Physico-Mechanical and Anatomical Properties of Normal and Tension Woods of Terminalia Superba (Engl. & Diels)

Abstract

ABSTRACT This study ascertained the physico-mechanical and anatomical properties of Terminalia superba tension wood, in comparison with its normal counterpart. Tension wood recorded higher green moisture content (75 ± 2%), and lower basic density (562 ± 11 kg/m3) than normal wood (71 ± 2.8% and 576 ± 7.9 kg/m3, respectively). The modulus of elasticity, modulus of rupture, and compression parallel to grain (11293 ± 227.5, 106 ± 4.5 and 65 ± 1.8 MPa, respectively) for normal wood were greater than tension wood (7276 ± 443.7, 50 ± 0.4 and 50 ± 3.5 MPa, respectively). The double wall thickness (66 µm) and diameter (37 µm) of normal wood were greater than those of tension wood (65.68 and 33.24 µm, respectively). Normal wood also recorded greater fibre length (1.4 mm) than tension wood (1.2 mm). However, fibre-lumen diameter (32.24 µm) and vessel diameter (156.80 µm) were wider for tension wood than for normal wood (29.34 and 147.93 µm, respectively). With their comparable properties besides strength, T. superba tension wood would substitute its normal counterpart for light construction works to maximise total recovery and efficient use of T. superba and other timbers with such strains.