Characterization of various fly ashes for preparation of geopolymers with advanced applications

2013 ◽  
Vol 24 (2) ◽  
pp. 495-498 ◽  
Author(s):  
Jadambaa Temuujin ◽  
William Rickard ◽  
Arie van Riessen
Keyword(s):  
Fly Ashes ◽  
Advanced Applications

Electrokinetic Phenomena and Surface Characteristics of Fly Ash Particles

1984 ◽  
Vol 43 ◽  
Author(s):  
R. I. A. Malek ◽  
D. M. Roy
Keyword(s):  
Fly Ash ◽  
Surface Characteristics ◽  
Ionic Species ◽  
Point Of Zero Charge ◽  
Fly Ashes ◽  
Electrokinetic Phenomena ◽  
Zeta Potentials ◽  
Low Calcium ◽  
High Calcium

AbstractThe zeta-potentials of two fly ashes were studied (high-calcium and low-calcium). It was found that they possess a point of charge reversal at pH = 10.5 to 12. The point of zero charge (low-calcium fly ash) was found to be at pH = 5. Furthermore, it shifted to more acidic values after the fly ash is aged in several calcium-containing solutions. The surficial changes that could happen when mixing fly ashes with cement and concrete were further evaluated by aging fly ashes in different solutions: Ca(OH)2, CaSO4·2H2O, NaOH and water solutions. Information from analyses for different ionic species in the solutions and characterization of the solid residues (XRD and SEM) was used in tentative explanations for the different behavior of the two types of fly ash in cementitious mixtures and concrete.

Characterization of Polymer-Ceramic Nanocomposites for Advanced Applications

2021 ◽  
pp. 139-154
Author(s):  
Kiran Sunku ◽  
Satesh Gangarapu ◽  
Mohd Rafie Johan ◽  
Putla Sudarsanam
Keyword(s):  
Advanced Applications ◽  
Ceramic Nanocomposites

Image Analysis of Fly Ash in the Characterization of the Shape of the Grains

1994 ◽  
Vol 370 ◽  
Author(s):  
M. Barrioulet ◽  
H. Cros ◽  
B. Husson ◽  
E. Ringot
Keyword(s):  
Image Analysis ◽  
Fly Ash ◽  
Mineralogical Composition ◽  
Fly Ashes ◽  
Particle Content ◽  
Power Stations ◽  
Fresh Material ◽  
Quantitative Image ◽  
Strength And Durability

AbstractFly ash from power stations is used as concrete additive to improve strength and durability. Surprisingly, studies of ashes of identical mineralogical composition from two different places have reported different results in terms of the rheological properties of the fresh material. The viscosity of the pastes made from these different fly ashes seems to be linked to the proportion of spherical and smooth-shaped grains found in them. A quantitative image analysis was carried out to characterize the shape of the grains of these two ashes from different geographical origins. The main result proves that the higher the glassy particle content of the fly ash, the more the hydraulic matrix is fluid.

Characterization of Fly Ash Reactivity by Isothermal Conduction Calorimetry

1987 ◽  
Vol 113 ◽  
Author(s):  
David J. Cook ◽  
H. Trinh Cao ◽  
Daksh Baweja
Keyword(s):  
United Kingdom ◽  
Fly Ash ◽  
Performance Prediction ◽  
The United States ◽  
Fly Ashes ◽  
Structural Concrete ◽  
Codes Of Practice ◽  
The United Kingdom ◽  
Direct Reflection

SUMMARYThe reactivity of fly ash is generally difficult to determine because neither a single physical nor chemical property nor any combination of these can be used characterize a particular sample completely. A direct reflection of this is the range of pozzolanicity tests proposed by standards worldwide and the applicability and relevance of such tests is currently being debated.In many countries, codes of practice and standards relating to fly ashes are currently under review. Some work has been carried out in countries including Australia, United Kingdom, and the United States on commercial fly ashes with a view to possible classification and implementation into standards [1-2]. It is generally recognized that current standards on fly ash do have some inadequacies with regard to performance prediction when included in concrete. Fineness requirements for fly ash for use in structural concrete (BS3892: Part 1) in the United Kingdom are currently being debated [2] with many workers suggesting that it would be possible to produce durable concrete with ashes which would not comply with the requirements of the standard [3].

Characterization of North American Lignite Fly Ashes II. XRD Mineralogy

1987 ◽  
Vol 113 ◽  
Author(s):  
G. J. McCarthy ◽  
D. M. Johansen ◽  
A. Thedchanamoorthy ◽  
S. J. Steinwand ◽  
K. D. Swanson
Keyword(s):  
Fly Ash ◽  
Bituminous Coal ◽  
Coal Fly Ash ◽  
Fly Ashes ◽  
X Ray ◽  
Mining Areas ◽  
Lignite Fly Ash ◽  
Coal Fly Ashes ◽  
Ferrite Spinel

ABSTRACTX-ray powder diffraction has been used to determine the crystalline phase mineralogy in samples of fly ash from each of the lignite mining areas of North America. The characteristic phases of North Dakota lignite fly ashes were periclase, lime, merwinite and the sulfate phases anhydrite, thenardite and a sodalite-structure phase. Mullite was absent in these low-Al2O3 ashes. Montana lignite ash mineralogy had characteristics of ND lignite and MT subbituminous coal fly ashes; mullite and C3A were present and the alkali sulfates were absent. Texas and Louisiana lignite fly ashes had the characteristic mineralogy of bituminous coal fly ash: quartz, mullite, ferrite-spinel (magnetite) and minor hematite. Even though their analytical CaO contents were 7–14%, all but one lacked crystalline CaO-containing phases. Lignite fly ashes from Saskatchewan were generally the least crystalline of those studied and had a mineralogy consisting of quartz, mullite, ferrite spinel and periclase. Quantitative XRD data were obtained. The position of the diffuse scattering maximum in the x-ray diffractograms was indicative of the glass composition of the lignite fly ash.

Physico-chemical characterization of crystalline phases in fly ashes

1994 ◽  
Vol 114-115 (1) ◽  
pp. 397-404 ◽  
Author(s):  
Luigi Paoletti ◽  
Marco Diociaiuti ◽  
Antonio Gianfagna ◽  
Giuseppe Viviano
Keyword(s):  
Chemical Characterization ◽  
Fly Ashes ◽  
Crystalline Phases ◽  
Physico Chemical
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