Loading...
Publication
Comportamento de argamassas com incorporação de terras de diatomáceas a altas temperaturas
| Name: | Description: | Size: | Format: | |
|---|---|---|---|---|
| 4.15 MB | Adobe PDF |
Authors
Abstract(s)
A indústria da construção civil é responsável por significativos impactos ambientais, principalmente devido à elevada emissão de CO₂ no processo de produção do cimento Portland e ao descarte inadequado de resíduos industriais. Nesse contexto, este trabalho investiga o comportamento em altas temperaturas de argamassas com incorporação de terra diatomácea residual (TDR), proveniente da filtração de vinhos, como alternativa sustentável para reduzir esses impactos. Foram analisadas três composições: uma de referência, uma com substituição de 15% do cimento e outra com 5% da areia por TDR, submetidas a temperaturas de 250 °C e 500 °C, com dois tipos de arrefecimento, gradual e acelerado. Avaliaram-se propriedades mecânicas como resistência à flexão, compressão e aderência. Nos ensaios de resistência à flexão em temperatura ambiente, as argamassas com substituição de cimento apresentaram ganhos de até 27,5%, enquanto as com substituição de areia alcançaram até 51,7%. Aos 250 °C, o arrefecimento acelerado proporcionou um ganho de 0,8% para as amostras com substituição de cimento e uma queda de 16% para as com substituição de areia; a 500 °C, todas as formulações apresentaram perdas significativas, com reduções de até 61,9% e 59,9%, respectivamente. Na resistência à compressão, a substituição de areia proporcionou ganho de 14,7% em temperatura ambiente, enquanto a de cimento resultou em queda de 31,4%. Aos 250 °C, no arrefecimento gradual, as formulações com substituição de areia e cimento apresentaram ganhos de 17,9% e 6,1%, respectivamente. No arrefecimento acelerado, as argamassas de referência tiveram melhor desempenho. Já a 500 °C, as argamassas com substituição de areia mantiveram ganhos de 77,9% e as com substituição de cimento 40,1%, embora a amostra de referência tenha apresentado fissuras visíveis após 24 horas. Nos ensaios de aderência, em temperatura ambiente, a substituição de areia resultou em ganho de 5,1%, enquanto a de cimento apresentou queda de 49,6%. Aos 250 °C, apenas as amostras de referência puderam ser ensaiadas, mantendo a aderência, enquanto as demais perderam completamente a aderência ainda na preparação, independentemente do tipo de arrefecimento. A 500 °C, todas as amostras perderam completamente a aderência, demonstrando falha total na interface argamassa-substrato. Os resultados evidenciam o potencial da terra diatomácea residual como adição sustentável, especialmente em termos de resistência à compressão, embora ainda existem desafios no que se refere à aderência em temperaturas elevadas.
The construction industry is responsible for significant environmental impacts, primarily due to high CO₂ emissions from Portland cement production and the improper disposal of industrial waste. In this context, this study investigates the high-temperature behavior of mortars incorporating residual diatomaceous earth (RDE), a byproduct from wine filtration, as a sustainable alternative to mitigate these impacts. Three mortar compositions were analyzed: a reference mixture, one with 15% cement replacement, and another with 5% sand replacement by RDE. These were subjected to temperatures of 250 °C and 500 °C, using two cooling methods: gradual and accelerated. Mechanical properties such as flexural strength, compressive strength, and bond strength were evaluated. In flexural strength tests at room temperature, mortars with cement replacement showed gains of up to 27.5%, while those with sand replacement reached 51.7%. At 250 °C, accelerated cooling resulted in a 0.8% increase for cement-replaced samples and a 16% decrease for sand-replaced ones; at 500 °C, all formulations showed significant reductions—up to 61.9% and 59.9%, respectively. In compressive strength, sand replacement yielded a 14.7% gain at room temperature, while cement replacement caused a 31.4% decrease. At 250 °C under gradual cooling, mortars with sand and cement replacement presented gains of 17.9% and 6.1%, respectively. Under accelerated cooling, reference mortars performed better. At 500 °C, mortars with sand replacement retained 77.9% gains, and those with cement replacement 40.1%, while the reference sample developed visible cracking after 24 hours. In adhesion tests at room temperature, sand replacement showed a 5.1% improvement, while cement replacement dropped by 49.6%. At 250 °C, only the reference samples retained adhesion; the others failed during preparation regardless of the cooling method. At 500 °C, all samples completely lost adhesion, indicating total failure at the mortar-substrate interface. The results demonstrate the potential of residual diatomaceous earth as a sustainable additive, particularly for improving compressive strength, although challenges remain regarding adhesion at elevated temperatures.
The construction industry is responsible for significant environmental impacts, primarily due to high CO₂ emissions from Portland cement production and the improper disposal of industrial waste. In this context, this study investigates the high-temperature behavior of mortars incorporating residual diatomaceous earth (RDE), a byproduct from wine filtration, as a sustainable alternative to mitigate these impacts. Three mortar compositions were analyzed: a reference mixture, one with 15% cement replacement, and another with 5% sand replacement by RDE. These were subjected to temperatures of 250 °C and 500 °C, using two cooling methods: gradual and accelerated. Mechanical properties such as flexural strength, compressive strength, and bond strength were evaluated. In flexural strength tests at room temperature, mortars with cement replacement showed gains of up to 27.5%, while those with sand replacement reached 51.7%. At 250 °C, accelerated cooling resulted in a 0.8% increase for cement-replaced samples and a 16% decrease for sand-replaced ones; at 500 °C, all formulations showed significant reductions—up to 61.9% and 59.9%, respectively. In compressive strength, sand replacement yielded a 14.7% gain at room temperature, while cement replacement caused a 31.4% decrease. At 250 °C under gradual cooling, mortars with sand and cement replacement presented gains of 17.9% and 6.1%, respectively. Under accelerated cooling, reference mortars performed better. At 500 °C, mortars with sand replacement retained 77.9% gains, and those with cement replacement 40.1%, while the reference sample developed visible cracking after 24 hours. In adhesion tests at room temperature, sand replacement showed a 5.1% improvement, while cement replacement dropped by 49.6%. At 250 °C, only the reference samples retained adhesion; the others failed during preparation regardless of the cooling method. At 500 °C, all samples completely lost adhesion, indicating total failure at the mortar-substrate interface. The results demonstrate the potential of residual diatomaceous earth as a sustainable additive, particularly for improving compressive strength, although challenges remain regarding adhesion at elevated temperatures.
Description
Mestrado de dupla diplomação com a Universidade Tecnológica Federal do Paraná
Keywords
Aderência Altas temperaturas Argamassa Arrefecimento Compressão Flexão Resíduos Terra diatomácea Vinho