scholarly journals Effect of modifiers and mineral additives from industrial waste on the quality of aerated concrete products

Technobius ◽  
2021 ◽  
Vol 1 (4) ◽  
pp. 0010
Author(s):  
Yerlan Sabitov ◽  
Duman Dyussembinov ◽  
Daniyar Bazarbayev
Keyword(s):  
Fly Ash ◽  
Polyvinyl Acetate ◽  
Raw Materials ◽  
Capillary Suction ◽  
Pulsation Apparatus ◽  
Rotary Pulsation Apparatus ◽  
Aerated Concrete ◽  
The Given ◽  
Mineral Additives

The given article is devoted to research of influence of polymer modifiers and mineral additives on quality of composite aerated concrete products. When selecting the composition of composite aerated concrete local raw materials and components were used: portland cement, sand, aluminum powder, polyvinyl acetate, fly ash, post-alcoholic bard and whey of milk. Preliminary polyvinyl acetate was combined with binder mixing water at a temperature above 55ºC to obtain a readily soluble polymer emulsion. Dispersion was carried out with a rotary-pulsation apparatus at a pressure of 0.5-1.0 MPa and a rotor speed of ~1200 rpm. In the same apparatus the complex modifier was produced. The offered technology of production of a complex modifier seems to be the most effective for composite aerated concrete. It made it possible to reduce water absorption and capillary suction of composite aerated concrete by an average of 25% and 45%, respectively. Moreover, different combinations of fly ash, polymer and modifier made it possible to achieve optimal values of thermal conductivity, compressive strength and frost resistance of composite aerated concrete.

scholarly journals Study of wheat straw delignification in a rotary-pulsation apparatus

2020 ◽  
pp. 103-110
Author(s):  
Larysa Sablii ◽  
Oleksandr Obodovych ◽  
Vitalii Sydorenko ◽  
Tamila Sheyko
Keyword(s):  
Wheat Straw ◽  
Production Technology ◽  
Raw Materials ◽  
Hydrolytic Enzymes ◽  
Bioethanol Production ◽  
Second Generation Bioethanol ◽  
Pulsation Apparatus ◽  
Rotary Pulsation Apparatus ◽  
Solid Water ◽  
Pre Treatment

This paper presents the results of studies of isolation lignin and hemicelluloses efficiency during the pre-treatment of wheat straw for hydrolysis in a rotary-pulsation apparatus. The pre-treatment of lignocellulosic raw materials for hydrolysis is a necessary step in the second-generation bioethanol production technology. The lignocellulose complex is destroyed during this process, and this allows hydrolytic enzymes access to the surface of cellulose fibers. The pre-treatment is the most energy-consuming stage in bioethanol production technology, since it usually occurs at high temperature and pressure for a significant time. One of the ways to improve the efficiency of this process is the use of energy-efficient equipment that allows intensifying heat and mass transfer. An example of such equipment is a rotary-pulsation apparatus, which are effective devices in stirring, homogenization, dispersion technologies, etc. The treatment of wheat straw in a rotary-pulsation apparatus was carried out under atmospheric pressure without external heat supply at solid/water ratios of 1:10 and 1:5 in the presence of alkali. It was determined that the treatment of the water dispersion of straw at ratio of 1:10 due to the energy dissipation during 70 minutes leads to the release of 42 % of lignin and 25.76 % of easily hydrolyzed polysaccharides. Changing the solid / water ratio from 1:10 to 1:5 leads to an increase in the yield of lignin and easily hydrolyzed polysaccharides to 58 and 33.38 %, respectively.

The Use of Anthracite Fly Ash for the Production of Autoclaved Aerated Concrete

2012 ◽  
Vol 512-515 ◽  
pp. 3003-3006
Author(s):  
Rostislav Drochytka ◽  
Vit Cerný ◽  
Karel Kulísek
Keyword(s):  
Heat Treatment ◽  
Fly Ash ◽  
Construction Industry ◽  
Raw Materials ◽  
Exothermic Reaction ◽  
Reaction Heat ◽  
Anthracite Coal ◽  
Concrete Production ◽  
Aerated Concrete ◽  
Cellular Concrete

Burning high-quality anthracite coal produces ash with a high content of unburned residues, which in many cases permanently exceeds 20%. These ashes usually contain high levels of amorphous phase providing the pozzolanic activity, this making them particularly useful if potentially applied in the construction industry. Such potential of effective treatment necessitates reducing the content of unburned residues, the best level here being less than 4% w/w. This paper deals with the results of testing heat treatment of fly ashes particularly using the resources of eastern Slovakia. Tests have shown that tested process of heat treatment can safely reduce the content of unburned residues in fly ash whilst maintaining high levels of the glass phase. Raw materials thus modified meet the requirements for the use in cellular concrete production technology with beneficial use of exothermic reaction heat from fly ash treatment in pre-heating the autoclaves.

Influence of Gypsum Additive on the Formation of Tobermorite in Autoclaved Aerated Concrete

2016 ◽  
Vol 714 ◽  
pp. 116-121 ◽  
Author(s):  
Ester Helanova ◽  
Rostislav Drochytka ◽  
Vit Cerný
Keyword(s):  
Chemical Composition ◽  
Hydrothermal Reaction ◽  
Raw Materials ◽  
Fly Ashes ◽  
Sem Images ◽  
X Ray ◽  
Autoclaved Aerated Concrete ◽  
Variable Chemical ◽  
Aerated Concrete

The quality of the aerated concrete strongly depends on the chemical composition of the raw materials, as well as the process of the hydrothermal reaction during autoclaving. Due to the variable chemical composition of fly ashes, it is necessary to identify the effect of each ion on the formation of the microstructure of aerated concrete. This paper examines the process of formation of tobermorite with the addition of sulphates in various percentage representation. The microstructure of aerated concrete is assessed using SEM images and the mineralogical by means of X-ray analysis.

scholarly journals Utilization of Construction and Demolition Waste, Fly Ash Waste in Autoclaved Aerated Concrete

2020 ◽  
Vol 3 (2) ◽  
Keyword(s):  
Fly Ash ◽  
Aluminum Powder ◽  
Power Plants ◽  
Raw Materials ◽  
Thermal Power ◽  
Construction And Demolition Waste ◽  
Construction Sector ◽  
Demolition Waste ◽  
Concrete Material ◽  
Aerated Concrete

China's industries are rapidly growing, and with that generation of waste is also increasing. Associated environmental concerns over construction and demolition waste, industrial waste such as fly ash generated by thermal power plants need to be utilized in some form. Autoclave aerated concrete is a lightweight material that can be used as an alternative building material; it is widely composed of raw materials such as cement, quicklime, sand, gypsum, and an aerating agent like aluminum powder. In this study, 40% waste will be utilized, Construction waste (5%,10%,15%....40%) and Fly ash (35%,30%,25….0%)respectively, keeping the aerating agent constant at 0.06% that is aluminum powder. The compressive strength of the material will be checked after autoclaving at 2000 temperature and 1Mpa Pressure for 6 hours. The study aims to design an autoclave aerated concrete material and to recycle the waste generated by various industries mainly from the construction sector.

The Influence of Sulfates on Tobermorite Formation in Lime-Ash Composite

2018 ◽  
Vol 916 ◽  
pp. 179-183
Author(s):  
Vit Cerný ◽  
Jindrich Melichar ◽  
Jan Fleischhacker ◽  
Rostislav Drochytka
Keyword(s):  
Fly Ash ◽  
Hydrothermal Synthesis ◽  
Building Material ◽  
Raw Materials ◽  
Mineralogical Composition ◽  
Positive Influence ◽  
Hydrothermal Conditions ◽  
Long Time ◽  
Aerated Concrete ◽  
Ecological Building

Autoclaved aerated concrete is an ecological building material with suitable properties and long-time tradition. The research of secondary raw materials usage and technology optimization is needed in order to increase the efficiency and sustainability of its production. It is important to focus on development of mineralogical composition while studying the influence of input materials and the parameters of hydrothermal synthesis on the properties of final product. This is especially important in case of tobermorite formation as the bearer of strength in the structure. Main focus of this paper is applicability of fly ash (silica component) and admixture of energo-gypsum (sulfate component) in production of lime-ash composite in hydrothermal conditions. The research was focused on autoclaving of samples at temperature of 170°C in three various isothermal sustains. Final samples were analyzed by XRD and SEM in order to proof the influence of input materials. Results show that 5% admixture of energo-gypsum had positive influence on tobermorite formation.

Hydrothermal Synthesis of Tobermorite at 170 and 190 °C from Fly Ash and Quartz Sand

2016 ◽  
Vol 865 ◽  
pp. 42-46 ◽  
Author(s):  
Ján Fleischhacker ◽  
Ester Helanová ◽  
Rostislav Drochytka
Keyword(s):  
Fly Ash ◽  
Hydrothermal Synthesis ◽  
Quartz Sand ◽  
Raw Materials ◽  
Molar Ratio ◽  
Hydrothermal Conditions ◽  
Temperature Combustion ◽  
Concrete Mechanical Properties ◽  
Aerated Concrete ◽  
High Temperature Combustion

Tobermorite is the main mineral which provides to aerated concrete mechanical properties. It is produces during hydrothermal conditions by reacting silicon and calcium oxides. Within this research was evaluated tobermorite formation using high temperature combustion fly ash and quartz sand, as the siliceous raw materials. As a binder was used lime. Emphasis was also placed on the molar ratio of C/S, which is crucial for the formation of tobermorite and was given 0.73 and 1.00. Hydrothermal synthesis was carried out in a laboratory autoclave at temperatures of 170 and 190 °C.

scholarly journals Features of use of unlawful kaolin for the manufacture of a cement clinker

2018 ◽  
pp. 6-13
Author(s):  
M.Yu. Tsybenko ◽  
L.P. Chernyak ◽  
V.G. Salnik ◽  
N.O. Dorogan
Keyword(s):  
Fly Ash ◽  
Phase Transformations ◽  
Raw Materials ◽  
Mineralogical Composition ◽  
Raw Material ◽  
Cement Clinker ◽  
The Subject ◽  
Clay Component ◽  
The Given ◽  
Scientific Ideas

Results over of research of the silicate systems of carbonate raw material with the varieties of clay component for making of cement clinker. The features of the chemical-mineralogical composition, phase transformations during burning and astringent properties of clinker are shown when unenriched kaolin and fly ash are used as alumina-silica-containing components of the initial raw material mixture. In the chemical technology of hydraulic mineral astringents, clay raw material serves, first of all, as a source of SiO , Al O , Fe O oxides, which must form from CaO during the baking of crystalline phases of silicates, aluminates and calcium aluminferrite, with the development of which impart the properties of the product of production. In turn, the above oxides arise in the process of technology during the heat treatment of raw mixtures due to the destruction of the lattice of rock-forming minerals. Hence the obvious dependence of the number and reactivity of oxides on the chemical and mineralogical composition of clay raw material, which, according to essential differences, is classified into a number of groups. Deepening of scientific ideas about this dependence can become an additional factor for im- proving the intensification of the technology of silicate binders, which became the subject of research in the given work. The chemical and mineralogical composition of the clay component of raw materials for the production of clinker and cement based on it is an important factor in the structure of the binder material at the stages of the technological process and the determination of the properties of the final product. Taking into account the peculiarities of the composition of unbleached kaolin (high content of kaolinite, quartz, feldspar), the feasibility of its application in the production of cement for clinker production is related to the possibility of adjusting the kinetics and the direction of phase transformations during the burning of the material. From the point of view of resource conservation and technology, the complex application of aluminum and silicon-containing raw materials components of natural (unaffected kaolin) and man-made (fly ash) origin is shown. Deepening of scientific ideas about this dependence can become an additional factor for improving the intensification of the technology of silicate binders, which became the subject of research in the given work.

Utilizing Iron Tailing, Sludge and Fly Ash to Prepare Ceramsites

2020 ◽  
Vol 13 (1) ◽  
pp. 16-25
Author(s):  
Zi Wang ◽  
Hongjun Chen ◽  
Chunhu Yu ◽  
Zeyang Xue ◽  
Pengxiang Wang ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Mechanical Performance ◽  
Sintering Temperature ◽  
Raw Materials ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Duration Time

Background: The deposits of iron tailing will pose a great risk of environmental pollution and serious landscape impact which will affect the quality of life of humans. Therefore, it is urgent to utilize iron tailing to produce valuable products. Methods: The tailing ceramsites were analysed by X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM). The roles of the tailing content, sintering temperature and duration time in the performance of the tailing ceramsites were analysed and the optimal sintering parameters were determined. Results: The bulk density, apparent density and cylinder compressive strength of the tailing ceramsites increase considerably with the increase of the sintering temperature and duration time. The cylinder compressive strength of the tailing ceramsites increases with increasing the tailing content. The optimal sintering parameter is 1100°C for 40 min. The cylinder compressive strength of the tailing ceramsites obtained at 1100°C for 40 min reaches 10.1 MPa. XRD analysis shows that the tailing ceramsites mainly consist of CaSiO3, Al2SiO5, MgSiO3, Ca7Si2P2O16, CaAl2Si2O8, Ca2Fe2O5 and SiO2 phases when the sintering temperature and duration time were increased to 1100°C and 40 min, respectively. Conclusion: The tailing ceramsites were obtained from iron tailing, sludge and fly ash as the raw materials at 1100°C for 40 min. The obtained ceramsites exhibited high mechanical performance.

Autoclaving Time Influence on Fly Ash Aerated Concrete Compressive Strength and Microstructure

2014 ◽  
Vol 897 ◽  
pp. 301-304
Author(s):  
Ester Helanová ◽  
Rostislav Drochytka ◽  
Radek Janovský
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Hydrothermal Reaction ◽  
Raw Materials ◽  
Concrete Strength ◽  
Use Value ◽  
Environmental Aspects ◽  
Concrete Compressive Strength ◽  
Modern Material ◽  
Aerated Concrete

The fly ash aerated concrete is a modern material combining high use value with environmental aspects of its production. It is mainly an utilisation of secondary raw materials with related minimum consumption of natural resources. The resulting properties the aerated concrete product obtains by autoclaving during which a complete line of calcium hydro silicates are formed due to occurring hydrothermal reaction and tobermorite mineral is the most important one. This mineral has a significant influence principally on aerated concrete strength. This article thus verifies the autoclaving time influence on tobermoritic phase developments and to this related compressive strength of the fly ash aerated concrete.

scholarly journals Utilization of Construction and Demolition Waste Along with Fly Ash waste in Preparing Non-Autoclaved Aerated Concrete

2020 ◽  
Vol 5 (3) ◽  
pp. 103-109
Author(s):  
Qunshan Wei ◽  
◽  
Kashif Ali Panhwar ◽  
Zuhair Nadeem ◽  
Kai Zhang ◽  
...  
Keyword(s):  
Fly Ash ◽  
Building Materials ◽  
Lightweight Concrete ◽  
Raw Materials ◽  
Low Cost ◽  
Thermal Power ◽  
Construction And Demolition Waste ◽  
Demolition Waste ◽  
Autoclaved Aerated Concrete ◽  
Aerated Concrete

China’s construction industries are rapidly increasing, and with that generation of Construction and Demolition waste is also growing, and another side industrial waste such as fly ash produced by a thermal power plant, Associated environmental issues, it is essential to utilize in any form; Studies by concrete experts have indicated the feasibility of suitably handling and recycling such waste in new concrete, mainly for basic-level applications. Non-autoclaved aerated concrete is a lightweight substance that could be used as substitute building materials; it is generally made up of raw materials such as Cement, quicklime, gypsum, sand, and expansion agent like an aluminum powder; in this study, 40% waste utilized, Construction and demolition waste (5%,10%,15%,20% ………40%) and Fly ash (35%,30%,25%,20%......0%) accordingly, while expansion agent maintained constant at 0.06%. The compressive strength of the final material checked after (7,14,21 and 28 days) respectively, obtained maximum strength after 28 days; this study goals to design a low cost, Non-autoclaved aerated concrete material and to reuse the waste produced from different sectors, mainly from the construction sector Keywords: Non-Autoclaved concrete, Lightweight concrete, Eco-friendly, Construction and Demolition waste, Fly ash

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