The sustainable development goals of Agenda 2030 prompt to do a quick Ecological Transition towards alternative materials with high-tech performance. In this scenario, alkali activated materials (AAMs) represent the green alternative to the traditional materials based on cement. This class of solid materials is synthesised by the mixing of a powdered aluminosilicate source with an alkaline solution [1]. Moreover, both natural materials and industrial by-products can be used as precursors in the alkaline process with a sustainable management of waste materials [2]. The huge deposits of volcanic ashes of Mt. Etna volcano can represent potential exploitable resources to produce sustainable and innovative materials with specific features. Indeed, previous works demonstrated both their suitability to alkaline environment thanks to chemical and mineralogical compositions [3, 4], as well as good physical-mechanical features of AA-products [5, 6]. In detail, the volcanic ashes resistance to high temperature [3] encouraged us to use them for the production of ceramics with improved thermal performances. In this scenario, the samples were prepared using sodium or potassium solutions, with the aim to compare them in terms of durability to high temperatures. For this purpose, a multidisciplinary approach was applied by means of in-situ infrared spectroscopy, differential thermal analysis, mechanical compressive tests at room temperature and after thermal treatment at 1000°C, and X-ray diffraction. Infrared spectroscopy allowed to control the formation kinetics of different networks, based on Al and Ca. Thermal analysis of no-treated samples underlined that the composition displaying the highest mechanical properties shows the least amount of water. The results of mechanical tests were interesting: the samples treated at 1000°C recorded higher compressive strengths than the corresponding cured at room temperature. The structural data of thermal treated at 1000°C samples highlighted the crystallization of different phases, based on the raw materials used: wollastonite, leucite and nepheline. Therefore, this work describes the high potentiality of volcanic ashes in alkaline environment for high temperature applications, as cost-efficient and sustainable materials, in comparison to traditional ones.
 
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3.        Finocchiaro C, Barone G, Mazzoleni P, et al (2020) FT-IR study of early stages of alkali activated materials based on pyroclastic deposits (Mt. Etna, Sicily, Italy) using two different alkaline solutions. Constr Build Mater 262:. https://doi.org/10.1016/j.conbuildmat.2020.120095
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5.        Fugazzotto M, Occhipinti R, Cristina Caggiani M, et al (2023) Restoration feasibility study by using alkali activated mortars based on Mt. Etna volcanic ash: The case study of Monreale Cathedral (Palermo, Italy). Mater Lett 333:133626. https://doi.org/10.1016/J.MATLET.2022.133626
6.        Finocchiaro C, Belfiore CM, Barone G, Mazzoleni P (2022) IR-Thermography as a non-destructive tool to derive indirect information on the physical-mechanical behaviour of alkali activated materials. Ceram Int. https://doi.org/10.1016/J.CERAMINT.2022.08.174