Relações entre anéis de crescimento e propriedades físico mecânicas da madeira de Pinus spp

Abstract

The structural use of wood of the Pine genus is increasing, due to the lack of native woods, conventionally used for structural purposes. Therefore, it is important to identify the characteristics of this structural material for its specific applications in order to guarantee good performance and resistance during its useful life in buildings. In this sense, the aim was to evaluate the relationship between the growth rings and the physical-mechanical and visual characteristics of Pine spp. Specimens of Pine spp. Wood, with dimensions of approximately 89 × 39 × 90 [mm3], were used. In the methodology, the apparent density was evaluated according to the technical standard and the growth rings of each sample were counted. The proportion of latewood in each specimen was analyzed using the image J software. Then, the mechanical tests were performed and the normal compressive strength values were compared according to the requirements of three studied standards. The specimens with the highest number of growth rings per inch had a higher apparent density, and as a consequence, greater were the mechanical properties; average modulus of elasticity (Ec90) of 451.89 [MPa] and the average compressive strength of fibers 10.83 [MPa] by the ABNT method; 11.92 [MPa] by the ISO method and 10.50 [MPa] by the ASTM method. The Fc90 results of the three norms analyzed among the five class: Tangential dense, Tangential non dense, Radial tangential dense, Radial tangential non-dense and Medular were different. The evaluation of the growth rings and apparent density showed significant contributions to the mechanical properties of Pinus spp