Evaluation and Repair of Full-Scale Prestressed Concrete Box Girders

摘要

The study was undertaken in order to provide further data on full-scale girdersthat have been in service for a number of years. Three precast, pretensioned, box girders, with a span of 70 feet (21.33 m), were tested. The girders had been in service for 20 years. The major objectives of the first part of the study were to examine strength and serviceability parameters and compare these value with existing code equations. The ultimate flexural strength, cracking strength, level of prestress, ductility and corrosion were investigated, since these factors profoundly affect the behavior of the girders. There was good agreement between code predicted and measured ultimate load. However both ductility and prestress losses differed significantly from code predictions. Expanations for these differences are presented.