Assessing the physico-mechanical properties of plantation grown albizia lebbeck from the savannah ecological zone

Abstract

The increasing scarcity of major commercial tropical hardwood species has necessitated the utilization of lesser known/used exotic wood species as a possibility of sustaining the wood resource base in Ghana. In order to make lesser known/used exotic wood species as good substitute for the dwindling scarlet species their wood properties must be investigated to expatiate their utilization potentials. This experiment was carried out to assess the physico-mechanical properties of a plantation grown Albizia lebbeck from Tamale fuel wood plantation reserve in the Savannah ecological zone. Three matured timber species with diameters (45-50 cm) at breast height (1.3 m) from the ground level were purposively selected and sampled at four stem height levels (0-25%, 26%-50%, 51%-75% and 76%-100% of tree height). The samples were prepared and sawn into the required sizes in accordance to the British standards, BS 373(1957) for testing. The morphology of the heartwood and sapwood proportions were evaluated and the samples further tested for oven-dry density at 12% MC, compression strength parallel to grain, shear strength parallel to grain, hardness, bending strength (MOR) and modulus of elasticity (MOE). Data collected were analysed and presented using descriptive and inferential statistics. The study showed that Albizia lebbeck has significant heartwood percentage than sapwood. The study also revealed that, Albizia lebbeck is a heavy timber with an overall mean density values of 868.64 kg/m3, 806.36 kg/m3, 695.26 kg/m3 and 564.7 kg/m3 at 12% MC for tree sections 0 - 25%, 26 - 50%, 51 - 75% and 76 - 100% respectively. In general the wood properties of the plantation grown Albizia lebbeck studied exhibited high strength values suggesting that it is endowed with outstanding properties for being an alternative species to supply the wood industry.