Composite Binder for Structural Cellular Concrete

2019 ◽  
Vol 945 ◽  
pp. 53-58 ◽  
Author(s):  
M.Y. Elistratkin ◽  
E.S. Glagolev ◽  
M.V. Absimetov ◽  
V.V. Voronov
Keyword(s):  
Building Materials ◽  
Negative Impact ◽  
Average Density ◽  
Construction Costs ◽  
Competitive Situation ◽  
Composite Binder ◽  
Mineral Supplements ◽  
Autoclaved Aerated Concrete ◽  
Aerated Concrete ◽  
Cellular Concrete

Non-autoclaved aerated concrete is the only viable alternative to gas silicate when organizing its manufacture on the basis of regional small and medium capacity production. This aims to improvement the competitive situation on the building materials market and optimizing the construction costs. The possibility of expanding the application field of this material due to the increase in strength characteristics while maintaining an unchanged average density is of special interest. The guarantee of proposed solutions economic and technical efficiency is the transition from traditional portland cement to composite binders based on it. The article discusses the quantity and composition of the mineral supplements feasibility to optimize the binder properties of the problem peculiarities to reduce consumption of cement and chemical modifiers that increase the rate of curing and totals of non-autoclaved aerated concrete investigated compatibility issues between components to eliminate their negative impact on the formation of porous structure of the final product.

scholarly journals ANALYSIS OF THE FACTORS OF INCREASING THE STRENGTH OF THE NON-AUTOCLAVE AERATED CONCRETE

2020 ◽  
pp. 59-68
Author(s):  
M.Yu. Elistratkin ◽  
M. Kozhuhova
Keyword(s):  
Building Materials ◽  
Pore Space ◽  
Average Density ◽  
Space Structure ◽  
Gas Generator ◽  
Autoclaved Aerated Concrete ◽  
Pore Space Structure ◽  
Mineral Additive ◽  
Aerated Concrete ◽  
The Creation

non-autoclaved aerated concrete is the only real alternative to gas silicate in the organization of its release on the basis of regional production of small and medium capacity. This will help improve the competitive environment in the building materials market and optimize the cost of construction. Of particular interest is the possibility of expanding the field of application of this material due to a significant increase in strength characteristics, while maintaining its average density in acceptable, in terms of thermal insulation properties, limits - not more than 1000 ... 1100 kg/m3. At a strength level of 10 MPa and above, in combination with dispersed reinforcement or the use of traditional non-metallic reinforcing elements, such aerated concrete can be used as a lightweight structural material for creating power elements of low-rise buildings, including in promising construction printing technologies; devices distributing the load belts; non-removable formwork; porous, stiffening, filling thin-walled tubular structures. The paper presents an assessment of the effectiveness of traditional ways to increase the strength of non-autoclaved aerated concrete. New solutions for the purposeful formation of the pore space structure are proposed and tested due to the creation and use of a gas generator with normalized gas evolution, which allows the creation of pores of a given volume. The key to the economic effectiveness of the proposed solutions is the transition from traditional portland cement to composite binders based on it. The substantiated choice of the amount and composition of the mineral additive makes it possible to optimize the properties of the binder under the particularity of the problem being solved, and to minimize the consumption of cement and chemical modifiers, increase the speed of durability and the final indices of non-autoclaved aerated concrete.

Non-Autoclaved Aerated Concrete Porosity and Factors Affecting it

2020 ◽  
Vol 992 ◽  
pp. 218-227
Author(s):  
L.A. Suleymanova ◽  
Inna A. Pogorelova ◽  
K.A. Kara
Keyword(s):  
Cement Hydration ◽  
Total Porosity ◽  
Average Density ◽  
Initial Water Content ◽  
Hydration Degree ◽  
Initial Water ◽  
Factors Affecting ◽  
Autoclaved Aerated Concrete ◽  
Aerated Concrete ◽  
Average Size

The total volume of cellular porosity, which comprises pores, interpore partitions, and air-entrained pores, depends on the spatial packing of pores, size distribution, maximum and average size, their shape, and the thickness of interpore partitions. Interpore partitions contain gel and capillary pores, which have a significant impact on the total porosity, thus affecting the operating properties of aerated concrete. This paper presents the calculations of gel, capillary, air, and total porosity in non-autoclaved aerated concrete of average-density grades D100...D1200 for different cement hydration degrees (0.6; 0.8, and 1) and water-cement ratios (0.5; 0.6, and 0.7); calculations use the author-developed methodology. Cement consumption depends on the average-density grade as well as on cement hydration degree. Reducing the latter from 1 to 0.6 in D500 concrete raises cement consumption by 7.4 %; other grades have similar patterns. This is why aerated concrete should be conditioned to maximize the utilization of the binder by enabling its complete hydration. The amount of water in the mixture is what determines the cement consumption and the water-cement ratio, whereby the density of cement dough will not depend on the average-density grade provided that the hydration degree and the WC ratio are constant. The finding is that the ability of cement to form its own pore structure is crucial to D500 and D400 aerated concrete if the mixture has high initial water content.

scholarly journals OPTIMIZATION OF RECEPTURAL-TECHNOLOGICAL PARAMETERS OF MANUFACTURE OF CELLULAR CONCRETE MIXTURE

2020 ◽  
pp. 30-36 ◽  
Author(s):  
Nataliya Alfimova ◽  
Sevda Pirieva ◽  
D. Gudov ◽  
I. Shurakov ◽  
Elena Korbut
Keyword(s):  
Production Efficiency ◽  
Mechanical Characteristics ◽  
Average Density ◽  
Concrete Mixture ◽  
Technological Parameters ◽  
Number Of Factors ◽  
Aerated Concrete ◽  
The Moment ◽  
The Impact ◽  
Cellular Concrete

aerated concrete at the moment is one of the perspective thermal insulation materials. However, the production of high-quality aerated concrete products is associated with a number of difficulties, primarily related to the features of the manufacturing technology and, in particular, to the formation of its structure during the period of gas evolution and the impact on this process of a large number of factors. The best conditions for the formation of cellular concrete are created when the maximum gas release and the optimum values of the plasticity-viscous characteristics of the aerated concrete mixture are found. Achieving optimal conditions is extremely difficult, which leads to a deterioration in the physico-mechanical characteristics of the final products. One of the ways to solve this problem is to increase the amount of mixing water, however, along with a positive effect (reducing the viscosity of the system), this leads to a decrease in the gas-holding capacity of the mixture. In this connection, the possibility of increasing the production efficiency of the cellular concrete mixture by optimizing the recipe-technological parameters was considered. With the help of the method of mathematical planning, a three-factor experiment was carried out, as the factors of variation were: the duration of the preliminary aging of the mixture, the dosage of the blowing agent and the water-hard ratio, the output parameters were the compressive strength and the average density of the final products. The obtained results made it possible to reveal the regularities of the change in the output parameters from the variable factors and to establish that the preliminary aging of the mixture before the introduction of the gassing agent positively affects the structure and, as a consequence, the physico-mechanical characteristics of the final products.

scholarly journals FOR THE STUDY OF PECULIARITIES OF STRUCTURE FORMATION OF COMPOSITE BINDERS FOR NON-AUTOCLAVED AERATED CONCRETE

2020 ◽  
pp. 41-47 ◽  
Author(s):  
V. Lesovik ◽  
M. Absimetov ◽  
M. Elistratkin ◽  
S. Shatalova
Keyword(s):  
Structure Formation ◽  
Raw Materials ◽  
Stage Structure ◽  
Average Density ◽  
Strength Performance ◽  
Molding Mixture ◽  
Autoclaved Aerated Concrete ◽  
Wide Range ◽  
Mineral Additive ◽  
Aerated Concrete

the basis of the modern market of cellular concrete is autoclaved gas silicate. At the same time, non-autoclaved aerated concrete is largely a more technological material, allowing the variation of its properties within a wide range, having a potentially wider field of application, less costly in the organization of production, which is of great importance for small and medium-sized businesses. The main problem of non-autoclaved aerated concrete is a higher cost of raw materials compared to silicate, and 20...30% lower strength performance. The proposed solution to this problem is the development of special composite binders with a limited content of clinker and mineral additives of various genetic types, taking into account the peculiarities of the two-stage structure formation of the material – gas porization and the formation of the microstructure of the stone. The article deals with some aspects of the interaction in the system “mineral additive – gypsum – by-products of the gas release reaction” in terms of the effect on the viscosity of the swelling mass and the strength of the stone at different times of hardening. Recommendations are given on the preferred compositions of composite binders and dosages of gypsum in the molding mixture when producing a material with an average density in the range of 500...700 kg/m3.

Theoretical Basis of Formation Highly Organized Porous Structure of Aerated Concrete

2019 ◽  
Vol 945 ◽  
pp. 309-317 ◽  
Author(s):  
L.A. Suleymanova ◽  
I.A. Pogorelova ◽  
M.V. Marushko
Keyword(s):  
Porous Structure ◽  
Cellular Structure ◽  
Control Cell ◽  
Air Entrainment ◽  
External Pressure ◽  
Average Density ◽  
Concrete Mixture ◽  
Concrete Technology ◽  
Aerated Concrete ◽  
Cellular Concrete

Theoretical principles of the formation of highly organized porous structure of cellular concrete are developed, based on model concepts of the dynamics of the expanding gas cavity in the liquid phase as a single control cell. The peculiarities of controlling the formation of cellular structure of aerated concrete based on the balance of forces in a three-phase disperse system on the model "gas pore - molding mixture" are revealed and a coalescing-aggregate scheme for porosity formation of the aerated concrete mixture is proposed. It is shown that, in accordance with the refined Rayleigh-Plesset equation, the determining factor in the formation of the cellular structure of aerated concrete is the pressure over the mixture to be poroused, the effect of the porosity being achieved by reducing the external pressure to the vacuum level. The division of pores by size in anaerated concrete mixture is proposed. The maximum pore size is determined by the capillary Laplace constant. The prospects of aerated concrete technology are associated with a decrease in the maximum and average size of cellular pores, as well as methods for eliminating pores of air entrainment and segmented pores. Reducing of the size of the pores will be reflected in the decrease of the Bond quantity and in the increase of the importance of capillary forces in the formation of the porous structure of aerated concrete. The concepts of the types of cellular structures are developed, depending on the average density and their boundaries for cellular concrete are established.

scholarly journals METHODS OF CELLULAR CONCRETE PRODUCTION USING FLY ASH

2021 ◽  
pp. 114-122
Author(s):  
T.А. Sasovsky ◽  
◽  
I.V. Chorna ◽  
S.V. Shalay ◽  
O.M. Lysiak ◽  
...  
Keyword(s):  
Fly Ash ◽  
Thermal Insulation ◽  
Building Materials ◽  
Practical Interest ◽  
Insulation Material ◽  
Capital Costs ◽  
Concrete Production ◽  
Aerated Concrete ◽  
Capital Construction ◽  
Cellular Concrete

Abstract. An analysis of modern capital construction state shows that the material and technical base of the construction industry does not allow the production of effective building materials and products in the required quantity without due consideration of the economic burden on the environment, and now significant financial costs are required to restore the ecological balance of the natural zone. Power plant fly ash is a man-made raw material for many industries, which is utilized up to 92% in dry form and is of practical interest in the production of effective thermal insulation building materials and products as a filler and an aggregate. In view of the instability of the chemical and mineralogical composition, the content of raw fuel, as well as the pozzolanic activity, the study of the profitability of the production of pozzolanic cements and concretes based on them was carried out, with an increase in sulfate resistance, corrosion resistance of the aggregate while preventing thermal cracking. The expediency of autoclaved gas-ash-slag concretes production with the use of cement with high content of highly basic minerals ‒ alite and tricalcium aluminate is proved. The technology of obtaining ash-alkaline cellular concrete using ash-removal and alkaline component is given. The economic efficiency of cellular ash-containing concretes is justified by the replacement of sand with ash, a 1.2-1.5-fold reduction in lime consumption compared to lime-sand concrete and a reduction of approximately 2 times the capital costs for extraction and processing of raw materials. Comparative physical and mechanical parameters of autoclave and non-autoclave aerated concrete products are given. The process of manufacturing products by vibro-vacuuming and vibratory compaction of ash concrete is presented. The strength data of vacuum concrete are given, which are 30-40% higher than that of vibro- compacted concrete from a rigid mixture. The investigated value of shrinkage as a result of the water-reducing effect of ash, provides a decrease in the water-cement ratio of concrete. Autoclaved and non-autoclaved aerated concrete can compete with such an effective thermal insulation material as mineral wool. They are more effective materials for low-rise and frame housing construction than traditional brick and concrete.

AERATED CONCRETE WITH THE USE OF FERRUGINOUS QUARTZITE PROCESSING WASTE

2020 ◽  
Vol 5 (4) ◽  
pp. 230-242
Author(s):  
Myroslav Malovanyy ◽  
◽  
Oksana Ilyash ◽  
Oleksiy Povzun ◽  
Valeriy Kalynychenko ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Mass Fraction ◽  
Average Density ◽  
Ferruginous Quartzite ◽  
Processing Waste ◽  
Concrete Mixtures ◽  
Processing Plants ◽  
Magnetic Enrichment ◽  
Aerated Concrete ◽  
Cellular Concrete

Waste (tailings) of mining and processing plants of Kryvbas were studied by the stages of their magnetic enrichment. The granulometric compositions of the tailings, the amount of iron (total and magnetic) and the mass fraction of solid in them are determined. The expediency of disposing of ferruginous quartzite waste at the first stage of enrichment as a silica component in cellular concretes is proved. Optimal compositions of aerated concrete mixtures are determined based on the following criteria: the average density of cellular concrete in the dry state and its compressive strength.

On the Question of the Application of Basalt Microfiber for Reinforcement of Thermal Insulation AAC

2020 ◽  
Vol 864 ◽  
pp. 122-127
Author(s):  
Svitlana Davydivna Lapovska ◽  
Tetyana Mykolaivna Demchenko ◽  
Oleksandr Yuriyovich Kovalchuk ◽  
Victoriya Oleksandrivna Chornovol
Keyword(s):  
Thermal Insulation ◽  
Autoclaved Aerated Concrete ◽  
First Results ◽  
Aerated Concrete ◽  
Reduced Density ◽  
Cellular Concrete

The article describes the first exploratory studies on the reinforcement of heat-insulating autoclaved aerated concrete with a basalt microfiber. The aim of the work is to obtain autoclaved aerated concrete of reduced density with improved tensile and bending characteristics. The first results obtained using basalt microfiber for reinforcing cellular concrete with a density of 150 kg/m3 are analyzed.

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