Mortars with nano-SiO2 and micro-SiO2 investigated by experimental design

Senff, L.; Hotza, Dachamir; Repette, Wellington Longuini; Ferreira, Victor; Labrincha, J.A.

doi:10.1016/j.conbuildmat.2010.01.012

Cited by 197 publications

(94 citation statements)

References 13 publications

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“…It has been reported that the nano-silica addition enhances the compressive strength and reduces the overall permeability of hardened concrete due to its pozzolanic properties, which result in finer hydrated phases (C-S-H gel) and densified microstructure (nano-filler and anti-Ca(OH) 2 -leaching effect) [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. These effects may enhance the durability of concrete elements and structures.…”

Section: Introductionmentioning

confidence: 99%

“…The main characteristics of nano-silica, such as the particle size distribution, specific density, specific surface area, pore structure and reactivity (surface silanol groups) depend on the production method [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. Despite the presence of several studies describing the main properties and characteristics of concrete containing nano-silica particles, most of them focus on the application of nano-silica as an antibleeding [20][21][22][23][24][25][26][27][28] and compressive strength enhancing additive [12,13,[27][28][29][30][31].…”

Section: Introductionmentioning

confidence: 99%

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SCC modification by use of amorphous nano-silica

Quercia

Spiesz

Hüsken

et al. 2014

Cement and Concrete Composites

229

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a b s t r a c tIn this study two different types of nano-silica (nS) were applied in self-compacting concrete (SCC), both having similar particle size distributions (PSD), but produced through two different processes: fumed powder silica and precipitated silica in colloidal suspension. The influence of nano-silica on SCC was investigated with respect to the properties of concrete in fresh (workability) and hardened state (mechanical properties and durability). Additionally, the densification of the microstructure of the hardened concrete was verified by SEM and EDS analyses. The obtained results demonstrate that nano-silica efficiently used in SCC can improve its mechanical properties and durability. Considering the reactivity of the two applied nano-silicas, the colloidal type showed a higher reactivity at early age, which influenced the final SCC properties.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

SCC modification by use of amorphous nano-silica

Quercia

Spiesz

Hüsken

et al. 2014

Cement and Concrete Composites

229

View full text Add to dashboard Cite

show abstract

“…In this case, the use of a 64 superplasticizer is required in order to guarantee workability [9]. Furthermore, the 65 strong tendency of NS to agglomerate also may make it necessary to use a dispersing 66 additive in order to overcome this problem and to ensure enough reactive surface for the 67 filling effect and C-S-H formation [7,10,11]. Dispersing additives are the so-called 68 plasticizers or superplasticizers, which have a water reducing action on cement 69 materials.…”

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confidence: 99%

Influence of nanosilica and a polycarboxylate ether superplasticizer on the performance of lime mortars

Fernández

Durán

Navarro-Blasco

et al. 2013

Cement and Concrete Research

122

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39The effect of individual and combined addition of both nanosilica (NS) and 40 polycarboxylate-ether plasticizer (PCE) admixtures on aerial lime mortars was studied. 41The sole incorporation of NS increased the water demand, as proved by the mini-spread 42 flow test. An interaction between NS and hydrated lime particles was observed in fresh 43 mixtures by means of particle size distribution studies, zeta potential measurements and 44 optical microscopy, giving rise to agglomerates. On the other hand, the addition of PCE 45 to a lime mortar increased the flowability and accelerated the setting process. PCE was 46shown to act in lime media as a deflocculating agent, reducing the particle size of the 47 agglomerates through a steric hindrance mechanism. Mechanical strengths were 48 improved in the presence of either NS or PCE, the optimum being attained in the 49 combined presence of both admixtures that involved relevant microstructural 50 modifications, as proved by pore size distributions and SEM observations. 51 the technical characteristics of the final product and/or addressing environmental issues 58 [3][4][5]. The addition of nanosilica (NS) has attracted increasing interest because of the 59 filling effect, which improves the particle size distribution, thus reducing porosity, and 60 the pozzolanic reaction between NS and calcium hydroxide (CH) yielding calcium 61 silicate hydrates (C-S-H). These actions result in enhanced mechanical strength [6][7][8]. 62The filling of the interparticle space leads to a denser packing and reduces the water 63 demand, as there is no need to fill the space with water. In this case, the use of a 64 superplasticizer is required in order to guarantee workability [9]. Furthermore, the 65 strong tendency of NS to agglomerate also may make it necessary to use a dispersing 66 additive in order to overcome this problem and to ensure enough reactive surface for the 67 filling effect and C-S-H formation [7,10,11]. Dispersing additives are the so-called 68 plasticizers or superplasticizers, which have a water reducing action on cement 69 materials. When superplasticizers are added, workability at a constant water/cement 70 ratio is improved. Alternatively, the same workability as that of plain cement paste can 71 be reached with an outstanding reduction in water content. In the latter case, cement 72 materials with higher mechanical strengths can be obtained. The adsorption of the 73 plasticizer molecules on the solid particles, either by modifying the surface charge (zeta 74 potential) of the particles, thus increasing the electrostatic repulsion, or by steric 75 hindrance, causes a dispersing action, which has been claimed to be responsible for the 76 increase in fluidity of the cement paste [12]. The interaction between the 77 superplasticizer and the particles of the binder could be affected by the presence of 78 4 mineral additions (such as NS, silica fume or fly ash), which means that the 79 compatibility between them needs to be studied [13]. 80 81The interest in usi...

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“…In both cases, the addition of nano-scale particles improves the performance of cement; for instance, an improvement of rheological properties has been observed in the fresh cement mixtures [10], whereas, the compressive strength was increased in the hardened state [11]. The nano-scale observations revealed the nano-crystallized structure of C-S-H cement phase [12,13], and the nanoparticles work as a nucleation site for the cement phase promoting a cement hydration [14,15].…”

Section: Introductionmentioning

confidence: 99%

Effect of Adding Silicon Carbide and Titanium Carbide Nanoparticles on the Performance of the Cement Pastes

Mahawish¹,

Ibrahim²,

Jawad³

et al. 2017

J Civil Environ Eng

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The nanoparticle is used into cement pastes to improve its engineering properties. In this paper, silicon carbide (SiC) and titanium carbide (TiC) nanoparticles with a particle size (20 nm) were added at different percentages 1%, 2%, 3%, 4%, 5% and 6%) to cement pastes. The cement pastes were tested for mechanical and physical properties at different curing ages (7, 14, 21, and 28 days). The results of mechanical and physical tests showed a significant improvement with all mixtures of nanoparticles, and the maximum values of the mechanical and physical tests were associated with the cement paste samples with 5% TiC at curing time 28 days. SEM results showed the control samples of cement paste had needle shapes to structure Ca(OH)2 with the of large pores. However, adding of nanoparticles resulted in absence of needle shape structures, pore spaces and produced a homogeneous structure of compounds (C-SH).

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Mortars with nano-SiO2 and micro-SiO2 investigated by experimental design

Cited by 197 publications

References 13 publications

SCC modification by use of amorphous nano-silica

SCC modification by use of amorphous nano-silica

Influence of nanosilica and a polycarboxylate ether superplasticizer on the performance of lime mortars

Effect of Adding Silicon Carbide and Titanium Carbide Nanoparticles on the Performance of the Cement Pastes

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