Sustainability of inorganic matrix-grid composites for strengthening of masonry structures

Fibre reinforced grout (FRG) composites can provide a strong contribution to the strengthening and preservation of existing masonry building against earthquakes because they exploit good adhesion to masonry structures. The bond behaviour of FRG externally bonded to a masonry substrate is different from that of FRP composites applied by means of epoxy-resin; for some types of fibres embedded in grout layers the debonding can occur inside the composite at the fibre-matrix interface, whereas with FRP the debonding is generally at the composite-masonry interface. This paper examines the results of experimental bond tests on tuff elements externally strengthened with FRG composites with the aim of studying their bond behaviour. The FRG composite investigated in this study is comprised of a glass fibre net and a non-cementitious matrix applied on both single tuff blocks and prisms made of three tuff blocks connected by mortar joints.