Impact of water storage on mechanical properties of spruce as detected by ultrasonics

Summary The impact of a five months water storage together with a bacterial treatment, on the mechanical properties of spruce is analysed by ultrasonic waves. The Bacillus subtilis is used to improve the permeability of spruce sapwood. The attack of bacteria on the torus of aspirated pits is expected to lead to a better transport of preservative liquids. The elastic constants were calculated through ultrasonic velocities which were measured at different types of specimens. The results were compared with the constant E_L as determined by a static bending test. The calculated loss of strength seems to be negligible but variations in the elastic properties of anatomical plaines consisting radial axes, can be well predicted.