Seismic Monitoring of Masonry Structures Using Smart Bricks: Experimental Application to Masonry Walls Subjected to In-Plane Shear Loading

Masonry is a construction material consisting of bricks and mortar layers, the compressive strength of which is significantly higher than its shear and tensile counterparts. Such a mechanical behavior makes masonry constructions particularly prone to brittle collapses when subjected to seismic loading. In light of this, structural health monitoring of masonry constructions, particularly for the existing ones, is of pivotal importance to evaluate the structural integrity of residential and cultural heritage buildings. In this regard, piezoresistive strain-sensing brick-like sensors, termed "smart bricks", have been recently developed for structure-scale monitoring of masonry constructions. Smart bricks, indeed, can be easily integrated within masonry load-bearing structures made of conventional clay bricks, providing measurable variations in their electrical outputs correlated to changes in their strain states. This paper focuses on the use of smart bricks for seismic monitoring of masonry constructions by presenting an experimental program carried out to investigate their effectiveness in measuring strains within masonry walls. To this aim, smart bricks with standard dimensions were produced and installed in full-scale masonry walls with different mechanical characteristics, which were tested under diagonal compression. The results demonstrate that smart bricks can be effective to early detect shear-induced damages when employed in such structural settings.