Some physical, mechanical and anatomical characteristics of stemwood and branchwood of two hardwood species used for structural applications

Interest in branchwood utilization is gradually increasing on account of increasing demand for wood for construction and furniture production. However, wood quality assessment involves consideration of physical, mechanical and anatomical characteristics. This present study compared density, MOE and MOR, and compressive strength at 17 ± 3 %MC and 10 ± 4 %MC and some anatomical characteristics of Khaya ivorensis and Entandrophragma cylindricum by following BS (British Standard) 373, Strength properties of timber 1–24, 1957; ISO (International Standard) 3131, International Standard; wood-determination of density for physical and mechanical tests, 1975) and IAWA committee protocol of 1989. Branchwood and stemwood samples were extracted from two natural forest reserves. Results indicated that branchwood of the species dried to 17 %MC and 10 %MC proved to be as good materials as their stemwood counterparts in terms of bending and compressive strength parallel to the grain. Branchwood had significantly (p < .01) higher density than stemwood but such high densities did not translate into significant higher strength values. Moisture content and wood types (stemwood or branchwood) had significant effect (p < .001) on density, MOE, MOR and compressive strength. Fibre and axial parenchyma quantities were, respectively, the highest and lowest in both stemwood and branchwood of the two species. Fibre proportions in stemwood and branchwood correlated positively with density, MOE, MOR and compressive strength. Compared to bending strength, compressive strength was less influenced by anatomical properties of stemwood and branchwood. It was concluded that branchwood of E. cylindricum and K. ivorensis are not inferior to their stemwood and therefore could be used for structural applications. Further studies including shear strength, adhesive bonding, and finishing properties should be carried out to confirm the possibility of utilising branchwood for structural applications.