BACKGROUND: Concrete beams can be repaired and strengthened with externally bonded carbon fiber reinforced polymer (CFRP) composite sheets or prefabricated CFRP laminates. The short-term behavior of these applications has been studied, and construction specifications for bonded repair were developed under NCHRP Project 10-59A. Nevertheless, research into their long-term performance is incomplete, and durability issues remain unanswered.

Proper use of CFRP systems requires knowledge of their durability. The effect of mechanical and environmental loading on bonded CFRP systems may be significant. The development of design guidelines and material selection criteria that consider the effects of mechanical and environmental loads on durability will permit designers to repair or strengthen structures more effectively. The research may identify dominant factors that need to be monitored to evaluate the condition of CFRP applications. The results of this study may also be applicable to evaluation of the durability of existing installations.

OBJECTIVE: The objective of this project is to develop design guidelines and material selection criteria that consider the effects of mechanical and environmental loads on the durability of bonded CFRP repair and strengthening of concrete beams

Status: Project is complete.  The final report is available as NCHRP Web-Only document 155, "Design Guidelines for Durability of Bonded CFRP Repair/Stregnthening of Concrete Beams".