Behavior of Prestressed Beam Strengthened with External Tendons

The prestressing technique using external tendons can be considered an effective method of strengthening bridges deteriorating due to increasing overloading and progressive structural aging. In order to analytically investigate the dynamic behavior of prestressed composite girder bridges, strengthened with external tendons, this paper focuses on a simply supported prestressed composite girder with alternative prestressing levels, eccentricity of the attached tendons, and tendons properties. The accuracy of the proposed analysis is verified by comparison with the results of dynamic tests on large-scale prestressed composite girders. Furthermore, as a practical example, the results of a dynamic test in which the strengthening method is applied to an actual bridge are discussed.