Estudo da estrutura anatômica e das propriedades físicas e mecânicas da madeira de Corymbia (Eucalyptus) citriodora e Eucalyptus grandis
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Data
2006-12-20
Autores
Benjamin, Cláudia Assumpção [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
Este trabalho teve por objetivo estudar as correlações existentes entre as propriedades físicas e mecânicas da madeira de eucalipto proveniente de árvores com presença de madeira juvenil e adulta. O estudo foi conduzido com a caracterização complementar da estrutura anatômica da madeira sob análise, a partir de análises microscópicas do lenho. Estudaram-se 12 árvores, sendo seis de E. grandis com 28 anos de idade e seis de Corymbia (Eucalyptus) citriodora com 29 anos de idade. As árvores foram disponibilizadas pela Estação Experimental de Ciências Florestais (EECF - LCF/ESALQUSP), localizada no município de Anhembi-SP. A partir do DAP, no sentido da base da árvore, foi retirada uma tora de 70 cm de comprimento. Da tora, foram retirados um disco para determinação da densidade básica da madeira da árvore e uma prancha central, para obtenção dos corpos-de-prova utilizados para os ensaios de propriedades físico-mecânicas e análises anatômicas da madeira. Nas 12 árvores amostradas foram mensuradas (ao longo do sentido medula-casca, lados direito e esquerdo) a densidade aparente da madeira, utilizando-se da técnica da densitometria de raios X e a densidade básica por mensuração e pesagem de corpos-de-prova. Ainda nesse sentido, em intervalos aproximadamente regulares de 35 mm, foram mensuradas as retratibilidades lineares e volumétricas. As resistências à compressão e à dureza paralela às fibras também foram medidas com a mesma regularidade ao longo do raio, com a madeira verde (na umidade de abate da árvore) e na umidade de equilíbrio ao ar ao longo de todo o raio. Para seis das 12 árvores (três árvores por espécie) foram mensuradas, 2 em três posições distintas na direção radial, algumas importantes características anatômicas do lenho, em regiões coincidentes com aquelas...
This paper had the objective of studying the correlation between physical and mechanical properties of Eucalyptus wood from trees with expressive presence of both juvenile and mature wood. The study was carried out with complementary characterization of the anatomical structure of wood, using microscopic analyses. It were sampled 12 trees, six from Eucalytpus grandis 28 years old and six from Corymbia (Eucalyptus) citriodora 29 years old. Trees were obtained from Forestal Science Experimental Station of ESALQ-USP - Escola Superior de Agricultura Luiz de Queiróz at Anhembi-São Paulo State - Brazil. From DBH to the base of each tree it was sawed a log, 70cm long, from which it was cut a disc, 7 cm thick, for specific gravity determination and, in the remaining log was cut a central board (approximately 63cm long) to produce specimens for physical and mechanical properties determination. On all the trees (from pith to bark, right and left sides) it were evaluated the radial variation of specific gravity and density (12% MC) using X-ray densitometry and conventional methods. On regular intervals of 35mm from pith to bark, using specimens, it were measured radial, tangential, longitudinal and volumetric shrinkage and compression and hardness parallel to grain strength (green wood and wood at EMC for mechanical tests). For three of the 12 trees, in three different position along one of the radius of the tree, it were also measured several anatomical characteristics, on region coincident with those of the specimens for physical and mechanical tests. With the obtained results it were established patterns of variation of all measured properties on radial direction, taking in account the effects of specie, side (right and 4 left) and important features of xylem (heart wood/sapwood and juvenile wood/mature wood). It were... (Complete abstract, click electronic access below)
This paper had the objective of studying the correlation between physical and mechanical properties of Eucalyptus wood from trees with expressive presence of both juvenile and mature wood. The study was carried out with complementary characterization of the anatomical structure of wood, using microscopic analyses. It were sampled 12 trees, six from Eucalytpus grandis 28 years old and six from Corymbia (Eucalyptus) citriodora 29 years old. Trees were obtained from Forestal Science Experimental Station of ESALQ-USP - Escola Superior de Agricultura Luiz de Queiróz at Anhembi-São Paulo State - Brazil. From DBH to the base of each tree it was sawed a log, 70cm long, from which it was cut a disc, 7 cm thick, for specific gravity determination and, in the remaining log was cut a central board (approximately 63cm long) to produce specimens for physical and mechanical properties determination. On all the trees (from pith to bark, right and left sides) it were evaluated the radial variation of specific gravity and density (12% MC) using X-ray densitometry and conventional methods. On regular intervals of 35mm from pith to bark, using specimens, it were measured radial, tangential, longitudinal and volumetric shrinkage and compression and hardness parallel to grain strength (green wood and wood at EMC for mechanical tests). For three of the 12 trees, in three different position along one of the radius of the tree, it were also measured several anatomical characteristics, on region coincident with those of the specimens for physical and mechanical tests. With the obtained results it were established patterns of variation of all measured properties on radial direction, taking in account the effects of specie, side (right and 4 left) and important features of xylem (heart wood/sapwood and juvenile wood/mature wood). It were... (Complete abstract, click electronic access below)
Descrição
Palavras-chave
Madeira - Tecnologia, Eucalyptus grandis, Densitometria, Madeira - Propriedades mecânicas, Corymbia (Eucalyptus) citriodora, C. citriodora, E. grandis, Wood technology, X ray densitometry
Como citar
BENJAMIN, Cláudia Assumpção. Estudo da estrutura anatômica e das propriedades físicas e mecânicas da madeira de Corymbia (Eucalyptus) citriodora e Eucalyptus grandis. 2006. xi, 158 f. Tese (doutorado) - Universidade Estadual Paulista, Faculdade de Ciências Agronômicas, 2006.