Setting Time, Microstructure, and Durability Properties of Low Calcium …
The setting time of concrete should be sufficient enough for concrete to be handled and casted before any sign of setting. The low-calcium class-F fly ash-based geopolymer has a high setting time, which can be reduced significantly by using heat curing [25,41] or by adding GGBFS [25,29]. Evaluating the parameters that influence the setting ...
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Low cost and sustainable repair material made from alkali …
The alkali activated high calcium fly ash exhibited good mechanical property but was lesser in strength when a low calcium fly ash was incorporated with slag [20] - [27]. ...
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Mechanical and microstructural properties of high calcium fly ash …
2.1. Materials. High calcium fly ash was used as the primary binder in this investigation. The chemical components of the high calcium fly ash used were detected by X-Ray fluorescence (XRF) and presented in Table 1.The fly ash was acquired from the Manjung Power Plant in Perak, Malaysia as a source of aluminosilicate materials for the production of one-part …
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Comparative mechanical and microstructural properties of high calcium …
The higher compressive strength achieved by OPG synthesised in this study is because of the lower water content in this mix system and the high CaO content in the fly ash used that was able to yield calcium-containing hydrate gel, which was compact and contributed to a better mechanical properties [27]. The finding of this study suggests that ...
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Phase Analysis of Alkali-Activated Slag Hybridized with Low-Calcium …
The low cementitious capability in alkali-activated high-calcium fly ash may be attributed to the unstable N-C-A-S-H gel structure with concurrent high Na and Ca contents.
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Dry Mix Slag—High-Calcium Fly Ash Binder. Part One: …
High-calcium fly ash produced from low-temperature combustion of fuel, like in circulating fluidized bed technology, reacts with water readily and is itself a good hardening activator for GGBFS ...
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Influences of the Ratios of High-Calcium Fly Ash to Low-Calcium Fly Ash …
Keywords: geopolymer; high-calcium fly ash; low-calcium fly ash; drying shrinkage; setting time. Abstract. N ew types of binders are b eing d eveloped as an alternative to traditional cement.
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Transforming MSWI fly ash into low-carbon and high …
Transforming MSWI fly ash into low-carbon and high-compatibility composites via designed calcium sulfoaluminate-based binders ... (MSWI FA) is a globally recognized hazardous waste. This study developed a low-carbon and high-compatibility calcium sulfoaluminate-enhanced ternary binders (PCG) composed of calcium sulfoaluminate cement, ordinary ...
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Evaluation of blends of high and low calcium fly ashes for …
Evidence included in this investigation reveal that quicklime presence accelerated the reaction rate of high-calcium fly ash, whereas in the case of lower-calcium fly ash, quicklime had a …
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Influences of the Ratios of High-Calcium Fly Ash to Low …
According to ASTM standard C168, fly ash is categorized into two types: class F and class C. This research focuses on the effects of using both types of fly ashes on …
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Strength, durability, and heat development characteristics of …
High-CaO fly ash is more highly reactive than low-CaO fly ash, probably because of its higher contents of highly active calcium aluminosilicate glass and crystalline compounds. …
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Effects of low- and high-calcium fly ash on the water …
To expand the application range of magnesium oxysulfate cement (MOSC) and the utilization of fly ash, the water resistance of MOSC mixed with low-calcium fly ash (L-FA) or high-calcium fly ash (H ...
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Geotechnical Properties of Low Calcium and High Calcium …
For high calcium fly ash, chemical and mineralogical differences have been observed for different size fractions. Compared to low calcium fly ash, optimum moisture content is low and …
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Dynamic properties of PVA short fiber reinforced low-calcium fly ash
The micromorphology of low-calcium fly ash and blast furnace slag is presented in Fig. 18. Low-calcium fly ash shows a complete spherical structure under SEM (Fig. 18 a), so fly ash can be used as an additive to improve the fluidity of concrete materials when preparing concrete. However, the spherical structure has a negative impact on concrete ...
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Workability and strength of coarse high calcium fly ash geopolymer
The strength increases with an increase in the curing time. A good strength of 48.5 ... This is rather unexpected as the literatures on the case of low calcium fly ash indicated that the high sodium silicate to NaOH ratio provided a higher compressive strength [4]. The variation in the ratio of sodium silicate to NaOH ratio affects the pH ...
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Properties of high-calcium fly ash-based geopolymer …
The fly ash used in the study, which has very high-calcium (≈43%), has not good results for 10 M concentration. The compressive strength results and the microstructure images of the pastes support the results.
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Properties of high-calcium and low-calcium fly ash …
This study presents the properties of a recycled aggregate geopolymer mortar made with a blend of high-calcium fly ash (HCF) and low-calcium fly ash (LCF). An experimental study was divided into two series. In series I, an effort was made to produce a more durable HCF geopolymer by partially replaci …
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Evaluation of blends of high and low calcium fly ashes for …
Part II: a fundamental estimation of the efficiency factor. Cem Concr Res 2002;32(10):1533–8. [23] Antiohos S., Tsimas S. Investigating the role of reactive silica in the hydration mechanisms of high-calcium fly ash/cement systems. Cem. Concr. Comp. In press. [25] Papadakis VG. Effect of fly ash on Portland cement systems. Part II: high ...
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Fly ash booklet for pdf
Fly ash utilization, especially in concrete, has significant environmental benefits including: (1) increasing the life of concrete roads and structures by improving concrete …
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A Mix Design Procedure for Alkali‐Activated …
In this paper, we propose a novel mix design methodology for alkali-activated high-calcium fly ash concrete (AAHFAC) in a rational approach. It should be noted that the method is easy to use because it is based on the ACI …
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Geotechnical Properties of Low Calcium and High Calcium Fly Ash …
In this paper, a comparative study has been made for physical and engineering properties of low calcium and high calcium Indian fly ash. The grain size distribution of fly ash is independent of lime content. Fly ash particles of size >75 μm are mostly irregular in shape whereas finer fractions are spherical for low calcium fly ash. For high calcium fly ash, chemical and mineralogical ...
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Low cost and sustainable repair material made from alkali …
In this work, a study on a low cost and sustainable repair material made from alkali-activated high-calcium fly ash (FA) incorporated with calcium carbide residue (CCR) is reported. The FA was partially replaced with CCR (additional calcium source) at the dosages of 0%, 10%, 20%, and 30% by weight of binder.
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Properties of high-calcium and low-calcium fly ash …
This study presents the properties of a recycled aggregate geopolymer mortar made with a blend of high-calcium fly ash (HCF) and low-calcium fly ash (LCF). An experimental study was …
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Evaluation of the Chemical and Mechanical Properties of …
For concrete containing high-calcium fly ash (FH, CaO more than 10%), the investigations are relatively insufficient. Due to the problems associated with the FH chemical …
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Properties of high-calcium and low-calcium fly ash …
shows a high early strength (Xie and Kayali, 2016). Fly ash is an aluminosilicate material that is widely used for the preparation of geopolymer composites, especially low-calcium fly ash (LCF)(NathandSarker,2017).Infact,oneofthemostimportantbenefits of using fly ash forgeopolymersynthesisis itseasyavailabilitycompared
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Fresh and Hardened Properties of High Calcium Fly Ash …
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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Alkali-Activated Controlled Low-Strength Material Utilizing High …
This study investigated the performance of alkali-activated, cement-based controlled low-strength materials (CLSMs). The CLSM was produced by mixing fly ash, steel slag, sodium hydroxide, and ...
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Effect of High Calcium Fly Ash, Ladle Furnace Slag, and …
Their availability, however, varies locally, and several other materials are being researched, based on local availability, such as high calcium fly ash (HCFA), metakaolin, ladle furnace slag (LFS), and rice husk ash . The present research investigates the use of HCFA, a by-product of lignite-fired power plants; LFS, a by-product of the ...
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Evaluation of the Chemical and Mechanical Properties of Hardening High
Papadakis [11,12] proposed that the compressive strength of cement-based materials, such as concrete containing low-calcium fly ash, high-calcium fly ash, and slag, can be estimated from the CSH content. Using the proposed hydration model considering both cement hydration and FH reaction (Equation (8d)), we can calculate the CSH contents for ...
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