Some Physical And Strength Properties Of Lesser Known Aphloia theiformis Timber From Lushoto Tanga, Tanzania

Abstract

Some physical and strength properties of lesser known Aphloia theiformis timber grown in and around Magamba Forest Reserve, Lushoto district, Tanga region
were determined. A total of three sample trees were randomly selected and felled for
this study. Test samples for moisture content, basic density and Strength properties determination were prepared and tested according to Lavers (1969), BS
373 (1957), ISO 3130 (1975), ISO 3131 (1975), ISO 3133 (1975) and ISO 3349
(1975). It was observed that Aphloia theiformis timber has a sapwood and
heartwood colour ranging from creamcoloured to whitish pink resembling that of
Grevillea robusta. The average basic density was 519 kg/m³ with a standard deviation of 4.2 which can be classified as medium-density timber. The basic density showed a slight decrease from butt end to top end. Regarding strength properties,
Aphloia theiformis timber had a mean modulus of rupture of about 55.8 N/mm² and modulus of elasticity of about 3854 N/mm². The work to the maximum load was about 0.06mmN mm^-3, while total work averaged 0.08mmN mm^-3. The compression and shear parallel to the grain were 37.4 and 12.6N mm^-2 respectively. Furthermore, all strength properties of Aphloia theiformis were positively correlated with basic density. The properties of this timber were also comparable to properties of Grevilea robusta and are always rated the same by timber dealers. While Aphloia theiformis had higher tearing strength than Grevillea robusta, the modulus of rupture and compression parallel to the grain values were comparable. Aphloia theiformis can therefore substitute Grevilea robusta in many areas of its application.

Keywords: Aphloia theiformis - lesser known - physical and strength properties

Tanzania Journal of Forestry and Nature Conservation Vol. 77 2008: pp. 1-8