New England highway bridge rebar corrosion

Rebar corrosion expands the steel, blows out concrete, creates highway potholes; full bridge-deck rebuilds required every ~20 years. Used to set up corrosion as steel's Achilles heel and motivate galvanized / stainless / nickel-base rebar substitution attempts.

What is the Achilles heel of steel? Corrosion, rust. Why do they galvanize that rebar? Why, when you're driving around New England in the summer, are they always tearing up the bridges on the highways? Because the rebar in the concrete rusted. The rust expands, causes the concrete to fall, and you end up with potholes on your highways. If someone hits them at 70 miles an hour they'll have a wreck. So they have to go in about every twenty years and rebuild the bridge deck to replace the rebar. People have tried plastic-coating the rebar, going to stainless steel rebar, they've even gone to nickel-base rebar — you couldn't afford to build all the bridges, there's not enough nickel in the world to do that. People have tried all kinds of things to fight that form of corrosion. The corrosion scientists estimate that in the United States we lose about 200 billion dollars a year in corrosion. And guess what — probably 80, 90 percent of that is steel, because 90 percent of all the metal made is steel.