scholarly journals Use fly ash for the production of lightweight building materials

2021 ◽  
Vol 43 (3) ◽  
Author(s):  
Lan Tran Thi ◽  
Duong Nguyen Anh ◽  
Anh Phan Luu ◽  
Man Tran Thi

Fly ash is a waste byproduct of thermal power plants or steel plants with a low density. Study on using fly ash to produce lightweight construction materials will is a new application of this material resource. Pha Lai fly ash is a byproduct from Pha Lai Thermal Power Joint Stock Company, in which the main mineral component was mullite (15-20%), quartz (14-16%), carbon (5-7%). The content of the amorphous component was about 67-73%. The chemical composition of Pha Lai mainly was SiO2 (51.73%), Al2O3 (23.22%), Fe2O3 (4.23%). To fabricate the lightweight material from Pha Lai fly ash, the fly ash was mixed with additive materials to create binders following two ways: (1) lime + fly ash and (2) geopolymer technology. For the way of lime + fly ash, with the optimal mixture ratio was fly ash:lime: water = 10:2:1, the lightweight material samples had the bulk density of 1.32g/cm3, the compressive strength of 3.91 MPa, satisfied the Vietnamese standard TCVN 6477-2011 for concrete bricks. Applying the geopolymer technology, with the optimal mixture ratio was fly ash: NaOH/Na2SiO3: Al powder = 100:45:0.15, NaOH/Na2SiO3 ratio = 1:2, the lightweight materials obtained the bulk density of 0,62g/cm3, the compressive strength of 1,54 MPa, satisfied the Vietnamese standard TCVN:9029-2017 for Lightweight concrete - Foam concrete and non-autoclaved concrete products-specification.

1999 ◽  
Vol 09 (03n04) ◽  
pp. 417-422 ◽  
Author(s):  
V. VIJAYAN ◽  
S. N. BEHERA

Fly ash is a major component of solid material generated by the coal-fired thermal power plants. In India the total amount of fly ash produced per annum is around 100 million tonnes. Fly ash has a great potential for utilization in making industrial products such as cement, bricks as well as building materials, besides being used as a soil conditioner and a provider of micro nutrients in agriculture. However, given the large amount of fly ash that accumulate at thermal power plants, their possible reuse and dispersion and mobilization into the environment of the various elements depend on climate, soils, indigenous vegetation and agriculture practices. Fly ash use in agriculture improved various physico-chemical properties of soil, particularly the water holding capacity, porosity and available plant nutrients. However it is generally apprehended that the application of large quantity of fly ash in fields may affect the plant growth and soil texture. Hence there is a need to characterize trace elements of fly ash. The results of trace element analysis of fly ash and pond ash samples collected from major thermal power plants of India by Particle Induced X-ray Emission (PIXE) have been discussed.


2021 ◽  
Vol 323 ◽  
pp. 8-13
Author(s):  
Jadambaa Temuujin ◽  
Damdinsuren Munkhtuvshin ◽  
Claus H. Ruescher

With a geological reserve of over 170 billion tons, coal is the most abundant energy source in Mongolia with six operating thermal power stations. Moreover, in Ulaanbaatar city over 210000 families live in the Ger district and use over 800000 tons of coal as a fuel. The three thermal power plants in Ulaanbaatar burn about 5 million tons of coal, resulting in more than 500000 tons of coal combustion by-products per year. Globally, the ashes produced by thermal power plants, boilers, and single ovens pose serious environmental problems. The utilization of various types of waste is one of the factors determining the sustainability of cities. Therefore, the processing of wastes for re-use or disposal is a critical topic in waste management and materials research. According to research, the Mongolian capital city's air and soil quality has reached a disastrous level. The main reasons for air pollution in Ulaanbaatar are reported as being coal-fired stoves of the Ger residential district, thermal power stations, small and medium-sized low-pressure furnaces, and motor vehicles. Previously, coal ashes have been used to prepare advanced materials such as glass-ceramics with the hardness of 6.35 GPa, geopolymer concrete with compressive strength of over 30 MPa and zeolite A with a Cr (III) removal capacity of 35.8 mg/g. Here we discuss our latest results on the utilization of fly ash for preparation of a cement stabilized base layer for paved roads, mechanically activated fly ash for use in concrete production, and coal ash from the Ger district for preparation of an adsorbent. An addition of 20% fly ash to 5-8% cement made from a mixture of road base gave a compressive strength of ~ 4MPa, which exceeds the standard. Using coal ashes from Ger district prepared a new type of adsorbent material capable of removing various organic pollutants from tannery water was developed. This ash also showed weak leaching characteristics in water and acidic environment, which opens up an excellent opportunity to utilize.


2021 ◽  
Vol 96 (4) ◽  
pp. 107-112
Author(s):  
YU.S. FILIMONOVA ◽  
◽  
E.G. VELICHKO ◽  

Modification of the composition and structure of heavy concrete with the use of a complex chemical-mineral additive consisting of fly ash from thermal power plants, a superplasticizer, a high-valence hardening accelerator AC and a fine-dispersed clinker component is considered. Modified concrete is characterized by an increase in compressive strength at a brand age by 67%, a decrease in the water content of a concrete mixture by 13.6% and an improvement in its workability by 11-12 cm. With the combined use of a superplasticizer and a high-valence hardening accelerator AC a significant synergistic effect is observed in the format of enhancing their plasticizing effect. The high efficiency of the application of the mixed-dispersed clinker component has been established.


Technobius ◽  
2021 ◽  
Vol 1 (3) ◽  
pp. 0003
Author(s):  
Aliya Aldungarova ◽  
Kapar Aryngazin ◽  
Vladimir Larichkin ◽  
Assem Abisheva ◽  
Kamilla Alibekova

The paper describes the technology of manufacturing a construction product by vibrocompression using ash and slag waste from thermal power plants in the Pavlodar region. The task of the experimental research was to obtain a hollow wall stone based on ash and slag waste with a strength grade that is not inferior to products made according to the traditional recipe. The obtained samples with different ratios of components in the mixture were investigated for compressive strength, moisture absorption, frost resistance. It has been established that when ash and slag waste are added to the composition of the concrete mixture in an amount of up to 35 % of the mass of dry components, the strength characteristics of the hollow wall stone correspond to the selected brand


2015 ◽  
Vol 3 (1) ◽  
pp. 53-56
Author(s):  
Кирил Безгласный ◽  
Kiril Bezglasnyy ◽  
Роман Скориков ◽  
Roman Skorikov ◽  
Артем Шаля ◽  
...  

This article shows the obstacles of using thermal power plant’s ash waste on an industrial scale. The results of determining the activity of fly ash and hydroremoval ash in a mixture with Portland cement are given. Schemes of translation ash from the category of waste with heterogeneous characteristics in the raw material with stable properties are offered. The most rational ways of using ash from thermal power plants in building materials are presented


2016 ◽  
Vol 865 ◽  
pp. 201-205 ◽  
Author(s):  
Michaela Fiedlerová ◽  
Rostislav Drochytka ◽  
Pavel Dohnálek

This paper deals with the evaluation of a partial replacement of cement by Czech fly ash in high strength floor screed in dosage of 10, 20, 30 and 40% and the assessment of the physical-mechanical properties such as compressive strength, water absorption and bulk density. Used fly ashes are from power plants Počerady, Opatovice and Tušimice. The experimental study showed that the use of Czech fly ash improves the compressive strength. The bulk density decreases and therefore water absorption increases. Reference samples become clearly the lowest compressive strength at age of 28 days (fc28). A significant increase in compressive strength (fc28) was observed in case of mix design with addition of 10% and 20% of fly ash Tušimice (10%ETU, 20%ETU) and 20% and 30% of fly ash Počerady (20%EPC, 30%EPC). The addition of 20% of fly ash Počerady (20%EPC) has noticeable influence on short-term compressive strength (measured at the age of 24 hours).


Author(s):  
Nitish Kumar

Abstract: In India, major part of electricity is produced from thermal power plants. These thermal power plants use different types of fuels for combustion. During combustion of coal as a fuel in these thermal power plants, a byproduct namely fly ash is produced. Indian coal has highest ash content as compared to coal found in other countries. There are nearly 85 thermal power plants in India which uses coal as source for power generation and thus produces a large amount of fly ash. This fly ash is disposed in soil, which in turn causes a lot of environmental problems. To overcome this disposal of fly ash into the soil, it can be used in concrete by partially replacing with cement. This study deals with investigation for M25 Grade of newlineconcrete to study the mechanical properties of Steel fiber reinforced concrete newline(SFRC) containing fiber of an interval of 0.5% from 0.0% to 2.0% by new line weight of cement. In this study are steel fibres are used and compare properties with conventional concrete. In this study we are casting 6 cubes and 6 cylinders out of which 2 each for 7, 14, 28 days. Keywords: Steel fibres, Cement and Compressive Strength, GGBS, Fly Ash, SFRC, Cement, Compressive Strength, Split Tensile Strength


2018 ◽  
Vol 61 (6) ◽  
pp. 439-446 ◽  
Author(s):  
G. S. Podgorodetskii ◽  
V. B. Gorbunov ◽  
E. A. Agapov ◽  
T. V. Erokhov ◽  
O. N. Kozlova

 The further development of the Russian coal industry, especially in the regions of Siberia and the Far East, in line with the  Energy Strategy, predetermines the need to address the problem of  utilization of ash and slag wastes in newly implemented projects.  The total amount of ash and slag in the ash dumps in Russia is more  than 1.5  billion tons, and the area occupied by fly ash and slag wastes  (FASW) is more than 220 km2. At the same time, the degree of FASW  use does not exceed 10  %. It is shown that the main solutions for the  recycling of the industrial solid waste generated by thermal power  plants are their use in the production of building materials, road construction, or the complex processing of FASW with the extraction  of metals and the production of building mate rials either. Some fly  ash can be used in agriculture. The physicochemical properties of  fly ash and slag wastes and, accordingly, the directions of their use,  as well as the choice of technology, are determined by the mineral  part of the fossil coals and the way they are burned. To use fly ash in  the construction industry, it is necessary to transfer the ash removal  system to the dry method, accompanied, on the one hand, by a large  volume of capital investments in equipment and facilities for storage,  classification, crushing and grinding, the transfer of new physical and  chemical properties to fly ash and slag waste, and on the other side,  an increase in organizational and transport barriers. Examples of proposed technologies for utilization of ash and slag wastes in the form of metal recovery and production of building materials are given. To  obtain iron-containing concentrates, one-stage magnetic separation  is used, but the quality of the concentrate does not meet modern requirements. The most technologically effective for the extraction of  metals from ash and slag wastes are technologies based on flotation  methods. At the same time, it follows from the provided data that  their application can be limited to economic, organizational factors  and the emergence of new environmental risks. The conclusion is  made on the possibility of using the above technologies for existing  coal-fired power plants only with state support.


2020 ◽  
Vol 61 (HTCS6) ◽  
pp. 10-18
Author(s):  
Dung Trong Nguyen ◽  
Lam Van Tang ◽  
Hung Xuan Ngo ◽  
Phi Van Dang ◽  
Cuong Anh Ho ◽  
...  

In Vietnam, thermal power plants produce millions of tons of fly ash per year and cause a lot of problems for the environment. The re-use of fly ash as mineral additives in the production of building materials such as cement, concrete etc is a comprehensive solution that brings high socio-economic efficiency. However, to achieve high efficiency, the technical specifications index of fly ash needs to be studied and evaluated in detail because the content of added fly ash is very important for producing and manufacturing processes. This paper aims to study the influence of Formosa fly ash on the mechanical properties at the early age of cement paste. The mechanical properties of the samples which contain alternatively 10÷30% of fly ash was measured at the early ages (1, 3, and 7 days) by experimental methods. In addition, the microstructure analysis and differential thermal analysis methods have been used to interpret the obtained results.


2016 ◽  
Vol 692 ◽  
pp. 54-65
Author(s):  
Mohammad Arif Kamal

Fly Ash, known for its proven stability for variety of applications as admixture in cement, concrete, mortar, lime pozzolan mixture (bricks. blocks) etc, is an industrial by-product from Thermal Power Plants with current annual generation of approximately 108 million tones. Fly Ash is not just environment friendly, but is known for its cost effectiveness as well. Its use as a building material helps increase buildings strength and stability. Fly Ash is believed to be a very promising alternative for the industry seeking to meet its development objectives. Fly Ash is being very effectively and economically used in building components such as bricks, doors, door-frames, etc. Fly Ash is also being used in construction of roads and embankments with some design changes. It is also used as raw material in agricultural and wasteland development programmes. The trend is clear, Fly Ash will soon be considered as a resource material and its potential will be fully exploited. Through development & application of technologies, Fly Ash has shifted from “Waste Material” category to “Resource Material” category. The purpose of this paper is to provide an overview of disposal and utilization of Fly Ash and its beneficial potential in application of civil engineering construction as well as others. The focus of this paper is to explore the properties of fly ash as building materials and also aims at the properties of geopolymer concrete, how these distinguish from general characteristics of ordinary Portland cement. It also lay emphasize on durability, properties of fly ash based geopolymer concrete and its advantage when used as a construction material as well.


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