Boulouki conducts interdisciplinary research, focusing on the deserted settlement of Agrilia as the case study for investigating the use of the local volcanic materials in the vernacular architecture of Therasia and Thera. The objective of this research is the partial retrieval of the forgotten craftsmanship underlying the cave structures of Santorini Archipelagos and the design of compatible and optimised materials which will be applied in selected locations of Agrilia settlement. The results of the research will be tested within an artistic experimentation in sculptural creations.
The volcanic tephra the locals call 'aspa' or the famous 'theran earth', as recorded in the history of materials technology, was mined in Thera-Therasia from early 19th to mid-20th century. Theran earth constituted an important mineral in the early Greek State’s industrial history; it was used as building material, especially in major marine and land construction projects like harbors and piers in Greece and abroad, due to its so-called hydraulic properties.
In the traditional architecture of Santorini Archipelago, local craftsmen used the 'theran tephra' mostly as collected in situ from the excavation debris during a cave dwelling construction. It constituted the primary component in the diverse building materials employed in the underground settlements network that was developed in the area throughout the history.
Deciphering the local building materials based on the use of theran tephra and lime entails the laboratory examination of a series of samples from Agrilia settlement. The aim is to unveil their physicochemical and mechanical properties, as well as their production technology and application process. In situ survey of the cave settlement of Agrilia, bibliographic research as well as interviews with local masons frame the scientific work as valuable sources for the documentation of traditional materials and techniques.
The field of study regards some of the most representative techniques of Therasia:
The binding mortars used for the stones’ assemblage in the cave structures.
The plastering techniques with emphasis on the special waterproofing coatings used in flooring systems and water cisterns
The pumice aggregate concretes, very similar to Roman Concrete technique, used to create the cast vaults of the cave dwellings and occasionally building units like bricks.
The prism of optimising the traditional materials is a crucial parameter in the conduction of the research and will be based on classic and innovative directions of the material science field, such as hydraulic technology and geopolymerisation. All conclusions drawn from the research will be employed towards the design of new materials, compatible for restoration and appropriate for sculptural use.
A collaboration with the Building Materials Lab of NTUA and Lithos Laboratory of the Hellenic Survey of Geological and Mineral Exploration (HSGME) has been already established by Boulouki, for the conduction of the analyses and interpretation of the results. Furthermore, the local materials’ investigation will be approached through the perspective of artistic expression. Students from the Athens School of Fine Arts (ASFA) will create original sculptural works based on the traditional materials and upon the research findings.
Throughout the research, scientific support and guidance will be provided by the international expert Marie D. Jackson, Associate Professor of the Department of Geology and Geophysics from the University of Utah, as an expert on volcanic materials and their use in mortars and concretes throughout the history of architecture.
Petrographic image from a “theran earth” sample, H.S.G.M.E. Dr. Christos Papatrechas
The understanding of the historic materials and local techniques, as well as the design of compatible restoration syntheses create the methodological toolset for an approach that complies with the modern principles of cultural heritage preservation. This is an approach which is appropriate for the documentation of a knowledge mostly forgotten, yet important for the history of architecture and of the area.
A modern restoration project that fosters the use of traditional techniques and engages local masons contributes towards the appreciation and rejuvenation of this knowledge while broaching how the historical knowhow may be integrated into restoration practices which are more consistent with the cultural and historical context of a place.
The interdisciplinary collaborations within this project are an in depth exploration of theran earth’s ‘character’; from its physicochemical characteristics and mechanical strength to its ability to be part of artistic expression and cultural values.