scholarly journals Effect of fly ash on the strength of cement paste at early age

2020 ◽  
Vol 61 (HTCS6) ◽  
pp. 10-18
Author(s):  
Dung Trong Nguyen ◽  
Lam Van Tang ◽  
Hung Xuan Ngo ◽  
Phi Van Dang ◽  
Cuong Anh Ho ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Cement Paste ◽  
Power Plants ◽  
Building Materials ◽  
High Efficiency ◽  
Thermal Power ◽  
Early Age ◽  
Technical Specifications ◽  
Mineral Additives

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.

TRACE ELEMENT ANALYSIS OF FLY ASH BY PIXE

1999 ◽  
Vol 09 (03n04) ◽  
pp. 417-422 ◽  
Author(s):  
V. VIJAYAN ◽  
S. N. BEHERA
Keyword(s):  
Fly Ash ◽  
Trace Element ◽  
Power Plants ◽  
Building Materials ◽  
Thermal Power ◽  
Trace Element Analysis ◽  
Chemical Properties ◽  
Solid Material ◽  
Thermal Power Plants ◽  
Element Analysis

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.

RESEARCH OF COMPLEX MODIFICATION OF HEAVY CONCRETE

2021 ◽  
Vol 96 (4) ◽  
pp. 107-112
Author(s):  
YU.S. FILIMONOVA ◽  
◽  
E.G. VELICHKO ◽  
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Power Plants ◽  
High Efficiency ◽  
Thermal Power ◽  
Thermal Power Plants ◽  
Complex Chemical ◽  
Composition And Structure ◽  
Combined Use ◽  
Mineral Additive

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.

scholarly journals CONTRADICTION ASH-AND-SLAG OF TPP

2015 ◽  
Vol 3 (1) ◽  
pp. 53-56
Author(s):  
Кирил Безгласный ◽  
Kiril Bezglasnyy ◽  
Роман Скориков ◽  
Roman Skorikov ◽  
Артем Шаля ◽  
...  
Keyword(s):  
Fly Ash ◽  
Portland Cement ◽  
Power Plants ◽  
Building Materials ◽  
Thermal Power ◽  
Raw Material ◽  
Industrial Scale ◽  
Thermal Power Plants

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

scholarly journals Study on the Properties of Epoxy Composites Using Fly Ash as an Additive in the Presence of Nanoclay: Mechanical Properties, Flame Retardants, and Dielectric Properties

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Tuan Anh Nguyen ◽  
Thi Mai Huong Pham
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Power Plants ◽  
Flame Retardants ◽  
Thermal Power ◽  
Impact Resistance ◽  
Fire Retardant ◽  
Dielectric Strength ◽  
Flame Retardant Properties ◽  
Main Factor

Small and light fly ash is a by-product of thermal power plants, in which oxides mainly present in fly ash are suitable to reinforce composite materials. Its content accounts for 10, 20, 30, 40, and 50% of those materials. However, due to the smooth surface, it cannot stick completely in plastics. Therefore, in this work, it was studied to combine nanoclay additive (I.30 E) with 1, 3, and 5% by weight to synergize to improve mechanical strength, fire retardation, and electrical properties. Mechanical properties and flame retardant properties have improved markedly. At the combined ratio of 40% by weight of fly ash and 3% nanoclay, nanocomposites have tensile strength values of 64.12 MPa, flexural strength of 89.27 MPa, compressive strength of 215.23 MPa, and impact resistance of Izod 14.45 kJ/m2, oxygen index limited to 26.8% of fire retardant material. In terms of dielectric strength, the electric strength of pure epoxy is 17.5 kV/mm, higher than that before adding nanoclay (12.7 kV/mm). The presence of nanoclays in the material creates a tortuous electric path, slowing the propagation of the power plant, which is the main factor that improves the breaking strength of the nanocomposite.

scholarly journals CHALLENGES AND OPPORTUNITIES OF UTILIZATION OF ASH AND SLAG WASTE OF TPP (THERMAL POWER PLANT). PART 1

2018 ◽  
Vol 61 (6) ◽  
pp. 439-446 ◽  
Author(s):  
G. S. Podgorodetskii ◽  
V. B. Gorbunov ◽  
E. A. Agapov ◽  
T. V. Erokhov ◽  
O. N. Kozlova
Keyword(s):  
Fly Ash ◽  
Power Plants ◽  
Building Materials ◽  
Thermal Power ◽  
Far East ◽  
Organizational Factors ◽  
Coal Industry ◽  
Ash And Slag Waste ◽  
Slag Waste ◽  
Extraction Of Metals

 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.

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
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Bulk Density ◽  
Power Plants ◽  
Building Materials ◽  
Thermal Power ◽  
Joint Stock Company ◽  
Mixture Ratio ◽  
Lightweight Material ◽  
Optimal Mixture Ratio

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.

Recycling of Fly Ash as an Energy Efficient Building Material: A Sustainable Approach

2016 ◽  
Vol 692 ◽  
pp. 54-65
Author(s):  
Mohammad Arif Kamal
Keyword(s):  
Fly Ash ◽  
Building Material ◽  
Power Plants ◽  
Building Materials ◽  
Construction Material ◽  
Thermal Power ◽  
Raw Material ◽  
Geopolymer Concrete ◽  
Promising Alternative ◽  
Resource Material

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.

scholarly journals Investigation of fly ash properties with purpose of its utilization as a secondary raw material for portland cement clinker production

2006 ◽  
Vol 60 (9-10) ◽  
pp. 245-252 ◽  
Author(s):  
Zvezdana Bascarevic ◽  
Miroslav Komljenovic ◽  
Ljiljana Petrasinovic-Stojkanovic ◽  
Natasa Jovanovic ◽  
Aleksandra Rosic ◽  
...  
Keyword(s):  
Fly Ash ◽  
Portland Cement ◽  
Power Plants ◽  
Building Materials ◽  
Thermal Power ◽  
Cement Industry ◽  
Raw Material ◽  
Cement Clinker ◽  
Physical Chemical ◽  
Portland Cement Clinker

In this paper the results of the investigated properties of fly ash from four thermal power plants in Serbia are presented. The physical, chemical, mineralogical and thermal characterization of fly ash was carried out, in order to determine the possibility to utilize this material in the building materials industry, foremost in the cement industry. It was determined that, although there are differences concerning the physical, chemical, and mineralogical characteristics of the investigated samples, they are very similar concerning their thermal characteristics. It was concluded that using fly ash as one of the raw components in the mixture for Portland cement clinker synthesis, not only enables the substitution of natural resources, but it might have a positive effect on the lowering of the sintering temperature.

Leaching Behavior and Immobilization of Heavy Metals in Geopolymer Synthesized from Red Mud and Fly Ash

2018 ◽  
Vol 777 ◽  
pp. 518-522 ◽  
Author(s):  
Hoc Thang Nguyen ◽  
Thu Ha Bui ◽  
Vo Thi Ha Quyen Pham ◽  
Minch Quang Do ◽  
Minh Duc Hoang ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Fly Ash ◽  
Red Mud ◽  
Industrial Waste ◽  
Power Plants ◽  
Building Materials ◽  
Negative Impact ◽  
Raw Materials ◽  
Thermal Power ◽  
Aluminum Production

Fly ash is an industrial waste from coal-fired thermal power plants whereas red mud is an industrial waste generated during aluminum production from bauxite. If both fly ash and red mud are not properly managed, they could cause negative impact on the environment. This study utilized red mud and fly ash in combination with sodium silicate solution to produce a geopolymer-based material which can be used as building materials. This study focussed on the leachability of heavy metals in the raw materials and the geopolymer as this would be significant in assessing the environmental impact of the product. Leachability of heavy metals such as Cu, Zn, Cd, Pb, Fe, and Cr was evaluated based on European standard (EN 124572 – 2, EU CEN TC292/ CEN TC 308) with pH values at 7. The results showed that raw materials (red mud and fly ash) have higher leachability than geopolymer specimens. And the values of leaching tests for heavy metals in the geopolymer - based materials belonged to limits of EULFD and USEPA.

Research of Physical and Mechanical Properties of Fly Ash Ceramics with SiO2 and Al2O3 Nanoparticles as Functional Addition

2021 ◽  
Vol 887 ◽  
pp. 528-535
Author(s):  
V.A. Kalneus ◽  
D.A. Nemushchenko ◽  
V.V. Larichkin ◽  
A.A. Briutov
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Water Absorption ◽  
Power Plants ◽  
Bending Strength ◽  
Thermal Power ◽  
Physical And Mechanical Properties ◽  
Ultimate Compressive Strength ◽  
Glass Waste

The article analyses the influence of SiO2 and Al2O3 nanopowders on properties of ceramics consisting of fly ash from thermal power plants, glass waste, and clay binder. Based on studies of physical and mechanical properties of the obtained ceramics (ultimate compressive strength, ultimate three-point bending strength, wear resistance, and water absorption), the paper shows the positive influence of the nanoadditives. The optimal number of SiO2 and Al2O3 nanopowders in the formulation is 0.5 wt. % that has the strongest effect on ultimate compressive strength and water absorption of the fly ash ceramics samples. The direction of further research on improving the properties of ceramic products is an application of the Al2O3 nanopowder as more perspective nanoadditive using clay dispersant.

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