ECR, in marine bridges was found to be
generally correlated with concrete chloride diffusivity, DApp, where significant corrosion was
observed at bridges with DApp as high as 10-7cm2/s but not for sound concrete locations in bridges with DApp as low as 10-9cm2/s. However, significant corrosion was observed in several pre-existing cracked concrete locations of a low DApp bridge. In such environment, well manifested enhanced chloride penetration occurs through the preexisting cracks. Early corrosion could then initiate for ECR with coating defects and extended coating disbondment.
An initial model formulation that may serve as a starting point for quantitative corrosion
forecasting of possible damage in those cases is introduced. Exploratory projections indicate
that, as expected, relatively isolated cracking should only create topical concrete damage with
modest maintenance requirements. However, if the crack orientation with respect to the rebar
were adverse and chloride transport were greatly enhanced (as it could be expected in
relatively wide cracks), projected corrosion damage could be more substantial.
Keywords: concrete, corrosion, crack, modeling, rebar, durability, epoxy