PROPERTIES EVALUATION OF MANGIUM (ACACIA MANGIUM Willd.) AT VARIOUS AGES

摘要

This paper presents the physical properties, viz: relative density, moisture content (MC) and shrinkage from green to 12%, 5% and oven-dry condition; and mechanical properties, viz: static bending, compression-parallel (c//) and perpendicular (c/)-to grain, shear, hardness and toughness including percentage lumber recovery and grades of 6-, 8-, 10-, and 12-year-old mangium trees from Surigao and Agusan del Sur. Three 6-year-old trees and 5 trees each of 8-, 10- and 12-year-old mangium were used. Each tree was cut into log portions (at least every 3 m) to represent the butt, middle and top. Discs 150 mm (6") thick was taken from the end of each height level for physical properties samples while the remaining bolts 2.85m (112.20") long were used for mechanical properties samples. Analysis of variance (ANOVA) showed that variation in physical properties between age and trees was not significant except in volumetric shrinkage between ages. The effect of height within tree within age was statistically significant. On the other hand, mechanical properties varied significantly with age. Difference between trees within age was likewise significant except in modulus of elasticity (MOE) in static bending, c/, and hardness. Variation in height within tree within age was not significant except in c//.