STRENGTHENING OF EXISTING BRIDGES BY POST-TENSIONING

The need to upgrade understrength bridges in the United States has been well documented in the literature. Through several Iowa Department of Transportation research projects, the concept of strengthening simple-span bridges and continuous-span bridges by post-tensioning has been developed. This strengthening scheme has been tested on laboratory bridge models and demonstrated on several existing bridges. This paper emphasizes the use of the post-tensioning strengthening scheme on existing structures.