Effect of elevated temperatures on the bond strength of FRP-strengthened bricks

Fiber Reinforced Polymer (FRP) composites have received extensive attention in the last years for Externally Bonded Reinforcement (EBR) of masonry structures. It is well known that the FRP-to-masonry bond behavior is a critical mechanism in this strengthening technique. Several experimental and numerical investigations have thus been devoted to investigation of the bond behavior. However, aspects such as long-term performance and durability of these systems under different environmental conditions are still unknown. This study aims at experimentally investigating the effect of elevated temperatures on the bond strength in FRP-strengthened masonry components. The specimens consist of GFRP-strengthened bricks prepared following the wet lay-up procedure. The specimens, after curing in the laboratory conditions, are exposed to constant temperature conditions from 70°C to 500°C and the changes in the bond strength are investigated by performing pull-off tests at different exposure times. The effect of application of a rendering mortar layer on the bond degradation at elevated temperatures is also investigated. The experimental observations and results are presented and discussed