PRECAST POST-TENSIONING ACCOMMODATES TRAFFIC FOR OHIO RIVER BOULEVARD BRIDGE REHABILITATION

The use of precast post-tensioned members enabled traffic to be maintained during construction on three concrete arch spandrel bridges on a major artery in Pittsburgh, PA. The bridges were built in the early 1930s, and the determination to rehabilitate the bridges was made in the early 1980s. The paper describes some of the main problems that had to be met in the rehabilitation design. The use of precast construction allowed for higher concrete strengths, better quality control, a potential for reduced dead load, and ease in maintaining traffic during construction. Another major advantage identified was the construction time saved using precast concrete decking, an important consideration when trying to minimize the construction period and reopen a vital roadway as quickly as possible.