Spruce wood has a low natural durability and is not very susceptible to impregnation, which we tried to improve by soaking the wood in water for a long time. The spruce wood was collected in the Dolenjska region near Mokronog and soaked in water for 1, 2 and 4 weeks immediately after felling. When the wood was air-dried, we started the experiments. We tested whether soaking the wood improved its impregnability and whether its mechanical properties and chemical structure changed. We carried out mechanical tests (three-point bending and compressive strength), a test of resistance to fungal attack, the contact angle of water on the wood, short- and long-term water and vapour absorption, and wet absorption of biocides using a vacuum method, and we determined the degree of aspiration of pits using scanning electron microscopy (SEM). After 4 weeks of soaking in water, spruce wood increases the wet absorption of biocides and resistance to fungal attack, the wood has a higher compressive strength and fewer aspirated pits. The bending strength of the wood decreases and the hydrophobicity remains the same compared to the control samples. By soaking spruce wood in water for 4 weeks we improve the impregnation properties of the wood, which is what we wanted to achieve. However, the mechanical properties also change, in particular the bending strength is lower and the wood is no longer hydrophobic. If we want to find out whether the bending strength and hydrophobicity also improve, we would have to carry out tests with wood that has been in water for even longer.
|