Abstract
<jats:p>The paper examines a cement-silicate composition with a filler based on flax shives. To improve the physical and mechanical properties, the composition was modified with a two-component hydro-active polyurethane compound Manopur 127. When in contact with the liquid phase of the composition, the polyurethane compound fills the free space of the pores, and when it expands, a 4-10-fold increase in the com-pound is achieved. Electron microscopy methods using energy-dispersive X-ray spectroscopy have shown an improvement in the structure of the modified composition due to blocking the internal surface of the pores, which allows stabilizing the pore sizes and eliminating their perco-lation. The results of the physical and mechanical properties of a modified composition based on flax shives are presented, including strength, thermal conductivity and water resistance. It has been shown that the addition of hydroactive polyurethane to the composition pro-motes additional porosity of the fluoroanhydrite composition while simultaneously blocking the mineral matrix with a polymer film, which limits the access of water into the structure of the material. The proposed innovative solution for the production of thermal insulation and structural thermal insulation materials using man-made waste contributes to increased economic efficiency. A possible improvement in the environmental situation in the places where flax shives are dumped has been noted due to the elimination of possible fires or their rotting during storage in waste heaps.</jats:p>