High-Quality Cement-Mineral Suspensions Using Stone Crushing Waste

2020 ◽  
Vol 992 ◽  
pp. 124-129
Author(s):  
E.A. Belyakova ◽  
R. Moskvin ◽  
V.S. Yurova

The quality of concrete is determined by the physico-mechanical and rheological properties of the original components. Rheological properties depend on the amount and concentration of the rheological matrix. Cement-mineral matrices of modern high-quality concrete are rheologically active suspensions which allow to provide the necessary fluidity and mobility of the concrete mix, as well as the required strength of concrete. The multicomponent composition of the water-dispersed phase is represented by cement, stone flour and hyperplasticizer. The article presents the results of studies confirming the possibility of replacing finely ground quartz with other highly dispersed rocks, including stone-crushing waste. It was revealed that increasing in the concentration of the water-dispersed phase by 10% made it possible to reduce the water-solid ratio while maintaining the required mobility of the mixture, and in some cases improved the spreadability of the suspension by 3-13%. It was determined that the physicomechanical properties of reaction-powder concretes depend on the density and porosity of finely dispersed components to a greater degree.

World Science ◽  
2020 ◽  
Vol 1 (4(56)) ◽  
pp. 45-47
Author(s):  
Бералиева Э. Б. ◽  
Керимбек Ж. С.

The article discusses the ways to solve the problems of low levels of active biological substances in the bakery product, with medicinal properties. In the process of the preparation of buns, the optimal dosages of the additives were calculated in order to determine an acceptable ratio of vegetable raw materials components and expand the range of bakery products with therapeutic and prophylactic effects. The article proposes new recipe for making buns with the addition of herbal additives such as stevia and licorice root. In addition, the study was conducted on the influence of licorice root and stevia additives on the rheological properties of the dough and the quality of the finished product. As a result, high-quality buns with the necessary consumer properties were obtained.


2020 ◽  
Vol 18 (4) ◽  
pp. 469-476
Author(s):  
A.A. Guvalov ◽  
◽  
S.İ. S.İ. ◽  

In this study, the effect of mineral and organic additives on the properties of mineral suspensions was studied. Disperse mineral additives are used in cement systems to increase the amount of rheological matrix and ensure high fluidity. Due to the high dispersion of mineral additives, high-efficiency plasticizers were used to regulate the rheotechnological properties of cement-based mixtures. The effect of sulfonaphthalene-formaldehyde oligomer and polycarboxylate-based hyperplasticizers on the rheological properties of cement systems as a plasticizer was evaluated according to the methodology proposed by prof. V.I.Kalashnikov. Based on the results obtained, it was determined that limestone powder is more effective than other stone powders. As a result of the research, the optimal amounts of mineral additives and plasticizers were determined and the possibility of obtaining efficient, high-strength cement stone on their basis confirmed.


2020 ◽  
Vol 309 ◽  
pp. 114-119
Author(s):  
Ekaterina S. Gerasimova ◽  
Elizaveta Gumirova

The paper is devoted to research of influence of “MC-Bauchemie” additions on the fine-grained concrete properties, namely compressive strength. The results of testing of fine-grained concrete made on the basis of two different natural sands are presented. Characteristics of the initial materials used in the work (Portland cement, sands and additions-plasticizers) are given. The basic methods of preparation of mixes and testing of hardened cement stone and concrete are described. The optimal quantity of the selected additions on the example of cement paste and stone are established. Mobility dependences of concrete mixes on a type and quantity of plasticizers are received. The dependence of the additions effectiveness on the mobility of the concrete mix on the quality of the fine aggregate is shown. It is established that the most effective additive is PowerFlow 3100, its optimal amount for obtaining fine-grained concrete on the basis of JSC “Kar’er Myisyi” sand is 0.2 %.


2016 ◽  
Vol 64 (4) ◽  
Author(s):  
К. G. IORGACHOVA ◽  
E. N. KOTUZAKI ◽  
O. V. MAKAROVA

The article is devoted to the research of applicability of gluten-free flours from cereal crops and from by-products of cereal crop processing - ground crumbs sifted out in a process of flake production from rice, corn and millet during the production of biscuit semi-finished products. Taking into account that viscosity is an important technological characteristic of foam-like biscuit dough, as it determines foam strength and dispersed medium stability, the influence of gluten-free flours on the structural and rheological properties of biscuit dough was studied. It is determined that the substitution of wheat flour for cereal flours leads to viscosity reduction of the dough as a consequence of absence of gluten-forming proteins in them. A comparative analysis of changes in viscous properties of biscuit dough based on flour from flakes crumb while warming it up to 60°C with dough based on cereal flours and dough based on wheat flour was held. It is shown that the presence of partially gelatinized starch granules in flour from flake crumb, as a result of technological peculiarities of their extraction, promotes greater demonstration of thickening properties already at the initial stage of baking than in cereal flours. This leads to an increase of dough viscosity and formation of desired rheological characteristics, which provide the porous structure of finished products. To provide the high quality of gluten-free biscuit semi-finished products, the recipe composition of gluten-free biscuit semi-finished product, based on flour mixture from millet flakes crumb, corn and rice flour, was optimized by using the method of mathematical design of experiments.  The porosity indicator was chosen as the criteria for the evaluation of influence of proportion of gluten-free flours on the quality of biscuit semi-finished products. The response surfaces of dependency of biscuit porosity from mass ratio of recipe components in the composite mixture were obtained. It was confirmed experimentally that the use of pre-gelatinized acetylated modified starches during the production of gluten-free biscuit semi-finished products, facilitates the stabilization of the structural and rheological properties of foam structure - viscosity growth of biscuit dough because of foam-stabilizing property, which is particular to them. It was demonstrated that the obtained gluten-free biscuit semi-finished products based on flour composite mixtures with addition of modified starches, had high quality indicators. Based on the results of the research conducted, the recipe was formulated, technological parameters of production of new types of gluten-free biscuit semi-finished products were determined. Key


Author(s):  
A. T. Kunakbaeva ◽  
A. M. Stolyarov ◽  
M. V. Potapova

Free-cutting steel gains specific working properties thanks to the high content of sulfur and phosphorus. These elements, especially sulfur, have a rather high tendency to segregation. Therefore, segregation defects in free-cutting steel continuously cast billets can be significantly developed. The aim of the work was to study the influence of the chemical composition of freecutting steel and casting technological parameters on the quality of the macrostructure of continuously cast billets. A metallographic assessment of the internal structure of cast metal made of free-cutting steel and data processing by application of correlation and regression analysis were the research methods. The array of production data of 43 heats of free-cutting steel of grade A12 was studied. Steel casting on a five-strand radial type continuous casting machine was carried out by various methods of metal pouring from tundish into the molds. Metal of 19 heats was poured with an open stream, and 24 heats – by a closed stream through submerged nozzles with a vertical hole. High-quality billets had a cross-sectional size of 150×150 mm. The macrostructure of high-quality square billets made of free-cutting steel of A12 grade is characterized by the presence of central porosity, axial segregation and peripheral point contamination, the degree of development of which was in the range from 1.5 to 2.0 points, segregation cracks and strips – about 1.0 points. In the course of casting with an open stream, almost all of these defects are more developed comparing with the casting by a closed stream. As a result of correlation and regression analysis, linear dependences of the development degree of segregation cracks and strips both axial and angular on the sulfur content in steel and on the ratio of manganese content to sulfur content were established. The degree of these defects development increases with growing of sulfur content in steel of A12 grade. These defects had especially strong development when sulfur content in steel was of more than 0.10%. To improve the quality of cast metal, it is necessary to have the ratio of the manganese content to the sulfur content in the metal more than eight.


2020 ◽  
Vol 29 (12) ◽  
pp. 52-58
Author(s):  
E.P. Meleshkina ◽  
◽  
S.N. Kolomiets ◽  
A.S. Cheskidova ◽  
◽  
...  

Objectively and reliably determined indicators of rheological properties of the dough were identified using the alveograph device to create a system of classifications of wheat and flour from it for the intended purpose in the future. The analysis of the relationship of standardized quality indicators, as well as newly developed indicators for identifying them, differentiating the quality of wheat flour for the intended purpose, i.e. for finished products. To do this, we use mathematical statistics methods.


2020 ◽  
pp. 52-58 ◽  
Author(s):  
A. A. Eryomenko ◽  
N. V. Rostunova ◽  
S. A. Budagyan ◽  
V. V. Stets

The experience of clinical testing of the personal telemedicine system ‘Obereg’ for remote monitoring of patients at the intensive care units of leading Russian clinics is described. The high quality of communication with the remote receiving devices of doctors, the accuracy of measurements, resistance to interference from various hospital equipment and the absence of its own impact on such equipment were confirmed. There are significant advantages compared to stationary patient monitors, in particular, for intra and out-of-hospital transportation of patients.


2018 ◽  
pp. 26-35
Author(s):  
Z. A. Agaeva ◽  
K. B. Baghdasaryan

The transthoracic echocardiography made by multifrequency probes with support of the mode of the second harmonic imaging, is a competitive method for visualization of the main coronary arteries and allows to estimate coronary blood flow with high quality. Of course, the method has considerable restrictions, most important of which is the low spatial resolution of a method, due to small acoustic window. Because of this the transthoracic visualization of coronary arteries perhaps will not become the leading method of anatomic reconstruction of separately taken coronary artery and especially all coronary arteries system. However uniqueness and indisputable advantage of this method is an opportunity to noninvasively estimate a coronary blood flow both once, and in dynamics.


2020 ◽  
Vol 18 (4) ◽  
pp. 739-752 ◽  
Author(s):  
R.M. Sadykov

Subject. This article deals with the issues of social justice and a high quality of life, creating favorable economic and social conditions. Objectives. The article aims to assess the rate and changes in poverty in Russia and the Republic of Bashkortostan and develop complementary measures to reduce it. Methods. For the study, I used the methods of logical, comparative, economic and statistical analyses, the results of sociological studies, and official statistics. Results. The article highlights additional measures to reduce poverty in the region, including the establishment of a minimum social standard of living in each particular region that determines the poverty rate. Conclusions. Various factors, such as economic sanctions, economic slowdowns, territorial and regional imbalances, lead to living standards decline and poverty rise.


Author(s):  
La Duc Minh ◽  
Nguyen Thi Hao ◽  
Vu Thi Thuy

Ethnic affairs play an important role in socio of ethnic groups’ solidarity, assurance of security and national defense stability. In -economic development, maintenanceorder to improve the quality of ethnic affairs, it is practical to carry out postgraduate training of officer implementing ethnic affairs using state budget with the aim of encouraging and enhancing officer quality to satisfy high-quality human resource in international integration.


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