Multiscale damage assessment of ancient structures

This project explores innovative approaches to characterize ancient structures and materials, addressing recently developed imaging techniques that analyze material composition and properties. The aim is to define experimental protocols that deliver a holistic view of the ancient structures, including a bottom-up reconstruction of chemo-mechanical aspects across multiple length-scales ranging from microscale to macroscopic scale. This multidisciplinary research will include recent advances in 3D reconstruction, chemical imaging, motion magnification, and modeling tools for in situ investigation and monitoring. Successful development and implementation of these techniques will provide novel multiscale material characterization strategies, and cost effective field damage assessments of valuable objects of cultural interest including ancient buildings, frescoes and mosaics.

Examples of advanced characterization tools available to study across scales the properties of ancient materials. Laser scanner technologies allow 3D reconstruction of the macroscopic surface of the ancient artifacts. This information can be used as a starting point for 3D modeling of structural and chemical properties of the mosaics or wall paintings. 3D large area Raman and Scanning Electron Microscopy (SEM) characterization tools provide chemical input for these models. Complex sample surface topography is reviled by True Surface Raman profilometery and exploited to collect Raman spectra throughout entire surface. Raman spectroscopy is very powerful tool for characterizing chemical the constituents of the analyzed volume and specifically the vibrational units such as carbonates, sulfates, organic matter, etc. However, it is unable to detect single atom ions because these units are not involved in covalent chemical bonding. For these species we use large area SEM equipped with Energy Dispersive X-rays Spectroscopy detectors (EDS) which provides precise insights into elemental composition of the region of interest and is perfectly complementing the Raman information. Atomic Force Microscopy (AFM) is used in correlative manner to collect the nanoscale surface features of the analyzed fragment (feature available on the Raman microscope).