Bridge Crossing Medicine Creek
Constructed in 2001, the bridge deck contains type 316 LN rebar. A nearby conventional comparison bridge deck (Bridge A6060) was built with epoxy-coated rebar. A condition survey was performed in July 2006, 5 years after concrete placement. Tests conducted included visual inspection, crack mapping, chloride content measurements, concrete coring, and half-cell potential.
The authors concluded that:
1. There was no delamination or spalling found on the surface of either bridge deck.
2. Very little cracking damage on either the stainless steel or the conventional deck.
3. Chloride data obtained by drilling showed only one location well above the black bar corrosion threshold at the level of the stainless steel bars
4. Half-cell maps were not conclusive because they are not calibrated for 316LN steel, but suggest a more corrosive environment than in the first inspection in 2001 but not rebar corrosion.
5. The chloride ions in the deck already would have caused corrosion to black steel and it was beneficial to have the stainless steel reinforcement.