Retrofit of Reinforced Concrete Bridges with Carbon Fiber Reinforced Polymer Composites

Abstract

In-situ lateral load tests of reinforced concrete bridge bents were conducted to determine the strength and ductility of existing and retrofitted bents with Carbon Fiber Reinforced Polymer (CFRP) composites. The CFRP composite retrofit included three columns, the cap beam and the three cap beam-column joints. Existing design guidelines were used for retrofit of the columns with CFRP composites. New design guidelines were developed for retrofit of cap beam-column joints. The design of the CFRP composite retrofit was based on doubling the displacement ductility of the bent. The CFRP composite was able to strengthen the cap beam-column joints effectively for an increase in shear stresses of 35 percent. The bent retrofitted with the CFRP composite reached a system displacement ductility of 6.3 as compared to the bent in the as-is condition, which reached a ductility of 2.8. The peak lateral load capacity was increased by 16 percent.