BEHAVIOUR OF CFRP-TO-STEEL INTERFACES IN ADHESIVELY BONDED JOINTS

The interface behaviour of carbon fibre reinforced polymer composite (CFRP) strips bonded to steel surfaces is a key aspect in assuring an efficient strengthening solution for structural or non-structural steel elements. The experimental program which is presented in this paper was developed at the Faculty of Civil Engineering and Building Services from Iasi, and it focused on the investigation of the behaviour of the CFRP-to-steel bonded interfaces. A number of 25 single lap shear specimens were prepared and tested up to failure. The parameters considered in this study were: the type of the CFRP composite strip, the type of the adhesives and their thicknesses. In addition, the influence of the surface preparation was analysed by comparing the results obtained for specimens with gritblasted steel surfaces and for untreated ones. The specific failure modes were identified and commented on the basis of the performed tests; the load-displacement curves were plotted and the strain distributions along the bond lengths were investigated at different load stages.