Repair of Prestressed-Concrete Girders Combining Internal Strand Splicing and Externally Bonded CFRP Techniques

Abstract

Collisions between overheight vehicles and bridges are becoming more commonplace. Collision damage, however, is generally far from catastrophic, although sound repair techniques are critical if additional damage (typically related to corrosion) is to be mitigated. Steel posttensioning, fiber-reinforced polymers (FRPs), strand splicing, and other repair techniques have been used throughout the United States to repair damaged prestressed girders. Whereas these techniques individually are quite effective, the combination of repair techniques has far greater impact. Physical and mechanical limitations associated with individual repair techniques clearly led to the adoption of hybrid or mixed repair approaches in which techniques are used in combination, leveraging the strengths of each repair technique and maximizing the degree of damage that may be repaired. This paper addresses the practical case of augmenting an internal strand-splice repair with externally bonded carbon fiber–reinforced polymer (CFRP) materials, thereby overcoming the limitations of each method. This paper describes design considerations for strand-splice and externally bonded CFRP repair techniques both individually and in combination. A prototype example is presented. The hybrid repair approach is shown to maximize the degree of damage that may be repaired.