Cultural heritage: volcanic ash or industrial waste for restoration

“We are developing new generation ‘green’ materials: alkaline-activated geopolymers, which can be generated from clays, volcanic ash and industrial waste, and be used in the restoration of Cultural Heritage, as well as in various other applications. This with an innovative and interdisciplinary approach to research, which allows qualified interventions to recover the artistic heritage “. So prof. Salvatore Magazù, full professor of Physics at the University of Messina, presenting the peculiarities of these innovative materials in a workshop, held at the Castle of Milazzo, as part of the Pon ‘AGM project for CuHe: Advanced green materials for cultural heritage’, in the Cultural Heritage specialization area of ​​the 2015-2020 National Program. “The AGM for CuHe project – explains Magazù – traces a path that, starting from the resources of the territory, through the development of new generation materials through interdisciplinary approaches, aims above all at restoring the cultural heritage”. Geopolymers are produced by means of a treatment at relatively low temperatures and, therefore, with a low environmental impact. These synthetic rocks are characterized by a chemical composition and mineralogical structure similar to those typical of natural rocks with, however, enhanced technical properties such as mechanical resilience, chemical stability and longevity. “The materials studied – explains Magazù – are eco friendly, smart and with excellent technical characteristics, which make them highly performing compared to conventional materials. Furthermore, by recycling volcanic ash, or waste from blast furnaces, it is possible to restore value to materials considered waste. The development of geopolymer products allows us to provide valid alternatives to traditional cementitious materials responsible for the consumption of large quantities of energy and water. Since it is estimated that by 2030 the activity of the cement industry will increase production by about 25%, the development of materials such as geopolymers is of increasing importance ”. In this regard, prof. Magazù illustrates an increasingly accredited hypothesis according to which the rocks that make up the great Egyptian pyramids “would consist of the two types of stone; one coming from quarries, the other artificially generated (the geopolymer) and thanks to the use of spectroscopic techniques, this discrimination is now possible. This hypothesis would explain how the builders of pyramids managed to build blocks of hundreds of tons using on-site mixtures ”. This hypothesis would explain “why the external facades of the pyramids are put together as pieces of a puzzle that fit together perfectly. The findings that emerge from these visual inspections are supported by experimental evidence obtained with complementary spectroscopic techniques that have revealed the synthetic nature of these materials “.” Finally, – continues Magazù – a not negligible aspect, these issues can relaunch some research and industrial vocational activities for the territory, also determining the growth of qualified tourism in the quarries of the island. These are limestone mining sites , pumice, tuff, sand, clay and gypsum that today could be recovered and converted to a geopolymer, creating new jobs and at the same time safeguarding the environment. Numerous projects have been developed in the past on clays such as “La Via dell ‘ clay for development and productivity ”, ‘From traditional tourism to a tourism system l integrated ocale ‘, the’ Central Tyrrhenian tourist center ‘,’ PIT 33 ‘Nebrodi’ which involved various municipalities in the province of Messina. Clay quarries and ancient industrial sites, assisted by laboratories serving companies operating in the area, could support companies with research and development activities. This is the case of the Hoffman furnaces in Venetico (Me), which can become places of research, development and tourist attraction; otherwise we would risk the irremediable loss of the history and memory of these territories “.