scholarly journals On the issue of expanding the base of mineral and complex additives for cement concrete

2019 ◽  
Vol 135 ◽  
pp. 01018
Author(s):  
Oleg Tarakanov ◽  
Elena Belyakova ◽  
Varvara Yurova

Modern materials science is characterized not only by the creation of high-strength building materials, but also by using a large number of raw materials and additives that improve the properties of concrete mixtures and concrete. The article considers the possibility of using both old and new generations of complex organomineral additives in concrete production. The nature of the effect of additives on the rheological behavior of cement systems and hydrate formation processes, as well as an assessment of the effect of mineral and organic additives on the composition of hydration products of cement systems, are revealed. Studies have shown that complex additives, which include hyper- and superplasticizers, lead to some slowdown in hydration and crystallization processes. The high efficiency of plasticizing additives helps to reduce water content, which in turn provides increased strength of cement concrete.

2018 ◽  
Vol 15 (4) ◽  
pp. 588-595 ◽  
Author(s):  
A. D. Tolstoy ◽  
V. S. Lesovik ◽  
A. S. Milkina

Introduction. The important national economic task is to provide the modern construction industry with high-strength and effective materials made using new technological approaches and artificiallyproduced materials. These materials differ from the usual one by high content of cement stone, smaller grain size, multicomponent composition, increased specific surface of the filler. Therefore, the research of such problem would be always relevant according to the constant growth of requirements for the building materials and structures quality.Materials and methods. Experimental studies were conducted in the laboratories of the Department of Construction Materials, Products and Structures. The literary sources’ analysis was made in the scientific and technical library of the Belgorod State Technological University named after V. G. Shukhov. At the same time, standard test procedures and the provisions of the operating instructions for individual devices and equipment were used in the research.Discussion and conclusions. As a result, the models of structure formation in high-strength hardening compositions, in which the principle of structure optimization consisting in creation of the high degree ordering of its constituent elements and tumors, as well as in increasing the adhesion of cement stone particles, are implemented. In addition, the usage of artificially-produced materials and organic additives produces the possibility of reducing the consumption of raw materials and consumption of energy and resources. The mechanism and principles of structure formation management are intensively studied and would be explained later on the basis of synergetic concepts.


2019 ◽  
Vol 51 (3) ◽  
pp. 285-294
Author(s):  
Dang Wei ◽  
H.-Y. He

High strength lightweight glass-ceramics were fabricated with coal gangue and clay as main raw materials. The utilization ratio of coal gangue, the ratio of the coal gangue with clay, mineralization agents, forming process and sintering process on the properties of the fabricated glass-ceramics were optimized. The utilization ratio of coal gangue reached 75, and the ratio of coal gangue to clay was 3/1, as an optimal property was observed. The optimal sintering temperature was found to be 1370?C. At this optimal temperature, the sintered glass-ceramics showed the main phase of mullite and spindle and so showed high strength, low density, and low water absorbance. The appropriate amounts of codoping of the TiO2, ZnO, and MnO2/dolomite as mineralization agents obviously enhanced the properties of the glass-ceramics. Process optimizations further determined reasonable and optimal process parameters. The high strength lightweight glass-ceramics fabricated in this work may be very suitable for various applications including building materials, cooking ceramics, and proppant materials, et al.


Author(s):  
V. Nelyubova ◽  
V. Babaev ◽  
Nataliya Alfimova ◽  
S. Usikov ◽  
O. Masanin

fiber concrete is one of the types of effective building materials that ensure the operational reliability of structures due to a set of unique properties. However, the maximum physicomechanical characteristics of this type of products are achieved only if the fiber is evenly distributed in the concrete matrix and the optimum ratio of raw materials is reached. In this connection, the aim of the work was to increase the production efficiency of fiber-reinforced concrete by optimizing the formulation and technological parameters of its manufacture. The optimal method of introducing the fiber into the concrete mix and the type of superplasticizer were previously determined, which allowed ensuring the maximum physicomechanical characteristics of the products. Optimization of prescription parameters was carried out using the method of mathematical planning of the experiment, where the amount of cement, superplasticizer and basalt fiber were varied. After processing the results, the dependences of the compressive strength on variable factors were obtained, which would allow to select the optimal dosages of raw materials for given mechanical characteristics of the products.


Author(s):  
O. V. Roman ◽  
V. T. Shmuradko ◽  
F. I. Panteleenko ◽  
O. P. Reut ◽  
T. I. Bendik ◽  
...  

The concept of creating electrical insulating ceramic materialsproducts from powder systems representing oxide and nonoxide chemical compounds was formed; a program document for materials science and technological logistics of physical and chemical transformation of technogenic mineral raw materials into electrical materials-products of various scientific, practical and specific technological purposes was created and implemented. The principal theoretical approach and its appliedpractical aspects of the development - research - creation of thermo- and chemically resistant structural electrical insulation materials - products for various scientific and practical purposes: automatic contact welding of tubular bimetals (for example, copper - aluminum), electron beam welding in vacuum of thickwalled large-sized structures made of high-strength aluminum alloys, high-temperature (1050 oC) hardening of drilling tools in vacuum furnaces in the medium of dissociated acetylene are considered, in electric transmissions of brake installations of quarry dump trucks (k/s) BelAZ.


2020 ◽  
Vol 24 (11) ◽  
pp. 14-18
Author(s):  
A.K. Kairakbaev ◽  
V.Z. Abdrakhimov ◽  
E.S. Abdrakhimova

The use of nanotechnogenic petrochemical raw materials-spent IM-2201 catalyst containing more than 70 % Al2O3, and as a clay binder-lowmelting clay from the Ilek Deposit in the Aktobe region allows you to get a ceramic brick that corresponds to the M150 brand. It is possible to build load-bearing walls of the lower floors of high-rise buildings (more than 10 floors) from M150 ceramic bricks. Innovative proposals for the use of waste from production and spent catalyst in the production of ceramic high-strength earthquake-resistant bricks with increased strength and frost resistance have been developed. The absolute advantage of using multi-tonnage waste and spent catalyst IM-2201 is to relieve the environmental situation.


Author(s):  
Grigory Yakovlev ◽  
Jadvyga Keriene ◽  
Valery Grakhov ◽  
Rostislav Drochytka ◽  
Anastasiya Gordina ◽  
...  

The research studies the properties of a high-strength anhydrite composition based on fluoroanhydrite, a waste product of hydrofluoric acid. To activate fluoranhydrite, Na3PO4 sodium phosphate was added to the composition in an amount of 3% of the mass. The physico-chemical studies of the structure and properties of activated fluoroanhydrite conducted using infrared spectroscopy and X-ray phase analysis showed changes in the composition of the hardened composite, and the study of the fluoroanhydrite microstructure revealed the formation of a denser matrix with the increased strength. An increase in the water resistance of the developed binder matrix was noted. The composition can be used as a cheap substitute for gypsum plaster due to the low prime cost of raw materials, and also contribute to the improvement of the environmental situation in fluoroanhydrite disposal sites.


2021 ◽  
Vol 288 ◽  
pp. 01071
Author(s):  
Irina Zhenzhurist

The article considers the causes of environmental problems in the energy sector. The increased demand for energy resources and the increasing shortage of natural fuels are leading to the search for renewable energy sources. The prospects of energy transmission by microwave radiation without wires as an alternative to traditional energy sources are considered. The article provides information on the results of research on obtaining a high level of energy transfer by a microwave beam from a geostationary orbit to the earth's surface in the near future, as well as developments in the field of creating a solar space power plant (SSP). The results of research on the sintering of inorganic substances in an electromagnetic field are presented, the prospects for this direction in materials science are considered. The results of sintering natural raw materials in a microwave field are considered. The formation of nanoscale phases in sintered compositions has been established. The effect of a low-melting mineralizing additive on the sintering process is shown. The increased strength characteristics of the samples obtained by high-speed firing in the microwave electromagnetic field, the prospects for developments in this direction for various types of materials are noted.


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.


2018 ◽  
Vol 143 ◽  
pp. 02010 ◽  
Author(s):  
Evgeniya Tkach ◽  
Vladimir Solovyov ◽  
Semen Tkach

The purpose of these studies is to justify the feasibility of recycling different types of industrial waste instead of conventional expensive raw materials in production of environmentally friendly aerated concrete with required construction and operational properties. The impact of wastes from various industries on the environmental condition of affected areas, as well as the results of their environmental assessment were analyzed to determine whether these wastes could be used in production of high-performance building materials. The assessment of industrial wastes in aerated concrete production suggests that industrial wastes of hazard class IV can be recycled to produce aerated concrete. An environmentally friendly method for large-scale waste recycling, including a two-step environmentally sustainable mechanism, was developed. The basic quality indicators of the modified aerated concrete proved that the environmental safety could be enhanced by strengthening the structure, increasing its uniformity and improving thermal insulation properties. The modified non-autoclaved aerated concrete products with improved physical and operational properties were developed. They have the following properties: density – D700; class of concrete – B3.5; thermal transmittance coefficient – 0.143 W/(m·°C); frost resistance – F75.


2020 ◽  
pp. 0734242X2093517
Author(s):  
Raheleh Talavari ◽  
Shokoufe Hosseini ◽  
GR Moradi

With the production of renewable biofuels, concerns about the end of fossil fuels have been partially eliminated. On the other hand, the utilization of low-cost and waste materials to provide the raw essential substances to manufacture these fuels is of paramount importance. Biodiesel is one of these fuels and the required raw materials for the reaction are oil (triglycerides), alcohol and catalyst. In this work, travertine stone powder (as waste in the manufacture of building materials) was used as a catalyst and waste frying oil as a source of triglyceride for biodiesel production. Using thermogravimetric and X-ray diffraction analysis, optimum temperature for catalyst calcination was selected at 900°C. Furthermore, X-ray fluorescence, Fourier transform infrared spectroscopy, Brunauer–Emmett–Teller, transmission electron microscopy and scanning electron microscopy analyses were performed. Using the design of experiments Response Surface Methodology, the optimum reaction conditions for biodiesel production yield of 97.74% were: reaction temperature 59.52°C (~60°C), time 3.8 h (228 min), catalyst concentration 1.36 wt.% and the methanol to oil molar ratio of 11:6. After reusing four times, the catalyst efficiency was reduced a little, and the biodiesel yield was 89.84%, indicating high strength and stability of the catalyst.


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