WOOD UTILIZATION OF Eucalyptus grandis IN STRUCTURAL ELEMENTS: DENSITIES AND MECHANICAL PROPERTIES

ABSTRACT Over the years, the species of eucalyptus has become a multipurpose raw material. In addition, the most relevant aspect of the use for various purposes is related to the production of a high quality wood, coming from short duration plantations, which is fundamental to the current demand of the industries. However, its use in civil construction has not yet reached a level of importance, due to the low knowledge of many of its resistance properties and the consequent popular fear in the use of reforestation woods, in particular the Eucalyptus grandis. This research investigated its main mechanical properties, aiming to reinforce its constructive applications in wood structures. For this, two physical properties and fourteen mechanical properties, in two different moisture conditions of the samples were evaluated, according to the norm NBR 7190 (1997). In the first moisture content, the samples were stabilized at 30%, while the second level considered the content of 12%. It was obtained 3580 determinations for the sixteen properties. From the 14 mechanical properties, only 7 had significant increases with the moisture reduction (30% to 12%), consisting of the rupture modulus in the parallel and normal compressions, normal traction and static bending; modulus of elasticity in normal compression and static bending and in shear strength.

摘要 多年来，桉树属（Eucalyptus）树种已成为一类多用途原材料。其各类应用中最受关注的核心方向，与短周期人工林产出的优质木材生产密切相关，而这一来源完全匹配当前工业界的实际需求。然而，桉树在民用建筑领域的应用尚未达到应有的重要程度，这主要源于学界对其诸多力学抗性性能的认知不足，加之大众对人工林木材（尤其是巨桉（Eucalyptus grandis））的使用普遍存在顾虑。本研究针对其主要力学性能展开探究，旨在拓展其在木结构中的工程应用场景。为此，本研究依据NBR 7190 (1997)标准，在两种不同含水率条件下对试样的2项物理性能与14项力学性能进行了测试评估。第一组试样的含水率稳定在30%，第二组则设定为12%。本次研究共获取16项性能的3580组有效测试数据。在14项力学性能中，仅7项性能随含水率从30%降至12%出现了显著提升，分别为顺纹压缩、横纹压缩的断裂模量，法向抗拉强度与静曲抗弯性能；横纹压缩、静曲抗弯的弹性模量以及抗剪强度。