Interaction mechanisms between Na montmorillonite clay and MPEG-based polycarboxylate superplasticizers

Ng, Serina; Plank, Johann

doi:10.1016/j.cemconres.2012.03.005

Cited by 181 publications

(93 citation statements)

References 24 publications

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“…Other researchers have proposed that the competition between clay grains and cement grains for the adsorption of PCE is the main reason for the incompatibility of PCE with clay: adding extra PCE could eliminate the side effects of the clay by offering more PCE for adsorption onto cement surfaces, benefiting the dispersion of cement particles (Sakai et al, 2006;Ng and Plank, 2012). However, based on the results obtained here, for a higher content of clay, adding more PCE did not significantly enhance the workability of the cement paste, which indicates that the competition between clay and cement might not be the main reason for the dysfunction of PCE on the dispersion of cement particles in the presence of clay.…”

Section: Resultsmentioning

confidence: 99%

“…Sánchez-Martín et al (2008) reported that more PCE was adsorbed on clay surfaces than on cement surfaces, due to the larger specific surface of the clay grains providing more adsorption sites. Ng and Plank (2012) revealed that PCE was adsorbed both chemically and physically on clay surfaces, with the adsorption amounts on clay approximately 100 times greater than on cement. Ferrari et al (2010) suggested that the water-reducing effect of PCE is highly dependent on the surface charge of particles and the interactions between particles.…”

Section: Introductionmentioning

confidence: 99%

“…Their crystal structures consist of alternating layers composed of sheets of silicon-centred tetrahedra and aluminium-centred octahedra. When dispersed in fluids containing ions, such as cement pore solution, cations can also adsorb on the negatively charged particle surfaces of clay grains (Ng and Plank, 2012). Large amounts of PCE are thus adsorbed on clay grains, which consequently reduces the amount of PCE adsorbed on cement surfaces, leading to a poor PCE performance.…”

Section: Introductionmentioning

confidence: 99%

“…With increasing requirements on construction quality and demands for high-performance concretes, the need for PCEs will increase (Aitcin et al, 1994;Nematollahi and Sanjayan, 2014). However, many researchers have reported that PCE is quite sensitive to clay, which can be present as an impurity in aggregates (Fernandes et al, 2007;Ng and Plank, 2012;Sakai et al, 2006). The presence of clay has been reported to result in a rapid loss of workability or a higher water demand to achieve the same workability (Lei and Plank, 2012a;Tan et al, 2016a).…”

Section: Introductionmentioning

confidence: 99%

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Interaction of polycarboxylate-based superplasticiser with clay in Portland cement systems

Gao

Ren

Liu

et al. 2018

Advances in Cement Research

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It is widely accepted that polycarboxylate-based superplasticisers (PCEs) are sensitive to the presence of clay in cement and concrete. The impact of clay content on the adsorption behaviour of PCE on cement grain surfaces was investigated, with the adsorption of PCE on clay and cement grains determined by means of total organic carbon analysis. In addition, the effect of the mixing sequence of clay and PCE in cement paste was also investigated to explore the mechanism of the low clay-tolerance of PCE. The results indicated that the addition of clay reduced the adsorption of PCE on cement grain surfaces. Accordingly, the workability of the cement paste mixed with PCE was also changed with the addition of clay. In the presence of clay, although the total consumption of PCE was increased, the fluidity of the paste decreased. The results from different mixing sequences revealed that, in the presence of clay, the adsorption amount of PCE on cement grain surfaces was highly reduced, leading to poor dispersion of the cement particles. NotationC 0 initial concentration of superplasticiser (SP) solution (mg/ml) C t concentration of SP solution after reaching adsorption equilibrium (mg/ml) c equilibrium concentration of SP solution (g/l) k adsorption constant (l/g) m mass of binder (g) R gas constant (8·314 J/K.mol) V total volume of solution (ml) T absolute temperature (K) Γ adsorbed amount of SP per gram of binder (mg/g) Γ s saturated amount of SP (mg/g) ΔG ads adsorption free energy

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Interaction of polycarboxylate-based superplasticiser with clay in Portland cement systems

Gao

Ren

Liu

et al. 2018

Advances in Cement Research

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“…With the wide application of concrete in the urbanization, the polycarboxylate superplasticizer develops fast [1][2].Some precast structures need enhance the early strength to speed up use of prefabricated mould [3][4][5]. In order to improve the early strength of concrete, generally we use low water-binder ratio or increase the dosage of cement [6][7] .Meanwhile this could cause the volume unstability of concrete and the cracking risk [8].…”

Section: Introductionmentioning

confidence: 99%

Study on preparation and properties of polycarboxylate superplasticizer with early-age strength

Li¹,

Ye²,

Zhou³

et al. 2015

Proceedings of the 2015 International Conference on Materials, Environmental and Biological Engineering

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Abstract. The shortcoming of polycarboxylate superplasticizer could delay the early strength of concrete, this limit its use in winter. In order to satisfy the application of polycarboxylate superplasticizer in the early strength constructional buildings. TEA was introduced into molecular chain of polycarboxylate superplasticizer, and the early-age strength of (3d and 7d) were investigated to find the optimal component. This type early-strength polycarboxylate superplasticizer has high superplasticizer, and it didn't impact the slumps and slump flow.

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Comb‐shaped copolymer as filtrate loss reducer for water‐based drilling fluid

Liu

Rong

et al. 2017

J of Applied Polymer Sci

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A new comb‐shaped copolymer was synthesized by free radical copolymerization of 2‐acrylamide‐2‐methyl propane sulfonic acid, acrylamide, N‐vinyl‐2‐pyrrolidone, and allyl polyoxyethylene ether (APEG) monomers. The copolymer was evaluated as a filtrate loss reducer in water‐based drilling fluid at 180 °C environment, and found to work well without causing high viscosity effect. Composition of the copolymer was determined by Fourier transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance spectroscopy, and gel permeation chromatography. FTIR, X‐ray diffraction,, and environmental scanning electron microscopy characterizations were used to probe the filtrate loss mechanism of the comb‐shaped copolymer. Thermogravimetry and differential scanning calorimetry results showed that thermal degradation of the copolymer is not obvious before 293.6 °C. The copolymer is found to be superior to its commercially available counterparts for controlling filtrate loss volume and maintaining a steady viscosity after 180 °C aging. Higher content of APEG in the copolymer helps maintain rheological properties of the drilling fluid after aging and reduces filtrate loss volume. The morphology of the copolymer in aqueous solution displays a comb‐shaped 3D structure and shows clear adsorption onto clay particles. The working mechanism for copolymer is that anchoring groups bind the copolymer onto clay particles through different binding mechanisms, while colloidal suspension stability is achieved by steric hindrance and electrostatic repulsion, as well as through PEG segment intercalation into clay lamellae. The copolymer is able to cover and seal the micro‐holes in the mud cake even at high temperature to reduce permeability. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45989.

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Interaction mechanisms between Na montmorillonite clay and MPEG-based polycarboxylate superplasticizers

Cited by 181 publications

References 24 publications

Interaction of polycarboxylate-based superplasticiser with clay in Portland cement systems

Interaction of polycarboxylate-based superplasticiser with clay in Portland cement systems

Study on preparation and properties of polycarboxylate superplasticizer with early-age strength

Comb‐shaped copolymer as filtrate loss reducer for water‐based drilling fluid

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