Hydration process of cement containing fly ash and silica fume: The first 24 hours

Lilkov, V.; Dimitrova, Elena; Petrov, O.

doi:10.1016/s0008-8846(97)00025-2

Cited by 42 publications

(11 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The absorptions at 3524.2 and 1795 cm −1 regions indicate that water molecules were adsorbed by the reaction products 19 . The –OH group vibrations 18 in the 3675.5 cm −1 region, similar to those in the solid products of Sample 1, are due to the small amount of CH in the solid residue. New absorptions identified in the solid products of Sample 2 are (Si–O) group vibrations v 3 centered at 425.5 cm −1 , 27 symmetrical stretch vibrations of the tetrahedral groups (TO 4 ) of zeolites centered at 671.5 and 713.0 cm −1 , 24 asymmetric stretching vibrations of [AlO 4 ] centered at 857.0 cm −1 , 28 and calcite (CO 3 − ) group vibrations centered at 1425.8 cm −1 20,21,29 .…”

Section: Resultsmentioning

confidence: 80%

“…22,23 There is an increase in the intensity of the band at 873.4 cm À1 , suggesting the formation of Si-OH. 24 The absorption centered at 1085.9 cm À1 shifts to a lower frequency (966.9 cm À1 ) and forms a shoulder in the spectra, indicating the formation of C-S-H. 18,23,25 Previous literature 26,27 suggested some SiO 4 4À groups are replaced by AlO 4 3À groups that behave as network formers in the structure of the C-S-H formed and the charge difference is equilibrated with an alkaline metal ion. The absorptions at 3524.2 and 1795 cm À1 regions indicate that water molecules were adsorbed by the reaction products.…”

Section: Resultsmentioning

confidence: 88%

See 1 more Smart Citation

Mineralogical Characterizations and Reaction Path Modeling of the Pozzolanic Reaction of Fly Ash–Lime Systems

Lü

Zhai

2008

Journal of the American Ceramic Society

View full text Add to dashboard Cite

Mineralogical studies show that fly ash–lime systems without NaOH produced Al‐rich calcium silicate hydrates and a small amount of ettringite. The presence of NaOH accelerates the pozzolanic reaction of fly ash. Fly ash–lime systems with NaOH produced Al‐rich calcium silicate hydrates, calcite, meixnerite, and NaX‐type zeolite (or zeolite precursor) after 28 days of reaction time. Carbonation of alkali‐activated fly ash–lime systems call for specific studies. The experimental work was supplemented with reaction path modeling, which provided a quantitative procedure to decipher the chemical nature of fly ash hydration and cementitious system formation.

show abstract

Section: Resultsmentioning

confidence: 80%

Section: Resultsmentioning

confidence: 88%

Mineralogical Characterizations and Reaction Path Modeling of the Pozzolanic Reaction of Fly Ash–Lime Systems

Lü

Zhai

2008

Journal of the American Ceramic Society

View full text Add to dashboard Cite

show abstract

“…The physico-chemical and micro-structural effect relates to all the modifications generated by the multiple interactions between the mineral admixtures particles on the hydration process of cement, and on structuring the hydrated products. Lilkov [6] showed that the quantity of the hydrates formed during the first 24 h in a cementing paste is more significant in mixtures with admixtures of silica fume and fly-ashes that in mixtures without admixtures. Hanna [7] showed that the quantity of heat released during the first 24 h in a cementing paste is modified by the incorporation of various percentages of silica fume.…”

Section: Introductionmentioning

confidence: 99%

Analysis of the Effects of Mineral Admixtures on the Strength of Mortars: Application of the Predictive Model of Feret

Boudchicha

Zouaoui

Gallias

et al. 2007

Journal of Civil Engineering and Management

View full text Add to dashboard Cite

The introduction of fine and ultra‐fine mineral admixtures in cementing materials generates a granular effect, a physico‐chemical and micro‐structural effect and, possibly, chemical effect. To analyse the specific share of each effect, we propose to use a methodology based on a volume substitution of cement by admixtures in mixes whose absolute volume of the solid phases and workability are preserved constant and then only the effects of the particles of admixtures in the cementing phase are taken into account. We expressed the compressive strength of mortars with admixtures according to a factor of compactness by applying to the mortars the principles of the predictive model of Feret. This factor makes possible to distinguish the modifications generated by the granular effect of the admixtures on the compactness of the cementing matrix independently of the physico‐chemical and chemical effects. The specific chemical action of each admixture has been evaluated by analysing the variation of the coefficient of activity K according to the rate of the cement substitution, by applying to the studied mortars the concept of the equivalent binder and by deducing the coefficient of activity from the predictive model of Feret.

show abstract

“…La présence de l'anhydrite dans les poussières de four (CaSO 4 ) est confirmée par les bandes relevées à 1158, 677, 613 et 596 cm -1 (Ghosh et Handoo 1980;Barkakati et al 1993;Luxan et al 1989). Après hydratation des CKD et un mûris-sement de 24 h, une nouvelle vibration apparaît à 3645 cm -1 attribuée aux groupements hydroxyles -OH de la portlandite suite à l'hydratation de la chaux libre (Lilkov et al 1997). Cette bande est localisée dans un massif situé entre 3000 et 3800 cm -1 .…”

Section: Analyse Par Spectrométrie Infrarouge (Ir)unclassified

“…Cette diminution observée par diffraction X et quantifiée par thermobalance peut s'expliquer par une interaction chimique de cette espèce avec d'autres ions pour former de nouveaux produits, entre autres, les CSH. En effet, le pic situé entre 970 et 964 cm -1 désigné comme étant une vibration propre au CSH (Lilkov et al 1997) des molécules d'eau par l'ettringite. Cependant, la présence de la syngénite mise en évidence par DRX, en présentant des vibrations aux nombres d'onde similaires à l'ettringite, peut entraîner une certaine interférence.…”

Section: Analyse Par Spectrométrie Infrarouge (Ir)unclassified

Comportement physico-chimique de mélanges à base de poussières de four de cimenterie et de cendres volantes

Bellaloui¹,

Tagnit-Hamou²,

Ballivy³

2002

Can. Geotech. J.

View full text Add to dashboard Cite

La valorisation des poussières de four de cimenterie en vue de leur exploitation en tant que barrière environnementale requiert, entre autres, l'ajout de cendres volantes afin d'améliorer les différentes propriétés nécessaires à une meilleure mise en place et assurer leur efficacité à long terme. En mettant à profit différentes techniques expérimentales, une attention particulière est accordée au comportement physico-chimique de différentes poussières de four associées aux cendres volantes. Selon la nature des ajouts considérés, un comportement différent peut conditionner l'évolution des mélanges avec une incidence sur leur stabilité. En effet, cette étude a confirmé l'amélioration des propriétés physico-chimiques des poussières mises en interaction avec les cendres volantes riches en silices, et pauvres en chaux, ce qui laisse de bons augures quant à leur utilisation en tant que barrière environnementale. Par ailleurs, le suivi a permis une meilleure compréhension de certains mécanismes générés par les systèmes abordés. Ainsi, après hydratation et différentes transformations chimiques, des phases à caractère expansif tels que l'ettringite, le gypse, la syngénite et la portlandite, prennent naissance dans la pâte et conditionnent, par conséquent, le comportement des mélanges élaborés.Abstract: Enhancing the value of the cement kiln dust so as to use it as an environmental barrier requires, amongst other things, the addition of fly ashes in order to improve the different properties needed to insure a better placing and a long term efficiency. Taking advantage of different experimental techniques, particular attention was devoted to the physicochemical behaviour of different kiln dusts associated with the fly ashes. Depending on the nature of the added compound, a different behaviour may condition the evolution of the mixtures with an effect on their stability. Indeed, this study has confirmed the improvement of the physicochemical properties of the dusts interacting with the fly ashes rich in silica and poor in lime, which argues well for their use as an environmental barrier. Moreover, the follow up has led to a better understanding of certain mechanisms generated by the systems dealt with. Hence, after hydration and different chemical transformations, some expansive phases as the ettringite, gypsum, syngenite, and portlandite develop in the paste, and therefore condition the behaviour of the mixtures worked out.

show abstract

Hydration process of cement containing fly ash and silica fume: The first 24 hours

Cited by 42 publications

References 17 publications

Mineralogical Characterizations and Reaction Path Modeling of the Pozzolanic Reaction of Fly Ash–Lime Systems

Mineralogical Characterizations and Reaction Path Modeling of the Pozzolanic Reaction of Fly Ash–Lime Systems

Analysis of the Effects of Mineral Admixtures on the Strength of Mortars: Application of the Predictive Model of Feret

Comportement physico-chimique de mélanges à base de poussières de four de cimenterie et de cendres volantes

Contact Info

Product

Resources

About