Experimental tests on FRCM strengthening systems for tuff masonry elements

The experimental tests discussed in this paper show different aspects of the bond behavior of the FRCM materials in order to validate an experimental methodology for such a strengthening technique. In particular, tensile tests on coupons made of different FRCM materials were carried out in order to investigate the interaction between fibers and mortar and the bond strength at the fiber/mortar interface. Then, the bond behavior between different FRCM systems and a masonry substrate made of Neapolitan yellow tuff was investigated by shear bond tests according to a single push-pull set-up. The experimental tests were carried out on three types of fibers embedded in cement-based grouts: a balanced glass grid (G-FRCM, i.e. Glass Fibers Reinforced Cementitious Mortar system), and two types of unidirectional fabric made of steel cords (SRG, i.e. Steel Reinforced Grout system) with different density. The readings obtained with traditional measuring instruments were integrated with those obtained by the Digital Image Correlation (DIC) technique.