Optimization of Technological Parameters of Foam Concrete Mix Preparation for Obtaining Foam Concrete with Improved Structure and Characteristics

2021 ◽  
pp. 43-49
Author(s):  
S. A. Stel’makh ◽  
E. M. Shcherban’ ◽  
K. E. Tkacheva
Keyword(s):  
Foam Concrete ◽  
Technological Parameters ◽  
Concrete Mix

scholarly journals Early structure formation of foam concrete mix containing modifying admixture

2015 ◽  
Vol 54 (02) ◽  
pp. 56-62 ◽  
Author(s):  
A.B. Steshenko ◽  
A.I. Kudyakov
Keyword(s):  
Structure Formation ◽  
Foam Concrete ◽  
Concrete Mix

scholarly journals Fundamentals of property and compositions management concrete mix and concrete

2021 ◽  
Vol 264 ◽  
pp. 02061
Author(s):  
Bakhridin Khasanov ◽  
Ruzimurot Choriev ◽  
Nikolai Vatin ◽  
Zukhra Ismailova ◽  
Alisher Tillaev ◽  
...  
Keyword(s):  
Raw Materials ◽  
Laboratory Data ◽  
Physical And Mechanical Properties ◽  
Concrete Mixture ◽  
Normal Density ◽  
Technological Parameters ◽  
Concrete Composition ◽  
Concrete Mix ◽  
Design Characteristics ◽  
The Given

The choice of the concrete composition following the set research tasks must satisfy the following requirements: 1-the maximum achievable strength on the given starting materials; 2-the required formability, corresponding to the accepted vibration-impact-peristaltic pressing; 3-a given level of dehydration of the concrete mixture, providing a residual W/C, close to the normal density of the cement paste. The accepted conditions are necessary and sufficient when using the physical-analytical method of designing concrete composition. Distinctive features of the method are the use of a large amount of information and the absence of arbitrary coefficients, technological constants, or parameters. The necessary data for the assignment of concrete compositions are determined according to the data of preliminary laboratory experiments, the given technological parameters of mechanisms and equipment, and the design characteristics of concrete and the structure to be formed. For the experimental study, a total of six independent information streams of initial data are used: 1-physical and mechanical properties of the constituents of concrete (Rc, ρc, ρc°, [V/C], рс, γ3, ρshch, γsh, γshch°); 2-laboratory data of tests of raw materials in concrete mix and concrete (a, b, c, Ku, A, B); 3-design characteristics of concrete mix and concrete (Rb, F, W, OK, Zh); 4-characteristics of the product to be concreted (V, h, l, μ); 5-technological characteristics of equipment, mechanisms, and devices (th, tb, TO, t0); 6-the cost per unit volume of raw materials (Sc, Cn, Ssh, Se, Sg). Obviously, the listed volume of initial information comprehensively characterizes the materials used and the conditions for forming the product. The previously developed technological conditions for forming concrete pipes, in addition to the above, require, when assigning the composition of concrete, to take into account the observance of the balance of masses in the concrete mixture and compacted, modified concrete. This should be manifested in checking the equation of absolute volumes for the original and compacted (dewatered) concrete.

scholarly journals Управление физико-механическими характеристиками бетона за счет варьирования высоты и шага технологических выступов хомутов виброцентрифугирующих устройств

2021 ◽  
Vol 46 (1) ◽  
Author(s):  
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Cross Section ◽  
Mechanical Characteristics ◽  
Experimental Studies ◽  
Strength Analysis ◽  
Technological Parameters ◽  
Axial Tensile ◽  
Concrete Mix ◽  
Physical And Mechanical Characteristics

Для регулирования вариатропной структуры центрифугированных изделий авторы данной статьи совместили процесс центрифугирования с вибрированием. Во время эксперимента вибрации формы обеспечивались за счет надетых на валы установки хомутов. Представлена авторская экспериментальная установка для создания виброцентрифугированных образцов кольцевого сечения с вариатропной структурой, а также способ их изготовления. Выделены технологические параметры вибрирования, которые оказывали наиболее значимое влияние на характеристики виброцентрифугированного бетона, конструкций и изделий из него. В опытах варьировались высота технологических выступов хомутов и шаг между ними. Исследовалось влияние этих факторов на физико-механические характеристики бетона: плотность; кубиковая прочность на сжатие; призменная прочность на сжатие; прочность на растяжение при изгибе; прочность на осевое растяжение. Приведен анализ результатов экспериментальных исследований и получены следующие физико-механические характеристики виброцентрифугированных бетонов, изготовленных с использованием хомутов: лучшие – с высотой технологических выступов 5 мм и шагом между ними 30 мм, самый низкий показатель – соответственно 2,5 мм при любом шаге. Ключевые слова: виброцентрифугированный бетон, физико-механические характеристики, прочность при сжатии, плотность, бетонная смесь, центрифугирование, прочность при изгибе To regulate the variatropic structure of centrifuged products, the authors of this article combined the process of centrifugation with vibration. During the experiment, vibrations of the mold were provided with clamps set on the shafts of the installation. The author's experimental setup for creating vibrocentrifuged samples of annular cross-section with a variatropic structure, as well as a method for their manufacture is presented. The technological parameters of vibration, which had the most significant effect on the characteristics of vibrocentrifuged concrete, structures and products made of it, were identified. In the experiments, the height of the technological protrusions of the clamps and the pitch between them were varied. The influence of these factors on the physical and mechanical characteristics of concrete was investigated: density; cube compressive strength; prismatic compressive strength; bending tensile strength; axial tensile strength. Analysis of the results of experimental studies is given and the following physical and mechanical characteristics of vibrocentrifuged concretes made using clamps have been obtained: the best ones with a height of technological protrusions of 5 mm and a step between them of 30 mm, the lowest indicator is, respectively, 2.5 mm at any step. Keywords: vibrocentrifuged concrete, physical and mechanical characteristics, compressive strength, density, concrete mix, centrifugation, flexural strength

Features of the Technology of Construction of Road Pavements from Vacuum-Treated Asphalt Concrete Mix

2020 ◽  
Vol 785 (10) ◽  
pp. 31-37
Author(s):  
S.V. NOSOV ◽  
◽  
B.A. BONDAREV ◽  
I.S. NOSOV ◽  
◽  
...  
Keyword(s):  
Rheological Properties ◽  
Asphalt Concrete ◽  
Frost Resistance ◽  
Construction Materials ◽  
Road Construction ◽  
Rheological Parameters ◽  
Roller Compaction ◽  
Technological Parameters ◽  
Road Asphalt ◽  
Concrete Mix

When changing the structural properties of road construction materials, their compaction technologies should be improved with the choice of the best compaction means and their technological modes of operation in specific conditions of work conduction. For a mixture evacuated at an asphalt concrete plant that has increased water and frost resistance characteristics, as well as changed rheological parameters, it is also necessary to determine the technological parameters of the compaction means used, taking into account the features of its rheological characteristics. The compaction technology of vacuum-treated hot asphalt-concrete mix by pneumatic wheel roller with the determination of the necessary number of passes on the trail, speed modes along the roller passages and the magnitude of the air pressure in the tires of the roller has been developed. Using a promising rheological approach, the dynamics of accumulation of the asphalt concrete mixture layer density along the roller passages was studied by simulation modeling, and the time when the pneumatic roller was finished and the compaction work was transferred to heavy smooth rollers was determined. Changing the rheological properties of the vacuum-treated asphalt mix increases the efficiency of its compaction, reducing material costs, increasing the productivity of compaction tools while improving the quality and durability of road asphalt pavements. Keywords: hot asphalt-concrete mix, rheological properties, water and frost resistance of asphalt concrete, road roller, compaction.

Studies of Heat Insulation Concrete

2020 ◽  
Vol 992 ◽  
pp. 130-134
Author(s):  
M. Elesin ◽  
N.A. Mashkin ◽  
E.A. Bartenjeva ◽  
V. Larichkin ◽  
M. Nikolaeva
Keyword(s):  
Frost Resistance ◽  
Heat Insulation ◽  
Flow Chart ◽  
Foam Concrete ◽  
Technological Parameters ◽  
Foaming Agent

The article analyzes the properties changes of non-autoclave foam on a protein foaming agent with the introduction of dispersed wollastonite and diopside. A decrease in the density of foam concrete (to the grade D300, D400), frost resistance of the material, as well as shrinkage deformations was noted. The optimal technological parameters have been determined, allowing to obtain more stable properties and structure of heat-insulating cement-ash non-autoclave foam concrete. The flow chart of the production of foam concrete of natural hardening in the separate preparation of foam and mortar is presented. The studies were performed at NSTU and NGASU (Novosibirsk) and the NII (Norilsk).

scholarly journals Assessment of Physical and Mechanical Behaviour of Foam Concrete using Bottom Ash and Fly Ash

2020 ◽  
Vol 9 (6) ◽  
pp. 392-396
Keyword(s):  
Hydrogen Peroxide ◽  
Fly Ash ◽  
Mechanical Behaviour ◽  
Lightweight Concrete ◽  
Thermal Power ◽  
Research Work ◽  
Bottom Ash ◽  
Foam Concrete ◽  
Split Tensile Strength ◽  
Concrete Mix

Foam concrete is a kind of air inflated lightweight concrete, which doesn’t contain coarse aggregate and can be regarded as an air inflated mortar. Foam concrete is made by adding foam into the cement slurry, the main use of foam in the cement mortar is to create air voids which act as a ball bearings inside the concrete mix. Foam is prepared by using foam generator or it can be made by sonication process of hydrogen peroxide. In this research work foam is formed by the sonication process of hydrogen peroxide separately then the foaming agent is diluted with water and air inflated to create the foam. Bottom ash from thermal power plant is collected and added in different proportions in the concrete mix to study the mechanical behaviour of the foam concrete. Mechanical properties such as compressive strength, split-tensile strength, flexural strength and thermal conductivity tests are carried out under controlled environment. The targeted design densities of all the specimens were expected to be 1600 kg/m3 . The binder to filler ratio used in this study is 1:1, with the sand being completely replaced with bottom ash and Fly ash.

scholarly journals Dependence of foam concrete properties on technological factors

2020 ◽  
Vol 164 ◽  
pp. 14010
Author(s):  
Alexander Drozdov ◽  
Irina Osipenkova ◽  
Olga Stupakova
Keyword(s):  
Mechanical Properties ◽  
Physical And Mechanical Properties ◽  
Mineralogical Composition ◽  
Foam Concrete ◽  
Concrete Technology ◽  
Influence Of Temperature ◽  
Technological Factors ◽  
Concrete Properties ◽  
Concrete Mix ◽  
Properties Of Materials

The dependences of foam concrete properties on various factors, which are divided into 4 groups, are considered. The dependence of physical and mechanical properties on the properties of materials, conditions for maintaining foam concrete, on the brand and mineralogical composition of cement was revealed. Joint and separate methods of preparing a foam concrete mixture using pressure-chamber turbulence-cavitation mixers and modernized standard forced-action mortar mixers are considered. The importance of technological influence of temperature in foam concrete technology is determined. Methods of transportation of foam concrete mix, which also affect the properties of the material, are considered.

Cellular Concretes Based on Nanostructured Perlite Binder

2014 ◽  
Vol 496-500 ◽  
pp. 2383-2386 ◽  
Author(s):  
Natalia Viktorovna Pavlenko ◽  
Valeria Valerievna Strokova ◽  
Alla Vasilievna Cherevatova ◽  
Daria Dmitrievna Netsvet ◽  
Evgeniy Vladimirovich Miroshnikov
Keyword(s):  
Mechanical Characteristics ◽  
Foam Concrete ◽  
Technological Parameters ◽  
Mechanisms Of Formation ◽  
Amorphous Aluminosilicate ◽  
Selection Of ◽  
Physical And Mechanical Characteristics

The article is devoted to the characteristics of foam concrete with the application of nanostructured binder (NB) on the basis is amorphous aluminosilicate rocks. The optimal technological parameters of the production of nanostructured perlite binder (NPB) were stated. The selection of foam generating agents was accomplished and mechanisms of formation of cellular composites on the basis of NPB were studied. Physical and mechanical characteristics of the obtained material were determined.

A possibility of using nickel concentrate, obtained as a result of hydrometallurgical enrichment of manganese-containing raw materials, at steel alloying

2020 ◽  
Vol 76 (7) ◽  
pp. 709-715
Author(s):  
O. Yu. Kichigina
Keyword(s):  
Raw Materials ◽  
Experimental Studies ◽  
Selective Extraction ◽  
Technological Parameters ◽  
Nickel Iron ◽  
Nickel Recovery ◽  
Nickel Concentrate ◽  
Steel Alloying ◽  
High Degree ◽  
Comprehensive Processing

At production of stainless steel expensive alloying elements, containing nickel, are used. To decrease the steel cost, substitution of nickel during steel alloying process by its oxides is an actual task. Results of analysis of thermodynamic and experimental studies of nickel reducing from its oxide presented, as well as methods of nickel oxide obtaining at manganese bearing complex raw materials enrichment and practice of its application during steel alloying. Technology of comprehensive processing of complex manganese-containing raw materials considered, including leaching and selective extraction out of the solution valuable components: manganese, nickel, iron, cobalt and copper. Based on theoretical and experiment studies, a possibility of substitution of metal nickel by concentrates, obtained as a result of hydrometallurgical enrichment, was confirmed. Optimal technological parameters, ensuring high degree of nickel recovery out of the initial raw materials were determined. It was established, that for direct steel alloying it is reasonable to add into the charge pellets, consisting of nickel concentrate and coke fines, that enables to reach the through nickel recovery at a level of 90%. The proposed method of alloying steel by nickel gives a possibility to decrease considerably steel cost at the expense of application of nickel concentrate, obtained out of tails of hydrometallurgical enrichment of manganese-bearing raw materials, which is much cheaper comparing with the metal nickel.

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