Effect of hydrothermal nanosilica on the performances of cement concrete

Потапов, В. В.; Efimenko, Yuriy; Fediuk, Roman; Gorev, D.S.

doi:10.1016/j.conbuildmat.2020.121307

Cited by 27 publications

(9 citation statements)

References 47 publications

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“…Hydrothermal synthesis of SiO 2 nanoparticles is the new technological method with a low production cost, high density of silanol groups, low toxicity, excluding the use of chemical reagents and other green chemistry methods of nanoparticle synthesis [ 1 , 2 , 3 ], and allows to obtain different forms of nanosilica—sols, gels, powders, products of the sol-gel process applied in concrete, agricultural plants, medicines, and other materials [ 4 , 5 , 6 , 7 ]. The technology of hydrothermal synthesis includes the stages of OSA polymerization, ultrafiltration membrane concentration of nanoparticles, the sol-gel process, vacuum sublimation, and others [ 4 , 5 , 6 ].…”

Section: Introductionmentioning

confidence: 99%

“…In [ 35 ], the model of Weres-Yi-Tsao [ 29 ] has been applied to experimental results in hydrothermal solutions because it can predict not only time dependence of the OSA concentration but also evaluate how the average size of SiO 2 nanoparticles depends on time. The main purpose of this work was to investigate nanoparticle size distribution dependence on the temperature, ionic strength, and other parameters of the polymerization process needed to regulate the characteristics of nanosilica sol, gel, and powders produced using the technology of hydrothermal synthesis [ 4 , 5 , 6 , 7 ]. For this purpose, it is necessary: (1) to study the dependence of surface tension σ sw , rate of molecular deposition R md , and Zeldovich factor Z on the temperature and pH to explain the mechanisms of their influence on the results of the polymerization process; (2) to examine the dependence of the average nanoparticle size and induction period on temperature, pH, and ionic strength; (3) to study the nanoparticle size distribution under conditions of time variable temperatures; (4) to verify the results of the numerical simulation with the experimental data in wide range of T, pH, and I s ; and (5) to compare the results of the numerical simulation under time-variable temperature conditions at different technological stages of the hydrothermal sol production with the results of determining the average size of SiO 2 nanoparticles and their size distribution using the DLS method.…”

Section: Introductionmentioning

confidence: 99%

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Silicic Acid Polymerization and SiO2 Nanoparticle Growth in Hydrothermal Solution

2022

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The approach of numerical simulation of orthosilicic acid OSA polymerization and SiO2 nanoparticle formation in hydrothermal solution have been developed based on the model of the homogeneous stage of nucleation and the subsequent growth of particles. The influence of surface tension on the interface of SiO2–water, the rate of molecular deposition, and Zeldovich factor Z were evaluated. Temperature dependence on time, pH, initial OSA concentration, and ionic strength are the main parameters that determine the kinetics of colloid phase formation, the final average size of SiO2 nanoparticles, and the particle size distribution and its polydispersity index. The results of the numerical simulation were verified with experimental data on OSA polymerization and measurement of nanoparticles sizes using the method of dynamic light scattering in a wide range of temperatures of 20–180 °C, pH = 3–9, SiO2 content Ct of 300–1400 mg/kg, and ionic strength Is of 0.0001–0.42 mol/kg. The results obtained can be used in the technology of hydrothermal synthesis of sols, gels, and nanopowders to regulate the kinetics of OSA polymerization and SiO2 nanoparticle growth, particle size distribution, morphology, and structure of products.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Silicic Acid Polymerization and SiO2 Nanoparticle Growth in Hydrothermal Solution

2022

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“…Nanoparticles can improve the concrete properties and reduce cement consumption in different countries [15][16][17]. The nanoparticles are usually used in concrete in powder form or distributed in solution [18][19][20]. The most important used nanoparticles are titanium nanoparticles (TiO2), aluminium nanoparticles (Al2O3), silica nanoparticles (SiO2), iron nanoparticles (Fe2O3), and clay nanoparticles (Nano-Clay) [21][22][23].…”

Section: Introductionmentioning

confidence: 99%

Retrofitting of RC Beams using Reinforced Self-compacting Concrete Jackets Containing Aluminum Oxide Nanoparticles

Faez

Sayari

Manei

2021

IJE

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The purpose of this study was to introduce a proposed method to retrofit RC beams. For this purpose self-compacting concrete containing aluminium oxide nanoparticles (ANPs) and silica fume (SF) was used in RC jackets. The laboratory experiment and numerical simulation were used to investigate the behavior of the beams. The experimental variables were included the amount of ANPs used in the jackets (0 and 2.5% by weight of cement) and the surface interaction between beam and jacket (75% and 100% of the side and bottom surfaces of the beam). Five RC beams with a length of 1.4 m and the same dimensions were made and subjected to four-point loading. After completing the laboratory steps, RC beams were simulated according to laboratory conditions using the finite element method and ABAQUS software. After verifying the used method, parametric analysis was performed and parameters such as beam span length (1.5, 3, 4.5 m), concrete jacket thickness (4, 8, and 12 cm), and the diameter of the bars used in the jacket (8, 10 and 12 mm) were examined. The results showed that the use of RC jackets containing ANPs, depending on the jacket thickness, the diameter of the bars used in the jacket, and the length of the beam span increased the beams flexural strength by 155 to 447%. It was observed that the crushing of concrete without nanoparticles compared to concrete contain nanoparticles is more severe because nanoparticles affected the concrete matrix and reduced its crushing in RC jackets.

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“…Much attention is paid to a direction in concrete technology associated with using nanostructures of carbon, oxides of silicon, titanium, iron, and others [1][2][3][4][5]. Among the modifying additives, the use of microfibrillar cellulose in cement composites is being actively studied.…”

Section: Introductionmentioning

confidence: 99%

Influence of Microfibrillated Cellulose Additive on Strength, Elastic Modulus, Heat Release, and Shrinkage of Mortar and Concrete

2021

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This work aimed to study the effect of a microfibrillated cellulose additive on strength, elastic modulus, heat release, and shrinkage of mortar and concrete. The dosage of the additive varies from 0.4 to 4.5% by weight of the cement. The change in strength with an increase in the dosage of the additive occurred in a wave-like manner. The uneven character of the change in the results also took place in the determination of heat release and shrinkage. In general, heat release and shrinkage decreased at increasing additive dosage. The additive showed the greatest decrease in the heat release of concrete at a content of 2%. The heat release of concrete practically differed little from the exotherm of the standard at an additive content of 1 and 1.5%. The addition of microfibrillated cellulose additive in small (0.5%) and large (1.5%) amounts reduced shrinkage compared to the reference, and at an intermediate content (1%), the shrinkage was higher than in the reference specimens. In this case, the water evaporation rate from concrete increased with an increase in the additive. With an increase in the additive dosage, the modulus of elasticity decreases. Thus, the microfibrillated cellulose additive provides concrete with lower values of the modulus of elasticity, heat release, and shrinkage, and the additive is recommended for use in concretes with increased crack resistance during the hardening period. The recommended additive content is 0.5% by weight of cement. At the specified dosage, it is possible to provide the class of concrete in terms of compressive strength C35/45.

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Effect of hydrothermal nanosilica on the performances of cement concrete

Cited by 27 publications

References 47 publications

Silicic Acid Polymerization and SiO2 Nanoparticle Growth in Hydrothermal Solution

Silicic Acid Polymerization and SiO2 Nanoparticle Growth in Hydrothermal Solution

Retrofitting of RC Beams using Reinforced Self-compacting Concrete Jackets Containing Aluminum Oxide Nanoparticles

Influence of Microfibrillated Cellulose Additive on Strength, Elastic Modulus, Heat Release, and Shrinkage of Mortar and Concrete

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