Effect of Test Set-Up on Bond Strength of Concrete Elements Externally Bonded with CFRP Plates

This paper deals with the comparison of the results of two experimental programs carried out by two laboratories (the Laboratory of Structural Testing of the University of Bologna and the Laboratory of Structural Engineering of the University of Naples Federico II) on similar specimens. The tests were aimed at investigating the bond behaviour of six types of Externally Bonded Carbon (EBR) plates within the activities of an international Round Robin Test organized by the fib TG 9.3. The two laboratories carried out the bond tests according to a similar scheme, a pull-pull single shear test, but realized according to two different experimental set-ups. The comparisons of the experimental results are aimed at investigating the influence of the testing procedure on the bond strength in terms of debonding load and strain distribution. To this purpose, a 3-Dimensional and a 2-Dimensional Finite Elements models have been developed for each testing configuration. The numerical results confirm some experimental findings and show limits of the 2D model in simulating correctly the experimental results that, by contrast, were better indentified by the 3D model.