Investigation on physical and mechanical properties of two Myanmar lesser-used timber species (Lagerstroemia tomentosa Presl. and Holoptelea integrifolia Planch.)

Alfeld

2004

S. 20-27

7 Abb., 10 Lit. Ang.

Artikel aus einer Zeitschrift

200109127

The utilisation-oriented technological properties and the variability of the properties of two Myanmar less-used timber species were investigated (10 sample trees for each species). The dimensional stability of the two species is less than 2.0 (ratio of tangential to radial shrinkage), although their total volumetric shrinkage is relatively high. The oven-dry specific gravity is 0.55 for Lagerstroemia tomentosa and 0.58 for Holoptelea integrifolia. The green moisture content of Lagerstroemia tomentosa (94 %) was higher than that of Holoptelea integrifolia (68 %). All investigated physical and mechanical properties show significant variations between trees and species. The shrinkage is neither increasing nor decreasing with tree height, but decreasing with the distance from the pith. The green moisture content seems to increase with height in Holoptelea integrifolia, but belongs to the variable type in Lagerstroemia tomentosa, and seems to decrease with the distance from the pith in both species. The specific gravity decreases with height in both species, and increases with the distance from the pith in Lagerstroemia tomentosa. It increases first with the distance from the pith and then decreases towards the cambium in Holoptelea integrifolia. Mechanical properties are found to vary within the trees, but rarely significantly different. Acoording to the results of mechanical properties. the two species are suitable for construction purposes, but not suitable for heavy construction.