Influence of the structures of polycarboxylate superplasticizer on its performance in cement-based materials-A review

Sha, Shengnan; Wang, Min; Shi, Caijun; Xiao, Yuchong

doi:10.1016/j.conbuildmat.2019.117257

Cited by 156 publications

(53 citation statements)

References 70 publications

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“…This can be attributed to a reduction in the amount of superplasticizer. The early hydration of binders is usually retarded as a result of high superplasticizer dosage in UHPC [20,21]. GGBS replacement at 60% caused an extensive dilution effect and heat flow started to slow down around 5.5 h as compared to that of the control mixture.…”

Section: Hydration Heatmentioning

confidence: 99%

Hydration heat, strength and microstructure characteristics of UHPC containing blast furnace slag

Yalçınkaya

Çopuroğlu

2021

Journal of Building Engineering

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Ultra-high performance concrete (UHPC) is an innovative cement-based composite with high mechanical performance under tensile and compressive loads, extremely low permeability, and excellent durability. Because of these features, UHPC has the potential to contribute to the development of new architectural perspectives and structural systems with prolonged service life; therefore, it is anticipated that the use of UHPC in cast-in-situ applications will increase in the near future. As a result of its high Portland cement dosage, the hydration heat of UHPC can be relatively high compared to that of conventional concrete. Thus, ground granulated blast furnace slag (GGBS) can be used in UHPC formulation for reducing Portland cement dosage thereby limiting hydration heat while also addressing ecological and engineering concerns. In the scope of this study, the effects of GGBS replacement (0%, 30%, and 60%) on the hydration heat, strength, and microstructural characteristics of UHPC were studied. Results showed that GGBS-bearing UHPCs are more sensitive to ambient temperature in respect to cumulative heat. 60% GGBS replacement reduced cumulative heat release by 36% and 28% at 20 • C and 35 • C respectively. So, the benefit of GGBS on reducing hydration heat is less pronounced in hot weather. Performance differences in strength depending on the replacement ratio were only noticeable on the first day of curing. Prolonged curing time and fiber inclusion eliminated strength differences. Microstructural investigations indicated that Ca(OH) 2 can be lowered up to 0.5%, and the Ca/Si ratio of the C-S-H phase was reduced below the value of 1.0 after 90 days of curing as a result of GGBS replacement.

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Section: Hydration Heatmentioning

confidence: 99%

Hydration heat, strength and microstructure characteristics of UHPC containing blast furnace slag

Yalçınkaya

Çopuroğlu

2021

Journal of Building Engineering

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“…[11][12][13] PCEs play an important role in modern concrete production due to their superior dispersing performance. [14][15][16] Over the past 40 years, PCEs have evolved from the very first generation, the so-called MPEG-type PCEs, to a large family with broad chemical and structural diversity. [11,12] It is believed that an improved understanding of the synthesisstructure-property-performance relationships of PCEs is crucial for the molecular design and optimization of such functional polymers.…”

mentioning

confidence: 99%

Phase Behavior of Partially Charged Polyelectrolyte Solutions with Salt: A Theoretical Study

Qiu

Wang

2021

Macro Theory & Simulations

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Weakly (or partially) charged polyelectrolytes represent an important subset of the polyelectrolyte family. For instance, polycarboxylate-based superplasticizers, or PCEs, are comb-shaped polyelectrolytes possessing anionic backbones grafted with neutral side chains. PCEs play an important role in modern concrete production. However, their behavior in salt solutions remain poorly understood. The present work builds upon a recently developed liquid-state theory for fully charged polyelectrolyte solutions and extends it to describe the phase behavior and salt partitioning of PCEs in a 2:1 salt solution. Previous studies have shown that there can be an additional short-range attraction, often referred to as the "calcium-binding" interaction between calcium ions and the negatively-charged carboxylate groups of PCEs. Such a calcium-binding interaction and how its strength affects the phase behavior are investigated. It is found that increasing the calcium-binding strength expands the phase-separated region and increases the critical extra salt concentration, and it also leads to a wider phase-separated region for salting-out and salting-in phenomena. The structural parameters of PCEs also affect the phase behavior. Increasing the side-chain length shrinks the phase-separated region, while increasing the acid-to-ether ratio expands the phase-separated region. Those results may find applications in molecular design of weakly charged polyelectrolytes like PCEs.

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“…Comb-like polycarboxylate (PCE) superplasticizers have recently been developed and have become an integral part of modern concrete technology [6,7]. Their effects on the workability properties of fresh cement pastes (fcps), such as on the evolution of the microstructure and hydration process during the early hydration stage, still remain to be investigated [8][9][10][11]. Most studies focused on the relationship between the structure of PCEs and the fluidity of cement paste, the effect of the changing of WFT in the presence of PCEs on the fluidity of cement paste, as well as the influence of PCE on the growth rate of hydration products and the fluidity.…”

Section: Introductionmentioning

confidence: 99%

Effects of PCE on the Dispersion of Cement Particles and Initial Hydration

et al. 2021

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The effects of polycarboxylate superplasticizers (PCEs) on the dispersing properties and initial hydration of cement particles with various water-to-cement (w/c) ratios was investigated, including the water film thickness (WFT), rheology, fluidity, adsorption of PCEs, zeta potential, degree of hydration, hydration products. The experimental results demonstrate that the initial rheological and fluidity parameters were more sensitive to the PCE dosage at a lower w/c because the WFT and the zeta potential on cement particles change more significantly. Moreover, the higher adsorption amounts of the PCEs at a lower w/c lead to a stronger inhibition of the initial hydration, whilst, at the same PCE dosage, the cement pastes have a more rapid fluidity loss and quicker hydration reactions at a higher w/c due to a lower adsorption amount of the PCE on cement particles.

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Influence of the structures of polycarboxylate superplasticizer on its performance in cement-based materials-A review

Cited by 156 publications

References 70 publications

Hydration heat, strength and microstructure characteristics of UHPC containing blast furnace slag

Hydration heat, strength and microstructure characteristics of UHPC containing blast furnace slag

Phase Behavior of Partially Charged Polyelectrolyte Solutions with Salt: A Theoretical Study

Effects of PCE on the Dispersion of Cement Particles and Initial Hydration

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