Soil genetics in its complex stabilization

The problem of the inter-repair time of automobile roads in Russia can be solved by the reinforcing the subgrade soils with cement. Soil is a multicomponent system affecting the deformation and strength properties of the composition (cement and soil). The cement-soil composition has drawbacks, especially in seasonal freezing regions, which affects its durability.In order to increase the composition efficiency, the Nicoflok polymer-mineral additive is used to strengthen subgrade with cement. However, the influence of the type regional and genetic soil on strength properties of the cement-soil + Nicoflok composition is yet studied.The paper presents the factor analysis of the influence of soil genetics on the composition strength properties. The study of the multicomponent system includes the response surface of the soil genetics on the strength properties of the composition. Additional studies are required to move from the qualitative evaluation of the soil genetics on the composition (cement-soil + Nicoflok) to the quantitative evaluation. These studies must be carried out according to a single scheme, which regards the seasonal freezing of subgrade soils in the northern regions of European Russia and West Siberia.

Development of alkaline concrete on the basis of active aggregates

The object of the research is the process of directed structure formation in the body of alkaline concrete, made using a reactive aggregate, in this case, basalt, and the process of deformation development in such concrete. The problem with using reactive aggregates is that they cause alkaline corrosion. It manifests itself in the form of cracks and layers of gel-like substances that form at the point of contact of the aggregate with the cement stone. During the research, methods of physical and chemical analysis were used (X-ray phase, differential thermal and thermogravimetric analyzes, electron microscopy, infrared spectroscopy, microprobe analysis). And also methods of mathematical planning of experiments have been used for the dependence of the physical and technical properties of cements and the directions of their structure formation. Also, the research has been carried out based on the analysis of world achievements in solving the problem of alkaline corrosion of concrete. The possibility of joint operation of the matrix of alkaline cements and active aggregates, represented by basalt, has been determined. The component composition of alkaline cement has been optimized and the need to increase the amount of the alkaline component in the system for the normal course of structure formation processes has been proved. The study of the influence of technical factors and conditions of hardening on the development of processes of structure formation of the investigated compositions has been carried out. The deformation properties of fine-grained concrete based on slag-alkaline cement and basalt aggregate have been investigated. It is shown that the expansion deformations of the samples, which accompany the process of alkaline corrosion of the aggregate in concrete, are directly related to the component composition and hardening conditions of the material. The obtained research results confirm the possibility of using active aggregates for the manufacture of building materials, in particular, based on alkaline cements. But for the safe course of the processes of structure formation, the component composition of the system has to be adjusted by introducing an active mineral additive and an additional alkaline component. The use of hydrophobizing additives makes it possible to increase the strength of the material even when operating under normal heat and humidity conditions.

Application of Ceramsite Dust as an Active Pozzolan Additive in the Cement-Based Compositions

Ceramsite (expanded clay) dust is a waste material, obtained in large volumes all over the world as a by-product of ceramsite gravel production. With the development of the construction industry and the ever-growing amount of ceramsite dust disposed in the landfills, the recycling and rational use of this material is becoming a relevant issue. The currently available technologies for the ceramsite waste recycling are very limited, this is why it is necessary to develop a new effective way to involve this waste into the new production. The present research is based on the assumption that ceramsite dust can be applied effectively as an active pozzolanic mineral additive in the cement-based materials. In order to study the composition, structure and properties of the original clay used for the production of ceramsite, as well as the dehydrated clay dust, captured in the dust removing systems of kilns at ceramsite gravel plants, physical and chemical analysis methods were used. Based on the experimental data, the influence of ceramsite dust on the structure and properties of cement compositions was evaluated. Mechanical tests of the samples showed that the introduction of ceramsite dust as an additive in the amount of 3% by the cement weight leads to an increase in compressive strength by 23% in comparison with the reference composition. The paper also presents the results of microstructural analysis, IR spectral analysis and differential thermal analysis of samples modified with the optimal amount of this microadditive. The study of the microstructure of the modified samples shows that the introduction of ceramsite dust into the composition of the cement stone does not only change the morphology of new formations, thus increasing the density of the structure, but also varies the mineralogical composition of the cement matrix with the formation of stronger and more water-resistant minerals in the form of calcium silicate hydrates and calcium aluminosilicate hydrates. This technology allows the recycling of waste from the production of ceramsite stone, thus improving the environmental situation and contributing to the creation of a circular economy.

Effect of the improved protein-mineral additive on structural-mechanical characteristics of minced meat

The results of research on the effect of protein-mineral improved additive (PMIA) on the rheological parameters of minced meat, which can be used for manufacturing culinary products, including chopped semi-finished products of a high degree of readiness, are presented. It has been proven, that the additive can be used both as an ingredient, enriching calcium-digestible compounds and to improve a number of technological properties of minced meat, in particular after freezing, storage and thawing. The aim of the study was to determine the dependences of changes in the structural and mechanical characteristics of minced meat after the addition of PMIA and subsequent freezing to a temperature of –16…–18 °C and storage for 20 days. It has been found, that the addition of up to 7 % of PMIA leads to a marked increase in the conditionally instantaneous modulus of elasticity and highly elastic modulus in 4.4 times for minced beef and 2.7 and 4.4 times for chicken, respectively. It has been established, that the best stabilization of these indicators after freezing occurs at the content of PMIA at the level of 2…5 %. Studies of plastic viscosity and adhesion have shown that the use of up to 7 % of PMIA leads to an increase of 11…20 % and 26…64 %, respectively. After freezing, the plastic viscosity and adhesion of minced beef in the control decreased by 22.0 and 52 %, respectively, minced chicken – by 23.4 and 40.9 %. In the samples with a content of 7 % of PMIA, the decrease in plastic viscosity and adhesion is 7.2 and 4.4 % in minced beef and in chicken – 5.9 and 3.1 % respectively. It has been proven, that the use of PMIA in the amount of up to 7 % in the technology of minced meat production minimizes the negative destructive effect of low temperatures on the structural and mechanical characteristics of the finished product. Thus, it is expedient to use up to 7.0 % of the improved protein-mineral additive in the composition of minced meat to enrich the finished product with digestible calcium compounds and improve their structural and mechanical characteristics, in particular after freezing and storage

Determining the influence of protein-mineral additives on the properties of butter cookies emulsion

This paper reports the results of studying the influence of two types of protein-mineral additives on the properties of butter biscuit emulsion. The additives are considered as a source of digestible calcium compounds and as a functional and technological component that can improve the quality of buttery flour products. The parameters for pre-hydration of additives in the environment of cow's milk for better implementation of their functional and technological characteristics have been substantiated. It was established that the use of protein-mineral additives in the manufacture of emulsions in the amount of up to 7 % leads to an increase in the emulsification capacity of model systems by 1.5...1.65 times. Improved emulsion resistance has been proven, in particular after heat treatment. It was established that using 5...7 % of the additive produces a pronounced thermal stabilizing effect. After heat treatment at a temperature of 90...95 °C during 3×60 s, when using the protein-mineral additive, a volume of the released water and fat phase increases by 12...25 %. When applying the improved additive, a volume of the released phases increases by 3...10 %. A lower degree of coalescence of the fat phase as part of the emulsion when using the improved protein-mineral additive was microscopically confirmed. The fact of increasing the effective viscosity of emulsions when using up to 7 % of the improved protein-mineral additive was established. This is a positive fact in terms of stabilizing the emulsions and improving their stability as one of the important factors related to the quality of finished flour confectionery. It was established that the improved form of the additive, due to the content of chondroitin sulfates, provides for a better effect on the characteristics of emulsions, which should have a positive influence on the quality of flour-based buttery products.

Fly ash from Coal-Combustion Waste as an Additive for Quality Improvement and Compressive Strength of Cement

A series of tests were carried out to determine the effect of the addition of coal combustion fly ash as an additional mineral (additive) on improving the quality and compressive strength of cement according to the Indonesian National Standard (SNI 15-2049-2004). Research methods include sample preparation, manufacture of cement with 0%, 5%, 8%, 12%, and 15% fly ash variations, chemical and physical properties of cement. The parameters measured were the level of chemical composition (%) using X-Ray Fluorescence Spectroscopy (XRF) ARL 9800 OASIS, free lime content (%) by volumetry, insoluble residue level (%) by gravimetry, compressive strength (kg/cm2), and smoothness cement (cm2/g). The results showed that the addition of fly ash increased the SiO2 content of cement, thereby increasing C3S and C2S compounds which are compressive strength components of a cement. Besides, the addition of fly ash is directly proportional to IR levels, compressive strength, smoothness, and inversely proportional to free lime levels. So the addition of fly ash can improve the quality of cement by increasing chemical components, increasing compressive strength, and reducing cracking or expansion of cement.

Pressed Magnesia Composites with Improved Weather Resistance Properties

The results of studies aimed at increasing the resistance to weathering of building products based on magnesia cement are presented. This goal was achieved by the use of mine burnt rock as a modifying additive and the use of molding sands compaction pressing method. The influence of the modifier on the compressive strength change of compressed composites in dried and water-saturated state, the softening and air resistance coefficients, as well as the linear deformations of the control samples after a specified number of alternating wetting and drying cycles, was investigated. The physical and mechanical characteristics of the control samples were determined according to the standard and generally accepted methods. The formation of a complex combined structure of modified magnesian composites, containing coagulation, condensation and crystallization phases with a clear predominance of the first, has been confirmed by the physicochemical analysis methods. It is shown that modification of magnesian cement with burnt rock purposefully changes the processes of structure formation and causes an increase in water and air resistance of pressed composites based on it. The proposed method for modifying pressed magnesia products prevents loosening of their structure under alternating stresses, reduces linear deformations and, as a result, slows down fatigue failure. The involvement of a secondary resource in the composition of molding sands as an active mineral additive leads to a decrease in the cost of products and allows the method of their production to be attributed to the best available technologies. The developed compositions of pressed magnesia composites are recommended for the production of small-piece products used in building envelopes, as well as for flooring in the rooms with more than 60% humidity.