Selected Answers

From Tom Schwerdt of Active Transportation Advocates on May 5, 2015:
If we simply look at effectiveness, you select the ...read more If we simply look at effectiveness, you select the most corrosion-resistant grade of stainless steel for your conditions and ensure it is properly heat-treated, pickled and passivated. Similarly, you select the most durable concrete mix design (low water:cement ratio, added fly ash, low reactivity aggregate, etc) and use large amounts of stainless steel rebar. Finish the concrete with something like a rubbed finish, only then following up with an extremely durable coating. Ensure that your overall design eliminates any area where salts and debris could collect, or water could puddle or infiltrate. Prevent the public from coming in contact with your structure. Several of these items add significant cost (though probably not the design portion - that's just being mindful while you design), but cost wasn't mentioned in the question.

From Warren Brand of Chicago Corrosion Group on May 4, 2015:
This is a complex question, with many variables. ...read more This is a complex question, with many variables. If aesthetics are not important, I would lean towards coatings with elastomeric characteristics and overcoat both the steel and concrete. If aesthetics are important, I would consider a bond-breaker solution, overcoating both substrates. We've designed and used both successfully.