Adhesion tests between brick and CFRP strip

In this paper, the results of an experimental investigation aimed at studying the strength of the brick-CFRP bonding, using shear test on brick reinforced with CFRP (Carbon Fiber Reinforced Polymer), are reported. The test setup selected to study the adhesion between brick and CFRP was a double-shear push test. All specimens were obtained by utilizing brick with the standard dimensions and CFRP sheets with constant width and different lengths. The collapse mode was always determined by de-bonding of a thin layer of brick adjacent to the masonry-to-adhesive interface (delamination). In all specimens, electrical resistance strain gauges were bonded to the sheet in a longitudinal direction every 15 mm in order to evaluate the strain distribution of the reinforcement. In particular, the strain path in the longitudinal direction of the sheet with respect to different load level, the mean shear stress distribution between the brick and the reinforcement versus load and the local shear stress-slip diagram were determined for all specimens. The experimental data were used to calibrate the analytical formulations proposed in CNR-DT 200/2004, based on a fracture mechanics theory derived by a linear approach.