Development of nano-technologies for monitoring and safeguarding of monumental heritages

The conservation of masonry cultural heritage requires a strategic shift from emergency-based interventions toward planned preventive maintenance. This thesis investigates the seismic vulnerability of existing built heritage, with particular focus on two masonry churches. The well-recognized vulnerability of these structures highlights the need for their preservation through continuous monitoring systems; to this end, an innovative material incorporating nanoparticles is experimentally developed for Structural Health Monitoring (SHM) applications. The research is structured around two main research lines: the implementation of a multi-level methodology for assessing the seismic vulnerability of existing buildings, with specific reference to masonry churches, and the development of an innovative, eco-sustainable, and self-sensing material for structural monitoring purposes. Regarding the first research line, the Italian multi-level code-based approach was applied and compared through two case studies: Saint Francis of Assisi Church in Italy and Jesus Resurrection Church in Romania. Finite element numerical modelling, performed at both local and global levels, enabled the analysis of macro-element response mechanisms and the evaluation of the overall seismic behavior of the structures. The second research line focused on the design, production, and mechanical, electrical, and electromechanical characterization of a novel lime-based mortar incorporating calcarenite powder. The latter, a waste by-product of quarrying activities, was valorized according to the principles of circular economy and compatibility with historical heritage. The incorporation of conductive nanomaterials endowed the mortar matrix with piezoresistive properties. Experimental results demonstrated the ability of the mortar to vary its electrical resistance according to the applied strain state, thereby functioning as a distributed, continuous, non-invasive, and resilient sensing system for the long-term preservation of monumental heritage.