The CaO distribution to mineral phases in a high calcium …

1996-2-1 · The distinguishing feature of high-calcium oil shale fly ash (HCOSFA) used in experiments is the high amount of free CaO and SO{sub 3} in form of lime and anhydrite. Strength development as well as the microstructure and composition of the new formations of fly ash binder (FAB) based on HCOSFA and low-calcium coal fly ash after curing in ...

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Stabilisation of clayey soils with high calcium fly ash and …

2005-2-1 · Abstract. The effectiveness of using high calcium fly ash and cement in stabilising fine-grained clayey soils (CL,CH) was investigated in the laboratory. Strength tests in uniaxial compression, in indirect (splitting) tension and flexure were carried out on samples to which various percentages of fly ash and cement had been added.

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The effect of high-calcium fly ash on selected properties of …

Low-calcium (FA) and high-calcium (HCFA) fly ash and granulated blast furnace slag (GBFS) are the most widely known, standardized and used SCMs in the composition of cement and concrete.

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High calcium fly ash geopolymer for application in textile …

2021-10-25 · This research involves a preliminary study of high calcium fly ash (HCFA) geopolymer and exploring the potential for textile reinforced mortar (TRM) application. The properties of the HCFA geopolymer added with styrene-butadiene rubber (SBR) were compared with normal cement mortar.

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The hydraulic activity of high calcium fly ASH | SpringerLink

2006-2-3 · Cementitious mixtures with so-called high calcium fly ash show better strength parameters as compared to the ones with conventional siliceous fly ash. This practical feature is the consequence of improved hydraulic activity. Differential thermal analysis and thermogravimetry were used, together with the other methods, to evaluate the reactivity of …

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Neutralization and Dissolution of High‐Calcium Fly Ash

The neutralization reaction for each fly ash showed three distinct buffer zones: a high-pH region (pH 12.0-10.5) accompanied by dissolution of Ca, a second region (pH 9.2-8.5) with the concomitant dissolution of Mg, and a third region (below pH 4.2), in which Al was released from the fly-ash matrix.

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Crystal Growth on Cenospheres from High-Calcium Fly Ash

2021-7-19 · This work presents a study of cenosphere separation from lignite high-calcium (~24 wt.%) fly ash by centrifugal method; this is the first report for Mae Moh, Thailand, fly ash with this high calcium content using this technique. The effect of centrifugal parameters on cenosphere yield and properties were investigated. Those properties include physical properties, …

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Mineralogy and Chemical Composition of High-Calcium …

2019-12-12 · To understand the formation mechanism of high-calcium fly ashes, the mineralogical, physical, and chemical properties of several high calcium fly ashes and their different density fractions (<1.0, 1.0−2.5, 2.5−2.89, and >2.89 g/cm3) from a coal-fired power plant were characterized by X-ray diffractometry (XRD), field scanning electron microscopy …

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High-Strength Geopolymer Using Fine High-Calcium Fly Ash

The effect of fineness of fly ash on the setting time of geopolymer paste, workability, strength development, and drying shrinkage of geopolymer mortars made from classified fine high-calcium fly ash was investigated. Air-classified fly ash with three different finenesses—coarse original fly ash (CFA), medium-fineness fly ash (MFA), and fine ...

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The Investigation on Setting Time and Strength of High …

Fly ash based geopolymer normally gets the optimum strength by heat curing. This is considered as a hindrance to in-situ applications. Therefore, development of fly ash based geopolymer that suitable for ambient curing will widen the application to the concrete structure. This paper reports the results of an experimental study on setting time and development of compressive strength …

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7 Utilizing high calcium fly ash in cementless precast …

Fly ash is classified as either class C or class F according to its chemical composition of Silica (Si), Alumina (Al) and Calcium (Ca). In Thailand, most of the fly ash is a by-product from the lignite coal-fired Mae Moh power station in Lampang Province. This fly ash contains a relatively high calcium oxide (Ca2+) content, typically around 12-25%

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Effect of calcium nitrite on high-performance concrete …

Characteristics of fly ash in Hong Kong and the durability of concrete for coastal and offshore engineering Author(s): Ma, Baoguo; Qi, Meng; Li, Zongjin 1999 ; Investigation of chloride diffusion for high-performance concrete containing fly ash, microsilica and chemical admixtures

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The fine high-calcium fly ash as the basis of composite

The fine high-calcium fly ash (d90 < 10 microns) selected from the fourth field of electrostatic precipitator was the source for high strength specimens. In the composition with a superplasticizer at a water:binder ratio of W/B = 0.25 the specimens were made and then cured from 1 to 120 days, with their compressive strength increasing from 17 ...

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Water | Free Full-Text | Investigation of Metal and Trace …

2021-8-17 · High-calcium fly ashes contain a large content of small particles including cenospheres of chemical constituents known to be similar to fly ash and the parent coal. Coal fly ash contains metal and trace elements that may leach out during disposal or utilization. This work aimed to understand an overview of cenosphere characteristics relating to fly ash and leaching …

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Evaluation of the Chemical and Mechanical Properties of …

High-calcium fly ash (FH) is the combustion residue from electric power plants burning lignite or sub-bituminous coal. As a mineral admixture, FH can be used to produce high-strength concrete and high-performance concrete. The development of chemical and mechanical properties is a crucial factor for appropriately using FH in the concrete industry.

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Fresh and Hardened Properties of High Calcium Fly Ash …

2019-12-23 · The results of the XRF test are reported in Table 3.Both fly ash samples were found to be high calcium fly ash (class C), with total content of SiO 2 + Al 2 O 3 + Fe 2 O 3 of 67.8% and 66.29% for FA1 and FA2, respectively, and the CaO level of more than 10% and with a very low loss on ignition (LOI) value. FA2 has higher CaO content than FA1.

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Crystal Growth on Cenospheres from High-Calcium Fly Ash

2021-8-7 · This work presents a study of cenosphere separation from lignite high-calcium (~24 wt.%) fly ash by centrifugal method; this is the first report for Mae Moh, Thailand, fly ash wit

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The use of a non-standard high calcium fly ash in concrete …

The use of a non-standard high calcium fly ash in concrete and its response to accelerated curing. July 2002; Materiales de Construcción 2002(267)

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Effects of calcium leaching from high volume fly ash …

Ponloa, W., Sajjavanich, S. Materials Today: Proceedings. 2018. 9453-9460

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Study on the Performances of the Mixture of High Calcium …

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Leaching characteristics of a high-calcium fly ash as a …

Abstract. Using a modified extraction procedure, the effect of pH on the leaching of selected elements from Ca-rich (Type C) power plant fly ash was studied. Continuous additions of acetic acid were used to maintain pH values of fly ash slurries at 4.0, 6.0 and 8.0 for 24 h and an additional set was leached at its natural pH (average 11.8) value.

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High-calcium fly ash recovery from wet-stored condition …

2018-9-7 · This work reports on an investigation of changes in physical and chemical properties of high calcium fly ash after recovering from the wet-stored conditions. Herein the high calcium lignite fly ash with calcium oxide constituent in a range of 20%–30% is the focus of this study. Important characteristics of fly ash have been studied, including ...

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Properties of lightweight high calcium fly ash

2015-9-30 · Chemical compositions of fly ash determined using X-ray fluorescence (XRF) technique are shown in Table 1 and its X-ray diffraction (XRD) is shown in Fig. 2. The sum of SiO 2, Al 2 O 3 and Fe 2 O 3 was over 75% which was in accordance which ASTM C618, however, the CaO content was high indicating a high calcium fly ash. The XRD analysis showed ...

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Fresh properties and compressive strength of high calcium al…

Properties of lightweight high calcium fly ash geopolymer

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Fresh properties and compressive strength of high calcium …

2017-10-1 · However, the ASTM C618-15 (Standard Specification for Coal Fly Ash and Raw or Calcined Natural Pozzolan for Use in Concrete, 2015) does not consider the calcium content in fly ash classification. Other standard such as the CSA A3001 uses a different approach for classification of fly ash based on the calcium oxide content.

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(PDF) The use of a non-standard high calcium fly ash in …

The use of a non-standard high calcium fly ash in concrete and its response to accelerated curing. Materiales de Construcción, 2002. Cengiz Atis. Download Download PDF. Full PDF Package Download Full PDF Package.

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Setting Time, Strength, and Bond of High-Calcium Fly Ash …

The results indicated that fresh geopolymer concrete had short setting time of 28–58 min due to the presence of high calcium content of fly ash. In general, strengths and modulus of elasticity increased with the increase in NaOH concentration. For compressive strength, the optimum Na 2 O content was around 12% of fly ash. The high-strength ...

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USING MINERAL ADDITIONS TO IMPROVE PROPERTIES …

2015-7-7 · Therefore, a study was undertaken to investigate the ways to improve the properties of high calcium fly ashes some of which could also be non-standard. In this part of the study other mineral additions such as silica fume, ground sand and ground glass were mixed with the high-calcium fly ash at various proportions to improve its properties.

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