Tensile Strength Properties of Tropical Hardwoods in Structural Size Testing
In Malaysia, there is no research done on the tensile strength of structural size timber. The tension stress found in the Malaysian code of practice, MS 544: Part 2: 2001, was not determined directly and it was taken as 60% of the bending strength values of small clear specimens. This paper presents the results of the tensile test on structural size timber specimens from selected Malaysian Tropical hardwoods namely Kedondong (Canarium spp), Keruing (Dipterocarpus spp) and Bintangor (Calophyllum spp) under the strength group SG5. A special tensile grip was fabricated using the model suggested in ASTM D198 and the tests were also conducted according to ASTM D198. The tensile strength characteristics evaluated include tensile strength, modulus of elasticity and Poisson’s ratio, and the data were analyzed statistically. In this study it was found that the grade stresses for structural size specimens were higher than that published in the Malaysian code of practice. Index Term— tensile strength, structural size, Malaysian
Effect of moisture content and particle size on beech biomass agglomeration
The utilisation of biomass agglomerates is an attractive option for heat and power production to reduce greenhouse gas emissions. Agglomeration of biomass, such as tableting, can increase bulk density, improve storability, reduce transportation costs and increase the quality of products. The purpose of this study is to analyse the effects of moisture content and particle size on beech biomass agglomerates and also to identify the optimal conditions of the process for producing tablets with high density. Beech biomass was compressed in a load cell by a hydraulic piston press with 25 mm diameter. Effects of the independent variables, including moisture content (4.71 wt.% to 19.55 wt.% with particle size < 1 mm, and 4.74 wt.% to 19.45 wt.% with particle size < 2 mm) were investigated. Results showed that at the same pressure, increasing moisture content resulted in lower density of the tablet, tablets made from raw material with the smaller particle size have lower strength than tablets made from material with the larger particle size, and a new compression equation can be introduced, which contains moisture content as parameter.
Cleavage Tests of Timber
The value of physical tests of the properties of most materials, prior to their use for construction and like purposes, is now so well established, that such tests are carried out as a matter of ordinary routine. Many of these, although apparently simple, prove, on detailed examination, to be much more complex than is apparent at a first glance, as for example various tests of hardness, which are extremely useful in practice, although their accurate scientific interpretation is still in an unsatisfactory state.