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In Brazil, standard ABNT NBR 7190 (1997) prescribes the determination of strength (fM) and modulus of elasticity (EM) in static bending from specimens measuring 5 cm × 5 cm × 115 cm. Thus, the relationship between the test span (L) and the specimen height (h) greater than or equal to 21 (L/h ≥ 21) is respected, ensuring that the effect of shear in the calculation of displacements is negligible (Euler Bernoulli Theory). Considering the expressive number of tree species cataloged in the Brazilian Amazon Forest, any procedure that aims to facilitate the realization of experimental tests is highly desirable because it provides the knowledge of unusual species. These wood species may potentially replace woods that have been traditionally used and historically exploited. Using five hardwood species, this research aimed to verify, while maintaining constant L/h ≥ 21 ratios, the influence of specimens dimensions in the determination of fM and EM. For all species studied, the statistical analysis found equivalence in the values of fM and EM determined as a function of the sample sizes. Therefore, respecting the ratio L/h ≥ 21, the size of the specimens does not influence the determination of strength and stiffness in static bending.

Made available in DSpace on 2020-12-10T20:07:25Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-08-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Use of lignocellulosic materials in particleboard has turned into an alternative for the reuse of such materials, which are abundant and may have precarious disposal techniques. The present study fabricated particleboards using industrial sawmill waste from tropical hardwoods (a mix of species) and sugarcane bagasse with castor oil-based bicomponent polyurethane resin and evaluated the influence of the incorporation of sugarcane bagasse (0, 10, 20, 30, 40, and 50%) on the physical and mechanical properties of the composites. The particleboards were produced according to the Brazilian Standard ABNT NBR 14810 (2018), and performance requirements were assessed using Brazilian and international standards. Some of the particleboards met standardized requirements, with Treatment 5 (50% sawdust and 50% bagasse) showing better performance, indicating the possibility for use indoors in dry conditions. The addition of sugarcane bagasse increased dimensional stability of particleboards when compared with panels manufactured with timber residue. Statistical analysis indicated the percentage of bagasse was significant, increasing physical and mechanical properties when compared with the reference treatment. West Sao Paulo Univ, Dept Civil Engn, Presidente Prudente, SP, Brazil Sao Paulo State Univ, Dept Civil Engn, Ilha Solteira, SP, Brazil Fed Univ Rondonia UNIR, Dept Civil Engn, Porto Velho, RO, Brazil Fed Univ Southern & Southeastern UNIFESSPA, Araguaia Engn Inst, Santana Do Araguaia, PA, Brazil Univ Fed Sao Carlos, Dept Civil Engn DECiv, Sao Carlos, SP, Brazil Fed Univ Minas Gerais UFMG, Dept Civil Engn, Belo Horizonte, MG, Brazil Univ Sao Paulo, Sao Carlos Sch Engn Sao Carlos, Dept Struct Engn, Wood & Timber Struct Lab, Sao Carlos, SP, Brazil Sao Paulo State Univ, Dept Civil Engn, Ilha Solteira, SP, Brazil