Mechanical properties of structural pieces of Pinus spp: relationship between tensile strength and visual grading

A redução da disponibilidade de espécies de madeiras nativas e seus efeitos na economia, associada ao fortalecimento dos conceitos de preservação ambiental, criou a necessidade de desenvolvimento de alternativas viáveis para utilização racional de espécies de reflorestamento. E uma das opções é a realização de classificação visual das peças. Autores de trabalhos desenvolvidos nessa linha de pesquisa verificaram a adequação das regras de classificação visual do Southern Pine Inspection Bureau (SPIB) dos EUA à madeira de Pinus do Brasil e apresentaram proposta para normalizar o processo de classificação visual dessa madeira. Nessa classificação, os aspectos com maior influência são: presença de nós, desvio de grã em relação ao eixo da peça e densidade de anéis de crescimento. Assim, esta pesquisa apresenta um estudo experimental que consistiu na classificação visual e determinação da resistência à tração de 85 peças de Pinus spp e um estudo teórico, que propôs uma equação para determinar a resistência à tração média de peças estruturais em função da classificação visual. Com este trabalho, foi possível observar a influência dos nós e dos anéis de crescimento sobre a resistência à tração das peças analisadas.The reduction in the availability the native lumber species and its effects on the economy, associated to the invigoration of the concepts of environmental preservation created the necessity of the development of viable alternatives for rational use of reforestation species. One of the options is the accomplishment of visual grading of the pieces. Research works verified the adaptation of the rules of visual grading of Southern Pine Inspection Bureau (SPIB) of the USA for the Brazilian lumber Pinus, presenting a proposal to normalize the process of visual grading of this lumber. In this classification, the most important aspects are the presence of knots, the inclination of the grain in relation of the axis of the piece and the density of growth rings. Therefore, the current work presents an experimental study consisting of a visual grading and determination of the stress strength of 85 Pinus spp pieces and a theoretical study that presents an equation to establish the average strength strain of structural pieces according to the visual grading. With this work, it was possible to observe the influence of the knots and growth rings in stress strength of the analyzed pieces

Influence of roof material on thermal comfort in broiler housings in the state of São Paulo

Este trabalho apresenta um estudo da influência de diferentes materiais de cobertura no conforto térmico de instalações destinadas à criação de frangos de corte. A pesquisa foi desenvolvida no Câmpus Experimental da UNESP de Dracena - SP. Quatro protótipos em escala real foram construídos, com área de 28 m² cada, cobertos com telha reciclada à base de embalagens longa vida, telha cerâmica, telha cerâmica pintada de branco e telha de fibrocimento. Os dados foram coletados durante o período de inverno de 2007, totalizando 90 dias. Com esses dados, foram calculados os índices de conforto térmico Carga Térmica Radiante (CTR) e a variável ambiental (Ta). Uma análise estatística por inferência e descritiva foi realizada com os valores do índice de conforto térmico e da variável ambiental. Com os resultados obtidos, é possível afirmar que a telha reciclada apresentou índices de conforto térmico semelhantes àqueles encontrados para as telhas cerâmicas. O protótipo coberto com telha de fibrocimento apresentou os maiores índices, e o coberto com telha cerâmica branca, os menores índices de conforto térmico. No entanto para o período de inverno e para os horários avaliados, todas as instalações apresentaram índices de conforto térmico fora da zona de termoneutralidade do frango de corte.This paper presents a different roof tiles influence study on the thermal comfort for broiler housings. The research was conducted at UNESP's Experimental Campus at Dracena, state of São Paulo, Brazil. Four prototypes in real scale were built, each with an area of 28 m². The prototype was covered with roof tiles made of recycled long-life packing material, ceramic tiles, ceramic tiles painted with white coating, and fiber/cement tiles. Temperatures inside the structures were recorded in the winter 2007 over a 90-day period. The results obtained indicated that recycled tile thermal behavior was similar to ceramic tiles. However for the winter period all the prototypes had presented comfort thermal index not in the broilers thermo neutral zone.FAPESPCNP

Roof modular system in wood and particle board (OSB) to rural construction

Wood is a material of great applicability in construction, with advantageous properties to form various structural systems, such as walls and roof. Most of the roof structural systems follow models that have remained unchanged for a long time. A roof modular system in distinguished materials is proposed: reforested wood (Pine), oriented strand board (OSB) and roof tiles made of recycled long-life packaging material in order to be applied in rural construction. In this alternative, besides the benefit of giving destination packages with long-life thermal comfort, it also highlights the use of reforestated wood being the cultivation of such species that provides incentive for agribusiness. The structural performance of this alternative was evaluated through computer modeling and test results of two modular panels. The analysis is based on the results of vertical displacements, deformations and stresses. A positive correlation between theoretical and experimental values was observed, indicating the model's feasibility for use in roof structures. Therefore, the modular system represents a solution to new architecture conceptions to rural construction, for example, storage construction, cattle handling and poultry, with benefits provided by prefabricated building systems

Roof modular system in wood and particle board (OSB) to rural construction

Wood is a material of great applicability in construction, with advantageous properties to form various structural systems, such as walls and roof. Most of the roof structural systems follow models that have remained unchanged for a long time. A roof modular system in distinguished materials is proposed: reforested wood (Pine), oriented strand board (OSB) and roof tiles made of recycled long-life packaging material in order to be applied in rural construction. In this alternative, besides the benefit of giving destination packages with long-life thermal comfort, it also highlights the use of reforestated wood being the cultivation of such species that provides incentive for agribusiness. The structural performance of this alternative was evaluated through computer modeling and test results of two modular panels. The analysis is based on the results of vertical displacements, deformations and stresses. A positive correlation between theoretical and experimental values was observed, indicating the model's feasibility for use in roof structures. Therefore, the modular system represents a solution to new architecture conceptions to rural construction, for example, storage construction, cattle handling and poultry, with benefits provided by prefabricated building systems.189193Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Otimização do uso de resina poliuretana de óleo de mamona em painéis OSB de bambu Dendrocalamus asper

This work presents a study of the optimization of castor oil polyurethane (PU) resin content for the production of Oriented Strand Boards (OSB) using bamboo (Dendrocalamus asper). For this study, medium-density (650 kg/m3) OSB panels were produced with different resin contents (8%, 10%, 12%, and 15%). The bamboo particles were characterized through physical, chemical and anatomical analyses, identifying the potential of this product as a raw material for OSB panels. Subsequently, the physical and mechanical properties of OSB panels were evaluated. The results indicated that bamboo and castor oil PU are suitable for the production of OSB panels, and all the conditions met the minimum requirements of the European standard EN 300 (2002), for OSB type 1. In particular, the best overall properties were obtained by the panels with a resin content of 12%, achieving the minimum requirements for applications as a structural panel (type 4), opening new opportunities for formaldehyde-free engineered bamboo materials for the built environment.Este trabalho apresenta um estudo da otimização do teor de resina poliuretana (PU) a base de óleo de mamona para a produção de painéis de partículas orientadas (OSB) utilizando bambu (Dendrocalamus asper). Para este estudo, painéis OSB de densidade média (650 kg/m3) foram produzidos com diferentes teores de resina (8%, 10%, 12% e 15%). As partículas de bambu foram caracterizadas através das análises física, química e anatômica, identificando o potencial deste produto como matéria-prima para a produção de painéis OSB. Posteriormente, foram avaliadas as propriedades físicas e mecânicas dos painéis OSB. Os resultados indicaram que o bambu e a resina PU a base de óleo de mamona se mostrou adequado para a produção de painéis OSB e todas as condições atendem aos requisitos mínimos da norma europeia EN 300 (2002), para OSB tipo 1. Em particular, as melhores propriedades em geral foram obtidas pelos painéis com um teor de resina de 12%, atingindo todos os requisitos mínimos para aplicações como um painel estrutural (tipo 4), abrindo novas oportunidades para materiais de bambu projetados sem formaldeído para o ambiente construído

OSB sandwich panel with undulated core of balsa wood waste

The production of wood-based materials is currently being expanded by the furniture industry and civil construction sector. In order to find new alternatives for the panel market, new configuration possibilities (geometry) of panels and the use of renewable raw materials must be explored. In this scope, the objective of this research was to evaluate OSB sandwich panels with an undulated core and flat faces (OSBUC panels) made of Balsa wood waste strands (Ochroma pyramidale) bonded with two-component castor oil polyurethane resin for use in civil construction. Two types of panels were produced with 13 % resin and varying the density of the core (OSBUC-T1 - faces 550 kg/m³ and core 400 kg/m³) and (OSBUC-T2 - faces 550 kg/m³ and core 500 kg/m³). The water absorption and thickness swelling of the face panels were determined based on the Brazilian standard NBR 14810 and the bending test properties of the OSBUC panels determined by the recommendations of the ASTM C393 standard. The results obtained were compared with the specifications of the PS-2-10 –“Performance Standard for Wood-Based Structural-Use Panels” that provides bending stiffness (EI) values and maximum bending moment (FbS) requirements for OSB panels according to different classes of use. The sandwich panels had maximum values of EI 6,48 x 106 N·mm²/mm and FbS 3065 N·mm/mm. The OSBUC-T1 treatment proved to be the most efficient, as it has mechanical properties that meet the normative recommendations for structural use and as flooring, with lower material consumption (lower density). &nbsp

Viabilidade Tecnica de Producao e Propiedades de Paineisde Particulas de Cascade Amendoim

No presente trabalho, considera-se o estudo do potencial de utilização de resíduos da casca de amendoim, com o intuito de agregar valor a este material, por meio da fabricação de painéis de partículas aglomeradas com resina ureia-formaldeído, prensados à temperatura de 100 oC. A qualidade dos painéis foi avaliada com base nas prescrições do documento normativo ASTM D 1037:2006 por meio de ensaios físico-mecânicos de densidade, inchamento em espessura, absorção de água e flexão estática. Os painéis avaliados apresentaram densidade média variando de 0,69 a 0,83 g cm-3, MOR 4,37 a 5,34 MPa e MOE 590 a 700 MPa, para painéis com e sem tratamento preservativo. É possível afirmar, baseando-se no documento normativo ANSI A208.1:1993, que o material apresenta potencial para utilização em ambientes internos, como revestimento superficial de residências, construções agrícolas, setor moveleiro e decorativo. Recomenda-se a intervenção no processo de fabricação do painel, para melhorar as propriedades mecânicas e possibilitar o uso estrutural do material.In this study, the potential use of residues of peanut husks was verified, in order to add value to these materials through the manufacture of panels of particleboards. For this procedure, it was used urea- formaldehyde resin and the panels were mechanical pressed at a temperature of 100 oC. The quality of the panels was evaluated based on the prescriptions of the normative document ASTM D 1037:2006, through physical and mechanical tests of characteristics, such as: density, swelling in thickness, water absorption and static bending. The panels evaluated showed bulk density varying between 0,69 a 0,83 g cm-3, MOR and MOE between 4,37 - 5,34 MPa and 590 - 700 MPa respectively, for panels with and without preservative treatment. It is possible to claim, based in the normative document ANSI A208.1:1993, that the material presents a potential for use in internal areas as superficial covering of residential buildings, agricultural buildings, furniture and decorative sectors. Intervention in the board production process is recommended, in order to improve the mechanical properties of the material and enable its structural use.Fil: Gatani, Mariana Pilar. Consejo Nacional de Invest.cientif.y Tecnicas. Centro Cientifico Tecnol.conicet - Cordoba. Centro Experimental de la Vivienda Economica(i); Argentina;Fil: Fiorelli, Juliano. Universidade Do Sao Paulo. Faculdade de Zootecnia e Engenharia de Alimentos; Brasil;Fil: Medina, Juan Carlos. Universidad Nacional de Santiago del Estero. Facultad de Cs.forestales; Argentina;Fil: Arguello, Ricardo Gustavo. Consejo Nacional de Invest.cientif.y Tecnicas. Centro Cientifico Tecnol.conicet - Cordoba. Centro Experimental de la Vivienda Economica(i);Fil: Ruiz, Agustin Pascual. Universidad Nacional de Santiago del Estero. Facultad de Cs.forestales; Argentina;Fil: do Nascimento, Maria Fatima. Universidade Do Sao Paulo. Faculdade de Zootecnia e Engenharia de Alimentos; Brasil;Fil: Savastano Jr., Holmer. Universidade Do Sao Paulo. Faculdade de Zootecnia e Engenharia de Alimentos; Brasil

PAINEL AGLOMERADO DE RESÍDUOS AGROINDUSTRIAIS

The present study aimed to develop particleboards of low density with peanut shell, coconut husk fiber green (hybrid) and two-component polyurethane resin based on castor oil. The experimental panels were manufactured with particles up to 8mm and 15% polyurethane resin. The pressing was carried out at 5.0 MPa for 10 minutes at 100°C of temperature. The physical-mechanical properties of the material were determined as recommended by ABNT 14810:2006. The results demonstrated a mechanical performance that meets the recommendations established by normative ANSI A208.1-1999 and ABNT 14.810-2:2006.http://dx.doi.org/10.5902/1980509819675O presente trabalho teve como objetivo desenvolver painéis de partículas aglomeradas de baixa densidade com casca de amendoim, fibra da casca do coco-verde (híbrido) e resina poliuretana bicomponente à base de óleo de mamona. Os painéis experimentais foram fabricados com partículas de até 8 mm de comprimento e 15% de resina poliuretana. A prensagem foi realizada a 5,0 MPa, por 10 minutos, a uma temperatura de 100°C. Foram determinadas as propriedades físico-mecânicas do material, seguindo as recomendações da norma ABNT 14810:2006. Os resultados demonstraram desempenho mecânico que atende às recomendações estabelecidas pela normativa ANSI A208.1-1999 e ABNT 14.810-2:2006