Strengthening of Impact-Damaged Bridge Girder Using FRP Laminates

The exterior prestressed concrete (PC) girder of Bridge A10062, located at the interchange of Interstates 44 and 270 in St. Louis County, Missouri, USA, was impact-damaged by an overheight truck. Removal of the loose concrete showed that two prestressing tendons were fractured due to the impact. This resulted in approximately 10 % reduction in flexural moment capacity. There has been limited research on the repair of PC bridge girders damaged by vehicular impact. Due to the repetitive nature of highway loading, repair methods such as internal strand splices and external post-tensioning were found to be questionable because they could not restore the ultimate strength to the damaged member. In this case study, it was decided to use carbon FRP (CFRP) laminates to restore the original structural capacity of the girder. It was demonstrated CFRP bonded reinforcement could be an effective repair technique in terms of installation as well as design. If the present trend in growing availability of FRP materials and design information were to continue, a sharp increase in FRP application could be forecast