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An experimental analysis of pinewood beams (Pinus caribea var hondurensis) reinforced with glass and/or carbon fibers is discussed. The theoretical model employed to calculate the beam's bending strength takes into account the timber's ultimate limit states of tensile strength and failure by compression, considering a model of fragile elastic tension and plastic elastic compression. The validity of the theoretical model is confirmed by a comparison of the theoretical and experimental results, while the efficiency of the fiber reinforcement is corroborated by the increased strength and stiffness of the reinforced timber beams

Este trabalho apresenta um estudo do potencial de utilização do bagaço de cana-de-açúcar para fabricação de painéis de partículas aglomeradas utilizando resina poliuretana à base de óleo de mamona. A qualidade dos produtos foi avaliada com base nas prescrições do documento normativo NBR 14810 (ABNT, 2006b), com a determinação da densidade, do inchamento, da absorção, do Módulo de Elasticidade (MOE) e Módulo de Ruptura (MOR) na flexão estática. Após análise dos resultados, os painéis avaliados apresentaram densidade média de 0,93 g cm-3 , MOR e MOE médios 24,4 e 2432 MPa, sendo classificados, segundo os indicativos da norma ANSI A208.1 (1993), como material de alta densidade, recomendado para uso industrial. A resina à base de óleo de mamona mostrou-se eficiente como matriz polimérica para fabricação de compósito à base de bagaço de cana-de-açúcar.

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This paper discusses the potential use of sugarcane bagasse in two different fiber lengths (5 mm and 8 mm) of the same density as a raw material for the production of particleboards, using castor oil-based two-component polyurethane adhesive. The quality of the product that can be manufactured industrially was evaluated based on density, thickness swell (TS), absorption (WA), modulus of elasticity (MOE), modulus of rupture (MOR) in static bending and internal bond (IB), according to the Brazilian NBR 14.810:2006 standard. The results revealed a significant difference between the particleboards made with 5-mm-long fibers and those made with 8-mm-long fibers. An analysis by scanning electron microscopy (SEM) indicates that the interparticle spaces are filled with castor oil-based two-component polyurethane adhesive, contributing to improve the physicomechanical properties of the particleboards. A durability assessment based on accelerated aging tests shows that waterproofed particleboards can be used in moist environments.