Temperature Effect on Bonding and Debonding Behavior between FRP Sheets and Concrete

Generally, epoxy resin will be softened and its bond capacity will decrease remarkably under a high temperature environment near to or higher than the glass transition temperature (Tg) or deflection temperature under load (HDT) of epoxy resin. This paper summarizes a series of investigations for confirming the temperature effect on bonding behavior between fiber reinforced polymers (FRP) sheets and concrete. An experimental program is designed by using prism specimens subjected to a direct tensile load. The temperature around the concrete prism and the types of epoxy resin are considered as the experimental parameters. The experimental results are exploited to determine the debonding fracture energy (Gf), failure mode, and effective bonding length (Le) of the test specimens. It is observed from results that the value of Gf decreases and Le increases largely at temperatures near to or higher than Tg or HDT. Moreover, the newly developed epoxy resin presents higher temperature-resistance behavior than ordinary epoxy resin.