Durability Performances of Carbon Fiber-Reinforced Polymer and Concrete-Bonded Systems under Moisture Conditions

The information on long-term durability of the carbon fiber-reinforced polymer (CFRP)-concrete bond interfaces in various environmental conditions is necessary to predict the service life of the structures. The assessment of the bond interfaces under moisture conditions were evaluated by shear and tension bond tests using six popular commercial CFRP and epoxy resin systems for the maximum immersion period of 18 months. The bond tests were also accompanied by the test in the mechanical properties of the resins and concrete. Two of systems showed 25 and 16% reductions in average shear bond strengths, while the remaining systems showed either improvement or a small reduction. Observation of the failure modes suggested that the durability against water-related deterioration is worst when the adhesion bonds between the concrete and resin interface are weaker than the cohesive bonds of the adjacent layers. Similarly, the average tensile bond strength reduction was found to vary from 19 to 41%, indicating that the durability of the bond is highly dependent on the CFRP composite systems