Investigations on selected properties of tonal wood of spruce from Grisons

This survey focuses on the mechanical properties of spruce tonal wood from three different locations in the canton of Grisons, Switzerland. In addition, the material from one location was stored under water for three months in order to test the influence of extractives. The tests included the analysis of the annual ring structure, measurements of the sound velocity with longitudinal and transverse waves in the three main directions, bending strength, bending modulus of elasticity (MOE), eigenfrequency, logarithmic decrement of the damping, sorption and swelling. Single specimens were taken to measure the extractives content. The tested wood properties suggest tonal wood of high quality for all the locations. No significant differences of the wood properties, except density-related ones, were found between the three locations. The water storage resulted in the removal of extractives, but no significant change in properties could be found.