Performance of Portland cement pastes containing nano-silica and different types of silica

Flores, Yemcy Calcina; Cordeiro, Guilherme Chagas; Filho, Romildo Dias Toledo; Tavares, Luís Marcelo

doi:10.1016/j.conbuildmat.2017.04.069

Cited by 93 publications

(39 citation statements)

References 42 publications

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“…On the other hand, NS addition lead to important changes from a rheological point of view: the yield-stress increased by a factor of about 2.5 in the presence of tapwater and by a factor of about 4 with seawater. Similar changes have been observed experimentally and attributed to the extremely high surface area of NS, with the higher water demand of nanoparticles thus resulting in a reduction of the fluidity of specimens (Flores et al 2017;Zhang et al 2019). Furthermore, the higher the applied shear-rate, the lower the difference between curves with and without NS, with plastic viscosities then being expected to be in the same order of magnitude.…”

Section: Initial and Final Setting Timesupporting

confidence: 82%

“…Furthermore, a decrement in the time required to reach the maximum rate was observed. It has been reported that silica nanoparticles, due to their ultrafine size, act as a nucleus for cement hydration, which results in faster formation of CH and more dynamic consumption of tricalcium silicate phase (C 3 S) during the binding period; in turn, this results in an accelerated cement hydration process (Xu et al 2016;Flores et al 2017;Kotsay 2017;Potapov et al 2019). As a result, the combination of seawater with NS resulted in a substantial acceleration of the hydration process.…”

Section: Resultsmentioning

confidence: 99%

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The effects of seawater and nanosilica on the performance of blended cements and composites

Sikora

Lootens²,

Liard³

et al. 2020

Appl Nanosci

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This study investigates the effects of seawater and nanosilica (3% by weight of cement), on the fresh and hardened properties of cement pastes and mortars produced with two types of low heat cements: Portland pozzolana cement (CEM II) and blast furnace cement (CEM III). The heat of hydration, initial and final setting times, rheological properties, strength development, sorptivity and water accessible porosity of the cement pastes and mortars were determined. The data reveal that cement type has a significant effect on the reaction rate of cement with seawater and nanosilica (NS). Specimens produced with slag-blended cement exhibited a higher cement reaction rate and the composite produced exhibited better mechanical performance, as a result of the additional reaction of alumina rich phases in slag, with seawater. Replacement of freshwater with seawater contributes mostly to a significant improvement of early strength. However, in the case of slag-blended cement, 28 day strength also improved. The incorporation of NS results in additional acceleration of hydration processes, as well as to a decrease in cement setting time. In contrast, the addition of NS results in a noticeable increment in the yield-stress of pastes, with this effect being pronounced when NS is mixed along with seawater. Moreover, the use of seawater and NS has a beneficial effect on microstructure refinement, thus improving the transport properties of cement mortars. Overall, the study has showed that both seawater and NS can be successfully used to accelerate the hydration process of low heat blended cements and to improve the mechanical and transport properties of cement-based composites.Publisher's Note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

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Section: Initial and Final Setting Timesupporting

confidence: 82%

Section: Resultsmentioning

confidence: 99%

The effects of seawater and nanosilica on the performance of blended cements and composites

Sikora

Lootens²,

Liard³

et al. 2020

Appl Nanosci

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“…e authors of research studies [37][38][39] identified the reduction in the workability and increase in viscosity of cement pastes due to modification by admixtures with progressively finer sizes, such as nanosilica. ey emphasized the importance to establish the optimal dosage of nanoparticles and observe the possibility to compensate the negative effect on workability by application of other admixtures, such as silica fume, fly ash, or superplasticizers.…”

Section: Introductionmentioning

confidence: 99%

Rheological Properties of Cement Pastes with Multiwalled Carbon Nanotubes

Skripkiūnas

Karpova

Barauskas

et al. 2018

Advances in Materials Science and Engineering

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The evaluation of rheological properties of cement systems is getting more relevant with growing interest to self-consolidating concrete (SCC), high-performance concrete (HPC) and ultrahigh-performance concrete (UHPC). The rheology models are a perspective tool to predict and manage the properties of cement systems in the fresh and hardened state. The current research is focused on the rheological test of cement systems modified by multiwalled carbon nanotubes (MWCNT) dispersion with and without polycarboxylate ether (PCE). The content of dispersion with 1% concentration of MWCNT in cement pastes varied from 0.125 to 0.5% by weight of cement. The dosage of PCE was taken as 0.6% by weight of cement. The cement pastes were prepared based on Portland cement without mineral additives. The rheological test was carried out at 5, 30, 60, and 120 min after mixing of cement paste. The rheological test established that modification of cement pastes by MWCNT dispersion in dosage 0.25% leads to the decrease of yield stress by 30.7% and increase of plastic viscosity by 29.6%. The combined modification by PCE and MWCNT dispersion shows the decrease in plastic viscosity of cement pastes by 9.90% in dosage of MWCNT equal to 0.5% by weight of cement, reduction of water demand by 20% for the same workability, and decrease of yield stress till 0 Pa. It gives the ability to obtain the self-compacting mixtures. The cement pastes with and without MWCNT dispersion revealed the shear-thinning behavior during 120 min after mixing. The modification of cement pastes by PCE with and without MWCNT dispersion showed the shear-thickening behavior which remains during 120 min after mixing.

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“…According to the author's knowledge, there are several studies on incorporating nanoparticles in mortar or concrete. Most of them have been reported on nano-SiO 2 [4] [5] [6] carbon nanotube and nano-Al 2 O 3 [6] in cement-based materials. However, the influence of others nanoparticles, such as nano-CuO, nano-ZnO 2 , nano-Fe 3 O 4 , and nano-Fe 2 O 3 on the physical and mechanical properties of cement-based materials was also investigated in a few researches [7] [8] [9].…”

Section: Introductionmentioning

confidence: 99%

Effect of Iron Powder (Fe<sub>2</sub>O<sub>3</sub>) on Strength, Workability, and Porosity of the Binary Blended Concrete

Largeau¹,

Mutuku²,

Thuo³

2018

OJCE

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In this study, the effect of iron powder (Fe 2 O 3 ) on the compressive strength, tensile strength, workability, and porosity of the binary blended concrete were experimentally investigated. For this purpose, Portland cement was partially replaced by 1.5%, 2.5%, 3.5%, and 5% by weighing of iron powder. The amount of water-binder-ratio was considered constant. The workability of the fresh composite concrete was determined using cone Abrams method; mechanical properties were determined included compressive and tensile strengths at 7, 14, and 28 days and durability evaluated by water absorption and permeable porosity. It was observed that the compressive and tensile strengths change with the replacement of iron powder by up to 5%. However, the maximum improvement was gained at 2.5 wt% for compressive strength and 1.5 wt% for tensile strength. The workability of the fresh mixtures decreased when iron powder amount increased. It was observed that the porosity decreased respectively by 21.88% and 26.77% at 1.5 wt% and 2.5 wt% replacement. Moreover, this present study shows the importance and benefits to improve concrete properties by using micro-particles materials.

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Performance of Portland cement pastes containing nano-silica and different types of silica

Cited by 93 publications

References 42 publications

The effects of seawater and nanosilica on the performance of blended cements and composites

The effects of seawater and nanosilica on the performance of blended cements and composites

Rheological Properties of Cement Pastes with Multiwalled Carbon Nanotubes

Effect of Iron Powder (Fe<sub>2</sub>O<sub>3</sub>) on Strength, Workability, and Porosity of the Binary Blended Concrete

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Performance of Portland cement pastes containing nano-silica and different types of silica

Cited by 93 publications

References 42 publications

The effects of seawater and nanosilica on the performance of blended cements and composites

The effects of seawater and nanosilica on the performance of blended cements and composites

Rheological Properties of Cement Pastes with Multiwalled Carbon Nanotubes

Effect of Iron Powder (Fe&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;) on Strength, Workability, and Porosity of the Binary Blended Concrete

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Product

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Effect of Iron Powder (Fe<sub>2</sub>O<sub>3</sub>) on Strength, Workability, and Porosity of the Binary Blended Concrete