Modification of the rate of formation and surface area of ettringite by polycarboxylate ether superplasticizers during early C3A–CaSO4 hydration

Dalas, Florent; Pourchet, Sylvie; Rinaldi, David; Nonat, André; Sabio, Serge; Mosquet, Martin

doi:10.1016/j.cemconres.2014.12.007

Cited by 94 publications

(55 citation statements)

References 32 publications

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“…This fast precipitation has been shown to be strongly modified by PCE polymers. 41 If the PCE is present in the mixing water, nucleation of ettringite is promoted and the specific surface increases, as demonstrated in the present paper. In consequence, more polymer adsorbs on ettringite and less on silicate, which attenuates the delay induced by the polymer otherwise.…”

Section: Model Clinkersupporting

confidence: 52%

“…Although it has already been mentioned in the literature, the reasons for this effect and the relation with the molecular structure of the PCEs have never been totally explained. [41][42][43] This will be further discussed below in the direct addition case. As an example of the effect of addition time, we consider Figure 3, which shows relative changes of the maximum hydration rates of tricalcium silicate (circles) and tricalcium aluminate (squares).…”

Section: General Observations and Differentiation Of Addition Modementioning

confidence: 99%

“…41,48,[81][82][83][84][85][86] However, it is also necessary to study the interaction between the different phases that might induce other reactions or kinetics as in pure phases systems. Lerch 87 and later Tenoutasse 30 illustrated in particular the importance of the balance between the silicates, the aluminates and the sulfates ( Figure SB3.2).…”

Section: Silicate-aluminate-sulfate Balancementioning

confidence: 99%

See 2 more Smart Citations

Molecular and submolecular scale effects of comb‐copolymers on tri‐calcium silicate reactivity: Toward molecular design

Marchon

Juilland²,

Gallucci³

et al. 2017

J Am Ceram Soc

124

110

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The impact of organic compounds on the processing and reactivity of inorganic materials has been a source of inspiration for materials scientists for decades and continues to trigger novel and innovative applications in a broad range of disciplines. However, molecular design of such compounds to reach targeted properties remains challenging, particularly for reactive and multicomponent systems. This outstanding challenge is met here by combining a model cement, hosting different coupled reactions of dissolution, nucleation and growth, together with combcopolymers that offer large and well-controlled variations of their molecular architecture. We show that silicate reactivity is affected by a combination of molecular and submolecular scale effects of these polymers. The first can be described by scaling laws from polymer physics, whereas the second involves specific chemical interactions. In particular, the ability of these polymers to hinder dissolution appears to be crucial, something for which strong experimental evidence is provided. K E Y W O R D Scalcium silicate,

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Section: Model Clinkersupporting

confidence: 52%

Section: General Observations and Differentiation Of Addition Modementioning

confidence: 99%

Section: Silicate-aluminate-sulfate Balancementioning

confidence: 99%

See 1 more Smart Citation

Molecular and submolecular scale effects of comb‐copolymers on tri‐calcium silicate reactivity: Toward molecular design

Marchon

Juilland²,

Gallucci³

et al. 2017

J Am Ceram Soc

124

110

View full text Add to dashboard Cite

show abstract

“…Recently it has been described that polycarboxylate-based superplasticizers can act as strong morphological catalyst for ettringite, and that they can impact the size as well as the aspect ratio of the crystals (Large and Plank 2015a; Large and Plank 2015b; Dalas et al 2015). In the first work, the authors present that this effect greatly depends on the PCE type and structural specifics.…”

Section: Cement Hydrated In the Presence Of Pcesmentioning

confidence: 80%

Early Hydration of Portland Cement Admixed with Polycarboxylates Studied Under Terrestric and Microgravity Conditions

Lei

Meier

Rinkenburger

et al. 2016

ACT

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The crystallization of ettringite at very early cement hydration (hydration period ~ 10 s) was studied under normal and zero gravity condition utilizing SEM microscopy. Furthermore, the impact of two polycarboxylate superplasticizers (one methacrylate ester-, one methallyl ether -based) on ettringite crystallization was investigated. It was found that under microgravity attained on parabolic flights, generally smaller, but a larger amount of ettringite crystals is formed resulting from the absence of convection and ion diffusion limited crystal growth. Furthermore, the PCE polymers were found to act as morphological catalysts for ettringite even under zero gravity condition.

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“…Some researchers also argue that SPs can alter the size of hydrates and make morphological change in hydrates. (Dalas et al 2015) For example, β-NS SP is said to be strong morphological catalyst for ettringite, on the other hand, PC SP does not have much impact. (Plank and Hirsch 2003) These effects can also be related to the decrease of adsorption of β-NS SP per unit area, observed in our experiment.…”

Section: Change In Adsorption Isotherm With Timementioning

confidence: 99%

Action Mechanism of Superplasticizer in Consideration of Early Hydration of Cement

Ohtsuka

Atarashi

Miyauchi

et al. 2015

ACT

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Superplasticizers (SPs) are widely used in various concrete made in Japan to decrease the amount of water required for cement mixing. The use of hot-weather concrete is increasing. The number of interstitial cement phases, such as the aluminate and ferrite phases, will be increased to treat waste and byproducts in the cement industry. In such cases, early hydration will affect cement phase fluidity. Therefore, chemical admixtures, especially SPs, are gaining importance. It has been reported that changes in concrete fluidity with time are affected by SP molecular structure. However, the mechanisms of fluidity change is still not completely clarified. It is therefore necessary to study the interaction between cement and SPs. This study focuses on the mechanism of SP action, especially during early hydration. Polycarboxylate-based SP showed better fluidity retention than naphthalene sulfonate-based SP. This difference in fluidity-retaining performance is related to the amount of SP adsorbed per unit area. The fluidity reduction of cement paste with naphthalene sulfonate-based SP is attributed to a decrease in residual SP concentration in the liquid phase.

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Modification of the rate of formation and surface area of ettringite by polycarboxylate ether superplasticizers during early C3A–CaSO4 hydration

Cited by 94 publications

References 32 publications

Molecular and submolecular scale effects of comb‐copolymers on tri‐calcium silicate reactivity: Toward molecular design

Molecular and submolecular scale effects of comb‐copolymers on tri‐calcium silicate reactivity: Toward molecular design

Early Hydration of Portland Cement Admixed with Polycarboxylates Studied Under Terrestric and Microgravity Conditions

Action Mechanism of Superplasticizer in Consideration of Early Hydration of Cement

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