Title: Deviator Behavior and Design for Externally Post-Tensioned Bridges
Author(s): R. J. Beaupre, L. C. Powell, J. E. Breen, and M. E. Kreger
Publication: Symposium Paper
Appears on pages(s): 257-288
Keywords: box beams; bridges (structures); models; post-tensioning; precast concrete; prestressing steels; segmental construction; structural design; tests; unbonded prestressing; Design
A laboratory investigation was performed to study deviation saddles, a type of tendon deviator used in externally post-tensioned precast segmental box girder bridges. Ten reduced-scale models of deviation saddles were fabricated and loaded to ultimate using a specially designed testing apparatus that applied load to each deviator just as would be applied to a deviator in a bridge. The objectives of the study were to: experimentally investigate the strength and ductility of deviators; evaluate deviator details in light of observed performance; define behavioral models for deviators; determine the effects of using epoxy-coated reinforcement; and establish design criteria. Data from the test series are presented, two analysis techniques are formulated, and design recommendations are made for design of tendon deviators.