An experimental study on delamination of FRP plates bonded to concrete

Results of an experimental campaign on FRP–concrete delamination are presented. Specimens with different bonded lengths and plate widths have been tested. Strain gauges along the FRP plate have been used to measure longitudinal strains. For long bonded lengths, progressive debonding along the specimens has been followed. Starting from experimental data, average shear stress–slips data have been computed. By post-processing these data, non-linear interface laws for two different plate widths have been calibrated. Increase of maximum shear stress with decreasing plate width has been observed, whereas no significant plate width effect on fracture energy and delamination force has been found. Experimental tests have been simulated by adopting a numerical bond-slip model and the above mentioned non-linear law for the FRP–concrete interface. Numerical results in good agreement with experimental results have been obtained, both at low and very high loading levels.