Environmentally-Friendly Dense and Porous Geopolymers Using Fly Ash and Rice Husk Ash as Raw Materials

This paper assesses the feasibility of two industrial wastes, fly ash (FA) and rice husk ash (RHA), as raw materials for the production of geopolymeric pastes. Three typologies of samples were thus produced: (i) halloysite activated with potassium hydroxide and nanosilica, used as the reference sample (HL-S); (ii) halloysite activated with rice husk ash dissolved into KOH solution (HL-R); (iii) FA activated with the alkaline solution realized with the rice husk ash (FA-R). Dense and porous samples were produced and characterized in terms of mechanical properties and environmental impact. The flexural and compressive strength of HL-R reached about 9 and 43 MPa, respectively. On the contrary, the compressive strength of FA-R is significantly lower than the HL-R one, in spite of a comparable flexural strength being reached. However, when porous samples are concerned, FA-R shows comparable or even higher strength than HL-R. Thus, the current results show that RHA is a valuable alternative to silica nanopowder to prepare the activator solution, to be used either with calcined clay and fly ash feedstock materials. Finally, a preliminary evaluation of the global warming potential (GWP) was performed for the three investigated formulations. With the mix containing FA and RHA-based silica solution, a reduction of about 90% of GWP was achieved with respect to the values obtained for the reference formulatio

The plasters of the Sacro Monte of Varallo Sesia. From the characterisation to the proposition of a restorative mix

Abstract In this paper, the systematic physical-chemical characterisation of historical plasters of the Sacro Monte of Varallo Sesia, Italy, the study of the local constructive techniques, as well as the evaluation of new restoration plasters is presented. The selected samples (from XVI to XVIIIth centuries) are in a quite good state of conservation despite the prolonged exposition to weathering agents. This behaviour is due to the good manufacturing and to the peculiar smooth finishing layers which reduce water permeability and allow water drops to slide off. The plasters characterisation realised in laboratory for in situ integration is also presented. These plasters should meet functional and aesthetical requirements and must satisfy the compatibility issues not only related to the physical-chemical aspects

“Materiale edilizio ottenuto da attivazione alcalina di minerali contenuti in prodotti e residui da attività estrattiva e lavorativa e processo di produzione di un tale materiale edilizio"

L'invenzione si riferisce a un materiale edilizio ottenuto da attivazione alcalina di minerali contenuti in prodotti e residui da attività estrattiva e lavorativa. La presente invenzione si riferisce altresì a un processo di produzione di tale materiale edilizio. In particolare, la presente invenzione si riferisce ai minerali presenti nei fanghi provenienti dal taglio di materiali lapidei ricchi di silicati o dall’impiego di altri prodotti di lavorazione ed estrazione da cava, quali ad esempio le cosiddette materie prime secondarie “MPS” costituite da scarti di lavorazione delle materie prime o dal recupero e dal riciclaggio dei rifiuti

Setup of Extruded Cementitious Hollow Tubes as Containing/Releasing Devices in Self-Healing Systems

N.M.P. is supported by the European Research Council (ERC Starting Grant Ideas 2011 BIHSNAM No. 279985 on ‘Bio-inspired hierarchical supernanomaterials’, ERC Proof of Concept (PoC) 2013-1 REPLICA2 No. 619448 on ‘Large-area replication of biological anti-adhesive nanosurfaces’, ERC PoC 2013-2 KNOTOUGH no. 632277 on ‘Super-tough knotted fibres’), by the European Commission under the Graphene Flagship (WP10 ‘Nanocomposites’, No. 604391) and by the Provincia Autonoma di Trento (‘Graphene nanocomposites’, No. S116/2012-242637 and regional deliberation No. 2266)

Experimental analysis of self-healing cement-based materials incorporating extruded cementitious hollow tubes

The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: N.M.P. is supported by the European Research Council (ERC Starting Grant Ideas 2011 BIHSNAM No. 279985 on ‘‘Bio-inspired hierarchical supernanomaterials,’’ ERC Proof of Concept (PoC) 2013-1 REPLICA2 No. 619448 on ‘‘Large-area replication of biological anti-adhesive nanosurfaces,’’ ERC PoC 2013-2 KNOTOUGH no. 632277 on ‘‘Super-tough knotted fibres’’), by the European Commission under the Graphene Flagship (WP10 ‘‘Nanocomposites,’’ No. 604391), and by the Provincia Autonoma di Trento (‘‘Graphene nanocomposites,’’ No. S116/2012-242637 and regional deliberation No. 2266)

Saving temporary exhibitions in virtual environments: The Digital Renaissance of Ulisse Aldrovandi – Acquisition and digitisation of cultural heritage objects

As per the objectives of Project CHANGES, particularly its thematic sub-project on the use of virtual technologies for museums and art collections, our goal was to obtain a digital twin of the temporary exhibition on Ulisse Aldrovandi called “The Other Renaissance”, and make it accessible to users online. After a preliminary study of the exhibition, focusing on acquisition constraints and related solutions, we proceeded with the digital twin creation by acquiring, processing, modelling, optimising, exporting, and metadating the exhibition. We made hybrid use of two acquisition techniques to create new digital cultural heritage objects and environments, and we used open technologies, formats, and protocols to make available the final digital product. Here, we describe the process of collecting and curating bibliographical exhibition (meta) data and the beginning of the digital twin creation to foster its findability, accessibility, interoperability, and reusability. The creation of the digital twin is currently ongoing

La conoscenza e il progetto di conservazione di alcuni intonaci storici del Sacro Monte di Varallo Sesia

La tesi di dottorato è caratterizzata da una forte interdisciplinarietà e ha come obiettivo lo sviluppo di un approccio trasversale alla conservazione delle superfici intonacate in cui la conoscenza del materiale, delle risorse del territorio, delle tecniche costruttive e l'applicazione di innovazioni tecnologiche sono alcune delle diverse prospettive di un unico tema. Il Sacro Monte di Varallo Sesia (VC), è stato scelto come sito sperimentale della ricerca in virtù degli intonaci storici di grande pregio che caratterizzano il sito. Il presente lavoro è suddiviso in due macroaree sperimentali correlate. I possibili interventi sull'intonaco sono infatti commisurati alla dimensione microscopica e macroscopica del degrado. In questo senso, la sintesi di materiali ibridi per il consolidamento corticale e la formulazione di intonaci compatibili per la reintegrazione, tali da garantire i requisiti di compatibilità e stabilità nel tempo, costituiscono le due fasi sperimentali che caratterizzano la ricerca. La prima macro-area della tesi prevede la sintesi e la sperimentazione di nuovi materiali ibridi organici-inorganici per il consolidamento corticale degli intonaci e la loro protezione. In questi materiali, da poco applicati nel settore della conservazione dei materiali lapidei, si coniugano le capacità di adesione, di resistenza meccanica, di idrofobicità, proprie delle resine organiche con la maggiore compatibilità verso il supporto offerta dalla componente inorganica. Inoltre, nell'ottica di un progetto di conservazione sostenibile per l'uomo e per l'ambiente, i materiali utilizzati contengono una bassa quantità di solventi. Per lo stesso motivo, è stata sperimentata anche una metodologia di polimerizzazione via redox che consente di reticolare in situ il polimero senza l'uso di ammine. Nella seconda macro-area l'attenzione è rivolta alle problematiche inerenti i degradi di tipo macroscopico e alla necessità di reintegrazione delle lacune. Sulla base delle conoscenze acquisite nella fase di analisi, sono state ricercate delle soluzioni percorribili rispetto alla complessità del palinsesto architettonico oggetto d'esame. In particolare è necessario che l'intervento sia coerente con il contesto non solo in termini materici, ma anche rispetto al contesto socio economico e culturale e capace di rispettare l'immagine consolidata del bene che, in questo caso, non può essere slegata dal forte significato devozionale. In un percorso di ricerca così strutturato, il progetto di conservazione compatibile e sostenibile si sviluppa nella sua multidimensionalit

Future-Centred Design Education. Projects and Perspectives for Future Challenges

The essay introduces the results of the second edition of the research project FutureDesignEd "Innovation in Design Education - Innovation in Education by Design" (2020), focusing on the topic of Future-Centred Design Education

Statistical significance of curing variables on geopolymerization of mining by-product untreated clay

The focus of this research is to investigate of the possibility of reusing mineral wastes and by-products from mining processes to produce more sustainable binders in large amounts. A mining by-product consisting of halloysite (approximately 48 wt%) was used to produce dense alkali activated solids. Attention was paid to the influence of temperature on the geopolymerisation process in terms of the microstructural characteristics of the samples obtained. The challenge was to alkali activate the clay as received without any firing pre-treatment. The fresh paste of untreated clay was cured at 50% relative humidity (RH%) at different temperatures: 40, 60, and 70 °C. The halloysite-bearing powder (HC) was then mixed with a low-quartz sand, a second by-product of the mining industry, to achieve higher chemical stability. The results showed a clear difference in chemical stability for samples containing sand compared to those without sand. Low percentages of metakaolin (5–15%) were also added to the same formulations to improve the chemical and physical properties of the samples and to reduce the curing time. For mixtures consisting of untreated clay and sand only NaOH was added as alkaline activator. The effect of curing temperature, curing time and addition of metakaolin (MK) on the microstructure of the geopolymers was analysed by different techniques: measurement of pH and ionic conductivity of the eluate of the chemical stability test in water, X-ray diffraction (XRD), scanning electron microscopy (SEM), bulk density, and compressive strength. Finally, a statistical approach was adopted to rationalise the effect of the curing conditions on the consolidation of the fresh pastes of samples with the untreated HC, sand and metakaolin. To test whether the parameters of the curing process, as well as the MK addition had an influence on the values of the ionic conductivity of the eluate from water sinking and/or the density of the solid final product, a 3-way ANOVA followed by Tukey-Kramer post hoc tests (p < 0.05) were performed. To further investigate the interaction between preparation parameters and the material properties, we also built a Generalized Linear model that provided an equation to predict the final results. Overall, we found that the addition of MK significantly reduced the conductivity while only marginally increasing the density of the material. This effect was extremely temperature-dependent, and it disappeared at 70 °C. In conclusion, it has been demonstrated how the addition of fillers, an easily controllable industrial step, can maximise the performance of the consolidated material, rather than controlling the curing time and temperature conditions