The aim of this work is to determine the physico-mechanical properties of modified wood (pine) to study the possibility of its use in parquet flooring.
The proposed modification method involves heating the wood using microwave technology and pressing it into a square cross-section. The density of pine increases significantly with the proposed technology and exceeds that of oak. The static hardness of the modified pine falls into the category of hardwoods. The core part of the sample is pressed more densely and belongs to the category of very hardwoods.
The compressive strength of the wood along the grain is 4 to 6 times greater than its strength across the grain. Therefore, from the perspective of compressive loads, parquet elements in the form of end-grain blocks are preferable. The compressive strength along the grain of the modified wood is practically equal to that of oak. The shear strength is probably the most vulnerable and, consequently, the most important strength characteristic for the proposed type of parquet; it is 10–13 MPa, compared to 6–12 MPa for common wood species.
Shrinkage and swelling of wood occur due to the removal of bound moisture from the cell walls; that is, if the wood's moisture content falls below the fiber saturation point, shrinkage reaches its maximum value. The proposed wood modification method (microwave technology) helps to avoid structural distortions associated with shrinkage. When wood is moistened up to its fiber saturation point, the wood cell walls thicken and swell, leading to an increase in the dimensions and volume of wooden products. The conducted experiments on the kinetics of swelling show that the modified wood is highly sensitive to changes in ambient humidity, which will undoubtedly lead to warping of the parquet. Therefore, this material can be recommended for use only on the condition that a completely waterproof coating is applied to the surface of the product. The thickness of the lacquer film should be at least 60 microns, and the quality of the lacquer coating should be no lower than class 3.

Keywords: wood, modified wood, determination of wood properties, mechanical properties of wood, influence of moisture on wood properties, wood swelling, parquet

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