1. The development and assessment of alkali activated paving blocksAna Frankovič, Vilma Ducman, Lubica Kriskova, Efthymios Tatsis, Petrica Petrica, Yiannis Pontikes, 2022, objavljeni znanstveni prispevek na konferenci Povzetek: In recent years great attention has been placed by the building sector on alkali-activated technology based on metakaolin, fly ash and ground granulated blast furnace slag (GGBFS), but also on emerging precursors such as by-products from non-ferrous metallurgy. The present work focuses on the development of alkali-activated binders from two slags, one from primary and one from secondary copper production, which were finely milled, blended with GGBFS, and activated with K-based alkali silicate solution with a 1.7 SiO2/K2O molar ratio. The aggregate to paste mass ratio was 2. The mixtures were cast, and cured for a designated time at room temperature and 60% RH. The so-obtained paving blocks were then tested in accordance with European standard for concrete paving blocks. The following properties were measured: splitting tensile strength, abrasion resistance, slip and skid resistance, resistance to freeze-thaw and resistance to freeze-thaw in the presence of de-icing salts. Their properties were compared to those of commercially available concrete paving blocks, and it was found that the performance of the alkali-activated pavers was generally comparable with the concrete pavers, while certain properties (e.g., abrasion resistance, freeze-thaw resistance and freeze-thaw resistance in presence of de-icing salts) were considerably better.
Ključne besede: slags, alkali activated pavers, properties
Objavljeno v DiRROS: 21.12.2023; Ogledov: 165; Prenosov: 62
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2. 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, izvirni znanstveni članek Povzetek: 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.
Ključne besede: construction and demolition waste, alkali activated materials, geopolymers, properties, up-scalimg
Objavljeno v DiRROS: 21.08.2023; Ogledov: 268; Prenosov: 145
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3. Mechanical, microstructural and mineralogical evaluation of alkali-activated waste glass and stone woolMajda Pavlin, Barbara Horvat, Ana Frankovič, Vilma Ducman, 2021, izvirni znanstveni članek Povzetek: Mineral waste wool represents a significant part of construction and demolition waste (CDW) not yet being successfully re-utilized. In the present study, waste stone wool (SW) and glass wool (GW) in the form received, without removing the binder, were evaluated for their potential use in alkali activation technology. It was confirmed that both can be used in the preparation of alkali-activated materials (AAMs), whether cured at room temperature or at an elevated temperature in order to speed up the reaction. The results show that it is possible to obtain a compressive strength of over 50 MPa using SW or GW as a precursor. A strength of 53 MPa was obtained in AAM based on GW after curing for 3 days at 40 °C, while a similar compressive strength (58 MPa) was achieved after curing the GW mixture for 56 days at room temperature. In general, the mechanical properties of samples based on GW are better than those based on SW. The evolution of mechanical properties and recognition of influential parameters were determined by various microstructural analyses, including XRD, SEM, MIP, and FTIR. The type of activator (solely NaOH or a combination of NaOH and sodium silicate), and the SiO2/Na2O and liquid to solid (L/S) ratios were found to be the significant parameters. A lower SiO2/Na2O ratio and low L/S ratio significantly improve the mechanical strength of AAMs made from both types of mineral wool.
Ključne besede: alkali activation, waste mineral wool, mechanical strength
Objavljeno v DiRROS: 31.07.2023; Ogledov: 248; Prenosov: 237
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