Title: Strengthening of Existing Bridges (simple and continuous span)
Author(s): F. Wayne Klaiber, Kenneth F. Dunker and W. W. Sanders, Jr.
Publication: Symposium Paper
Appears on pages(s): 207-228
Keywords: bridges (structures); flexural strength; loads (forces); post-tensioning; renovating; research; spans; strengthening; stresses; structural design; tests; unbonded prestressing; Design
Approximately 40 percent of the bridges in the United States are classified as deficient and in need of rehabilitation or replacement. Of these bridges, many are classified as deficient because their load-carrying capacity is inadequate for today's increased traffic. This insufficient load-carrying capacity has resulted from poor maintenance, increase in legal load limits, deck overlays, changes in design specifications, and other factors. In response to the need for a simple, efficient procedure for strengthening existing bridges, the authors have been investigating the use of post-tensioning. They have investigated its use on simple span bridges as well as continuous span bridges. Various post-tensioning schemes have been tested on laboratory models and actual bridges. The paper briefly reviews the post-tensioning research that has been completed by the authors in the past few years. This work indicates that post-tensioning is a viable, economical technique for flexural strengthening of steel-beam composite-concrete deck bridges.