Delamination Buckling of FRP: Experimental Tests and Theoretical Model

In scientific literature many studies have focused on the aspects of debonding mainly due to bending and/or shear in steel/concrete beams strengthened with fiber reinforced polymers (FRPs). Few experimental investigations on delamination buckling process of fiber reinforced polymer (FRP) strip/sheet utilized as strengthening in structural damaged elements, beams or slab, have been carried out. This paper analyses about the experimental delamination buckling of two type of FRP: steel reinforced polymer (SRP) strips and basaltic reinforced polymer (BFRP) strips glued on the surface of slender homogeneous beam models. Several experimental tests have been done considering beam models made of homogeneous material marble assuming this material without tensile strength. The specimens strengthened with a double layer of FRP strips glued on both up and down surfaces were tested under increasing compressive force until the failure due to delamination buckling of strengthening. Analysis of experimental process has been developed considering an appraisal theoretical model. Finally, theoretical results with experimental data are compared and discussed.