Activation of blended cements containing fly ash

Qian, Jueshi; Shi, Chenghua; Wang, Zhi

doi:10.1016/s0008-8846(01)00526-9

Cited by 151 publications

(58 citation statements)

References 8 publications

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“…Beneficial effect of mechanical activation (grinding of fly ash) used together with chemical activation by Na 2 SO 4 was confirmed in [74,110].…”

Section: Moderate Alkali Activationmentioning

confidence: 93%

“…In this case, the best results of compressive strength were registered with the use of Na 2 SO 4 as an activator. Beneficial influence of addition of Na 2 SO 4 and CaO into fly ash-cement mixture on up to 28-day compressive strength was presented by authors of [110].…”

Section: Moderate Alkali Activationmentioning

confidence: 98%

“…Sodium hydroxide (Na ? , OH -) is also produced during the [16,19,36,43,49,60,74,103,110,115,116]. Ca(OH) 2 needed for the reaction may come from different sources: cement hydration, introduction of additional amount of Ca(OH) 2 into the system or as component of used supplementary cementitious material (e.g.…”

Section: Moderate Alkali Activationmentioning

confidence: 99%

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Influence of selected activating methods on hydration processes of mixtures containing high and very high amount of fly ash

Wilińska

Pacewska

2018

J Therm Anal Calorim

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Binders containing fly ash as cement substitute have been used for many years. Typical amount of fly ash in cement composite does not exceed 35% of mass of binder. Replacement of substantial amount of cement mass by fly ash results in retardation of hydration of binder and deterioration of some concrete properties, e.g. delay in setting time and reduction in early compressive strength. These inconveniences may be reduced using proper method of activation. In this paper, possibilities to activate binding mixtures containing high and very high amount of fly ash and low amount of Portland cement were discussed basing on the literature reports as well as on our own research results. Several activating methods were described, such as mechanical activation, exchanging of part of components of binder (cement, fly ash or both of them) by more reactive fine-grained material, chemical activation by the use of alkaline activators as well as combined methods. Possibilities of using these methods were discussed in relation to amount of fly ash introduced as replacement of cement and kind of fly ash used. Usefulness of calorimetry and thermal analysis methods was also presented.

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“…Beneficial effect of mechanical activation (grinding of fly ash) used together with chemical activation by Na 2 SO 4 was confirmed in [74,110].…”

Section: Moderate Alkali Activationmentioning

confidence: 93%

Section: Moderate Alkali Activationmentioning

confidence: 98%

See 1 more Smart Citation

Influence of selected activating methods on hydration processes of mixtures containing high and very high amount of fly ash

Wilińska

Pacewska

2018

J Therm Anal Calorim

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“…Activation of Portland-fly ash and lime-fly ash cements was accelerated using Na 2 SO 4 , resulting in increased compressive strength at early ages [20]. Na 2 SO 4 had a better effect when using a higher fly ash percentage, and a grinding process applied to the fly ash was shown to increase the strength significantly.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of activated high volume fly ash systems using Na 2 SO 4 , lime and quicklime in mortars with high loss on ignition fly ashes

Velandia

Lynsdale

Provis

et al. 2016

Construction and Building Materials

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Article available under the terms of the CC-BY-NC-ND licence (https://creativecommons.org/licenses/by-nc-nd/4.0/) eprints@whiterose.ac.uk https://eprints.whiterose.ac.uk/ Reuse Unless indicated otherwise, fulltext items are protected by copyright with all rights reserved. The copyright exception in section 29 of the Copyright, Designs and Patents Act 1988 allows the making of a single copy solely for the purpose of non-commercial research or private study within the limits of fair dealing. The publisher or other rights-holder may allow further reproduction and re-use of this version -refer to the White Rose Research Online record for this item. Where records identify the publisher as the copyright holder, users can verify any specific terms of use on the publisher's website. TakedownIf you consider content in White Rose Research Online to be in breach of UK law, please notify us by emailing eprints@whiterose.ac.uk including the URL of the record and the reason for the withdrawal request. The effect of sodium sulfate, added as an activator, is significant in terms of compressive strength at early age for two of the fly ashes studied; in this case, the parameter used to correlate with the compressive strength evolution is the amount of portlandite consumed through pozzolanic reactions. However, sodium sulfate does not have the same effect on fly ashes with a high amount of Fe 2 O 3 , in which portlandite consumption is much lower.

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“…Physico-chemical activation of pulverised fuel ashes (PFA) using grinding and various alkalis has been studied extensively (Juhasz 1998;Arjunan et al 2001;Wang 2003;Qian et al 2001;Blanco et al 2006). Simultaneous application of mechanical and chemical activation of PFA was reported to produce strength above that of reference mortar at 20% replacement level (Blanco et al 2006) and the improvements were also greater when compared with the 20% replacement level of silica fume (SF).…”

Section: Introductionmentioning

confidence: 99%

Hydration Kinetics of a Low Carbon Cementitious Material Produced by Physico-Chemical Activation of High Calcium Fly Ash

Sadique

Al-Nageim

2012

ACT

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The hydration kinetics of a ternary system containing high lime fly ash activated with alkali sulphate rich fly ash has been studied. The effect of low intensive mechanical activation of fly ashes influencing the particle packing and water demand was undertaken. A ternary blend of fly ashes and silica fume was found to show improved bond strength between the binder paste and aggregate rather than the binder paste matrix with progressive hydration after 90 days. Analogous physico-chemical properties of the developed ternary blend with the control cement were revealed. Quick dissolution of K + , Na + and SO 4 2-into the liquid phase as well as consumption of Ca 2+ by silica fume in a high-pH environment were the predominant factors for producing a dense non-expansive hydration product by the ternary blend.

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Activation of blended cements containing fly ash

Cited by 151 publications

References 8 publications

Influence of selected activating methods on hydration processes of mixtures containing high and very high amount of fly ash

Influence of selected activating methods on hydration processes of mixtures containing high and very high amount of fly ash

Evaluation of activated high volume fly ash systems using Na 2 SO 4 , lime and quicklime in mortars with high loss on ignition fly ashes

Hydration Kinetics of a Low Carbon Cementitious Material Produced by Physico-Chemical Activation of High Calcium Fly Ash

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