Catene metalliche negli edifici storici in muratura. Primi risultati di una ricerca in corso

The object of the research are the metallic tie-rods, being relevant structural elements in historic masonry buildings. They actually contribute to guarantee an efficient connection between walls playing a decisive role in the control of horizontal thrusts (both permanent, as in the case of arches and vaults, or environmental, as in the case of seismic actions). The idea of focusing the research on tie-rods derives from the evidence that, despite their role, scarce studies have been conducted on these structural elements. This results in a lack of knowledge on their technological features, in a scarcity of data on their mechanical properties and, finally, in many unaware replacement interventions. For these reasons, the research aims at: defining a simple non-destructive or micro-invasive assessment procedure of tie-rods, providing a more rational evaluation of their macroscopic parameters as well as their damage and degradation processes. The project will lead to: an improvement of the structural models of heritage buildings, resulting in more reliable seismic analyses and, indeed, in optimized strengthening interventions; a reduction of the number of replacements, resulting in a higher conservation of tangible assets (the tie-rods) and intangible values (e.g. ancient techniques of productions, local identity).