CARACTERIZAÇÃO ANATÔMICA E DESCRIÇÃO FÍSICO-QUÍMICA E MECÂNICA DA MADEIRA DE Mimosa schomburgkii

O uso de madeira de especies alternativas na construcao civil e uma alternativa para reduzir a utilizacao concentrada em poucas especies e evitar a falta de materia prima no mercado. Diante do exposto, o objetivo deste estudo foi avaliar propriedades fisicas, quimicas, anatomicas e mecânicas da madeira de Mimosa schomburgkii visando identificar o seu potencial para o uso na construcao civil. Foi utilizada a madeira de Mimosa schomburgkii , com idade de 33 anos. As caracteristicas anatomicas avaliadas foram as dimensoes dos elementos de vasos (diâmetro e frequencia), dos raios (altura e largura) e das fibras (comprimento, largura total, espessura de parede e de lume). Foi determinada a constituicao quimica com a quantificacao do teor de extrativo, lignina e holocelulose.  Para a caracterizacao fisico-mecânica, foram avaliadas a densidade basica e aparente, contracoes, o coeficiente de anisotropia, a resistencia a flexao estatica, a compressao paralela as fibras, a tracao paralela as fibras, ao cisalhamento e a dureza Janka (paralela e perpendicular as fibras). A madeira possui fibras libriformes, com comprimento medio de 1180 μm, sendo classificadas como curtas. A densidade basica da madeira e em media 0,80 g.cm -3 (alta densidade), o coeficiente de anisotropia, em media 1,74. A madeira apresenta elevada resistencia mecânica, sendo classificada como pertencente a classe C 60. Pelos resultados obtidos no estudo, a madeira de jurema ( Mimosa schomburgkii ) apresenta aspectos esteticos atrativos e elevada resistencia mecânica, sendo, portanto, indicada para uso na construcao civil. Palavras–chave: Propriedades da madeira, construcao civil, elevada resistencia mecânica, alta densidade basica. Abstract Anatomical characterization and physical-chemical and mechanical description of Mimosa schomburgkii wood. The use of wood of alternative species in civil construction has been an option to reduce the concentrated use of few species and to avoid the lack of raw material in the market. The objective of this study was to evaluate the physical, chemical, anatomical and mechanical properties of Mimosa schomburgkii wood, in order to identify its potential use in civil construction. Mimosa schomburgkii wood, at the age of 33 years, was used. The anatomical characteristics evaluated were the dimensions of vessel elements (diameter and frequency), rays (height and width) and fibers (length, width, wall thickness and lumen thickness). The chemical constitution was determined with the quantification of extractive content, lignin and holocellulose. For the physical-mechanical characterization, it was evaluated the specific gravity and apparent density, contractions, anisotropy coefficient, static bending strength, compression strength parallel to grain, traction strength parallel to grain, shear strength and Janka hardness (parallel and perpendicular to grain). The wood has libriform fibers, average length of 1180 μm, and it is classified as short. The wood basic density is on average of 0.80 g.cm -3 (high density). The anisotropy coefficient is on average of 1.74. The wood presents high mechanical strength, being classified as C 60 class. From the results obtained in this study, the Mimosa schomburgkii wood presents attractive aesthetic aspects and high mechanical resistance. Therefore, this wood is indicated for use in civil construction. Keywords: Wood properties, civil construction, high mechanical strength, high specific gravity.