In this work, bamboo chips (Dendrocalamus asper) were crushed according to four particle size classes (A = -35+40 mesh; B = -40+48 mesh; C = -48+60 mesh; D = -60+65 mesh) to produce particleboards with four different compositions (100%A; 75%A + 25% B; 50%A + 50%B; 25%A + 25%B + 25%C + 25%D). Each composition was considered a treatment. The aim was to verify the effect on the physical and mechanical properties of panels. The test methods and requirements to evaluate the properties were based on NBR 14810 Brazilian standard. The results showed that the particle size used in compositions showen no significant effect on moisture content, density, thickness swelling (24 hours), internal bonding or resistance to screw withdrawal (face and side) of panels. Significant effects were verified on water absorption (2 and 24 hours), thickness swelling (2 hours), MOR and MOE to static bending.

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RESUMOO objetivo deste trabalho foi analisar a qualidade da madeira de árvores jovem de Eucalyptus camaldulensis plantada em Rio Tinto, Paraíba, para sua utilização na arquitetura rural. Foram realizados ensaios físico-mecânicos, por meio da caracterização simplificada da madeira. Nos ensaios físicos foram obtidos o teor de umidade, massa específica básica e aparente e retratibilidade da madeira, além do coeficiente de anisotropia; e no ensaio mecânico para a tomada da compressão paralela às fibras foram utilizados transdutores de deslocamento linear (LVDTs) acoplados à amostra e ao sistema de aquisição de dados para a determinação dos valores de resistência e rigidez da madeira. Os valores obtidos demonstraram que a madeira jovem de E. camaldulensis se enquadra na classificação de resistência C 20 para madeiras de folhosas, determinada pela Norma Brasileira, não sendo recomendada para fins estruturais, porém pode ser aplicada em elementos secundários de arquitetura rural, como cercas, parques e mobiliário rural.Palavras-chave: caracterização simplificada, propriedades da madeira, mobiliário rural. Physical and Mechanical Characterization of Eucalyptus camaldulensisYoung Wood for Rural Architecture Uses ABSTRACTThis study aimed to analyze the quality of Eucalyptus camaldulensis young wood of planted trees in Rio Tinto, Paraíba, Brazil, for use in rural architecture. Physico-mechanical tests were carried out through simplified characterization. The physical tests obtained were moisture content, basic and apparent specific gravity and shrinkage of the wood, in addition to the anisotropy coefficient. To obtain the compression parallel to fibers results, linear variable differential transformers (LVDTs) bound to the sample and the data acquisition system for the determination of the resistance and stiffness values of wood were used. The values obtained showed that the young wood of E. camaldulensis fits in 20 C strength rating for hardwoods, determined by the Brazilian Standard, still not being recommended for structural purposes, but appropriate to be applied in secondary elements of rural architecture, as fences, playgrounds and for rustic furniture manufacture.

The work aimed to carry out the anatomical and physical characterizations of adult bamboo rods of Dendrocalamus giganteus Munro. So, four rods were collected and sectioned in culms of 2.10 m long. From the ends of the culms were obtained 5.0 cm thick disks that were transformed into samples for anatomical and physical characterizations. In this study, were measured the percentage of fibers, vessels, parenchyma, the moisture content, the basic specific gravity and oven dry specific gravity and shrinkage. The studied bamboo has 0 to 4 vessels mm -2 , with average of 2 vessels mm -2 , with average fiber length of 2.72 mm and 50.72% consists of parenchyma tissue. The moisture content was quantified at 60%, the basic specific gravity in 0.66 g cm -3 , the oven dry specific gravity in 0.83 g cm -3 and volumetric shrinkage in 15.40%. It was observed that the bamboo physical characteristics were influenced by the layout and anatomical elements proportion.

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The thermal modification of particles of the paticleboards constituted of agroforest and industrial waste can improves the dimensional stability (thickness variation) and reduces the use of chemicals that can raise the costs of the process or be hazardous to humans and the environment. This study evaluated the effect of the thermal modification on the physical-mechanical properties and density profile of particleboards manufactured from sugarcane bagasse and bamboo (Dendrocalamus asper) (Schult f.) Backer ex Heyne). A mixture of 75% bamboo particles and 25% sugarcane bagasse was subjected to 220 °C temperature for 201 min. Urea-formaldehyde (UF)-based adhesive with three solids contents (10, 12 and 14%) based on the dry mass of the particles was used for the aggregation of the materials. Both temperature and increases in the adhesive content improved their dimensional stability, however, the thermal treatment reduced the mechanical properties. The particleboards composed of treated particles did not meet the minimum specifications established by the Brazilian norm utilized. The densitometric profiles were negatively influenced by the thermal modification and improved by the increase in adhesive content.

RESUMOEste trabalho teve o objetivo de verificar o efeito da concentração na ascensão de soluções preservativas no tempo de tratamento em moirões de Eucalyptus urophylla × Eucalyptus grandis. Foram preparadas soluções com quatro concentrações de ingredientes ativos de borato de cobre cromatado -CCB, com 0,5; 1,0; 2,0; 3,0%. Foi empregado o método de substituição de seiva por transpiração radial e tratados cinco moirões para cada concentração. O tempo de ascensão para as respectivas concentrações foram de 8, 7, 5 e 3 dias. A penetração foi analisada em quatro posições nos moirões e a retenção, na posição correspondente à zona de afloramento em moirões instalados. As penetrações de boro e cobre foram satisfatórias para os moirões tratados com solução de 3,0%, tendo aqueles tratados com 2,0% atingido valores próximos aos recomendados pela legislação brasileira. As retenções nas amostras externas dos discos atingiram valores recomendados, exceto nos moirões tratados com 0,5%. O incremento da concentração da solução causou a diminuição do tempo de tratamento dos moirões.Palavras-chave: madeira tratada, moirão de cerca, substituição de seiva. Effect of Concentration on Ascension of Preservative Solutions Prepared with CCB in Eucalyptus Fence Posts ABSTRACTThe aim of this study was to verify the influence of concentration on ascension of preservative solutions in the treatment time of Eucalyptus urophylla x Eucalyptus grandis fence posts. The solutions were prepared with four concentrations of chromated copper borate -CCB, with 0.5; 1.0; 2.0; and 3.0% active ingredients. The sap displacement method by radial transpiration was employed, and five fence posts were treated for each concentration. The ascension times of the respective concentrations were of 8, 7, 5, and 3 days. Penetration was analyzed at four positions on fence posts and retention was analyzed at the position corresponding to the ground zone of installed fence posts. Boron and copper penetrations were satisfactory for the fence posts treated with 3.0% solution, and fence posts treated with 2.0% solution reached values close to those recommended by the Brazilian legislation. Retention in the samples of external disks reached the recommended values, except for the fence posts treated with 0.5% solution.Increased solution concentration caused a reduction in the treatment time of fence posts.