Understanding Cement Hydration of Cemented Paste Backfill: DFT Study of Water Adsorption on Tricalcium Silicate (111) Surface

Qi, Chongchong; Liü, Lang; He, Jianyong; Chen, Qiusong; Yu, Li‐Juan; Liu, Pengfei

doi:10.3390/min9040202

Cited by 47 publications

(36 citation statements)

References 53 publications

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“…It is also worth noting that in addition to zeolites, calcium silicates also play an important role in the composition of Portland cement, and thus have significant environmental impact. 43 There has been much work done in the field of cement science that seeks to optimize cement composition, improve cement hydration rates, and in turn lower the carbon footprint of global cement use. [44][45][46]…”

Section: Cyclizationmentioning

confidence: 99%

Understanding initial zeolite oligomerization steps with first principles calculations

et al. 2020

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Zeolites are porous aluminosilicate materials that find various applications in the chemical industry in separations, catalysis, ion exchange, and so forth. However, despite their widespread use, the reaction mechanisms occurring during zeolite growth are still unclear. Herein, we use density functional theory calculations to gain insights into the thermodynamics of oligomerization, which constitute the initial steps of zeolite growth. By taking into consideration solvent and temperature effects, our results demonstrate that the growth of aluminosilicate systems is significantly more exothermic than their pure silicate counterparts. Under pH neutral conditions, water prefers to dissociate on the early-growth-stage aluminosilicate complexes rather than desorb, thus generating potential Brønsted acid sites on the oligomers. Additionally, (alumino)silicate growth pathways are evaluated in the presence of Na + cation, as well as the Ca 2+ cation for the pure silicate pathway. The presence of cations increases the exothermicity of growth, with Ca 2+ exhibiting the most energetically favorable growth environment for the silicate systems. Importantly, we demonstrate through reaction extent analysis that the presence of cations modulates the speciation of the formed oligomers, with Na + favoring linear species in addition to the generally preferred cyclic ones. Overall, this work provides a fundamental understanding of the thermodynamics of complex reaction paths that occur during early stages of zeolite growth and suggests that the initial growth steps can have significant impact on the final zeolite structure.

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Section: Cyclizationmentioning

confidence: 99%

Understanding initial zeolite oligomerization steps with first principles calculations

et al. 2020

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“…At the same time the structure, elastic, and mechanic properties have been several reported by Ayuela and co-workers since a few years ago [5][6][7][8]. Other recent studies proposed the chemical structure of some cement clusters studied at the DFT level [9].…”

Section: Introductionmentioning

confidence: 62%

Adsorption of PET on concrete nano-structures: an in-silico assay

Bárcenas¹,

Aguilera‐Granja²,

Ramírez-García³

et al. 2020

Proceedings of the 5th World Congress on Recent Advances in Nanotechnology

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The present work analyses the first approach of the use of PET as a component of a sustainable alternative to generate an enforced concrete. Through the computational study of one nanostructured concrete model and two monomers PET system, the adsorption energies of PET on concrete were evaluated in the present work, which was exergonic (-7.67 eV) and therefore can be formulated as a perspective a sustainable concrete using one of the principal waste in the world, applied to the construction industry.

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“…At the same time, it was found that the variation of temperature rise rate with time is different for backfill bodies at different concentrations. This is because the heat release rate of the cement hydration reaction is affected by both time and temperature: different temperatures of backfill bodies at the same time leads to different heat release rates, and then the subsequent temperature rise is different [41].…”

Section: Temperature Distributionmentioning

confidence: 99%

Experimental Research on Heat Transfer and Strength Analysis of Backfill with Ice Grains in Deep Mines

2019

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In deep mines, two urgent problems are a high temperature thermal environment and solid waste. Filling the goaf with slurry mixed with ice grains is an effective way to solve these two problems simultaneously. The thermal property and mechanical property of the ice-added backfill have a great influence on the cooling effect in the deep mine. In this study, an experimental facility for measuring the temperature distribution of ice-added backfill slurry was established, and the temperature of backfill slurry with different proportions was measured. Then, the thermal properties of temperature distribution and cooling capacity and the mechanical property of uniaxial compressive strength of the backfill specimens were analyzed, and the results indicated the following: firstly, the cooling capacity of ice-added backfill specimens is negatively related with the slurry concentration C and is positively related with the ice-water ratio Ω; secondly, the strength of backfill specimens is affected by the slurry concentration C and ice-water ratio Ω by a contrary law compared to the cooling capacity; thirdly, ice-added backfill slurry with an ice-water ratio Ω of 1:1 has the best mechanical property after solidification. The effects of the slurry concentration and ice-water ratio on the thermal and mechanical properties were analyzed, and the results indicated that the optimum proportion of ice-added backfill slurry is a slurry concentration of 74% and an ice-water ratio of 1:1 in the present research range. This study is significant for the deep mine cooling method with ice-added backfill.

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Understanding Cement Hydration of Cemented Paste Backfill: DFT Study of Water Adsorption on Tricalcium Silicate (111) Surface

Cited by 47 publications

References 53 publications

Understanding initial zeolite oligomerization steps with first principles calculations

Understanding initial zeolite oligomerization steps with first principles calculations

Adsorption of PET on concrete nano-structures: an in-silico assay

Experimental Research on Heat Transfer and Strength Analysis of Backfill with Ice Grains in Deep Mines

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