Buyskikh N. Efficiency of lower grade pine timber using.

Thesis is focused on finding solutions of scientific and practical problem of efficient lower-grade round timber materials with knots and cracks using. Prevalence of these defects in different zones of the trunk; physical and mechanical values, for knots wood and trunk wood zones corresponding to them were determined for considerable area of pine growth. Imitating model of round wood drying was designed and offered method of round specimens internal stress control by moisture content measuring of their surface and central part. It allows studying the influence of different methods and drying schedules for providing process without defects. Strength of compression parallel to the grain and cross grain bending of wood for building timber sizes with different moisture content were also evaluated. Various effects of the largest knot location in pine whorl on its strength were experimentally calculated under a static bending load, which depends on a place of load application. For the first time values of bending strength for round timber products with defects and without them were calculated. They exceed twice the standard requirements which suggest a strong possibility of small-diameter round timber use in construction, wich allow save the timber of large diameters.