Design and Construction of CFRP Rod Panel Retrofit for Impacted RC Bridge Girders

CFRP Rod Panels (CRPs) have been recently developed to externally strengthening concrete structures in flexure, especially over multi-lane highways. Both exterior beams of a reinforced concrete (RC) bridge traversing southbound Interstate 71 (I-71) in Kentucky were damaged by an over-height truck impact. Rebars within the bottom mat of each exterior beam were severely bent due to the impact. CRP 195, with CFRP rods 3.96-mm (0.156 in) in diameter, and having a capacity of 870 kN (195.6 kips) per 300 mm (12 in) width of panel, were selected for flexural strengthening. CRPs were chosen due to their modular construction capability permitting a smaller work crew to carry out the retrofit construction while requiring closure of only a single lane of traffic on I-71. As current codes do not address CRPs, the retrofit design was based on American Association of State Highway and Transportation Officials (AASHTO) guidelines for externally bonded FRP. A load rating of the impacted girders was carried out for the as-built, damaged, and retrofitted stages. This paper details the retrofit construction of the bridge girders, highlighting the advantages of the CRPs