Rheology of CAC-based cement pastes and the relationship to penetrability through nonwoven fabric reinforcements

Claramunt, Josep; Ventura, Heura; Raso, Mònica Ardanuy

doi:10.1016/j.cemconcomp.2018.08.014

Cited by 16 publications

(10 citation statements)

References 34 publications

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“…This minimum thixotropic area evidenced the easy homogenization of the cement paste under the application of a lower shearing rate, which could be seen at the naked eye during the mixing of the paste. Similar behavior reported previously for hydrophilic additives was attributed to the formation of lubricant layers . Given the hydrophilic nature of LDH, the rheological behavior could be explained by the lubrication effect caused by the hydration layer at the surface of the RLDH platelets.…”

Section: Resultssupporting

confidence: 82%

“…Similar behavior reported previously for hydrophilic additives was attributed to the formation of lubricant layers. 52 Given the hydrophilic nature of LDH, the rheological behavior could be explained by the lubrication effect caused by the hydration layer at the surface of the RLDH platelets. The efficiency of this effect was also associated with the ease of lamellar flow of the 2D RLDH nanoparticles, which became less effective with the preferential aggregative growth of crystallites along the c axis, inducing the dimensional conversion of the nanoparticles from 2D to 3D.…”

Section: Pfmentioning

confidence: 99%

See 1 more Smart Citation

MgAl-Layered Double Hydroxide Nanoparticles as Smart Nanofillers To Control the Rheological Properties and the Residual Porosity of Cement-Based Materials

Almeida

Santos

Rosa

et al. 2022

ACS Appl. Nano Mater.

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Nanotechnology in building materials has still not been widely explored, despite its great potential in developing a new generation of smart and eco-efficient cementitious materials based on the addition of nanoparticles. In this context, layered double hydroxides (LDH) are a family of anionic clays that can regenerate their nanostructure after thermal decomposition to the corresponding mixed oxides (MO). This memory effect involves the reversible recrystallization of the LDH nanoparticles from nanocrystalline MO in contact with water or anionic solutions. It has shown promise in the immobilization of different anions, such as chloride and carbonate, that could compromise the durability of reinforced concrete. This study proposes the incorporation of nanocrystalline MO in the cementitious matrix to control the rheological properties of the paste and reduce the porosity of the cement because the regeneration of the lamellar nanostructure occurs by the dissolution and reprecipitation of LDH nanoparticles inside the pores formed during the consolidation of the paste. Time-resolved wide-angle X-ray scattering (WAXS) was used to study the mechanism of regeneration of the LDH structure following contact of the MO with the cement pore solution. The results showed that the regeneration of the LDH, which occurs by an aggregative growth of anisotropic nanoparticles, changed the rheological behavior by increasing the elastic modulus (G′) and consequently contributing to the consolidation of the paste, demonstrating the potential of these materials for application in threedimensional (3D) printing. Regarding the pore structure of the hydrated cement, a porosity reduction of up to 20% was observed with the addition of 2.0 wt % of MO. Furthermore, after 28 days of hydration, the specific surface area of the cement was reduced from 60 to 36 m 2 g −1 with the incorporation of 1.0 wt % of MO. The use of LDH nanoparticles as a cement smart nanofiller proved to be advantageous in the kinetic control of cement curing and improvement of the porous structure of the hydrated cement.

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Section: Resultssupporting

confidence: 82%

Section: Pfmentioning

confidence: 99%

MgAl-Layered Double Hydroxide Nanoparticles as Smart Nanofillers To Control the Rheological Properties and the Residual Porosity of Cement-Based Materials

Almeida

Santos

Rosa

et al. 2022

ACS Appl. Nano Mater.

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“…Moreover, even with a water/solid ratio of 1.2 in mass (solid volume fraction of 32%), the paste presented a considerably high yield stress. This value is comparable to both Portland cement suspension paste with a high volume fraction of solids such as 55% [34] and the apparent yield stress of CAC pastes produced with a water/cement ratio of 0.35 [35]. The calculated Bingham viscosity presented similar values of recycled cement pastes with a water/cement ratio of 0.55 [36].…”

Section: Rheometrysupporting

confidence: 69%

Rehydration of katoite as a layered double hydroxide: an in situ study

et al. 2021

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Calcium aluminate layered double hydroxides (Ca-Al LDHs) constitute a considerable part of cementitious waste fines. Although cementitious waste fines have proven to be recyclable by thermal treatment at moderate temperatures (400–700 °C), understanding how each phase rehydrates and contributes to the binding properties of rehydrated cementitious materials is still necessary. In this study, the de(re)hydration of katoite is investigated through in situ techniques, and its applicability as an alternative cement or supplementary cementitious material (SCM) is discussed. The research employed X-ray diffraction, isothermal calorimetry, in situ wide-angle X-ray scattering (WAXS), and rotational/oscillatory rheometry. Katoite synthesized by a mechanochemical process was dehydrated at 400 °C, producing mainly mayenite. During rehydration, calorimetry presents high heat production in the first minutes. WAXS shows prompt recovery of katoite and increasing formation of monocarboaluminate (Ca-Al LDH) after 30 s of rehydration. The findings confirm the direct association between rapid heat release and phase reformation. Rehydrated pastes present a high yield stress and an increasing storage modulus, indicating rapid binding properties. The consolidation is also correlated with cumulative heat and monocarboaluminate formation. The results indicate the potential of calcined katoite for use as rapid set alternative cement or SCM.

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“…The rich content of amorphous alumina and silica in MK can be dissolved under an alkaline condition, 35,36 showing the potential to hinder the phase transformation shown in Equations () and (). However, only a few studies are available regarding the influence of MK on the conversion and mechanical properties of hydrated CAC 25,37,38 . It is found that CAC blends with 50% MK yields better mechanical properties than the blends with the same content of GGBS when cured at 20°C, and it gains continuous strength development at 40ºC within one year 25 .…”

Section: Introductionmentioning

confidence: 99%

“…However, only a few studies are available regarding the influence of MK on the conversion and mechanical properties of hydrated CAC. 25,37,38 It is found that CAC blends with 50% MK yields better mechanical properties than the blends with the same content of GGBS when cured at 20°C, and it gains continuous strength development at 40ºC within one year. 25 There is little or no C 3 AH 6 existing in the sample containing MK, and CAH 10 is still can be found in it even after one year, indicating the effective arrest of the metastable phase conversion.…”

Section: Introductionmentioning

confidence: 99%

Influence of metakaolin on the conversion and compressive strength of quaternary phase paste

Ding

Lü

et al. 2020

J Am Ceram Soc

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Rheology of CAC-based cement pastes and the relationship to penetrability through nonwoven fabric reinforcements

Cited by 16 publications

References 34 publications

MgAl-Layered Double Hydroxide Nanoparticles as Smart Nanofillers To Control the Rheological Properties and the Residual Porosity of Cement-Based Materials

MgAl-Layered Double Hydroxide Nanoparticles as Smart Nanofillers To Control the Rheological Properties and the Residual Porosity of Cement-Based Materials

Rehydration of katoite as a layered double hydroxide: an in situ study

Influence of metakaolin on the conversion and compressive strength of quaternary phase paste

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