Homewater content in slag cement and fly ash
ONLINE CIVIL ENGINEERING: BLEEDING OF FRESH CONCRETE
ABSTRACT: Plastic cracking of concrete such as plastic settlement and plastic shrinkage cracking is directly related to the bleeding of concrete, which is a natural timedependent process in a fresh concrete mix. A portion of the mixing water together with very fine materials finds its way to the surface of the concrete during this process.
Get priceBlast Furnace Slag Cement sciencedirect
Concrete is made up of cement, aggregate, water, air and additives. Currently used cement types in the Netherlands are: Portland cement, blast furnace slag cement and Portland fly ash cement. The clinker consists of the following minerals: 3CaO.AlO 3, 3CaO.SiO 2 and 2CaO.SiO 2.
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"Effects of Water to Cementitious Ratio on Compressive Strength of Cement Mortar Containing Fly Ash" by Tarun R. Naik, Shiw S. Singh and Amr S. Hassaballah ABSTRACT This study was directed toward studying performance of ASTM Class C and F fly ashes in mortars under varying water to cementitious materials ratio.
Get priceWhat is composite cement? Quora
Composite Cement is covered under IS: 164152015 and presents a good opportunity to produce high strength concrete which is highly durable. Composite cement is a mixture of high quality clinker (IS:163532015), fly ash (IS:3812 (Part 1) 2013), g
Get priceUses, Benefits, and Drawbacks of Fly Ash in Construction
Fly ash is a pozzolan, a substance containing aluminous and siliceous material that forms cement in the presence of water. When mixed with lime and water, fly ash forms a compound similar to Portland cement. This makes fly ash suitable as a prime material in blended cement, mosaic tiles, and hollow blocks, among other building materials.
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However, only grade I is recommended for manufacture of Portland pozzolana cement. Effects of Fly Ash on Concrete 1. On Amount of Mixing Water. The use of fly ash in limited amounts as a replacement for cement or as an addition to cement requires a little more water for the same slump because of fineness of the fly ash.
Get priceFly Ash, Slag, Silica Fume, and Natural Pozzolans, Chapter 3
Fly Ash, Slag, Silica Fume, and Natural Pozzolans Fly ash, ground granulated blastfurnace slag, silica fume, and natural pozzolans, such as calcined shale, calcined clay or metakaolin, are materials that, when used in conjunction with portland or blended cement, contribute to the properties of the hardened concrete through hydraulic or
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calcium content of the fly ash as shown in Table 3. The calcium content of the fly ash is perhaps the best indior of how the fly ash will behave in concrete (Thomas 1999), although other compounds such as the alkalis (Na 2 O and K 2 O), carbon (usually measured as LOI), and sulfate (SO 3) can also affect the performance of the fly ash.
Get priceThe Difference in Slag Cement and Fly Ash
The Slag Cement Association with member company and industry input have broken down the differences in slag cement and fly ash and how they both affect concrete performance. 1: Slag cement has a more consistent chemical and physical structure than fly ash from source to source and from a
Get priceWhat''s the Allowable Fly Ash Limit? Concrete Construction
Mar 15, 2002 · He indied that as a result of the report, the design engineers changed the concrete pavement specifiion to require 25%35% Type F or N fly ash (or 40%50% ground granulated blastfurnace slag) in all concrete for pavements, and they anticipate requiring the same percentages for all other concrete.
Get priceOptimal Design of the Cement, Fly Ash, and Slag Mixture in
In addition, in Table 6, Mix1 with 30 MPa and Mix2 with 40 MPa both have the same cement and water content, but the slag content of Mix2 is much higher than that of Mix1. The binder in concrete consists of cement, fly ash, and slag. As Mix2 has a higher binder content, the water–to–binder ratio of Mix2 is lower than that of Mix1.
Get priceEstimation of the degree of hydration of blended cement
cement pastes containing fly ash or slag. For plain portland cement pastes, the results for the degree of cement hydration obtained by the SEM pointcounting technique were consistent with the results from the traditional lossonignition (LOI) of nonevaporable watercontent measurements agreement was
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Fly Ash and BlastFurnace Slag. Fly ash is a byproduct of coal combustion, and is not usually thought of as an admixture in the same sense as the chemical admixtures discussed above. Fly ash can be used in grout as a pumping aid or to provide a greater slump with less water.
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Because most concretes today contain supplementary cementitious materials such as fly ash, slag cement, silica fume, or natural pozzolans, the w/cm ratio is more appropriate. Water content and
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Fig. 3: Effect of water content on Flowability and setting time of geopolymer mortar Based on the results of Fig. 3, water content considerably affects the setting time of slag and fly ash based geopolymer mortar. The initial and final setting times of 0.23w/b mix were 23min and 32 min respectively, while those of 0.25w/b mix were 24 min and 40
Get priceResearcher tests fly ash for stronger concrete Phys
Mar 15, 2017 · ZC concrete combines an aluminasilica rich material such as fly ash, calcined clay, mine tailings or blast furnace slag with alkali activator such
Get priceThe European Research Project GEOASH: The development of
slag and water, the various required chemical components used in (K,Ca)poly(sialatesiloxo) cement and cured at room temperature. The best compressive strength values for the geopolymeric method were obtained by applying the following conditions: 10 g Ksilie solution, 15 g slag, 5 g water, 50g to 85 g fly ash.
Get priceWhat is fly ash and slag? Quora
Fly Ash is the fine ash that is produced from at coalfired power plants, which develops cementitious properties when it is mixed with cement & water. Fly ash improves overall quality & performance of concrete. Where Does Fly Ash Come From? A byp
Get priceModeling the hydration of concrete incorporating fly ash
Maekawa [10–12] proposed a general hydration model (DuCOM) for concrete incorporating fly ash and slag. Fly ash and slag reactions are treated separately from those of ordinary Portland cement, and some interactions are taken into account through the free water content
Get priceGeopolymer Cements from Slag, Fly Ash and Silica Fume
Three different types of geopolymer cement from granulated blast furnace slag (GBFS), pulverized fly ash (FA) and silisa fume (SF) were prepared. The cements were activated by sodium hydroxide (SH) and water glass (WG) which were dissolved in mixing water.
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influence of the cementitious content on concrete performance at specific watertocementitious materials ratios. The experimental variables included watertocementitious materials ratios ranging from 0.40 to 0.55, mixtures containing portland cement only, and mixtures containing 40% slag cement or 25% fly ash. Concrete performance was evaluated
Get priceConcrete: Cement Substitutes GGBS, PFA and more
To varying degrees, cement substitutes work in two ways: • First, they hydrate and cure like portland cement. • Second they are "pozzolans," providing silica that reacts with hydrated lime, an unwanted byproduct of concrete curing. Pulverised Fuel Ash (PFA), aka ''Fly ash'' as a cement substitute.
Get priceWhat are the Factors Affecting Workability of Concrete?
The use of fly ash in improves the workability of concrete by reducing the water content required for same degree of workability or slump value. The use of steel or synthetic fibers in concrete reduces the workability of concrete as it makes the movement of aggregates harder by reducing the lubriing effect of cement paste.
Get priceThe Risks of LowCement Concrete Concrete Construction
Slag is also strictly a pozzolan and comes in three grades: 80, 100, and 120. Generally, the higher number indies a higher strength at later ages, all things being equal. Slag is sensitive to the alkali content of the cement (and fly ash) and is sensitive to temperature. So if your cement is a low alkali (Na2O) it will gain strength slower
Get priceAppliion of Slag–Cement and Fly Ash for Strength
Appliion of Slag–Cement and Fly Ash for Strength Development in Cemented Paste Backfills Yue Zhao, Amin Soltani *, Abbas Taheri *, Murat Karakus and An Deng indied an optimum water content of wopt = 8.7% and a maximum dry unit weight of g dmax = 20.2 kN/m3, which are both on par with that reported for natural
Get priceGround granulated blastfurnace slag Wikipedia
Groundgranulated blastfurnace slag (GGBS or GGBFS) is obtained by quenching molten iron slag (a byproduct of iron and steelmaking) from a blast furnace in water or steam, to produce a glassy, granular product that is then dried and ground into a fine powder.
Get priceWhat is fly ash and slag? Quora
Fly Ash is the fine ash that is produced from at coalfired power plants, which develops cementitious properties when it is mixed with cement & water. Fly ash improves overall quality & performance of concrete. Where Does Fly Ash Come From? A byp
Get priceWhat is fly ash and slag? Quora
Fly Ash is the fine ash that is produced from at coalfired power plants, which develops cementitious properties when it is mixed with cement & water. Fly ash improves overall quality & performance of concrete. Where Does Fly Ash Come From? A byp
Get priceWhat are the Factors Affecting Workability of Concrete?
The use of fly ash in improves the workability of concrete by reducing the water content required for same degree of workability or slump value. The use of steel or synthetic fibers in concrete reduces the workability of concrete as it makes the movement of aggregates harder by reducing the lubriing effect of cement paste.
Get priceClass C and Class F Fly Ash: Comparisons, Appliions
Class C vs. Class F Fly Ash for Concrete Pavement • If you combine portland cement and water you basically form two things (combined we call hardened cement) • Calcium Silie Hydrate (CSH) – Slag Cement (current solution) – Natural Pozzolans (emerging solution)
Get priceThe Risks of LowCement Concrete Concrete Construction
Slag is also strictly a pozzolan and comes in three grades: 80, 100, and 120. Generally, the higher number indies a higher strength at later ages, all things being equal. Slag is sensitive to the alkali content of the cement (and fly ash) and is sensitive to temperature. So if your cement is a low alkali (Na2O) it will gain strength slower
Get priceModeling the hydration of concrete incorporating fly ash
Maekawa [10–12] proposed a general hydration model (DuCOM) for concrete incorporating fly ash and slag. Fly ash and slag reactions are treated separately from those of ordinary Portland cement, and some interactions are taken into account through the free water content
Get priceFly ash and slag ScienceDirect
The introduction of 5% silica fume into concrete composition allowed to obtain frostresistant concrete with a 45% content of fly ash in cement mass . Nanosilica is a common additive used in the composition of ash cements. This amorphous additive with a high surface reacts much faster with Ca(OH) 2 forming CSH phase, when compared to fly ash.
Get priceModeling the hydration of concrete incorporating fly ash
Maekawa [10–12] proposed a general hydration model (DuCOM) for concrete incorporating fly ash and slag. Fly ash and slag reactions are treated separately from those of ordinary Portland cement, and some interactions are taken into account through the free water content
Get priceUses, Benefits, and Drawbacks of Fly Ash in Construction
Fly ash is a pozzolan, a substance containing aluminous and siliceous material that forms cement in the presence of water. When mixed with lime and water, fly ash forms a compound similar to Portland cement. This makes fly ash suitable as a prime material in blended cement, mosaic tiles, and hollow blocks, among other building materials.
Get priceUse of Fly Ash and Slag in Concrete: A Best Practice Guide
Use of Fly Ash and Slag in Concrete: A Best Practice Guide proportioning of the concrete mixture such as reducing the W/CM or adding silica fume to produce a ternary blend.
Get priceAppliion of Slag–Cement and Fly Ash for Strength
Appliion of Slag–Cement and Fly Ash for Strength Development in Cemented Paste Backfills Yue Zhao, Amin Soltani *, Abbas Taheri *, Murat Karakus and An Deng indied an optimum water content of wopt = 8.7% and a maximum dry unit weight of g dmax = 20.2 kN/m3, which are both on par with that reported for natural
Get priceFly Ash
preconsumer) This credit is awarded if concrete consists of at least 30% fly ash, slag, or other cement substitute and/or 50% recycled content or reclaimed aggregate by volume, or 90% recycled content or reclaimed aggregate based on the IS0 14021 definition. LEED v4 recognizes fly ash as preconsumer recycled product.
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Often, the ratio refers to the ratio of water to cementitious materials, w/cm. Cementitious materials include cement and supplementary cementitious materials such as fly ash, ground granulated blastfurnace slag, silica fume, rice husk ash and natural pozzolans. Supplementary cementitious materials are added to strengthen concrete.
Get priceWhat is Concrete Proportioning? Slag Cement
Slag cement does not contain carbon and therefore should not cause fluctuations in air content. Slag cement is also compatible with pozzolans such as fly ash or silica fume. The percentage of slag cement to use for maximum strength development is usually between 40 and 50 percent.
Get priceEffect of Alkaline Activator, Water, Superplasticiser and
/ Effect of Alkaline Activator, Water, Superplasticiser and Slag Contents on the Compressive Strength and Workability of SlagFly Ash Based Geopolymer Mortar Cured under Ambient Temperature. In: International Journal of Civil, Environmental, Structural, Construction and Architectural Engineering. 2016 Vol. 10, No. 3. pp. 308312.
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Fly Ash and BlastFurnace Slag. Fly ash is a byproduct of coal combustion, and is not usually thought of as an admixture in the same sense as the chemical admixtures discussed above. Fly ash can be used in grout as a pumping aid or to provide a greater slump with less water.
Get priceWhat are the Factors Affecting Workability of Concrete?
The use of fly ash in improves the workability of concrete by reducing the water content required for same degree of workability or slump value. The use of steel or synthetic fibers in concrete reduces the workability of concrete as it makes the movement of aggregates harder by reducing the lubriing effect of cement paste.
Get priceGeopolymer Cements from Slag, Fly Ash and Silica Fume
Three different types of geopolymer cement from granulated blast furnace slag (GBFS), pulverized fly ash (FA) and silisa fume (SF) were prepared. The cements were activated by sodium hydroxide (SH) and water glass (WG) which were dissolved in mixing water.
Get priceGeopolymer concrete for environmental protection
carbon content of the fly ash, as indied by the loss on ignition by mass, was as low as less than 2%. The particle size distribution tests revealed that 80% of the fly ash particles were smaller than 50 µm [7, 8, 1118]. The reactivity of lowcalcium fly ash in geopolymer matrix has been studied by FernandezJimenez, et al [19].
Get priceThe European Research Project GEOASH: The development of
slag and water, the various required chemical components used in (K,Ca)poly(sialatesiloxo) cement and cured at room temperature. The best compressive strength values for the geopolymeric method were obtained by applying the following conditions: 10 g Ksilie solution, 15 g slag, 5 g water, 50g to 85 g fly ash.
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