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Analysis of the thermal performance of mortars with diatomaceous earth
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A concentração de CO2 atingiu níveis sem precedentes, com emissões significativas do sector energético. O consumo de energia nos edifícios e a produção de cimento são os principais contribuintes para as emissões de CO2 e devem ser minimizados para cumprir as metas climáticas. Materiais ecológicos, como a terra diatomácea gasta (SDE) proveniente da indústria de filtração de bebidas, têm sido
considerados para utilização em argamassas de reboco para melhorar o isolamento térmico e promover a sustentabilidade. O SDE oferece melhor plasticidade, propriedades mecânicas e isolamento térmico, tornando-o um material promissor para substituir cimento e areia em composições de argamassa. Para além das vantagens
citadas, a sua incorporação em argamassas ajuda a reduzir os resíduos em aterros, contribuindo para o desenvolvimento de argamassas sustentáveis. Esta pesquisa teve como objetivo analisar o comportamento térmico de argamassas de reboco utilizando resíduos de terra diatomácea. Foram produzidas amostras de argamassa de referência (REF) e duas composições de SDE: uma com
15% de substituição de cimento (C15R) e outra com 3,5% de substituição de areia (S3,5R) com base nos resultados obtidos de propriedades físicas e mecânicas para estas composições em estudo prévio. As amostras foram testadas usando a Placa Quente Protegida para determinar seus coeficientes de condutividade térmica.
Adicionalmente, foram construídos dois painéis de parede em alvenaria, um rebocado com argamassa REF e outro com a argamassa C15R, que apresentou maior potencial para desempenho térmico, e foram ensaiados em Hot Box para determinação da
resistência térmica e transmitância. Esses painéis também foram modelados e analisados numericamente utilizando o software Ansys, e respectiva comparação com resultados analíticos.
The concentration of CO2 has reached unprecedented levels, with significant emissions from the energy sector. Energy consumption in buildings and cement production are major contributors to CO2 emissions and must be targeted to meet climate goals. Environmentally friendly materials, such as spent diatomaceous earth (SDE) from the beverage filtration industry, have been considered for use in plaster mortars to improve thermal insulation and promote sustainability. SDE offers better plasticity, mechanical properties, and thermal insulation, making it a promising material to replace cement and sand in mortar compositions. Additionally, its use helps to reduce landfill waste, contributing to the development of sustainable mortars. This research aims to explore an alternative approach to what is commonly found in the literature, analyzing the thermal behavior of plaster mortars using spent diatomaceous earth. Reference mortar samples (REF) and two SDE compositions were produced: one with 15% cement replacement (C15R) and the other with 3,5% sand replacement (S3,5R), based on the results obtained from physical and mechanical properties for these compositions in a previous study. The specimens were tested using the Guarded Hot Plate to determine their thermal conductivity coefficients. Additionally, two masonry wall panels, one plastered with REF mortar and the other with C15R, which showed greater potential for thermal performance, were built and tested in the Hot Box to determine their thermal resistance and transmittance. These panels were also modeled and analyzed numerically using Ansys software, and analytical calculations were performed. The results indicated that C15R mortar had the best thermal performance, with a thermal conductivity coefficient of 0,232 W/m.K at 20°C, compared to 0,256 W/m.K for S3,5R and 0,263 W/m.K for REF. Although favorable, the thermal conductivity values do not classify the mortars as thermal mortars, as they should have values below 0,200 W/m.K. The findings for thermal resistance and transmittance showed a 5,77% improvement for wall assemblies with C15R mortar compared to REF. For the mortar plaster layer, the improvement in thermal resistance and transmittance was 16,88%, based on experimental, analytical, and numerical analyses.
The concentration of CO2 has reached unprecedented levels, with significant emissions from the energy sector. Energy consumption in buildings and cement production are major contributors to CO2 emissions and must be targeted to meet climate goals. Environmentally friendly materials, such as spent diatomaceous earth (SDE) from the beverage filtration industry, have been considered for use in plaster mortars to improve thermal insulation and promote sustainability. SDE offers better plasticity, mechanical properties, and thermal insulation, making it a promising material to replace cement and sand in mortar compositions. Additionally, its use helps to reduce landfill waste, contributing to the development of sustainable mortars. This research aims to explore an alternative approach to what is commonly found in the literature, analyzing the thermal behavior of plaster mortars using spent diatomaceous earth. Reference mortar samples (REF) and two SDE compositions were produced: one with 15% cement replacement (C15R) and the other with 3,5% sand replacement (S3,5R), based on the results obtained from physical and mechanical properties for these compositions in a previous study. The specimens were tested using the Guarded Hot Plate to determine their thermal conductivity coefficients. Additionally, two masonry wall panels, one plastered with REF mortar and the other with C15R, which showed greater potential for thermal performance, were built and tested in the Hot Box to determine their thermal resistance and transmittance. These panels were also modeled and analyzed numerically using Ansys software, and analytical calculations were performed. The results indicated that C15R mortar had the best thermal performance, with a thermal conductivity coefficient of 0,232 W/m.K at 20°C, compared to 0,256 W/m.K for S3,5R and 0,263 W/m.K for REF. Although favorable, the thermal conductivity values do not classify the mortars as thermal mortars, as they should have values below 0,200 W/m.K. The findings for thermal resistance and transmittance showed a 5,77% improvement for wall assemblies with C15R mortar compared to REF. For the mortar plaster layer, the improvement in thermal resistance and transmittance was 16,88%, based on experimental, analytical, and numerical analyses.
Descrição
Mestrado de dupla diplomação com a UTFPR - Universidade Tecnológica Federal do Paraná
Palavras-chave
Sustentabilidade Terra diatomácea gasta Condutividade térmica Análise térmica Argamassa