Rehabilitation of a Historical Bridge Exhibiting Severe Corrosion Damage in Florida

摘要

The “Bridge of Lions” is a National Historic Landmark located in St. Augustine, Florida (thernoldest continuously occupied European city in the U.S.). The bridge was built in the 1920's and uses arncombination of structural steel and steel reinforced concrete to provide an arch type substructure withrna Mediterranean styled deck. During its 80 plus years of service, the aggressive marine environmentrnat the location has promoted severe corrosion induced damage throughout all its components. Thernmost affected portions of the bridge are the structural steel girders and the substructure componentsrnin direct contact with the water.rnIn 2004, the Florida Department of Transportation awarded a contract to rehabilitate thernbridge. The contract included among others: replacement of some bridge elements, impressed currentrncathodic protection on selected reinforced concrete elements that could not be replaced, andrnthermally applied zinc on steel girders and structural steel attachments. It is anticipated that thernrestoration work will be completed in 2010, but the corrosion control methods will be operational uponrninstallation to avoid the onset of corrosion during the construction period.rnThis paper discusses the design and installation of the corrosion control measures as well asrntheir initial performance.