In this work, we present for the first time the feasibility of applying Alkali Activated Materials (AAMs) synthesized by recycling stone sawing sludges as precursors for Cultural Heritage restoration and conservation purposes. AAMs are inorganic polymeric materials originating from the dissolution of aluminosilicate powdered compounds in alkaline solutions and the consequent condensation of the resulting pastes in a solid 3D network (Davidovits, 1991). AAMs could potentially have a lower environmental impact than traditional restoration and conservation products given that they offer the possibility of recycling stone wastes, which in turn, prevents the exploitation of new raw materials, promoting a circular economy (Barone et al., 2021; Portale et al., 2023). Moreover, their synthesis takes place at room temperature and without any precursor pre-treatment. In this way, production costs, thermal energy demand and, therefore, CO2 emissions are lowered (Turner and Collins, 2013). The waste materials chosen for this study are stone sawing sludges (SS) composed of powders deriving from rock cutting and polishing processes mixed together with water for cooling down the sawing tools. SS are the most abundant products resulting from the stone processing industry: they amount up to 41% of the total processed rocks (Montani, 2021). The disposal of this waste is regulated by EWC 010413 in Europe and by D.lgs. n. 156/06 in Italy. Nevertheless, disposing means deprivation of a future for these potential geo-resources and it is therefore why their reuse has become an interesting challenge in the view of a circular economy. The present work focuses on the characterization studies carried out on both SS and SS-based AAMs to investigate their chemical, mineralogical, microstructural and physical-mechanical features by means of analytical techniques such as XRF, XRD, FT-IR, SEM, colorimetry, uniaxial compressive and bending tests. The samples were also investigated by means of Oddy test, useful to investigate the potential harmful impact when using on or displaying AAMs with real artifacts. In addition, the research presents preliminary results of the SS-based AAMs application for the conservation of archaeological pottery. Selected compositions were used as fillers on no-value ceramic pots to simulate the potential behaviour on real artifacts. Changes in the physical properties of the pastes, as well as their interaction with the ceramic bodies, were monitored over time, starting from the moment of application up to a month after that: a score from one (very bad) to five (very good) was assigned to features such as ease of mixing and application, stickiness, working time, contamination of ceramic, reversibility and flexibility. The obtained results lead us to promising outlooks in the fields of conservation and restoration.
New geo-resources for the conservation of Cultural Heritage: feasibility study on the application of stone sawing sludges-based Alkali Activated Materials
Portale S.
Primo
;Barone G.;Mazzoleni P.
2023-01-01
Abstract
In this work, we present for the first time the feasibility of applying Alkali Activated Materials (AAMs) synthesized by recycling stone sawing sludges as precursors for Cultural Heritage restoration and conservation purposes. AAMs are inorganic polymeric materials originating from the dissolution of aluminosilicate powdered compounds in alkaline solutions and the consequent condensation of the resulting pastes in a solid 3D network (Davidovits, 1991). AAMs could potentially have a lower environmental impact than traditional restoration and conservation products given that they offer the possibility of recycling stone wastes, which in turn, prevents the exploitation of new raw materials, promoting a circular economy (Barone et al., 2021; Portale et al., 2023). Moreover, their synthesis takes place at room temperature and without any precursor pre-treatment. In this way, production costs, thermal energy demand and, therefore, CO2 emissions are lowered (Turner and Collins, 2013). The waste materials chosen for this study are stone sawing sludges (SS) composed of powders deriving from rock cutting and polishing processes mixed together with water for cooling down the sawing tools. SS are the most abundant products resulting from the stone processing industry: they amount up to 41% of the total processed rocks (Montani, 2021). The disposal of this waste is regulated by EWC 010413 in Europe and by D.lgs. n. 156/06 in Italy. Nevertheless, disposing means deprivation of a future for these potential geo-resources and it is therefore why their reuse has become an interesting challenge in the view of a circular economy. The present work focuses on the characterization studies carried out on both SS and SS-based AAMs to investigate their chemical, mineralogical, microstructural and physical-mechanical features by means of analytical techniques such as XRF, XRD, FT-IR, SEM, colorimetry, uniaxial compressive and bending tests. The samples were also investigated by means of Oddy test, useful to investigate the potential harmful impact when using on or displaying AAMs with real artifacts. In addition, the research presents preliminary results of the SS-based AAMs application for the conservation of archaeological pottery. Selected compositions were used as fillers on no-value ceramic pots to simulate the potential behaviour on real artifacts. Changes in the physical properties of the pastes, as well as their interaction with the ceramic bodies, were monitored over time, starting from the moment of application up to a month after that: a score from one (very bad) to five (very good) was assigned to features such as ease of mixing and application, stickiness, working time, contamination of ceramic, reversibility and flexibility. The obtained results lead us to promising outlooks in the fields of conservation and restoration.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
