Bond behaviour of basalt FRCM composites applied on RC elements

In the last decades fibre reinforced polymers (FRP) composites have been extensively studied and used for strengthening and retrofitting existing reinforced (RC) concrete structures. A valid alternative to the use of FRP composites is represented by fibre reinforced cementitious matrix (FRCM) composites, which are comprised of high strength fibres embedded within a cementitious matrix. Although experimental and analytical studies about FRCM composites with carbon, glass, PBO, and steel fibre are available in the literature, very few studies concerning basalt FRCM composites can be found and their application is thus limited. In addition to their lower environmental impact, basalt fibres present suitable mechanical properties, good resistance to high temperature, and competitive costs. This paper shows the results of single-lap direct-shear tests on basalt FRCM-concrete joints employed to study the bond behaviour and mode of failure of this composite. Different composite bonded lengths were applied to investigate the presence of an effective bonded length, i.e. the length needed to fully develop the composite load-carrying capacity