Influence of particle size distributions on yield stress and viscosity of cement–fly ash pastes

Bentz, Dale P.; Ferraris, Chiara F.; Galler, Michael A.; Hansen, Andrew S.; Guynn, John

doi:10.1016/j.cemconres.2011.11.006

Cited by 224 publications

(76 citation statements)

References 14 publications

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“…Not only the shape and surface texture of FA particles, but also the loss on ignition (LOI), sulfate content, and particle size distribution of FA particles are factors that influence the HRWR requirements of cement pastes and concretes containing FA. Previous observation showed that w/b ratio or HRWR needed to obtain a paste of normal consistency is greater for FA with high carbon content, irregular or harsh grain content or with large mean grain size [32][33][34]. From Fig.…”

Section: Hrwr Demandmentioning

confidence: 99%

“…Another reason for reduction of plastic viscosity with increasing percentage of SF can be attributed to the higher packing density of SF mixtures when compared to that of PC mixtures. There is an assumption that spherical particles typically pack better than irregularly-shaped ones [33]. SF particles owing to have spherical morphology can pack better than PC particles.…”

Section: Plastic Viscositymentioning

confidence: 99%

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Effect of various supplementary cementitious materials on rheological properties of self-consolidating concrete

Ahari

Erdem

Ramyar

2015

Construction and Building Materials

110

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h i g h l i g h t sThe effect of binder type and content on the benefits of SCM in SCC was investigated. Metakaolin was able to increase the plastic viscosity of SCC by 90%. Silica fume and blast furnace slag reduced the plastic viscosity of SCC. Yield stress of the mixtures with SCM was higher than that of the control mixtures. a r t i c l e i n f o b s t r a c tIn design of self-consolidating concrete (SCC) for a given application, the mixture's rheological parameters should be adjusted to achieve a given profile of yield stress and plastic viscosity. Supplementary cementitious materials (SCM) can be useful for this adjustment in addition to their other advantages. In this study, the rheological properties of 57 SCC mixtures with various SCM were investigated for a constant slump flow value. For this aim, various amounts of silica fume (SF), metakaolin (MK), Class F fly ash (FAF), Class C fly ash (FAC) and granulated blast-furnace slag (BFS) were utilized in binary, ternary, and quaternary cementitious blends in three water/binder ratios. Results showed that SF and BFS decreased plastic viscosity and V-funnel time values in comparison with mixtures containing only Portland cement (PC). However the opposite tendency was observed when MK, FAC and FAF were incorporated with PC. Substitution of PC with SF, MK and FAC increased high range water reducer (HRWR) demand in the SCC mixtures having constant slump flow. Use of SCM in SCC mixtures increased yield stress values. Good correlations were established between plastic viscosity and V-funnel flow time values for all w/b ratios.

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Section: Hrwr Demandmentioning

confidence: 99%

Section: Plastic Viscositymentioning

confidence: 99%

Effect of various supplementary cementitious materials on rheological properties of self-consolidating concrete

Ahari

Erdem

Ramyar

2015

Construction and Building Materials

110

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“…The decrease in torque plastic viscosity due to the presence of SF in the SCC mixture was attributed to the following facts: The sphericity of SF particles provides better packing than PC particles resulting in lower shear stress and lower plastic viscosity values [21,48]. Another reason for reduction of h with increasing percentage of SF can be related to the difference in the volume of the binders.…”

Section: Torque Plastic Viscositymentioning

confidence: 99%

“…In the case of mixtures containing SF, except some irregularity in mixtures having w/b ratio of 0.44, breakdown area values were also increased. Since spherical particles can be assumed to pack better than angular ones, like those of PC [48], higher packing density of the mixtures containing FAF and SF, which have spherical particles ( Fig. 2c and e), can reduce the equilibrium torque values.…”

Section: Breakdown Area Valuesmentioning

confidence: 99%

Thixotropy and structural breakdown properties of self consolidating concrete containing various supplementary cementitious materials

Ahari

Erdem

Ramyar

2015

Cement and Concrete Composites

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Supplementary cementitious materials Thixotropy Breakdown Drop in apparent viscosity Yield value at rest a b s t r a c tIn this study, thixotropy and structural breakdown of 57 self-consolidating concrete (SCC) mixtures containing various supplementary cementitious materials (SCM) were investigated by different approaches. The effects of SCM type and content on high range water reducer demand and plastic viscosity were also studied. For these purposes, various amounts of silica fume (SF), metakaolin (MK), Class F fly ash (FAF), Class C fly ash (FAC) and granulated blast-furnace slag (BFS) were utilized in binary, ternary, and quaternary cementitious blends in three water/binder (w/b) ratios. Results showed that except BFS, use of SCM in SCC mixtures increased thixotropy values in comparison with the mixtures containing only portland cement (PC). Good correlations were established between structural breakdown area and drop in apparent viscosity values for all w/b ratios. The different methods used to evaluate the thixotropy and structural breakdown got more consistent with each other as w/b decreased.

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“…Additionally, as a possible factor, the chemical admixtures used in this research are affected by changing packing density under wet conditions, which induces errors between predicted viscosity and dry packing density. For better prediction, although the wet packing conditions of suspension should be evaluated with the influence of chemical admixtures, as per Bentz et al (2012), it is difficult to evaluate the influence of superplasticizers on packing conditions of suspensions. Furthermore, according to Wallevik and Wallevik (2011), superplasticizer is considered to only affect yield stress of cement paste; furthermore, VMA changes the medium of the suspension rather than the particles.…”

Section: Rheology Of the Mortar Samplesmentioning

confidence: 99%

Critical Grain Size of Fine Aggregates in the View of the Rheology of Mortar

Han

Kim

Lee

et al. 2017

Int J Concr Struct Mater

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The aim of this research was to investigate the validity of the Krieger-Dougherty model as a quantitative model to predict the viscosity of mortar depending on various aggregate sizes. The Krieger-Dougherty model reportedly predicted the viscosity of a suspension, which includes cement-based materials. Concrete or mortar incorporates natural resources, such as sand and gravel, referred to as aggregates, which can make up as much as 80% of the mixture by volume. Cement paste is a suspending medium at fresh state and then becomes a binder to link the aggregate after its hydration. Both the viscosity of the suspending medium and the characteristics of the aggregates, therefore, control the viscosity of the cement-based materials. In this research, various sizes and gradations of fine aggregate samples were prepared. Workability and rheological properties were measured using fresh-state mortar samples and incorporating the various-sized fine aggregates. Yield stress and viscosity measurements were obtained by using a rheometer. Based on the packing density of each fine aggregate sample, the viscosity of the mortar was predicted with the Krieger-Dougherty model. In addition, further adjustments were made to determine the water absorption of fine aggregates and was transferred from successful experiment to simulation for more accurate prediction. It was also determined that both yield stress and viscosity increase when the fine aggregate mean size decreases throughout the mix. However, when the mean size of the fine aggregates is bigger than 0.7 mm, the yield stress is not affected by the size of the fine aggregate. Additionally, if aggregate grains get smaller up to 0.3 mm, their water absorption is critical to the rheological behavior.

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Influence of particle size distributions on yield stress and viscosity of cement–fly ash pastes

Cited by 224 publications

References 14 publications

Effect of various supplementary cementitious materials on rheological properties of self-consolidating concrete

Effect of various supplementary cementitious materials on rheological properties of self-consolidating concrete

Thixotropy and structural breakdown properties of self consolidating concrete containing various supplementary cementitious materials

Critical Grain Size of Fine Aggregates in the View of the Rheology of Mortar

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