Durabilidade natural da madeira de cinco espécies amazônicas

Abstract

The aim of this study was to evaluate the natural durability of wood from five forest species used commercially. Five species were studied: Erisma uncinatum (cedro); Qualea sp. (Cambará); Hymenaea courbaril (Jatoba); Diplotropis purpúrea (Sucupira Preta); Trattinnickia burserifolia (Amescla). They were defined two areas of study, the first in a in open area with underbrush (open field) and the other in a fragment of native forest. During 12 months ( every 30 days) , they were taken from 25 specimens of each deterioration of environment taking care to remove the same specimens , for monitoring the loss of mass and evaluation of the structural properties of wood by non- testing destructive to the structural integrity analysis with the aid of a transmitter equipment ultrasonic waves . For the characterization of the modulus of rupture, the bodies of the test piece were subjected to mechanical tests in universal testing machine. The T. burserifolia species was the most susceptible to deterioration in the two study sites (native forest and open field) was observed difference in the speed of propagation of the waves in relation to other species exposed to decay. For the kind of T.burserifolia and Qualea sp. the modulus of elasticity differs statistically from exposure to the deterioration test. The greatest weight loss occurred in the forest especially T.burserifolia. The bodies of the test piece coming from inside the forest presented more degraded compared to those outside the forest. The results suggest that the environment influence the biodegradation of the species studied, as well as reductions in their resistance and mechanical.