Strengthening of an Impact-Damaged PC Girder

epair of impacted prestressed and reinforced concrete (PC and RC, respectively) structures using traditional and emerging technologies has been the subject of several studies. Fiber-reinforced polymer (FRP) systems composed of fibers embedded in a polymeric matrix exhibit properties that make them suitable for their use as structural reinforcing elements. FRP composites are characterized by excellent tensile strength in the direction of the fibers and by negligible strength in the direction transverse to the fibers. FRP composites are corrosion resistant and are expected to perform better than other construction materials in terms of weathering behavior. Several types of fibers have been developed for use in FRP composites. For this project, carbon fibers, which are recognized to be the stiffest and most durable, were used. Scope The objective of this project was to restore the original ultimate flexural capacity of an acciden-tally impact-damaged PC girder of Bridge A5657 located on Route 28 over the Gasconade River, south of Dixon, Missouri. Two prestressing tendons in the central girder of the north span of the bridge were fractured due to the impact. Similar projects involving the strengthening of damaged bridge girders have been conducted (Nanni 1997), including two in the State of Missour