Many highway bridges in the United States are in a deteriorating condition as a result of aging, environmental effects, and inadequate strength for today's heavy loads. To extend the remaining life of some of the bridges it is possible to strengthen them by various methods. This project will investigate the feasibility of strengthening steel bridge girders by prestressing the girder to increase its load supporting capabilities. This project follows a previous project which is investigating the static strength, ductility, reliability and load-deflection characteristics of the strengthened composite steel girder. The emphasis for this phase of the investigation will focus on the fatigue strength of the strengthened composite steel girders.
