Many existing conventionally reinforced concrete deck-girder (RCDG) bridges, particularly those from the 1950’s, were originally designed with relatively light shear reinforcing and poor flexural detailing. These bridges can exhibit diagonal cracking that has been attributed to increased truck loads and volumes as well as temperature and shrinkage effects. Load rating of older RCDG bridges, especially for shear, may limit or preclude permit and legal loads on the bridge. To renew or strengthen existing RCDG bridges, surface-bonded carbon fiber -reinforced polymers (CFRP) have become an attractive option. As an example, the Oregon Department of Transportation (ODOT) has applied surface-bonded CFRP for live-load shear strengthening of many RCDG bridges in their inventory as part of a significant transportation infrastructure reinvestment. The current practice for some transportation agencies is to consider surface-bonded CFRP as a temporary measure, thereby requiring further retrofits or bridge replacement in the future. This is due to the relatively short performance history of CFRP for bridge applications and uncertainties related to long-term durability. Studies on the performance of surface-bonded CFRP for RC bridge members under long-term environmental exposure are lacking.