THERMO MODIFIED WOOD AS CONSTRUCTION MATERIAL
The field of wood application as a construction material depends on its properties. Various heat treatment conditions help to obtain wood with desired properties. Comparative analysis of various heat treatment revealed that physical and mechanical properties of the heat-treated wood vary and depend on the species and conditions of the heat treatment. According to the experimental data of foreign investigations the general tendency can be described as the following - the higher is the processing temperature the better is the wood’s biological durability; hygroscopicity and the level of the equilibrium moisture content decrease; thermal insulation properties improve. At the same time, with the increase of the processing temperature the strength properties of the wood reduce. However, in rare cases results of experimental studies of the heat-treated wood properties may not only differ slightly, but also be opposite. This proves the need for further experimental studies of the heat treatment effect on wood properties. The studies are needed to explain and compare the obtained results with the similar foreign ones. Some authors show remarkable fungus resistance of the wood treated at high temperatures of 230-240 °С. However, according to other works, thermo treatment process does not have any positive effect on fungus resistance. On the contrary, with the temperature increase to 240 °С the rate of decay by fungi increases. A perspective direction of the research is an elaboration of technology aimed to saturate thermo modified wood with nanoscale materials (e.g. nano-structured shungite) during the third phase of stabilization, cooling and water saturation by wood. Addition of nanoscale composites into the steam at this stage, which together with water vapor will saturate the wood throughout the volume, helps to get significant changes in wood properties. The expedience of the research in this area is confirmed by the effectiveness of nanomodifiers’ usage in the chipboard production technology.