scholarly journals METHODS OF CELLULAR CONCRETE PRODUCTION USING FLY ASH

Author(s):  
T.А. Sasovsky ◽  
◽  
I.V. Chorna ◽  
S.V. Shalay ◽  
O.M. Lysiak ◽  
...  

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.

2012 ◽  
Vol 512-515 ◽  
pp. 3003-3006
Author(s):  
Rostislav Drochytka ◽  
Vit Cerný ◽  
Karel Kulísek

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.


2017 ◽  
Vol 265 ◽  
pp. 124-128 ◽  
Author(s):  
A.A. Vishnevskiy ◽  
F.L. Kapustin

There is experience of the production and use of low density autoclaved aerated concrete. It is shown that fly-ash from Reftinskaya State District Power Plant efficiently substitutes the quartz sand aerated concrete technology. Its use opens up additional opportunities for AAC with the density of 300-400 kg/m3. In order to optimize the structure and properties it has been suggested to introduce the gypsum aerated concrete additive into the autoclave in the amount of 3-5% by weight of the dry components. The introduction of gypsum ensures the creation of a uniform homogeneous structure, resulting in the increased strength properties and reduced drying shrinkage. The resulting aerated concrete has thermal conductivity of 0.075-0.100 W/m·K, it allows using and creating single-layer fencing structures without additional insulation. The low-density gas-ash concrete production allows extending the scope of cellular concrete application and increasing its competitive advantages over other walls and insulating materials.


2019 ◽  
Vol 945 ◽  
pp. 53-58 ◽  
Author(s):  
M.Y. Elistratkin ◽  
E.S. Glagolev ◽  
M.V. Absimetov ◽  
V.V. Voronov

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.


2011 ◽  
Vol 250-253 ◽  
pp. 507-512
Author(s):  
Zi Sheng Wang ◽  
Hao Chi Tu ◽  
Jin Xiu Gao ◽  
Guo Dong Qian ◽  
Xian Ping Fan ◽  
...  

Aerogel is regarded as one kind of super thermal insulation materials which could be large-scalely used as building materials. However, the aerogel’s production cost and poor mechanical property limit the its applications. In this paper, we put forward a new low cost way to produce a novel building thermal insulation material: synthesized the aerogel within the expanded perlite’s pores, and using sodium silicate as precursor without adopting supercritical fluid drying and surface modification. The thermal conductivity of expanded perlite was successfully decreased after modified by aerogel.


2019 ◽  
Vol 10 (2) ◽  
pp. 78-91
Author(s):  
A. V Bolotin ◽  
S. M Sergeev ◽  
A. A Lunegova ◽  
E. A Kochetkova

Modern technologies are not standing still, and scientists are trying not only to invent new building materials, but also to find non-standard use of various raw materials that were previously considered unsuitable for use. Innovative technologies are actively used for modern construction of buildings, in particular, some types of new materials are used in the construction of various facilities. This is especially true in areas where it is not possible to import or use ordinary building materials for various reasons. Often, when designing a building, developers are wondering whether it is worth making the house warm during construction, and which insulation for the walls of the house is better to choose. This article addresses the question of which insulation for walls is most suitable for construction. The most common are mineral insulation, which are represented on the market today in the form of basalt slabs, fiberglass, etc. They have such advantages as low thermal conductivity, good thermal insulation and vapor permeability. The article presents a table with comparative performance characteristics of a mineral wool stone slab and a fiberglass slab. Stone or basalt wool has several advantages. It is able to withstand significant temperatures and temperature changes, the mats are easy to transport, convenient to install. In our opinion, a serious alternative to basalt in the production of thermal insulation materials is volcanic ash. One of the main features of volcanic ash are its building qualities, such as good thermal insulation and an environmentally friendly composition. Since here we are considering the possibility of producing insulation materials based on volcanic ash, we performed a thermal calculation of the enclosing structures. Also in the tables are the costs of transportation of volcanic ash from the field to the point of the proposed production of insulating material. Volcanic ash can be widely used in countries with high volcanic activity as an inexpensive raw material for the manufacture of building materials. It does not require additional processing and has a number of useful properties.


2019 ◽  
Vol 8 (4) ◽  
pp. 7692-7694

This article presents theoretical studies on the mathematical modeling of the structure of constructive thermal insulation building materials. The developed principle block is a diagram of the methodology of structural and simulation modeling of cellular concrete.


Author(s):  
Raphaele Malheiro ◽  
Adriana Ansolin ◽  
Christiane Guarnier ◽  
Jorge Fernandes ◽  
Lívia Cosentino ◽  
...  

The building sector plays a significant role in reducing global energy use and carbon emissions. In the European Union (EU), the building stock represents 40% of total energy use and in which cooling and heating systems represent over 50%. Portugal is one of the EU countries where the consequences of energy poverty are most evident due to the families' financial inability to adequately climate their homes. The reasons are several, but they are mainly linked to buildings' poor passive thermal performance, resulting from inadequate adaptation to the climatic context and reduced thermal insulation. Thus, it is necessary to develop solutions to increase buildings’ thermal performance and reduce their potential environmental impact, which arises mainly from the significant use of active systems. In this sense, natural building materials are a promising solution, reducing energy use and carbon emissions related to buildings. This research studies the potential use of reed found in Portugal (Arundo donax) as a thermal insulation material. Its physical characterisation and the influence of geometry configuration on its thermal performance are evaluated. Its durability was studied too. Reed stalks were used to carry out the physical and durability tests. A reed board (150 x 150 mm) was built, and its thermal performance was tested in a hotbox. According to the results, the characteristics of reeds found in Portugal make it suitable to be used as a building material. Furthermore, regardless of the configuration studied, the reeds have a satisfactory thermal performance to be used as thermal insulation, under the requirements defined by Portuguese thermal regulation, Re ≥ 0.30 (m2.oC)/W. There is a trend to the mould growth in the reed, but only under favourable conditions. Additionally, considering the abundance of reed throughout the Portuguese territory, this is an eco-friendly and low-cost option that gathers all requirements to be more used in the construction market.


2014 ◽  
Vol 953-954 ◽  
pp. 710-713
Author(s):  
Zhi Pan Gu ◽  
Yuan Hai Jiang ◽  
Xiang Jiang Zhou ◽  
Jing Liu ◽  
Xiao Yan Wu

This paper has studied using steam injector to recycle waste steam emission from autoclave kettle and it will produce great economic benefits and environmental benefits. Autoclave kettle which is a kind of resistance to high temperature high pressure steam curing equipment, and it’s mainly used for pipe pile, lime-sand brick and aerated concrete production. We will get more technical and economic benefits, if the research results can be popularized and applied in the national building materials products production.


2014 ◽  
Vol 540 ◽  
pp. 213-216
Author(s):  
Chuan Wei Du ◽  
Guo Zhong Li ◽  
Xiao Long Li

In this paper, expanded perlite / fly ash floating beads insulation material was made of expanded perlite, fly ash floating beads, cement, fly ash and VAE emulsion by adding decent additives, like waterproof agent, in the pressure forming process. The effects of molding pressure, VAE emulsion content, fly ash floating beads content and waterproofing agent content on the properties of thermal insulation material were studied, and the internal microscopic morphology of thermal insulation material was observed by SEM. Besides, the related action mechanism was explored. The test results show that the optimum ratio as follows: molding pressure of 0.46 MPa, VAE emulsion content of 20%, fly ash floating beads content of 20%, waterproof agent content of 7%.


2013 ◽  
Vol 539 ◽  
pp. 271-275 ◽  
Author(s):  
Ya Qing Jiang ◽  
Jun Yang ◽  
Yun Chen

Cellular concrete characterizes low mass density and low thermal conductivity is one of the durable and economic wall insulation materials which have good market prospects. The present paper investigated the composition of ternary cementitious materials, mixture design and production process of cellular concrete panel (CCP). Experimental results indicated that a higher compressive strength of CCP may be obtained by blended PⅡ52.5 Portland cement with pulverized low temperature clinker (PLWC) made of water treatment sludge and fly ash in the mass ratio of 0.70: 0.15: 0.15. CCP with dry density of 226 kg/m3, thermal conductivity of 0.056 W/ (m•K), compressive strength of 0.6 MPa and water absorption ratio of 7.6 vol. % was modified by high range water reducer, polypropylene fiber and water resistant agent. Mathematic models for controlling temperature of mixing water and for calculation quantity of gas forming admixture were established. Insulated moulds were specially designed for taking advantage of hydration heat of cement to speed up moulds turnover. Meanwhile, internal microcrack of CCP was avoided. CCP incorporating PLWC and fly ash may be used as external insulation material of walls.


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