TECHNOLOGY AND THE PROPERTIES OF THE FIRE-RETARDANT FIBROGIPSOVERMIKULITOBETONNYKH COMPOSITES WITH THE APPLICATION OF THE VOLCANIC ROCKS

Fire-retardant composites with the application of gypsum, unslaked lime, distended vermiculite, tuffaceous sand, basaltic fibers and resin of wood of that saponified are developed. The methods of the preparation of fire-retardant mixture and molding of articles made of the composites are investigated. Are given the results of experimental and theoretical studies of the fire resistance of armotsementnykh elements with the fire-retardant layer from the gipsovermikulitotufobetonnykh and fibrogipsovermikulitotufobetonnykh composites

THE HIGH-TEMPERATURE (OXIDATION-RESISTANT) FIBROVER-MIKULITOBETON COMPOSITES WITH THE PUMICE APPLICATION

High-temperature (oxidation-resistant) composites with the application of portland cement, distended vermiculite, pumice, basaltic fibers are developed. Are investigated compositions and properties of the vermikulitobeton composites. Are obtained the mathematical models of the dependence of the strength of the high-temperature (oxidation-resistant) fibrovermikulitobeton composites on the percentage of reinforcement and ratio of fiber length to their diameter

EFFECT OF VACUM TREATMENT ON TECHNOLOGICAL PROPERTIES OF HEAT-RESISTANT CERAMZYT-CONCRETE ON COMPOSITIONAL BINDING

Objectives The aim of the study is to study the effect of vacuum treatment, heating temperature, mixing time and load force on the strength of heat-resistant expanded clay concrete for lining thermal units.Method The study is based on the vacuum processing technology of heat-resistant concrete based on a composite binder for lining the hearth of a trolley of a brick kiln, vacuum-packed concrete mix.Result The effect of vacuum processing of the mixture on the technological properties of heat-resistant expanded clay concrete on a composite binder made from Portland cement and finely ground expanded clay activated in a planetary mill (Activator-4M) is investigated. Compositions have been developed and the technological properties of expanded clay concrete have been investigated depending on the heating temperature and the amount of finely ground additives.Conclusion The results of the analysis of the dependence of the strength of expanded clay concrete on the heating temperature, the mixing time and the load strength confirm that the concrete strength indicators during evacuation are higher than for concrete without vacuum treatment; the increase in concrete strength after vacuum treatment under various technological exposure conditions is explained by an increase in workability indicators, which is characterized by the mobility and stiffness of the concrete mixture, denser packing of aggregate in the concrete structure, and also the large effect of vacuum compaction associated with the suction of water and air as well as static sealing due to the difference in atmospheric pressure and vacuum cavity pressure. The magnitude of the effective force reaches 70-75 kN / m2 with the removal of water and air from the vacuum surface; the pressure transmitted to the concrete is reduced, since part of the load is spent on determining the forces of internal friction and the development of contact stresses in the solid phase

THE INFLUENCE OF THE FILLER GRAIN COMPOSITION ON THE PROPERTIES OF THE HEAT-RESISTANT BASALTIC CONCRETE

Objectives. The optimal granulometric composition of filler compound ensures the production of concrete having improved  physical and mechanical characteristics, as well as minimal binder  consumption. The properties of heat-resistant concrete largely  depend on the type and the ratio of its components. Taking this into  account, the aim of the study is to determine the optimal grain composition of heat-resistant concrete.Methods. Methods for optimising the properties of heatresistant basaltic concrete with a composite binder and  mechanochemical activation of the filler grains were used during the  course of the research.A simplex-centroid experiment design is  applied for this purpose. The composite binder was subjected to  mechanochemical activation. Samples were made by vibration-pressing from a concrete mix with a cone draught of 2 cm.Results. The grain composition of heat-resistant concrete is proved  to be the most important variable factor, regulating which the  properties of concrete can be varied. The compositions of heat- resistant basaltic concrete with activated composite binder having a  maximum application temperature of 700 ºС are developed. The  influence of the grain composition of the basaltic filler on the  properties of basaltic concrete using mathematical experiment planning methods is determined. The regression equations for the ultimate tensile strength and bending stress of basaltic concrete are  obtained for heating temperature of 700ºC.Conclusion. The granulometric composition of heat-resistant basaltic concrete based on the activated binder is optimised for basic physical and technical properties. The optimal granulometric  design of the composition of heat-resistant concrete indicates that as the coarse fraction (particles greater than 0.63 mm) in the filler  composition increases, the ultimate tensile strength and bending  stress of heatresistant basaltic concrete is increased when heated to  a temperature of 700ºС. This is due to a more compact arrangement of sand grains