A prestressed mechanically-fastened FRP system was developed to retrofit deteriorated prestressed concrete bridges. The system was designed to be cost-effective, rapidly installed without the need for special equipment, and easily inspected. The efficiency of the system was demonstrated under laboratory conditions on full-scale prestressed C-channel beams and cored slabs taken from bridges that were in service for more than 40 years. The system was designed as a short-term retrofit to extend the service life of prestressed concrete bridges by increasing load postings, or preventing closure, until such time that the superstructure may be replaced. To date, the retrofit system was installed on three in-service prestressed concrete C-channel bridges in North Carolina. After extending the service life of these bridges for at least two years, the bridge superstructures were recently replaced. During demolition of two of the existing retrofitted bridges, five retrofitted C-channel beams were retained and delivered to the laboratory for testing. In addition, seven un-strengthened C-channel beams were retained to serve as control specimens and to allow for additional testing as necessary. Salvaging these existing bridge beams provided the unique opportunity to perform a comprehensive condition assessment and destructive testing to investigate the performance of the retrofit after being exposed to loading and the environment on in-service bridges. The experimental campaign included material testing and full-scale destructive testing of the C-channel beams. The results show the condition and performance of the system after being in-service for at least two years was as expected, with no indication of deterioration of the effectiveness of the retrofit.