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

Abstract

ResumoO uso de madeira de espécies alternativas na construção civil é uma alternativa para reduzir a utilização concentrada em poucas espécies e evitar a falta de matéria prima no mercado. Diante do exposto, o objetivo deste estudo foi avaliar propriedades físicas, químicas, anatômicas e mecânicas da madeira de Mimosa schomburgkii visando identificar o seu potencial para o uso na construção civil. Foi utilizada a madeira de Mimosa schomburgkii, com idade de 33 anos. As características anatômicas avaliadas foram as dimensões dos elementos de vasos (diâmetro e frequência), dos raios (altura e largura) e das fibras (comprimento, largura total, espessura de parede e de lume). Foi determinada a constituição química com a quantificação do teor de extrativo, lignina e holocelulose. Para a caracterização físico-mecânica, foram avaliadas a densidade básica e aparente, contrações, o coeficiente de anisotropia, a resistência à flexão estática, à compressão paralela às fibras, à tração paralela às fibras, ao cisalhamento e a dureza Janka (paralela e perpendicular às fibras). A madeira possui fibras libriformes, com comprimento médio de 1180 μm, sendo classificadas como curtas. A densidade básica da madeira é em média 0,80 g.cm -3 (alta densidade), o coeficiente de anisotropia, em média 1,74. A madeira apresenta elevada resistência mecânica, sendo classificada como pertencente à classe C 60. Pelos resultados obtidos no estudo, a madeira de jurema (Mimosa schomburgkii) apresenta aspectos estéticos atrativos e elevada resistência mecânica, sendo, portanto, indicada para uso na construção civil. Palavras-chave: Propriedades da madeira; construção civil; elevada resistência mecânica; alta densidade básica. Abstract Anatomical characterization and physical-chemical and mechanical description of Mimosa schomburgkiiwood. 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...

Determination of Physical and Mechanical Properties of Wood Specie Dinizia excelsa Ducke

“…The average compressive strength parallel to the grain (f c,0k ) was 78 MPa, close to the result obtained by Grobério and Lahr (77.5 MPa) [12] with the same wood specie and higher when compared with Mimosa tenuiflora (58.25 MPa) [13], Mimosa schomburgkii (64.7 MPa) [4], Toona ciliata (27 MPa) [14], Eucalyptus camaldulensis (25.3 MPa) [15] e Eucalyptus benthamii (37.34 MPa) [16].…”

“…Among the sectors that use wood as raw material, civil construction sector is the one of the most exigent in terms of physical and mechanical properties. Then, it causes a certain limitation in the number of wood species with characteristics that could be used in this sector [4,5].…”

EFFECT OF ACETYLATION ON TECHNOLOGICAL CHARACTERISTICS OF Jacaranda copaia WOOD: PART 2 – CHEMICAL AND COLORIMETRIC CHANGES

“…High holocellulose and lignin contents in non-treated wood can affect the material's mechanical properties. Costa et al (2017) reported that the mechanical strength of wood to some types of loads is not associated only with thickness, but also with the amounts of their chemical components, such as cellulose, hemicellulose, lignin, and the percentages of extractives in the lumen. Gomes et al (2021) reported that renewable lignocellulosic materials tend to present different cellulose, hemicellulose, and lignin compositions and that these chemical properties are factors that can limit the material applicability.…”

Influence of Anatomy on the Mechanical Resistance of Woods in an Agroforestry System

“…The variations that occur in the anatomical parameters of wood change the dimensions and frequency of the cells, thus directly affecting its physical and mechanical properties (COSTA et al, 2017). Mechanical strength can be determined from static bending, compression, and hardness tests, in which the mechanical parameters of the material reflect the existing relationship between the response or deformation when subjected to a stimulus or force (KOL et al, 2017).…”