Evaluation of reinforcement effect of deteriorated PSC beamthrough cutting its external tendons

摘要

In this study, a PSC (Pre-Stressed Concrete) beam bridge reinforced by externalrnpost-tensioning is tested to verify the strengthening effects. The variations of the displacementsrnand strain at mid-span of each beam are measured at the moment when the external tendons arernremoved in sequence. The structural behavior of the bridge is examined by using load tests beforernand after all external tendons were removed. From the test results, the characteristics ofrnstructural behavior of the bridge do not change significantly, but the natural frequency is decreasedrnafter the external tendons were removed. The effects of strengthening for PSC bridgesrncan be estimated approximately by analytical methods. As the results of this study, we knowrnthat deteriorated PSC beam bridges can be retrofitted effectively by the strengthening methodrnwith external tendons, and the strengthening effects can be predicted through accurate structuralrnanalysis.