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Publication
Comportamento termomecânico de painéis compósitos de madeira/cortiça
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Abstract(s)
utilização da cortiça como material de construção em Portugal é uma alternativa promissora devido à sua ampla disponibilidade, rentabilidade e sustentabilidade em comparação com outros materiais. Pesquisas nessa área tornam-se cada vez mais relevantes, considerando que, em média, 5.000 civis morrem anualmente na Europa devido a incêndios.
Este estudo tem como objetivo fabricar e investigar diferentes composições de aglomerados, analisando a influência de parâmetros como espessura, tipo de resina e percentual de madeira e cortiça nos ensaios de condutividade térmica, reação ao fogo e resistência mecânica.
Ao todo, foram desenvolvidas sete composições distintas, variando em espessura (20 ou 25 mm), tipo de resina (UF ou MUF) e proporção relativa entre cortiça e aparas de madeira.
Todas as composições geraram o mesmo número de amostras que foram utilizadas em testes de reação ao fogo no calorímetro de cone seguindo a norma EN ISO 13927 com um fluxo de calor de 50 kW/m², ensaios de flexão em 3 pontos consoante à norma ISO EN 310 com velocidade de 40 mm/min e testes de condutividade térmica de acordo com a norma BS EN 12667:2001 com uma variação de temperatura de 15 ºC.
Os dados de HRR e THR demonstraram que, embora as resinas possuam um comportamento similar, a UF é levemente mais reativa ao fogo do que a MUF. Espessuras maiores apresentaram picos superiores de liberação de calor, muito por conta da quantidade maior de material a ser queimado. O percentual de madeira na composição resultou em picos inferiores de liberação de calor, mas a queima ocorreu mais rapidamente.
Nos ensaios mecânicos, as amostras com maior percentual de cortiça demonstraram resistência superior às que continham mais aparas de madeira, apresentando valores de elasticidade e resistência à rutura próximos ou superiores ao dobro. A espessura, nesse caso, não influenciou significativamente os resultados.
Quanto à condutividade térmica, a variação na espessura das composições não apresentou impacto significativo, tanto térmica quanto mecanicamente. As composições com maior percentual de aparas de madeira foram as que exibiram maior condutividade térmica.
The use of cork as a construction material in Portugal is a promising alternative due to its wide availability, cost-effectiveness, and sustainability compared to other materials. Research in this area is becoming increasingly relevant, considering that an average of 5,000 civilians die annually in Europe due to fires. This study aims to manufacture and investigate different compositions of agglomerates, analyzing the influence of parameters such as thickness, type of resin, and the percentage of wood and cork in tests of thermal conductivity, fire reaction, and mechanical resistance. In total, seven distinct compositions were developed, varying in thickness (20 or 25 mm), resin type (UF or MUF), and the relative proportion of cork and wood shavings. All compositions produced the same number of samples, which were used in fire reaction tests in a cone calorimeter following the EN ISO 13927 standard with a heat flux of 50 kW/m², three-point bending tests according to ISO EN 310 at a speed of 40 mm/min, and thermal conductivity tests according to the BS EN 12667:2001 standard with a temperature variation of 15 ºC. HRR and THR data showed that, although the resins exhibited similar behavior, UF is slightly more reactive to fire than MUF. Greater thicknesses resulted in higher peaks of heat release, mainly due to the increased amount of material available for combustion. The higher the wood content in the composition, the lower the heat release peaks, but combustion occurred more quickly. In mechanical tests, samples with a higher percentage of cork demonstrated superior resistance compared to those with more wood shavings, showing elasticity and rupture resistance values close to or exceeding twice as much. In this case, thickness did not significantly influence the results. Regarding thermal conductivity, variations in the thickness of the compositions did not have a significant impact, either thermally or mechanically. Compositions with a higher percentage of wood shavings exhibited greater thermal conductivity.
The use of cork as a construction material in Portugal is a promising alternative due to its wide availability, cost-effectiveness, and sustainability compared to other materials. Research in this area is becoming increasingly relevant, considering that an average of 5,000 civilians die annually in Europe due to fires. This study aims to manufacture and investigate different compositions of agglomerates, analyzing the influence of parameters such as thickness, type of resin, and the percentage of wood and cork in tests of thermal conductivity, fire reaction, and mechanical resistance. In total, seven distinct compositions were developed, varying in thickness (20 or 25 mm), resin type (UF or MUF), and the relative proportion of cork and wood shavings. All compositions produced the same number of samples, which were used in fire reaction tests in a cone calorimeter following the EN ISO 13927 standard with a heat flux of 50 kW/m², three-point bending tests according to ISO EN 310 at a speed of 40 mm/min, and thermal conductivity tests according to the BS EN 12667:2001 standard with a temperature variation of 15 ºC. HRR and THR data showed that, although the resins exhibited similar behavior, UF is slightly more reactive to fire than MUF. Greater thicknesses resulted in higher peaks of heat release, mainly due to the increased amount of material available for combustion. The higher the wood content in the composition, the lower the heat release peaks, but combustion occurred more quickly. In mechanical tests, samples with a higher percentage of cork demonstrated superior resistance compared to those with more wood shavings, showing elasticity and rupture resistance values close to or exceeding twice as much. In this case, thickness did not significantly influence the results. Regarding thermal conductivity, variations in the thickness of the compositions did not have a significant impact, either thermally or mechanically. Compositions with a higher percentage of wood shavings exhibited greater thermal conductivity.
Description
Mestrado de dupla diplomação com a Universidade Tecnológica Federal do Paraná
Keywords
Aglomerado de cortiça