The dissertation is devoted to the development and implementation of a scientific hypothesis of increasing the operational properties and strength of porous natural stone by impregnating with water-soluble silicon organic compositions. The porous natural stone of silicate (sandstone, tuff) and carbonate (limestone and shell) chemical composition, which is widely used in construction for facing, is chosen as a research object on the basis of analysis and generalization of theoretical data. It was established that the impregnation with organosilicon compounds is an innovative direction of increasing of the porous natural stone operational properties. The use of water soluble organosilicon preparations of domestic manufacturers has been proposed. The comparative estimation of siloxanes application efficiency on the parameters of air permeability, adhesion to masonry solution, change of mass, water-repellent properties, concentration of impregnating compositions is carried out. The optimal correlation between the time and depth of impregnation of porous natural stone with the organosilicon compounds is determined and it is established that open porosity has the decisive influence on the kinetic parameters of the impregnation process. The depth of penetration in massive materials is from 12 to 43 mm, and the time of impregnation varies in the range of 1250–3000 seconds. The advantages of using alkali metal siliconates have been experimentally proved. Siliconates provide water-repellent properties at the level of polyorganosiloxanes, but higher adhesion to the solution of masonry solutions. required level of air permeability; speed and sufficient depth of impregnation; increased mechanical strength. Optimal concentrations for organalsiliconates are 1–3 wt.%. 10 binary and three component water-soluble compositions based on alkali metal siliconates and ethylsilicate hydrolysate have been developed to solve the problem of ambiguity of the effects of individual silicone substances on the properties of impregnated stone. It was established that after the impregnation with alkaline metal siliconate based compounds, the relative index of bending strength of carbonates increases by 2.1–3.6, while the compression ratio – 4.4–13.2 times compared with unimpregnated materials. The corresponding properties of silicates increase in 2,2–2,4 and 2,6–10,3 times. The mathematical models were obtained taking into account the dependence of impregnated porous natural stone properties on the ratio of silicon organic compounds components, which allowed to optimize them. When using the optimal compositions of silicon organic compositions, the water absorption of porous natural stone decreases by 4.7–6.8 times, bending strength –1.3–1.8 times, compression – 1.3–2.1 times. The regularities of the mechanism of silicon organic compounds interaction with dispersed stone are revealed. It is shown that they can be fixed both by the chemical interaction with the active centers of the stone surface and by physical adsorption. It is suggested to take into account the noted features when evaluating the operational reliability of impregnated stone. The commodity estimation of the properties of porous natural stone impregnated with the developed compositions is carried out. It has been experimentally proved that water absorption of impregnated porous natural stone after 60 cycles of complex action of atmospheric factors with the use of the most effective silicone formulations is in 1.13–2.42 times lower than the corresponding index of unimpregnated stone: 12 vs. 29 wt.% for tuff; 11.7 vs. 14.6wt.% for limestone; 3.4 vs. 7.1 wt.% for shellfish; 3.2 vs. 3.6wt.% for sandstone. The loss of mass of impregnated stone decreases in 3,3–8,7 times as compared with unimpregnated. It was established that the use of silicon organic compounds for impregnation of porous carbonates can increase acid resistance. Relative acidity of limestone compared to the source material is 82.1–88.0%, and shellfish – 70.2–81.4%. According to the results of the examination of the stability of the consumer properties to the effects of environmental factors and heat aging, the most efficient compositions for each type of stone are recommended. Approbation of the results of the dissertation research in industrial conditions was carried out and a patent for a utility model was obtained.
