Evaluation Of Properties Of Dendrocalamus Giganteus Culms At Different Ages

In this research, anatomical and physical properties of Dendrocalamus giganteus (Dragon bamboo) culms at different ages were studied. Perimeters studied included tissue composition, vascular bundle density, fiber morphology and shrinkage rate and strengths of culms.Dragon bamboo culms consisted of 55.64% to 70.75% ground tissue, 3.27% to 7.94% conductive tissue and 28.69% to 39.84% fiber. Density of vascular bundle increased with culms age and with increasing height, ranging from 151/cm2 for one year old culms to a maximum 198/ cm2 for four year old culms and from 128/ cm2 at the base to 172/ cm2 at mid height to 223/ cm2 at the top. Vascular bundles were mainly franked with a detached fiber sheath, but double-franked vascular bundles also were observed in the middle part of culms at the ground level. Fiber length did not vary with culm age, but fibers at mid height were slightly longer than those at the based and top sections. The average fiber length was found to be 2.27 mm. The average fiber width was 19.12μm, and the average aspect ratio was 119.Dragon bamboo culms had internodes between 30 to 45 cm in length and a basic density between 0.419 to 0.670 g/cm3. The culm density increased with increasing height, and it also increased with culm age, reaching a maximum at the forth year. Three year old culms had the lowest oven-dry volumetric shrinkage age at 12.8%, and shrinkage rate usually increased with increasing culm height. Variation of the mechanical properties of Dragon bamboo culms followed the variation pattern of its basic density, i.e., increased with increasing age and increasing culm height. The average compression strength (parallel to grain), bending strength, bending modulus and shear strength (parallel to grain) were 76.23 MPa, 287.14 MPa, 26.45 GPa and 7.72 MPA, respectively.