##tihuan2##An optional requirement for Class F fly ash is to limit its alkali content to 1.5% maximum. Class C fly ash, which has usually higher lime (CaO) content than Class F, is considered less effective to prevent ASR unless a higher replacement of cement is used. ASTM C441 is used to evaluate fly ash with a 75% reduction in expansion at 14 …
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##tihuan2##Using fly ash in concrete reduces cracking, permeability, and bleeding, creating a dense, high-durability concrete that is resistant to …
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##tihuan2##This paper reports the compaction and strength properties of fly ash activated with different concentrations of lime, cement, and alkali solution. The lime and cement content has …
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##tihuan2##Sodium and potassium are the common alkalis present in fly ash. Excessive amounts of fly ash alkalis can cause efflorescence problems in concrete products and raise …
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##tihuan2##While increasing the alkali-activated fly ash content in concrete, the fresh property of the SCC increased in terms of flowability and workability with no addition of more water. It resulted in an increase in the passing and flow capability of concrete to 11 s for 10% fly ash, 9 s for 15% fly ash, 6 s for 20% fly ash, 7 s for 25% fly ash, and 6 ...
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##tihuan2##Fly ash, especially Class F fly ash, is effective in three ways in substantially reducing alkali-silica expansion: 1) it produces a denser, less permeable concrete; 2) when used as a cement replacement it reduces total alkali content by reducing the Portland cement; and 3) alkalis react with fly ash instead of reactive silica aggregates.
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##tihuan2##The degree of reactivity, formulated through the integration of reaction volume and amorphous silica-aluminum content, was identified as a robust predictor of …
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##tihuan2##In this study, municipal solid waste incineration (MSWI) fly ash was subjected to mineral carbonation with the aim of investigating CO2 sequestration in waste material. The conducted study follows the trend …
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##tihuan2##Alkali-activated materials (AAMs) have high potential as alternative binder to ordinary portland cement (OPC), because of their high performance beside lower CO2 emissions.
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##tihuan2##In alkali-activated fly ash, the dominant gel is N–A–S–H, whereas alkali-activated slag exhibits a structure primarily dominated by C–A–S–H gel. ... The effects of ground granulated blast-furnace slag blending with fly ash and activator content on the workability and strength properties of geopolymer concrete cured at ambient ...
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##tihuan2##Abstract Fly ash is a by-product of coal-fired power plants and a rich source of aluminosilicate. This paper reports the compaction and strength properties of fly ash activated with different concentrations of lime, cement, and alkali solution. The lime and cement content has been varied as 0, 2.5, 5, 7.5, and 10% of dry weight
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##tihuan2##Alkali-activated lime fly ash pastes with high levels of fly ash in an alkali-activated system have been described by Shi (Citation 1996a, Citation 1996b). The alkali activation catalysis of hydration reaction in slags (which contain about 50% calcium) is reported with and without fly ash (Soong et al. Citation 2006 ).
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##tihuan2##The fly ash had a much higher alkali content (4.27% Na 2 O eq). Though, due to their low solubility, alkalis in fly ash were not expected to significantly contribute to the ASR reactions and the associated expansion [10, 35]. Aggregates were composed of either inert pea gravel with a maximum size of 10 mm, reactive sand with a fineness …
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##tihuan2##Fly ash (FA) is mainly composed of silica, alumina, and other metal oxide components, and has a positive stabilizing effect on soil heavy metals. Biochar composites produced from FA and corn stover (CS) can improve its remediation performance. Therefore, a batch of biochar composites (alkali-fused F …
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##tihuan2##1. Introduction. Alkali-activated materials (AAMs), manufactured by the reaction between alkaline activator and solid aluminosilicate powders, i.e. fly ash (FA), ground granulated blast furnace slag (GGBFS) and calcined clay, have attracted much interest in academic and industrial fields over the past decades [1], [2].AAMs present …
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##tihuan2##One of the primary benefits of fly ash is its reaction with available lime and alkali in concrete, producing additional cementitious compounds. The following …
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##tihuan2##The content of volatile parts in wood biomass ranges between 69.3 and 81%. Ash content varies between 2.6 and 18.3%. The wood calorific value ranges from 13.6 MJ/kg to 17.4 MJ/kg. ... Jukić M, Ćurković L, Šabarić J, Kerolli-Mustafa M (2017) Fractionation of heavy metals in fly ash from wood biomass using the BCR sequential …
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##tihuan2##Furthermore, use of 20% fly ash reduced the expansion by 45% compared to 10% fly ash samples, but still the expansion level of the samples was within the category of slowly reactive aggregate ...
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##tihuan2##It is not recommended to use a high-carbon (greater than 5 percent) content fly ash, but if it must be used, the proper air content can be reached by increasing the dosage of an air-entraining agent. ... Some class C fly ash will not protect against the alkali-aggregate reaction. Lastly, it is important for the precast concrete producer to test ...
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##tihuan2##The present study investigated the physicochemical properties of binder gel in alkali-activated fly ash/slag exposed to high temperatures. Strength test results showed that the strength increased until exposure to 400 °C and thereafter started to decrease.The strength increase below 400 °C was attributed to the binder gel which formed after …
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##tihuan2##IP cement with a Class F fly ash that had an available alkali content of 0.50 percent. This investigation included fly ash from nine different sources. Five fly ashes were Class C and four were Class F as defined by ASTM C618. These fly ashes are presented in Table 2. Seven fly ash sources were selected on the basis of their clas
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##tihuan2##Alkali Content of Fly Ash – Measuring and Testing Strategies for Compliance
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##tihuan2##Alkali ash material (AAM) concrete is a unique material that is sustainable and cost-effective because it utilises waste fly ash, and has properties superior to other …
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##tihuan2##In light of the high content of SiO 2 and Al 2 O 3 in fly ash, many efforts have been made for the fabrication of microporous inorganic membrane filters from it for large volumes of effluents treatment (Dong et al., 2009, Cao et al., 2014). 4.4. Ceramic industry. Fly ash contains a great number of metal oxides Al 2 O 3, SiO 2, Fe 2 O 3, and …
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##tihuan2##In this study, municipal solid waste incineration (MSWI) fly ash was subjected to mineral carbonation with the aim of investigating CO2 sequestration in waste material. The conducted study follows the trend of searching for alternatives to natural mineral materials with the ability to sequestrate CO2. The mineral carbonation of MSWI fly ash …
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##tihuan2##Fly ash, especially Class F fly ash, is effective in three ways in substantially reducing alkali-silica expansion: 1) it produces a denser, less permeable concrete; 2) …
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##tihuan2##In this paper, an investigation related to the rheological behaviour of alkali-activated fly-ash pastes (AAFA) is described. Those pastes were prepared by mixing the fly ash with an alkaline dissolution containing 85% of a 12.5 M NaOH solution and 15% of waterglass and adding some commercial chemical admixtures usually used in the …
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##tihuan2##Alkali-activated fly ash (AAF) is a promising material that exhibits comparable material properties as cement-based materials but with much less CO 2 emission. In the present work, the effect of activating solution (SiO 2 and Na 2 O content) on the performance of AAF was studied by means of isothermal calorimetry and X-ray …
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##tihuan2##In this study, low-calcium fly ash and ground granulated blast-furnace slag were used as precursors (P), the chemical composition and the average particle size of which are presented in Table 1.Based on the authors' previous study [21], a mixture of SH solution with molarity of 10 and SS solution with modulus (molar ratio of [SiO 2]/[Na 2 …
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