Cyclic bond behavior of FRCM composites applied on masonry substrate

Fiber Reinforced Cementitious Matrix (FRCM) composite materials represent a recent strengthening technique, which can provide a complex scenario of different mechanical behaviors and failure mechanisms. The presented experimental study is aimed at improving the knowledge about the tensile and bond behavior of FRCMs with a focus, in particular, on the effects of cyclic loading at high stress levels. To this purpose, tensile characterization tests and single-lap shear tests were carried out on six different FRCM types, discussing and clarifying the different bond behaviors and the resulting failure modes. The experimental tests showed that the global behavior of the samples is affected not only by properties of composite grids and mortars, but in particular by the textile-matrix adhesion mechanism. The effects of cyclic loading were experimentally evaluated for each strengthening system type in terms of maximum bond capacity, failure mechanism, stress-slip behavior and bond degradation through cycles. In general, application of load cycles didn't remarkably affect the performance of FRCM systems, proving their reliability under seismic forces.