Bukhanova K. Gypsum concrete on low-burning vermiculite with high physical and mechanical properties

The dissertation is devoted to the complex development of gypsum concrete composition on low-burning vermiculite with high physical and mechanical properties, which form the optimal ratio of strength and thermal characteristics to the cost of the final product. The problems of constructive-technological features of light concretes used in Ukraine are considered. The use of low-fired expanded vermiculite as a filler in the manufacture of gypsum vermiculite concrete (GVC) is substantiated. Prospects for expanding the use of lightweight concrete in Ukraine due to the introduction of Ukrainian vermiculite deposits are shown. Issues related to the study of additives that increase the physical and mechanical properties of concrete are considered. Insufficient research on the crack resistance characteristics of lightweight concrete has been revealed. The scientific hypothesis about increase of physical and mechanical properties of gypsum concrete on low-burning vermiculite due to addition of fine vermiculite powder (FVP) for the purpose of synthesis of additional crystal hydrates is formulated, which will lead to consolidation of both contact zone and "filler-matrix". The existing problems in obtaining gypsum concrete on low-burning vermiculite and ways to solve them are considered. A method for controlling the properties of light heat-insulating concretes by solving the problem of optimizing the composition of concrete is proposed. The choice of additive-fine vermiculite powder, to increase the strength and crack resistance of gypsum concrete is substantiated. The dispersion of the additive was determined empirically with further examination by electron microscopy. Technological regulations for the production of GVC are proposed. The calculation of technical and economic indicators revealed the competitiveness of GVC with FVP on low-burning vermiculite with the main thermal insulation and structural concrete, as well as its advantage in price indicators. The calculations 10 presented in the section showed the economic feasibility of using low-burning vermiculite as a filler.