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- Evaluating the fire behaviour of cement-based lightweight materials with textile waste incorporation using a cone calorimeterPublication . Magalhães, Leandro; Conde, Otávio Sateles; Mesquita, L.M.R.; Briga-Sá, Ana; Ferreira, DéboraThe conscientious utilization of natural resources and the efficient waste management have become a matter of great concern in recent years due to the harmful impacts on the environment. The construction sector presents itself as one of the sectors that most contributes to raw materials consumption and waste generation, demanding the investigation of more sustainable and ecofriendly building materials, where the valorisation of wastes originated from other industries can be promising. Following the sustainability concept in construction materials, this work investigates the potential use of textile waste in cement-based lightweight construction material, evaluating the fire reaction of the material using the cone calorimeter equipment. The samples were tested at three different radiant heat fluxes (35 kW/m2, 50 kW/m2, 75 kW/m2) to simulate different fire situations. For the highest heat flux, the lightweight construction element with textile waste incorporation showed a Heat Release Rate Average ≤ 18 kW/m2, a peak Heat Release Rate Average ≤ 60 kW/m2, and a Total Heat Release Average ≤ 33 MJ/m2. These results reveal a very satisfactory fire behaviour compared to other materials and show the suitability of using textile waste as lightweight cement-based materials.
- Thermal performance characterization of cement-based lightweight blocks incorporating textile wastePublication . Briga-Sá, Ana; Gaibor, Norma; Magalhães, Leandro; Pinto, Tiago; Leitão, DinisTextile industry is one of the most important sectors of the global economy, but at the same rate as production, millions of tons of textile waste (TW) are generated worldwide, causing negative impacts on the environment. To mitigate CO2 emissions and TW landfilled, its reuse and recycling are considered promising in fulfilling the circular economy principles. Furthermore, its valorization as building materials components may be a contribution towards sustainable construction. Studies already developed in this domain demonstrate that more research work is needed so the suitability of TW as building insulation materials can be assessed. In this context, it is intended with the research work here presented to propose cement-based lightweight blocks (LWB) incorporating TW and discuss their application as insulation materials purposes. The studied TW was fabric leftovers from the textile industry, constituted by 70 % wool, 25% viscose, and 5% elastane. TW percentages of 6.25%, 8.16%, and 8.75% were considered in the cement mixture composition of LWB1, LWB2 and LWB3, respectively, and their influence on the LWB thermal performance was analyzed. The LWB thermal performance characterization was carried out by analyzing heat fluxes, inner surface temperatures, thermal transmission coefficients, and infrared thermal imaging. The obtained results revealed their suitability for thermal insulation applications. Values of 0.34 m2◦C/W, 0.61 m2◦C/W, and 0.67 m2◦C/W were estimated for the thermal resistance of LWB1, LWB2 and LWB3, respectively, achieving higher thermal stability when higher percentage of TW is incorporated in the cementitious mixture composition. A comparison of the LWB with currently available building materials, such as simple masonry walls and insulating concrete forms, was also performed showing promising results for the proposed textile waste-based materials.
- Enhancing concrete sustainability with spent diatomaceous earth from the wine industry: Long‐term experimental and statistical analysisPublication . Magalhães, Leandro; Ferreira, Débora; Ramos‐Gavilán, Ana BelénSpent diatomaceous earth, a by-product of wine filtration, holds significant promise for use in concrete mixtures due to its pozzolanic properties, which enhance concrete performance. This research explores the application of spent calcined diatomaceous earth (SCDE), heat-treated at 700 C to remove organic content, as a partial substitute for cement or sand in concrete. The high silica content of SCDE contributes to the formation of additional calcium silicate hydrates during the hydration process, leading to improvements in mechanical strength over time. The study includes a preliminary analysis of cement replacements ranging from 5% to 10% and sand replacements from 2.5% to 15%, assessing their effects on workability, density, water absorption, and compressive strength at 7 and 28 days. The testing program focuses on three key compositions: the reference concrete and optimal mixtures with 10% cement and 5% sand replacements. Compressive strength tests are conducted at 7, 28, 90, 180, and 360 days. The results, validated through ANOVA, demonstrate the influence of SCDE on concrete strength over time, with distinctive behavior patterns identified for different mixtures. The strength of concrete with replacements correlates with the reference strength, with a multiplicative factor that varies from 7 to 90 days and then. When SCDE replaces cement, the factor is less than one before 28 days due to the slow pozzolanic reaction, whereas for sand replacement, it always exceeds one because of the initial filler effect. After 90 days, the strength multiplicative factors are 1.13 for cement replacement and 1.30 for sand replacement, demonstrating the potential of SCDE for sustainable concrete manufacturing and its positive long-termimpact on mechanical performance.
- Fire behaviour of mortars with portland cement and residual diatomaceous earthPublication . Magalhães, Leandro; Zolin, Renan Calvo; Alves, Matheus Henrique; Barreira, Luísa; Ferreira, Débora; Luso, Eduarda; Mesquita, L.M.R.; Óscar, LimaThe high pollution levels produced by the manufacturing of conventional Portland cement have motivated several studies in an attempt to modernize this process with alternative binders and the conscious use of natural resources. The correct treatment of residues has become a matter of great concern. The project “BacchusTech” aims to reuse diatomaceous earth from wine filtrations, introducing them into the composition of cement mortars through the reduction of cement and sand, seeking to valorise this winemaking residue and contributing to a sustainable construction. Three compositions of Portland cement-based mortars introducing residual diatomaceous earth are studied and fire behaviour tests are performed to the obtained specimens of mortars. The characterisation of these elements regarding their reaction to fire is performed using the cone calorimeter equipment.
- Reuse of residual diatomaceous earth for the production of geopolymers - a reviewPublication . Magalhães, Leandro; Ferreira, Débora; Luso, Eduarda; Lima, ÓscarThe high pollution levels produced by the manufacturing of conventional Portland cement have motivated several studies in an attempt to modernize this process with alternative binders such as cements based on use of alkaline activation of aluminosilicates. The reaction between aluminosilicates (such as metakaolin, fly ash and blast furnace slag) and an alkaline solution (sodium hydroxide or potassium hydroxide) triggers a geopolymerization process, developing a material with good mechanical and thermal properties, with a vast spectrum of applications in construction, helping in the reduction of the environmental impact and due to it, lower carbon footprint. Most geopolymer concrete was focused on fly ashes, metakaolin and blast furnace slag, this paper focuses on use of residual diatomaceous earth in the manufacture of geopolymer concrete, which are very rich in aluminosilicates. This review paper presents an extensive bibliographic review of studies related to the manufacture of geopolymer cements based on diatomaceous earth. The chemical composition of diatomaceous earth, density, surface area, absorption capacity, different drying methods and different calcination processes are investigated factors. Mortar blends based on diatomaceous earth, temperatures and curing times, physical and mechanical properties of the obtained samples are also subject to analysis.
- Fire behaviour of mortars with portland cement and residual diatomaceous earthPublication . Magalhães, Leandro; Ferreira, Débora; Zolin, Renan Calvo; Alves, Matheus Henrique; Barreira, Luísa; Luso, Eduarda; Mesquita, L.M.R.; Óscar, LimaThe high pollution levels produced by the manufacturing of conventional Portland cement have motivated several studies in an attempt to modernize this process with alternative binders and the conscious use of natural resources. The correct treatment of residues has become a matter of great concern. The project “BacchusTech” aims to reuse diatomaceous earth from wine filtrations, introducing them into the composition of cement mortars through the reduction of cement and sand, seeking to valorise this winemaking residue and contributing to a sustainable construction. Three compositions of Portland cement-based mortars introducing residual diatomaceous earth are studied and fire behaviour tests are performed to the obtained specimens of mortars. The characterisation of these elements regarding their reaction to fire is performed using the cone calorimeter equipment.