Прочность древесно-цементного композита при воздействии химических добавок на заполнитель

Abstract

The work is devoted to the study of the dependence of the strength of a wood-cement composite on the type of chemical additives used to neutralize the water-soluble substances contained in the wood filler (sugar, starch, tannins, gum, phenol, organic acids) that negatively affect the processes of hydration and hardening of cement. Chemical additives were used in the work ‒ forming hardly soluble compounds with sugars, accelerating the hardening of cement, forming mineral films on the surface of wood particles. An increase in the strength of a wood-cement composite was experimentally established with the introduction of a complex additive consisting of 1 % CaCl2 and 1 % ScSl2. It is determined that salts of arsenic and chromic acids also have a positive effect on increasing the strength characteristics of wood-cement composite. The use of hydrofluoric acid salt for the production of wood-cement composite can significantly increase the biological resistance of wood-cement composite. Combined chemical additives accelerating the hardening of wood-cement composite — aluminum chloride, sodium sulfate, ammonium nitrate and sodium metalluminate — have been established. The types and costs of the most effective chemical additives combining calcium chloride, liquid glass, aluminum sulfate, lime and ethanolamines for various types of wood are determined. The experiments carried out confirmed the previously obtained data that the strength of the wood-cement composite is influenced not only by the combination of various chemical additives, but also by the order of their introduction into the wood-cement composite.