Bending strength and nondestructive evaluation of structural bamboo

Optimization on the use of bamboo requires comprehensive understandings of the physical, mechanical, and chemical properties. When using bamboo as a building material, one needs to know its specific gravity, stiffness and bending strength properties. This work investigated density, stiffness, bending strength properties and nondestructive evaluation of four-year old Bambusa vulgaris 'Vittata', very common in Manaus, used on the construction of an ecological and sustainable village for Amazonia. Flexural bending strength samples were cut from eight culms in three 3-m segments (base, middle, and top). The 3-m long culms were first tested nondestructively through axial sonic vibration of a Stress Wave Timer (SWT), then in thirdpoint loading static bending with a clear span of 2.71 m. The average moisture content and density of the bamboo culms tested were 12.95% and 646 kg m−3, respectively. The average dynamic modulus of elasticity was 17.3 GPa. The average ultimate load, modulus of rupture and modulus of elasticity were 7.9 kN, 88 MPa and 9.6 GPa, respectively. Analysis of the results showed that bamboo culm density and dynamic modulus of elasticity can be used to determine its strength and stiffness. Also, SWT can be used for nondestructive evaluation of bamboo culms strength and stiffness.