Effect of freeze-thaw cycles on the bond durability between fibre reinforced polymer plate reinforcement and concrete

Deterioration of infrastructure is one of the most pressing concerns facing today's civil engineering community. As a result, new rehabilitation techn iques, such as the external bonding of fibre reinforced polymer (FRP) plate s and sheets, are being developed. To apply these rehabilitation methods in Canada, the durability of the rehabilitated structures in cold regions mus t be assessed. This paper examines the effects of freeze-thaw cycling on th e bond between FRP and concrete. An experimental investigation was conducte d using both single lap pull-off and bond beam specimens. Only uniaxial car bon FRP strips were considered. The specimens were exposed to up to 300 fre eze-thaw cycles consisting of 16 h of freezing and 8 h of thawing in a wate r bath. After exposure, the specimens were tested to failure. The developme nt of strain along the bond length and the failure mode are presented for b oth types of specimens. Load deflection curves are presented for the beam s pecimens. The results indicate that the bond between carbon FRP strips and concrete is not significantly damaged by up to 300 freeze-thaw cycles.