Determination of structural properties of naturally dried Kabete Blue-gum timber

Abstract

For several years, Blue-gum has been used for non-structural purposes. lis usage as a structural material has been inhibited by lack of its engineering properties. With its abundance coupled with the sky rocketing prices of other structural materials, availability of its properties will enhance its utilisation as a structural material. This study was done to meet this goal. In this study, the following engineering properties of Blue-gum were evaluated; tensile, compressive, and bending strengths; and viscoelastic behaviour. Thirty test were carried on small clear specimens of dimensions 100 mill x 15 mm x 10 nun, 100 rnrn x 20 mill x 20 mm and 360 mm x 35 mm x 20 nun for tensile, compression and bending respectively. For viscoelastic behaviour, specimens used were of sizes 300 mm x 20 rnm x 20 mm. The results indicates that Blue-gum timber has tensile strength of 123 MPa, compressive strength of 49 MPa and bending strength of 86 MPa. This strength values were obtained at moisture content of 17%. Blue-gum timber was found to be linearly viscoelastic at a stress equivalent to a third of ultimate bending strength. The study concluded that with high values of strength and the ability to predict its limedependent behaviour, Blue-gum timber is a good structural material.