Abstract
Corrosion of steel in reinforced concrete bridges is a major concern for the structural integrity, long-term durability, and maintenance of the highway infrastructure. The corrosion mechanisms vary greatly due to the multitude of engineered highway systems with the varying exposure environments, chemistry, and construction materials. Of the many engineering systems in the highway infrastructure, corrosion of reinforcing steel in bridge substructures has been critical. It is therefore highly advantageous to evaluate the performances of implemented corrosion control measures. Five bridges in Florida utilizing various corrosion mitigation strategies were revisited in 2021 to provide a prospective of their corrosion durability after several decades of service. The assessment compared plain to epoxy coated rebar, use of fly ash, and the use of concrete coatings. The presence of flyash in concrete mix designs allow for slower chloride diffusion rates. The presence of concrete surface coatings can allow lower chloride surface concentrations to develop. Bridge service life assessment should not account for chloride ion diffusivity alone as it was shown that elevated initial chloride concentrations can facilitate corrosion conditions. The barrier provided by epoxy-coated rebar can extend the time to initial concrete degradation caused by corrosion, but corrosion can still develop on the coated reinforcing steel.
