Variability of density and bending properties of Picea abies structural timber

Abstract

Density, modulus of elasticity and bending strength were measured on 333 boards from 54 Picea abies trees, sampled from six sites in a small area in southern Norway. The variability of the properties was analysed in a linear mixed model with relative tree size and log type as fixed effects, and with site and tree as random variables. Relative tree size was the most important fixed effect, and both density, MOE and MOR all decreased with increasing relative tree size. Log type explained a smaller part of the variance, but it was important when predicting MOR from MOE since these had different longitudinal variations.

Keywords:

• Bending strength
• density
• modulus of elasticity
• Norway spruce
• Picea abies
• structural timber

Acknowledgements

This article is based on data from a project that Silvinova AS has accomplished with financial support from the Research Council of Norway. The data analyses and the writing have been supported by the Research Council of Norway project no. 178330/I10. The authors are grateful to Mathiesen Eidsvolds Værk for providing timber to the study, to Bjørn Slette for assistance in the laboratory, and to Ola Øyen for initiating the project.