Fly ash aggregate developed by means of cold-bonding

This graduation thesis is concerned with the development of a fly ash based aggregate by\ud means of the cold-bonding process, by casting and then crushing into individual fractions.\ud Three different proportions of Portland cement, i.e. 10%, 20%, and 30%, were used in the\ud mixture as a binder. Prior to use, the chemical and mineral characteristics of the fly ash were\ud determined, as well as the corresponding loss of ignition. The comparative aggregate was\ud developed by means of the cold bonding pelletization process. Based on the results of tests\ud of the tensile and compressive strengths of the crushed aggregate, a cement ratio of 10 %\ud was used in this process. Density, water adsorption capacity, and porosity, as well as tensile\ud and compressive strengths, were determined for the produced aggregates after aging them\ud at constant humidity. SEM investigations were also performed, and the results obtained in\ud the case of both produced aggregates were compared. In order to assess performance of the\ud aggregates in practice, both of them were used in concrete, and the results of tensile and\ud compressive strength tests were compared with those achieved in the case when the\ud concrete was made using limestone aggregate

Evaluation of innovative façade panels with a finishing layer of alkaliactivated industrial and construction waste

V sklopu magistrskega dela smo preiskali fizikalno-mehanske lastnosti, ki določajo obstojnost na novo razvitih fasadnih panelov iz alkalijsko aktiviranih materialov. S pomočjo energijskih simulacij in modeliranja smo primerjali njihov vpliv na notranje toplotno udobje s standardno kontaktno toplotnoizolacijsko fasado (ETICS). Paneli z visoko vsebnostjo industrijskih in gradbenih odpadkov so bili razviti v sklopu mednarodnega projekta H2020 InnoWEE in so sestavljeni iz dveh slojev ekspandiranega polistirena in zaključnega sloja. Zaključni sloj sestavljata vezivo iz alkalijsko aktivirane mešanice metakaolina, elektrofiltrskega pepela in granulirane plavžne žlindre ter agregat iz gradbenih odpadkov (beton, keramika, opeka in malta). Ker so alkalijsko aktivirani proizvodi razmeroma nov material, ki v praksi še ni primerno ovrednoten in za njegovo preizkušanje ni predpisanih standardnih metod, je treba pred uvedbo na trg izvesti obsežna testiranja. Tako smo na fasadnih panelih izvedli naslednje preiskave: vpijanje vode, prepustnost za vodno paro, določanje odtržne trdnosti, določanje gostote, poroznosti in porazdelitve por zaključnega sloja, določanje zmrzlinske odpornosti, določanje odpornosti na zmrzovanje-tajanje ob prisotnosti soli, odpornost na udarce, odpornost na karbonatizacijo, alkalijsko-silikatna reaktivnost in odpornost na sulfate. Na podlagi rezultatov teh preiskav smo podali oceno uporabnosti fasadnih panelov. Prav tako smo s programoma Ubakus in DesignBuilder na enostavnem objektu enodružinske hiše določili vpliv fasadnih panelov na prehod toplote in snovi skozi konstrukcijski sklop zunanje stene ter preverili njihov vpliv na energijsko učinkovitost objekta. Rezultate smo primerjali s klasično kontaktno toplotnoizolacijsko fasado.Within the scope of the master\u27s thesis we investigated the physical and mechanical properties that determine the durability of newly developed façade panels made of alkali-activated materials. Using energy simulations and modelling, we compared their effects on thermal comfort in interiors with a standard contact thermal insulation façade system (ETICS). The panels with a high proportion of industrial and construction waste were developed as part of the international H2020 project InnoWEE and consist of two layers of expanded polystyrene and a finishing layer. The final layer consists of a binder consisting of an alkali-activated mixture of metakaolin, fly ash and granulated blast furnace slag and an aggregate of construction waste (concrete, ceramics, bricks and mortar). As the alkali-activated products are a relatively new material which has not yet been sufficiently evaluated in practise and there are no prescribed standard methods for testing it, it is necessary to carry out extensive testing before placing it on the market. Thus, we have carried out the following tests on façade panels: water absorption, water vapour permeability, determination of the bond strength, determination of the density, porosity and pore distribution of the finishing layer, freeze-thaw behaviour, freeze-thaw resistance in the presence of de-icing salt, impact strength, carbonation resistance, alkali silicate reactivity and sulphate resistance. Based on the results of the tests carried out, we gave an assessment of the usability of the façade panels. We also used the Ubakus and DesignBuilder programs to determine the influence of façade panels on the passage of heat and matter through the structural assembly of the exterior wall on a simple building model (single-family house) and to verify their impact on the energy efficiency of the building. The results obtained were compared with a classic external thermal insulation composite façade system (ETICS)

Mechanical, microstructural and mineralogical evaluation of alkali-activated waste glass and stone wool

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

The development and assessment of alkali activated paving blocks

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

Up-scaling and performance assessment of façade panels produced from construction and demolition waste using alkali activation technology

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