1. Detoxified spent pot lining from aluminum production as (alumino-)silicate source for composite cement and autoclaved aerated concreteArne Peys, Mateja Košir, Ruben Snellings, Ana Mladenovič, Liesbeth Horckmans, 2021, original scientific article Abstract: New sources of supplementary cementitious materials (SCMs) are needed to meet the future demand. A potential new source of SCM is spent pot lining, a residue from aluminum production. The present work showed that the refined aluminosilicate part of spent pot lining (SPL) has a moderate chemical reactivity in a cementitious system measured in the R3 calorimetry test, comparable to commercially used coal fly ash. The reaction of SPL led to the consumption of Ca(OH)2 in a cement paste beyond 7 days after mixing. At 28 and 90 days a significant contribution to strength development was therefore observed, reaching a relative strength, which is similar to composite cements with coal fly ash. At early age a retardation of the cement hydration is caused by the SPL, which should most likely be associated with the presence of trace amounts of NH3. The spent pot lining is also investigated as silica source for autoclaved aerated concrete blocks. The replacement of quartz by spent pot lining did not show an adverse effect on the strength-density relation of the lightweight blocks up to 50 wt% quartz substitution. Overall, spent pot lining can be used in small replacement volumes (30 wt%) as SCM or as replacement of quartz (50 wt%) in autoclaved aerated concrete blocks. Keywords: spent pot lining, construction materials, recycling, autoclaved aerated conctrte, supplementary cementitious material Published in DiRROS: 04.12.2023; Views: 376; Downloads: 150
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2. Life cycle assessment of prefabricated geopolymeric façade cladding panels made from large fractions of recycled construction and demolition wasteDavor Kvočka, Anja Lešek, Friderik Knez, Vilma Ducman, Matteo Panizza, Constantinos Tsoutis, Adriana Bernardi, 2020, original scientific article Abstract: The construction and demolition sector is one of the biggest consumers of natural resources in the world and consequently, one of the biggest waste producers worldwide. The proper management of construction and demolition waste (CDW) can provide major benefits for the construction and recycling industry. However, the recycling rate of CDW is relatively low, as there is still a lack of confidence in the quality of recycled CDW materials. Therefore, new research projects are looking for innovative solutions within recycling of CDW in order to overcome uncertainties currently associated with the use of construction products made from recycled or re-used CDW. In this paper, a “cradle-to-cradle” life cycle assessment (LCA) study has been conducted to investigate the environmental performance of the prefabricated geopolymeric façade cladding panels made from large fractions of CDW. The LCA results indicate that the majority of the environmental burden arises within the manufacturing stage; however, the environmental burden can be reduced with simple optimisation of the manufacturing process. Furthermore, the environmental impact of the prefabricated geopolymeric façade cladding panels is generally lower than the environmental burden associated with the façade cladding panels made from virgin materials. Keywords: construction and demolition waste, alkali activated materials, geopolymers, LCA Published in DiRROS: 24.08.2023; Views: 428; Downloads: 217
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3. Up-scaling and performance assessment of façade panels produced from construction and demolition waste using alkali activation technologyAna Frankovič, Vilma Ducman, Sabina Dolenec, Matteo Panizza, Sergio Tamburini, Marco Natali, Katherine-Maria Pappas, Constantinos Tsoutis, Adriana Bernardi, 2020, original scientific article Abstract: Novel prefabricated insulating façade panels were developed from construction and demolition waste (CDW) aggregates under the framework of the European H2020 project InnoWEE. These non-structural components, aimed at improving the thermal efficiency of existing buildings, consist of an insulating plate covered by a facing layer made of CDW aggregates bound with metakaolin, furnace slag and class F fly ash activated by a potassium silicate solution. The paper presents the design and assessment of the binder and panels for exterior use, taking into account mechanical performance, behaviour in the presence of water and durability issues. Testing was carried out on both laboratory prototypes and panels from the pilot industrial production. Keywords: construction and demolition waste, alkali activated materials, geopolymers, properties, up-scalimg Published in DiRROS: 21.08.2023; Views: 438; Downloads: 254
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4. Optimization and mechanical-physical characterization of geopolymers with construction and demolition waste (CDW) aggregates for construction productsMatteo Panizza, Marco Natali, Enrico Garbin, Vilma Ducman, Sergio Tamburini, 2020, original scientific article Abstract: The paper presents the mechanical and physical characterization of a metakaolin-slag-fly ash-potassium silicate geopolymer mortar embedding inorganic recycled aggregates from Construction and Demolition Waste (CDW). The binder was holistically optimized to comply with the pilot plant requirements for producing architectural panels of satisfactory quality, among them: reduced viscosity, minimum open time of 1 h, use of commercial reagents, sufficient strength and limited shrinkage. Size and aspect ratio of small scale cylindrical specimens were investigated in compression, comparing the performance of tested geopolymers to available provisions for natural rocks, cement concrete and mortars. Empirical correlations between compressive and splitting tensile strength were calibrated through the results of about 130 geopolymer mixtures produced in former and current activities. Lastly, the suitability of reusing geopolymers at their end-of-life as recycled aggregates in a new geopolymer production was preliminarily assessed to explore the feasibility of a closed-loop process. Keywords: construction and demolition waste, alkali activated materials, geopolymers, properties Published in DiRROS: 17.08.2023; Views: 507; Downloads: 254
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