Structural Tali timber (Erythrophleum ivorense A. Chev.;Erythrophleum suaveolens Brenan.) Assessment of strength and stiffness properties using visual and ultrasonic methods
The physical and mechanical properties (density, bending strength and stiffness) of 82 sawn pieces of Tali wood (Erythrophleum ivorense A. Chev.;Erythrophleum suaveolens Brenan.) from Guinea and Cameroon were estimated using the EN 408 (2003) test standard. Timber pieces had a cross section of 80 mm×80 mm and 200 mm×250 mm and were visuallygraded according to British Standard BS 5756 (1997) in a single HS grade. The efficacy of this test was analyzed. The velocity of propagation of ultrasound waves had previously been measured by means of equipment specially designed for structural timber (Sylvatest Duo). The results of visual grading according to BS 5756 (1997) show very low output with an excessive percentage of rejected pieces. Due to this, modifications are proposed to some of the specifications with the aim of reducing this percentage. Furthermore, visual grading does not facilitate to clearly separate the mechanical properties of HS grade and rejected pieces. The use of ultrasonic measurements shows good accuracy for the evaluation of stiffness properties, but not for strength. Visual grading makes it possible to reach a strength class of D50, while ultrasonic method could be used as an added parameter for grading. © 2006 Springer-Verlag.
| Main Authors: | , , , |
|---|---|
| Format: | journal article biblioteca |
| Language: | eng |
| Published: |
2006
|
| Online Access: | http://hdl.handle.net/20.500.12792/4873 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|