Scholarly record
FORMATION AND EARLY DEVELOPMENT OF MAGNESIUM SILICATE HYDRATE UNDER CONTROLLED CURING CONDITIONS
Abstract
Magnesium silicate hydrate (M-S-H) is a promising binder phase for the development of low carbon cementitious materials. However, its formation mechanisms, phase evolution, and dependence on curing conditions remain poorly understood, particularly during the early and intermediate stages of hydration. This study investigates the formation and development of M S-H in model systems using reactive MgO and diatomite as the silica source, focusing on Mg/Si molar ratios of 0.75, 0.90, 1.05, and 1.20 under controlled curing at 40 degrees Celsius and relative humidity exceeding 95% for 30 and 60 days. Phase evolution was monitored by X-ray diffraction (XRD) and microstructural development by scanning electron microscopy (SEM) combined with energy dispersive spectroscopy (EDS). The results demonstrate that elevated temperature curing is essential for M-S-H gel formation within practically relevant timescales, with characteristic amorphous XRD humps appearing exclusively in thermally activated samples and intensifying with prolonged curing duration. Lower Mg/Si ratios (0.75–0.90) promoted more advanced M-S-H development, while higher ratios retained excess unreacted brucite. SEM-EDS confirmed progressive infilling of diatomite frustule pores by fibrous M-S-H gel, with Mg/Si ratios in gel-rich zones of 0.6–1.0, consistent with reported M S H stoichiometry. This study provides the first systematic characterisation of M-S-H formation in MgO–diatomite systems under controlled curing, demonstrating that diatomite is a viable reactive silica source provided sufficient thermal activation is applied.
Publication details
References15
R. M. Andrew, "Global CO 2 emissions from cement production, 1928-2017," Earth System Science Data, vol. 10, no. 4, pp. 2213-2239, 2018.
K. Zheng, X. Xie, G. Gou, X. Chen, Y. Huang, and J. Gao, "Comparative study on characteristics and microstructure of magnesium silicate hydrate utilizing quartz and silica fume as siliceous raw materials," Case Studies in Construction Materials, vol. 19, p. e02313, 2023, DOI: 10.1016/j.cscm.2023.e02313.
M. A. Shand, "5 - Magnesium silicate hydrate cements," in Magnesia Cements. Oxford: Elsevier, 2020, pp. 173-181.
C. Sonat, W. Teo, and C. Unluer, "Performance and microstructure of MgO-SiO2 concrete under different environments," Construction and Building Materials, vol. 184, pp. 549-564, 2018, DOI: 10.1016/J.CONBUILDMAT.2018.07.032.
E. Bernard, B. Lothenbach, A. German, and F. Winnefeld, "Effect of carbonates on the formation of magnesium silicate hydrates (MSH) and magnesium alumino silicate hydrates (MASH)," in International RILEM Conference on Synergising expertise towards sustainability and robustness of CBMs and concrete structures, 2023: Springer, pp. 553-561, DOI: 10.1007/978-3-031-33187-9_51.
C. Sonat and C. Unluer, "Development of magnesium-silicate-hydrate (MSH) cement with rice husk ash," Journal of Cleaner Production, vol. 211, pp. 787-803, 2019, DOI: 10.1016/J.JCLEPRO.2018.11.246.
M. Simoni, C. L. Woo, H. Zhao, D. Iuga, P. Svora, T. Hanein, H. Kinoshita, and B. Walkley, "Reaction mechanisms, kinetics, and nanostructural evolution of magnesium silicate hydrate (MSH) gels," Cement and Concrete Research, vol. 174, p. 107295, 2023, DOI: 10.1016/j.cemconres.2023.107295.
T. Zhang, E. Dieckmann, S. Song, J. Xie, Z. Yu, and C. Cheeseman, "Properties of magnesium silicate hydrate (MSH) cement mortars containing chicken feather fibres," Construction and Building Materials, vol. 180, pp. 692-697, 2018, DOI: 10.1016/J.CONBUILDMAT.2018.05.292.
A. Nye, S. Vineet, O. Christopher, S. Barnaby, and C. Chris, "Use of olivine for the production of MgO-SiO2 binders," 2021, DOI: 10.3389/FBUIL.2021.640243.
Y. Zhang, M. Nath, J. Wang, Y. Li, S. Zhang, T. Zhu, Z. Xue, and J. Chen, "Temperature-dependent rehydration of magnesium silicate hydrate (MSH): Development of no-cement binder through MD/DFT validation," Ceramics International, vol. 48, no. 5, pp. 7063-7070, 2022, DOI: 10.1016/J.CERAMINT.2021.11.265.
Y. Akınay, "Synthesis and dielectric properties of magnesium silicate hydrate deposited with SnO2," Sakarya University Journal of Science, vol. 24, no. 3, pp. 455-459, 2020, DOI: 10.16984/SAUFENBILDER.659958.
Q. Zhang, X. Zhang, L. Wang, and S. Zhang, "Synthesis, characterization, and cementitious activity of the magnesium silicate hydrate and calcium silicate hydrate from coal gangue," Molecules, vol. 30, no. 8, p. 1725, 2025, DOI: 10.3390/molecules30081725.
Y. Jia, X. Zou, Y. Jiang, Y. Zou, S. Song, J. Qin, Y. Wang, and L. Zhu, "Study on the stability of low-carbon magnesium cementitious materials in sulfate erosion environments," Materials, vol. 16, no. 11, p. 4042, 2023, DOI: 10.3390/ma16114042.
T. K. Ivanova, I. P. Kremenetskaya, V. V. Marchevskaya, M. V. Slukovskaya, and S. V. Drogobuzhskaya, "Magnesium Silicate Binding Materials Formed from Heat-Treated Serpentine-Group Minerals and Aqueous Solutions: Structural Features, Acid-Neutralizing Capacity, and Strength Properties," Materials, vol. 15, no. 24, p. 8785, 2022, DOI: 10.3390/ma15248785.
Y. Peng and C. Unluer, "Magnesium-silicate-hydrate cement pastes: Rheological behavior and strength development," Case studies in Construction materials, vol. 20, p. e03400, 2024, DOI: 10.1016/j.cscm.2024.e03400.