Issue 50

E. D. Pasiou, Frattura ed Integrità Strutturale, 50 (2019) 560-572; DOI: 10.3221/IGF-ESIS.50.47 560 Focused on the research activities of the Greek Society of Experimental Mechanics of Materials Restoring stone monuments: Enlightening critical details by the combined use of innovative sensing techniques Ermioni D. Pasiou Laboratory for Testing and Materials, Zografou Campus, National Technical University of Athens, Greece Acropolis Restoration Service (YSMA), Ministry of Culture and Sports, Athens, Greece epasiou@teemail.gr A BSTRACT . The experience gathered during the implementation of long series of laboratory experimental protocols, aiming to study the mechanical response of restored structural elements, is summarized. Conclusions are drawn con- cerning the proper exploitation of the laboratory results in field applications in the frame of on-going restoration projects of ancient stone monuments. The need of continuous bidirectional interaction between the scientific personnel working in the site and the scientists working in the laboratory is emphasized. The role of the Digital Image Correlation technique in quantifying parasitic effects influencing the laboratory data is proven decisive. The need to use modern sensing techniques, providing data from the interior of loaded restored complexes (simulating restored structural elements), like the Pressure Stimu- lated Currents and the Acoustic Emissions ones, according to a combined manner is highlighted. The capability of these two techniques to monitor the damage evolution within the mass of the elements tested and to provide clear pre-failure indicators renders them flexible tools in the hands of engineers designing the restoration projects. K EYWORDS . 3D digital image correlation; Acoustic emissions; Pressure stimu- lated currents; Dionysos marble; Monuments. Citation: Pasiou, E.D., Restoring stone monu- ments: Enlightening critical details by the com- bined use of innovative sensing techniques, Frattura ed Integrità Strutturale, 50 (2019) 560-572. Received: 26.01.2019 Accepted: 29.05.2019 Published: 01.10.2019 Copyright: © 2019 This is an open access article under the terms of the CC-BY 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. I NTRODUCTION he restoration of monuments of Cultural Heritage is a demanding project since each monument is unique with its own special needs and requirements. The monuments of the Acropolis of Athens are among the worldwide known monuments under restoration. They were built in the 5 th century BC. Pentelic marble blocks were used for the construction without any binding material between the surfaces of the blocks. The structural elements (marble volumes) were connected to each other with “I”-shaped connectors and dowels made of layers of soft pure iron and tough steel [1,2], which were placed in mortises (grooves) of suitable geometry. After the placement of the metallic elements the grooves were filled with molten lead [3]. T