Preliminary results on experimental investigation of fuse-based cross ties used in out-of-plane stabilization of masonry facades

Vintage unreinforced masonry constructions often lack adequate connections between their fa-cades and transverse structures, making them vulnerable to out-of-plane failures during earth-quakes. Historically, cross ties have been used to prevent such failures and maintaining the box-like behavior of masonry structures, essential for their seismic stability. The strength and the brittle or ductile behavior of cross ties are highly influential on the response of masonry facades. Experiments available in the literature have shown that cross ties may develop limited ductility due to the threading necessary for their installation and tightening. The research investigates a novel approach where a plastic fuse element is integrated into the cross-tie system to improve ductility and simplify repair by predetermining the failure location. A sacrifice element, made of a plastic material, is connected to carbon-steel rods by means of threaded turnbuckles. To investigate the behavior of these fuse-based cross ties tensile tests are performed. Preliminary experimental results show strength and elongation reduction due to threading, but the fuse-based cross ties have an elongation still significantly more ductile than standard threaded carbon-steel cross ties.