Колонка редактора - Eng
Рубрика: Строительные материалы и технологии их производства
The objects of the research are topping floors. The purpose of the research is the determination reasons of the decrease of strength topping layer and elimination these reasons. The analytical method in the research is used. The analysis of the requirements and parameters of quality imposed on topping floors is made. The reasons for decrease of strength toppings layer are identified.
Karmanova A.S., Cherepanov A.M.
The article presents the results of studies of various methods for assessing the activity of the cement binders. The samples were tested according to the methods specified in the standards for the product. Samples tested at different ages and with different grain composition.
Influence of multi-walled carbon nanotubes on the structure and properties of lightweight autoclaved aerated concrete
S.V. Leontev, V.A. Golubev, V.A. Shamanov, A.D. Kurzanov
The results of analysis composition and structure of the modified thermal insulation AAC demonstrate that multi-walled carbon nanotubes serve as centers of crystallization of calcium hydrosilicates in hardening lightweight autoclaved aerated concrete and stimulate the structure forming of hardening lime-silicate binder with high crystallinity in comparison with the plain check sample. Calcium hydrosilicates of the increased density form a space frame that provides thermal insulation autoclaved aerated concrete with the enhanced physical and technical properties.
K.A. Saraykina, V.A. Golubev
Protect of basalt fiber by chemical corrosion in cements possible using of ultra-dispersed active modifiers. It can reduce alkaline of environment, in this case, it increase the density of the cement matrix in the contact with basalt fiber by including nano-dispersed additives due to the structural modification of the system. The paper is assessed the combined influence of metakaolin and the dispersion of carbon nanotubes on the basalt fiber concrete structure and properties. conducted researches demonstrate the effectiveness of metakaolin to protect basalt fiber by alkaline degradation of cement concrete due to the formation of calcium hydroaluminosilicates, and the use of carbon nanotubes contributes to compaction the contact zone of the "basalt fiber - cement stone", thereby increasing the durability and strength characteristics of basalt fiber concrete in whole.
V.A. Shamanov, V.A. Golubev
Results of the analysis of the main reasons for decline in quality of a gas concrete of autoclave curing are presented in article. It is shown that change only of the technological modes by production of blocks from cellular concrete of autoclave curing doesn't promote decrease in average daily volume of marriage lower than 10%, at the same time the greatest percent of marriage should be connected not only with a human factor. For example, change of quality of a silicic component on an indicator of content of active silicon dioxide doesn't fit into normal distribution that exerts considerable impact on stability of characteristics of an autoclave gas concrete. By results of research it is established that instability of quality of the applied input products is the prime reason of decline in quality of products.
V.E. Yuzhaninov, K.K. Karpova
The article deals with one of the most common materials traditionally used in the construction of buildings and structures - ceramic brick. As with any production materials, the ceramic brick production has defect. Defect reduces the quality of the finished product, it is necessary to control the defect does not prevent it in the first stages of production to improve product quality. The authors describe the possible causes of the defect reception of ceramic bricks in its production. This stage of production product such as pressing, drying and firing. Based on the author analysis we presented possible ways of reducing the defect of products at every stage of its production.
The article presents the results of research on the composition of coloured dry mortars for floors strengthening. The type of pigment used for creating coloured toppings is defined. The optimum quantity of colouring pigments of different tones due to criteria of an appropriate shade and minimum cost is selected.
Development of the composition and method of production of gypsum binder on the basis of screenings of crushing
Anferov E.P., Pirozhkov N.A., Cherepanov
The article presents the results of the results of the development of the composition and method of production of low-grade gypsum binder on the basis of screenings of crushing. The researchers conducted experiments to determine the physical properties of the gypsum binder by the corresponding regulatory documents. The general technique of the laboratory production knitting is determined. It is received plaster knitting various quality. Comparison of characteristics plaster knitting from different tests is carried out. Comparison of characteristics plaster knitting with three different modes of cooking is carried out. Requirements to low-branded plaster knitting are revealed.During an experiment it is revealed that the most difficult achievable requirement is the brand on durability on compression, and also terms of a setting and curing. According to requirements, the analysis of possible production of the plaster screenings crushing knitting on the basis of eliminations is carried out. Urgent scopes of eliminations of screenings crushing are revealed.
E.A. Ashpalatova, A.A. Spiridonova, V.M. Sultanova
The use of complex modifiers based on polycarboxylate plasticizers and carbon nanotubes is becoming acquires wide popularity in modern materials science. This article presents the effect of complex additives on the rheological characteristics of the cement test and on the physico-mechanical characteristics of building composite materials. So, with the constant appearance of new types of hyperplasticizing additives, work is underway to create new studies to assess their effect on the quality of cement composites for the preparation of higher-quality and high-strength composite materials based on cement binders. It was found that the introduction of DS-5 hyperplasticizers on the basis of polycarboxylate esters significantly reduces consumption of mixing water and cement when introduced into the formulation in small amounts. Using of carbon nanotubes in the hyperplasticizer improves the plasticizing properties and improves the mechanical characteristics of the cement astringent. Also, the incomplete dispersion of carbon nanotubes in the carboxylate environment and the mixed sorting in the structure of the cement matrix reduce their effectiveness.
D.I. Baranyuk, V.A. Shamanov
The article deals with the problems of increasing the strength and water resistance of gypsum by using aluminum-containing waste. In the framework of the experiment, a comparison was made of the physico-mechanical characteristics of samples with different amounts of waste with Al2O3 content with the results of testing the control samples. The comparison was based on various parameters of the quality of the gypsum binder: water-gypsum ratio (В/Г), compression breaking strength and compressive strength in bending (Rсж и Rизг), mass specific gravity (ср), water absorption by mass (Wm) and softening coefficient (Kp) ). According to the results of the study, it was found that adding a waste with Al2O3 content to the gypsum mixture helps to increase physical and chemical parameters, such as compression breaking strength, compressive strength in bending and mass specific gravity. Such changes in quality indicators can be related to the compaction of gypsum stone structure, as well as to a possible change in the morphology of gypsum crystals and an increase in the degree of their crystallization. In the course of the experiment it was found that the compositions containing alumina-containing waste should be used only in air-dry conditions, providing additional measures to protect the products from moisture, for example, surface treatment with hydrophobic liquids.
The use of a concrete mixture based on microsilica and boron carbide for the erection of monolithic structures exposed to fire
D.I. Voloshin, V.I. Yamov
As the result of the fires there can be partial or total destruction of the monolithic constructions. The general state of the construction, the ability of its further exploitation and the method of its strengthening can be estimated due to the temperature in the hotbed of the fire that influences concrete constructions. Monolithic constructions made of common concrete mixture are not able to be used after the influence of the temperature more than 700 º degrees because of the concrete strength reduction from the heating. The concrete mixture with boron carbide and silica fume gives the opportunity to build monolithic constructions that can be used in case of fires. Technical result of this mixture usage is the increasing of the fire resistance of the ferroconcrete constructions even in the situation of changing building cost.
Research of properties of Portland cement in the joint application of microsilica and hyperplasticizer EthacrylТМ HF
A.V. Voronova, E.A. Ashpalatova, V.M. Sultanova
It has been studied the influence of plasticizer based on polycarboxylate ether with a finely dispersed additive of technogenic character on the physical and technical properties of cement composite. The introduction of microsilica reduces the fluidity of the cement mixture, so it is advisable to use it in combination with the hyperplasticizing agent Ethacryl HF, which reduces the water requirement of the binder. Also, the stabilized aqueous suspensions of microsilica were obtained experimentally and their sedimentation properties were noted. Analysis of the results of mechanical tests for 7 days showed that the introduction of a complex of additives based on a polycarboxylate plasticizer and microsilica into cement binders in an amount of 0.05 and 5 %, as well as 0.9 and 30 %, respectively, increases the compressive strength by 31 %. The use of modifying additives promotes to reduce the water-binding ratio, intensify the hydration process and harden the cement composite. This leads to the formation of a dense and durable cement stone.
Zhukov A.I., Merzlyakov A.V., Gordina A.F., Polyanskikh I.S.
The article presents the results of the production of a ceramic composite material based on acid fluoride hydrides which is modified by microsilicasuspension. Using microsilicasuspension in the composition increases the physical and mechanical performance, including compression strength. This development result brings economic benefits due to the low cost of the binder, it also contribute to solve resource-saving problem as well as to improve the environment situation on the region through the utilization of acid fluoride dumps.
Studying of kinetics of gas generation of aluminum paste in the presence of the plasticizing additive on the basis of air of polycarboxylats
A.S. Karmanova, A.M. Cherepanov
The article considers the relevance of studies on the use of plasticizers, which are used in the production of heat-insulating autoclaved aerated concrete. Experiments were conducted to identify the optimum temperature of water and the optimal dosage of limestone, which provide maximum allocation of hydrogen from the concrete mixture. The article also presents the results of researches of influence of plasticizing additive on the pore formation of concrete mixtures. In addition, experiments were conducted to determine the optimal dosage of plasticizing additive, which can provide maximum allocation of hydrogen and the completeness of expansion.
Evaluation and ways to improve the quality of the raw batch for the production of solid ceramic bricks
The modern state of research in the field of production of ceramic materials based on low-grade clay raw materials with the use of additives - modifiers is considered. The possibility of improving the quality of the initial clay batch by introducing an additive of alkali-silicate cement, which improves the sinterability of the ceramic shard, is described.
A.D. Kurzanov, S.V. Leont’ev, E.P. Anferov, V.A. Shamanov
Non-autoclaved aerated concrete properties as a macroporous building material, depend on the macrostructure quality strongly. The macrostructure formation occurs at the stage of expansion and hardening of given composition mortar mix. The aerated concrete large-pore cellular structure formation mechanism, which involves two simultaneous processes: the expansion of mortar mix and hardening of the interporous space are presented in this article. Herewith, as the researchers note, when the structure formation mode deviate from the optimal product quality decreases up to a critical value. The low quality products formation (spoilage) can be due to several reasons, which are outlined in this work. The authors systematized prescription and technological factors influencing the material macrostructure formation. It was noted, at present the AC structure formation management is mainly provided by the adjustment of the initial composition; technological parameters, due to the insufficient study of their influence on the array expansion and hardening processes in modern technology given less attention. In conclusion, the study authors noted that the fast management of the structure formation processes will improve the products quality and reduce the spoilage number.
Influence of complex modifier based on Fulvec 100 and MuraplastFK-49 on the physic-technical properties of cement concrete
V.A.Novikova, A.F. Gordina, G.I. Iakovlev, I.A. Pudov
The object of research. Cement concrete modified with 1% plasticizer MuraplastFK-49. Purpose of research. Improvement physic-technical parameters of cement concrete by introducing a modifier Fulvec 100 and selection of rational composition of the modified concrete. Methods. The mobility of the concrete mix was determined according to GOST 10181-2014 "Concrete Mixtures. Test methods"; the average density was determined according to GOST 10181-2014 after 28 days; compressive strength was determined at 28 days according to GOST 10180-2012 "Concrete. Methods of determining strength on test specimens"; water resistance was determined by the method of "wet spots" in accordance with GOST 12730.5-84 "Concrete. Methods of determination of water resistance".IR-spectral methodhas been usedto determinephysic-chemical properties. Results. Rational composition of the concrete mixture modified Muraplast FK-49 and containing additive Fulvec 100 in the amount of 0.12% was carried out, which increases workability, density samples, the compressive strength and water resistance.
Determination of the properties of Portland cement in presence of silica fume and superplasticizer C-3
A.A. Spiridonova, A.V. Voronova, V.M. Sultanova
In this article, the problems of the influence of chemical and mineral admixtures on the properties of cement binder are discussed. The main goal is the analysis of the studies of the properties of Portland cement with the introduction of microsilica and superplasticizer C-3. Tests were carried out to determine the fluidity of the microsilica slurry and its stratification, the water demand of silica fume and cement, and the strength of the composite binder for compression at day 7. When obtaining a slurry of microsilica with a content of NTFC and superplasticizer, it was determined that the acid leads to stratification of the suspension and the superplasticizer to homogeneous system of its solid phase. During the tests to determine water demand and compressive strength of cement, it was found that its characteristics improved as a result of the interaction of additives, namely, to increase the strength, reduce water consumption, increase strength, etc.
V.M. Yakimov, D.R. Nugumanov, V.M. Latypov
In modern individual construction there are a number of problems that increase the cost and speed of erection. Three-layer expanded polystyrene concrete panels WALLSSAVING solve the problem of both the speed of erecting a residential individual building and its cost. The object of the study was an individual building in the Novo-Troevka settlement of the Republic of Bashkortostan, in which the technical condition of the WALLSSEVING polystyrene concrete panels was examined. The individual building was built in 2012, and the research was carried out in 2016. The building does not have a roof, walls insulation, a floor attic floor device, internal walls and external cladding. The construction was carried out specifically to study the weather resistance of WALLSEWING panels in the climatic conditions of the central zone of the Russian Federation. By results of researches it is established, that polystyrene concrete panels have enough high weather resistance and can be recommended to mass application.
D.A. Kartashova, K.D. Mikhailina - Perm National Research Polytechnic University, Perm, Russian Federation
Today aerated concrete is a popular building material. Gas-forming agents are used in the process of its production. As there is a large number of gas-forming agents, manufacturers need to choose an additive with the most suitable characteristics. The main quality measure of aerated concrete is porosity, as it determines thermophysical and mechanical properties of concrete. Thus, in the study of original characteristics, much attention is given to gas-forming agents. According to the research, aluminum powder that appears one of the most widely used agents. The article studies gas emission kinetics of aluminum powders by different producers and in different countries. Gas-volumeter can be applied to determine the volume of the released gas. The method is based on changing the hydrogen volume as a result of reaction behavior of aluminum particles with sodium hydroxide. Laboratory environment made it possible to define the following additives: those with the largest and smallest gas emission, the ones with the smoothest kinetics of gas emission and those with higher and lower gas emission intensity at different time.
V.A. Golubev, K.A. Saraykina, A.S. Ketov Perm National Research Polytechnic University, Perm, Russian Federation;
the concrete composite durability, other things being equal, must be assessed based of the chemical-mineralogical hydrated new formations composition characteristics, pore structure and character of the contact zones "matrix - filler", "matrix - reinforcing component." Therefore besides obtaining high physical and mechanical characteristics of the material, it is necessary to take into account the issues of formation and management of optimal composite structure to achieve high durability of the material. The paper considers the influence of multi-walled carbon nanotubes and high activity of metakaolin on the processes of modified basalt fiber concrete (BFC) structure formation. The introduction of nanostructured additives in the BFC contributes to the protection of basalt fiber from the alkaline corrosion due to compaction of the composite structure and bind of free Ca (OH)2 by metakaolin into insoluble calcium hydroaluminosilicates, and to increase their adhesion to the surface basalt fiber by directional formation morphology growths and composition that leads to a positive effect on the composite durability.
R.V. Radygin, K.S. Koryakova Perm National Research Polytechnic University, Perm, Russian Federation;
The article is devoted to the research of additives influence on cement setting time at high temperature (500C). It is known that with the use of some additives the characteristics of the material can be changed. In the article, much attention is given to the determination of the normal consistency and presents a detailed analysis of the cement setting time. The paper gives information about each of the additives and their influence on cement characteristics. In addition, it speaks in detail about the testing procedures. The author comes to the conclusion that it is possible to raise the production without changing the time.
Optimization of the lightweight autoclaved aerated concrete modified with carbon nanotubes dispersions to the complex criterion of quality
S.V. Leontev, V.A. Shamanov, A.D. Kurzanov Perm National Research Polytechnic University, Perm, Russian Federation
The results of research aimed at obtaining of the thermal insulation autoclaved aerated concrete with the required level of the structure strength are presented in this article. The studies found that joint introduction in aerated concrete mixture of the specialized blowing agent with monodispersed particles, polycarboxylate and multi-walled carbon nanotubes dispersions to obtaining the enhance of strength properties of the thermal insulation autoclaved aerated concrete and slight decrease in its density and thermal conductivity by filling cracks crystalline blocks tumors ordered structure and redistribution of the volume of micropores and capillaries in aerated concrete structure. Optimization of autoclaved aerated concrete composition was performed by complex criterion of its quality by means of «Decon-SM» software product.
A. E. Sobianin, V.A. Shamanov Perm National Research Polytechnic University, Perm, Russian Federation
The article considers the problem of accommodation in the nature of aluminium-containing waste. The practicability and relevance of secondary use of such wastes. Described and analyzed the existing and promising methods of use of such wastes: a comprehensive recycling scheme and the use of building materials. Proven efficiency of the use of aluminium-containing waste in construction materials and listed the specific types of building materials suitable for use in such waste. The characteristics specific vysokouglerodistogo waste and optimal scope of usage of this waste ceramic.
G.V. Sopegin Perm National Research Polytechnic University, Perm, Russian Federation
Any construction cannot do without the use of heat-insulating materials, the main quality indicators are: thermal conductivity, average density and porosity. To ensure the necessary operational parameters heat-insulating materials must have high porosity, low average density and low values of the thermal conductivity coefficient. An important criterion is also theirs durability and environmental safety. However, few of the currently used heat-insulating materials meet the requirements of safety and durability. The most effective heat-insulating material from the point of view of operational, physical and mechanical properties is foam glass. It is obtained by foaming a glass-forming mass with different types of blowing agents. High porous structure and inorganic composition of foam glass to provide the high thermal properties and resistance to aggressive media. This article presents the comparative characteristic of modern heat-insulating materials. The main disadvantages of heat-insulating materials are revealed. It is shown that foam glass is the most effective heat-insulating material for Russian climatic conditions. Presents the main types and properties of foam glass, the field of its application.
A.M. Cherepanov , V.A. Shamanov - Perm National Research Polytechnic University, Perm, Russian Federation
The article presents the analysis of the main trends of production development, implementation of autoclaved gas concrete in the world. The aim of the publication is to identify possible ways of promotion and widespread use of gas by statistical data analysis, familiarization with foreign experience. The article presents the study of the historical development of this construction material from its invention to present day with bringing statistics on its production and use in Russia, the former Soviet Union and Europe. The analysis of stocks of raw materials for the production of autoclaved gas concrete on the example of Perm Region. The main factors hindering the development of the production of silicate on the territory of specific region. The main tasks of solving the problem of availability of quality raw materials on the territory of specific state.
The reasons of peeling of a protective polymeric covering of concrete with the strengthened top layer
V.A. Shamanov - Perm National Research Polytechnic University, Perm, Russian Federation;
The possible reasons of peeling of a protective polymeric covering of concrete with the strengthened top are described. Presumably, abnormal conditions of curing of concrete and a top-layer, or high content of alkalis on a top ping surface during an initial stage of his curing can be the reasons of peeling of a protective polymeric covering. For establishment of the reasons of peeling of a protective polymeric covering influence of conditions and time of curing of the strengthening concrete layer (top-layer) for tendency to peeling of a protective polymeric covering has been studied. During the experiments it is established that peeling of a protective polymeric covering isn't connected with abnormal conditions of curing: peeling of a protective polymeric covering was observed at the sample with a “green” top-layer hardening later drawings a covering in normal temperature and moist conditions. At the same time, peeling of a protective polymeric covering comes from the strengthened layer (to-layer) in the first 2-3 hours from the moment of a add-water that corresponds to the period of the greatest release of hydroxide of calcium from cement system up to the end of process of loss of mobility of a cement. Recommendations about performance of work about the device of a protective polymeric covering of a top-layer are offered no earlier than in 4 hours from the moment of his topping.