Smart Bricks for Monitoring Strain in Full-Scale Masonry Structures: Recent Advances and First Field Application

Many masonry constructions have a cultural or historical value which needs to be preserved in time. Because of the aging of construction materials, lack of maintenance, exposure to amplified service loads or natural hazards, and the occurrence of structural pathologies, such as foundation settlements, ancient masonry structures often demand for retrofit interventions during their service conditions. Such interventions are aimed at restoring/improving their structural integrity for in-time preservation and to ensure a safe living of their occupants. Structural Health Monitoring (SHM) systems can be effectively used as a source of knowledge of the structural performance of masonry buildings to optimize such structural interventions. Recently, new piezoresistive smart sensors, similar in appearance to the traditional clay bricks and therefore called "smart bricks", were developed to achieve diffuse strain monitoring in masonry structures, thus facilitating the large-scale deployment of monitoring systems to such a building typology. This paper presents the recent advances achieved in smart brick technology, including the first field application of such smart sensors for monitoring strain in a full-scale masonry building prototype subjected to controlled damage. The production of smart bricks, their deployment within the masonry load-bearing structure, and the first results of the experimentation are presented.