Influência do lenho de reação na resistência mecânica da madeira de Eucalyptus sp.

Abstract

The use of the Eucalyptus wood in the Brazilian sector forest has increased due the its fast growth and improvements of the wood‟s properties. Even though this increasing, the quality of the final product can be affected, due the presence of defects in wood, such as reaction wood and juvenile wood. The objective of this study was to evaluate the mechanical resistance to different positions radials and longitudinal in a tree of Eucalyptus sp, with the high degree of bole inclination. The tree was divided among log of 1,3 m, measured in center of the bole. In the center planks of wood, we were removed the logs of the wood tractioned, wood opposite, wood right and left of the reaction timber. The samples were assayed by the tests to statics bending, parallel compression of the fibrils, perpendicular traction the fibrils, cracking, shear and hardness. There was no significant difference in mechanical properties studied from the longitudinal sense of the tree, and between wood and position of the length in the tree height. In the radial position, the traction wood displayed more value of the elastic module in the parallel compression of the fibrils. The Eucalyptus sp. wood showed little variation in the mechanical properties in the sense longitudinal.