Measurement of mechanical and physical properties of Aspen (Populus alba) for establishing its allowable design values

Mechanical tests were conducted on matched small clear specimens of populus wood, which is a fast growing piece. The tests were made by adopting D143-06 specification of ASTM standard. modulus of rupture and modulus or elasticity, tension parallel to grain and tension perpendicular to grain, compression parallel to grain and compression perpendicular to grain, shear parallel to grain, cleavage, hardness, nail withdrawal and toughness of this species were measured. Density and shrinkage rate of this species were also measured as well. The target for measuring mechanical properties of populus was to determine its clear wood strength for establishing corresponding design value. In the case of green state these values were obtained: modulus of rupture 38.1 (N/mm2) and modulus of elasticity 6297 (N/mm2), tension parallel to grain 64.6 (N/mm2) and tension perpendicular to grain 1.9 (N/mm2), compression parallel to grain 20.1 (N/mm2) and compression perpendicular to grain at limit point 2.0 (N/mm2) and in the 1 mm deformation 3.5 (N/mm2)و shear parallel to grain 4.0 (N/mm2), cleavage 27.5 (N/mm2), side hardness 1.5 (KN), nail withdrawal 0.56 (KN) and toughness 2.6 (Kg. m). In the case of air dried state these values are obtained: modulus of rupture 65 (N/mm2) and modulus of elasticity 8097 (N/mm2), tension parallel to grain 73.3 (N/mm2) and tension perpendicular to grain 3.2 (N/mm2), compression parallel to grain 34.8 (N/mm2) and compression perpendicular to grain at limit point 4.3 (N/mm2), shear parallel to grain 4.9 (N/mm2), cleavage 42.3 (N/mm2), nail withdrawal 0.43 (KN). The average physical properties are density (apparent) 0.38 gr/cm3 and shrinkage: (radial) %3.2, (tangential) %5.2 and (volumetric) %8.4.