Background: Use of externally bonded fiber-reinforced polymer (FRP) systems for the repair and strengthening of reinforced and prestressed concrete bridge structures has become accepted practice by some state highway agencies because of their technical and economic benefits. Such FRP systems are lightweight, exhibit high tensile strength, and are easy to install; these features facilitate handling and help expedite repair or construction, enhance long-term performance, and result in cost savings. In addition, research has shown that external bonding of FRP composites improves flexural behavior of concrete members and increases the capacity of concrete bents and columns.
In spite of their potential benefits, use of externally bonded FRP systems is hampered by the lack of nationally accepted design specifications for bridges. Research is needed to review available information and develop a recommended guide specification, in AASHTO LRFD format, for the design of externally bonded FRP systems. This specification will help highway agencies consider FRP systems among the options for the repair and strengthening of concrete bridge elements and select options that are expected to yield economic and other benefits.
Objective: The objective of this research is to develop a recommended guide specification, in AASHTO LRFD format, for the design of externally bonded FRP composite systems for repair and strengthening of reinforced and prestressed concrete highway bridge elements.
Status: The project is complete. The research developed a reliability-based guide specification for the design of externally bonded Fiber-Reinforced Polymer (FRP) systems for the repair and strengthening of concrete bridge elements. The specification employs Load and Resistance Factor Design (LRFD) methodology and is accompanied by commentaries that are necessary for explaining the background, applicability, and limitations of the respective provisions. In addition, design examples are provided to illustrate use of the recommended guide specification for different strengthening requirements. The final has been published as NCHRP Report 655.