Olson, Steven A.French, Catherine E.Leon, Roberto T.2013-09-162013-09-161992-01https://hdl.handle.net/11299/156904Prestressed concrete has been used as a bridge construction method in the United States since 1949. Presently, there are thousands of pretensioned prestressed concrete bridges in service in North America. Each year, approximately 200 girders are damaged as a result of impact damage (primarily overheight vehicles striking a bridge from below). This thesis describes the results of a four girder test series which evaluated impact damage and repairs. The girders used for the study were fabricated in 1967 and placed in service. They were removed from service in 1984 as a result of a road realignment project. The objectives of the research project were: 1) to determine the effective prestress in the strands after 20 years, 2) to determine the influence of impact damage on girder performance, 3) to evaluate the performance of two impact damage repair schemes under static, fatigue, and ultimate loadings, and 4) to develop a model to estimate the strand stress ranges in damaged girders.en-USConcreteGirdersPrestressed concreteReport