Calcium silicate hydrates: Solid and liquid phase composition

Abstract

This paper presents a review on the relationship between the composition, the structure and the solution in which calcium silicate hydrate (C-S-H) is equilibrated. The silica chain length in C-S-H increases with the silicon concentration and the calcium content in the interlayer space with the calcium concentrations. Sodium and potassium are taken up in the interlayer space, preferentially at low calcium concentrations and thus by low Ca/Si C-S-H. Aluminium uptake in C-S-H increases strongly at higher aluminium concentrations in the solution. At low Ca/Si, aluminium substitutes silica in the bridging position, at Ca/Si > 1 aluminium is bound in TAH. Recently developed thermodynamic models are closely related to the structure of C-S-H and tobermorite, and able to model not only the solubility and the chemical composition of the C-S-H, but also to predict the mean silica chain length and the uptake of aluminium.

Mineralogical stabilization of Ternesite in Belite Sulfo-Aluminate Clinker elaborated from limestone, shale and phosphogypsum

“…This result is agrees with previous published results [18,24,25]. The strätlingite, C 2 ASH 3 , is formed from the reaction of belite which consumes a portion of AH3 produced by hydration of ye'elimite according to the reaction (5) The same results, deduced here, are obtained by Y.Shen and al.…”

Creep Mechanisms of Calcium–Silicate–Hydrate: An Overview of Recent Advances and Challenges

“…This would be a reason why the creep of semiamorphous C-S-H prepared by synthesis is higher than that of tobermorite minerals as experimentally measured (Nguyen et al 2014). However, it is still unknown how to accurately access the atomic ordering in C-S-H due to its small dimensions, although some advanced nanoscale characterization techniques have shed some lights on it (Nonat 2004;Lothenbach and Nonat 2015;Chae et al 2013). In addition, the chemical composition and pore solution species are both likely to affect the structure of C-S-H (Lothenbach and Nonat 2015).…”

“…However, it is still unknown how to accurately access the atomic ordering in C-S-H due to its small dimensions, although some advanced nanoscale characterization techniques have shed some lights on it (Nonat 2004;Lothenbach and Nonat 2015;Chae et al 2013). In addition, the chemical composition and pore solution species are both likely to affect the structure of C-S-H (Lothenbach and Nonat 2015). Therefore, it is not surprising that the Ca/Si ratio of C-S-H, additive of admixtures (e.g.…”

A new model for the C-S-H phase formed during the hydration of Portland cements

“…Despite some recent progress in understanding the mechanism of cement hydration, [11] and also in 146 understanding the structure of the C-S-H formed, [3] …”