Characterization of Corymbia citriodora wood for construction

Floresta e Ambiente, 2019

This study aimed at evaluating thermal modification in mechanical properties of Corymbia citriodora and Eucalyptus saligna woods compared with a control. To do so, three samples of each species were selected, with approximately 40 years, which had the first two three-meter long logs removed. Wood thermal modification was done through final temperatures of 140 °C, 160 °C e 180 °C for 2.5 hours, and the control as well, using a forced air circulation greenhouse. Mechanical properties tests consisted of maximum impact resistance evaluation, static bending, and fiber parallel compression. Generally, results showed that thermal modification increases wood resistance up to a certain point and reduces in the highest temperature.

Revista do Instituto Florestal

The pulp and paper industry is important to the Brazilian economy. In the present study, we investigated Corymbia citriodora wood in three soil types: Quartzarenic Neossol, Red Latosol and Red Nitosol. We aimed to determine how differences in physical, chemical and water-holding capacity among these three types of soils can cause changes in wood density and anatomical ratios in C. citriodora wood, important parameters in the production of pulp and paper. We used standard techniques in the methodology. Soil types did infuence wood quality and could be used as a factor in considering the fnal quality of the product. Corymbia citriodora wood have not previously been considered for use in paper/pulp production. However, if we consider wood density as a key factor, wood from Red Nitosol - NV trees can be used since lower basic densities were identifed and are most appropriate for the production of printing and writing paper, owing to fber features. Otherwise, woods from Quartzarenic Neos...

Scientia Forestalis, 2016

Objetivou-se verificar a influência da densidade e da umidade da madeira na energia específica de corte. Utilizou-se madeira de Corymbia citriodora Hill & Johnson, de plantios no Vale do Rio Doce, no Brasil. Retirou-se a tábua diametral de 60 x 18 x 5 cm (comprimento x largura x espessura, respectivamente), acima de 1,3 m do solo. Nos ensaios de usinagem, utilizou-se serra circular de 400 mm de diâmetro com 24 dentes "WZ", velocidade de avanço de 10 m.min-1 , velocidade de corte 61 m.s-1 e torque instantâneo máximo de 92,5 N.m. Durante os cortes foram retirados corpos de prova com aresta de 1,5 cm alternado e paralelo a cada corte, em 6 posições radiais, que foram usados para a determinação da umidade e densidade da madeira. Observou-se que a energia especifica de corte foi positivamente correlacionada com a densidade da básica e aparente da madeira, porém a umidade foi negativamente correlacionada com a energia de corte. A densidade básica foi a propriedade física que melhor explicou a variação da energia específica de corte. A umidade demonstrou ser uma propriedade importante para explicar a relação entre a energia específica de corte específica e a densidade aparente da madeira.

2022

The quantitative evaluation of longitudinal drying strain can provide relevant information for the processing wood and lumber industry, especially with regard to reaction wood in Corymbia, since little has been published. The objective of this work was to evaluate the effect of the steam conditioning and the cooling on the longitudinal drying strain (LDS) obtained from a strain gauge, called extensometer, in boards of both normal and tension wood of Corymbia citriodora. Lumbers 30 mm thick were produced and kiln dried at the initial temperature of 40°C, final temperature of 65°C and drying potential of 2,1. The LDS were measured before and after steam conditioning on hot and cold lumbers. It was observed that the conditioning did not reduce the LDS. Hot lumbers showed higher LDS values than the cold lumbers. The LDS values measured in normal, tension and opposite woods were statistically similar, indicating that the type of wood was not an influential factor in the appearance of longitudinal drying stresses. Extensometer proved to be feasible for measuring LDS, allowing its easy and quick quantification.

International Journal of Materials Engineering, 2014

This study aimed to investigate, based on three points static bending tests, the influence of ratio between length (L) and diameter (d) in structural round timber of Corymbia citriodora to determine the modulus of elasticity (MOE) using equations that do not consider shear influence in beam displacements. Non-destructive tests were carried out in 24 round pieces, medium length 750cm and average diameter 30 cm, moisture content around 12%. Modulus of elasticity for six different ratios (L/d) between length and diameter 18, 21, 24) were determined, providing obtains six distinct values of MOE for each structural elements. Hypothesis tests results indicated equivalence of modulus of elasticity only to ratios (L/d) 24, 21 and 18. This implies that for proper use of the simplified equation to obtain MOE, based on static bending tests over structural round timber, it is necessary to respect L/h≥18 ratio.

Journal of Civil Engineering Research, 2013

The wood is one of the most applicable materials in industrial activit ies due to its availability allied to its satisfactory mechanical p roperties, presenting a good strength/density relation. Its versatility is fundamental fo r the large expansion of its use on structure building. The explorat ion, init ially selective, turned to be selective and also predatory, what lead to a shortage, raising systematically the prices until the mo ment where it was not anymore probable to use it on the quantities registered until then. The solution was to define species, between more than 5.000 variet ies in AmazonicaTropical Forest, which could substitute the 100 co mmercially used ones. However, due to technical limitations, these species cannot be completely characterized, what leads to a misusing of timber, once its behaviour is not known completely when it is under mechanical stresses. This research presents some results of the characterizat ion of the following timber species: Canelão, Env ira Branca, Guarajá, Quaruba Rosinha and Breu Vermelho. These species are found close to Sinop (Mato Grosso-Brazil), and the results obtained reveal clearly the potential of each species under mechanical stresses, showing that some of them can be good substitutes to the commonly wood speciesused.

Research, Society and Development, 2021

Effect of soil type on mean annual increment, wood anatomy and properties of 33year-old Corymbia citriodora (Hook.), K. D. Hill, & L. A. S. Johnson Efeito do tipo de solo no incremento médio anual, anatomia e propriedades da madeira de Corymbia citriodora (Hook.), K. D. Hill, & L. A. S. Johnson, de 33 anos de idade Efecto del tipo de suelo sobre el incremento anual medio, la anatomía y las propiedades de la madera de Corymbia citriodora (Hook.), K. D.

Ciência Florestal

O estudo teve como objetivo analisar as propriedades físicas e mecânicas do carvão de clones de eucalipto por análise de componentes principais e demonstrar as correlações entre essas propriedades, a fim de avaliar qual propriedade de carvão deve ser almejada no processo para obter um produto de alta qualidade. Desta forma, foram cortados oito clones de Eucalyptus e dois de Corymbia, coletando três árvores por clone e cinco discos em diferentes alturas. Os discos foram transformados em amostras para ensaio, totalizando uma média de 75 amostras por clones, que foram carbonizados sob condições específicas para a análise da densidade aparente, compressão paralela às fibras e degradação linear e volumétrica devido à alta temperatura. Vale ressaltar que os dados foram ponderados pelo disco e por árvore, para a uma média mais próxima da realidade. Para as correlações, foi utilizada a análise multivariada de componentes principais. Nisto, verificou-se a ação da densidade aparente do carvão...

Pesquisa Agropecuária Tropical, 2019

The use of fast-growing trees is a good economic strategy for charcoal production. Wood with adequate chemical and physical properties generally is positively correlated with charcoal quality. The objective of this research was to evaluate wood quality from fast-growing hybrids for charcoal production. Three Corymbia citriodora x Corymbia torelliana and four Corymba torelliana x Corymba citriodora hybrid clones were evaluated. Parameters used to evaluate wood quality were wood basic density, elemental and structural chemical composition, energy efficiency and thermogravimetric analysis and the parameters evaluated for charcoal quality were apparent relative density, gravimetric yield, high heating value, proximate analysis and energy efficiency. All clones had wood basic density superior than 0,5 g cm-3 and ash inferior than 1%, which are desirable for a good quality of charcoal. Lignin content did not differ among clones with an average less than the 28% recommended for energetic use. Although clones differed in wood parameters, as dry matter, high heating value, energy density, total extractives, holocellulose content, it did not reflect in charcoal quality differences. Wood from all clones had equal and satisfying high heating value of charcoal and energy efficiency quality for charcoal production and differed in apparent relative density and ash content.