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Exposure of Portland-limestone cement – metakaolin paste to cold chloride-sulfate environment: NMR spectroscopy assessment of structural changes in hydrated phases and relation to chloride ingress
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SYSNO ASEP 0573017 Document Type C - Proceedings Paper (int. conf.) R&D Document Type Conference Paper Title Exposure of Portland-limestone cement – metakaolin paste to cold chloride-sulfate environment: NMR spectroscopy assessment of structural changes in hydrated phases and relation to chloride ingress Author(s) Sotiriadis, Konstantinos (UTAM-F) RID, ORCID, SAI
Mazur, A. (RU)
Tolstoy, P. M. (RU)
Ševčík, Radek (UTAM-F) RID, SAI, ORCIDNumber of authors 4 Source Title International RILEM Conference on Synergising Expertise towards Sustainability and Robustness of Cement-based Materials and Concrete Structures. SynerCrete’23, 2. - Cham : Springer, 2023 / Jędrzejewska A. - ISSN 2211-0844 - ISBN 978-3-031-33186-2 Pages s. 966-973 Number of pages 8 s. Publication form Print - P Action International RILEM Conference on Synergising Expertise towards Sustainability and Robustness of Cement-based Materials and Concrete Structures. SynerCrete’23 Event date 14.06.2023 - 16.06.2023 VEvent location Milos Island Country GR - Greece Event type WRD Language eng - English Country CH - Switzerland Keywords Portland-limestone cement ; metakaolin ; chloride ingress ; sulfate attack ; NMR Spectroscopy OECD category Materials engineering R&D Projects GC21-35772J GA ČR - Czech Science Foundation (CSF) Institutional support UTAM-F - RVO:68378297 EID SCOPUS 85162179626 DOI 10.1007/978-3-031-33187-9_88 Annotation The effect of sulfates on chloride ingress and microstructure in Portland-limestone cement – metakaolin paste was studied. Crystalline and amorphous phases were investigated with X-ray powder diffraction and solid-state nuclear magnetic resonance spectroscopy. Free chlorides were determinedwith ion chromatography. The influence of metakaolin on the microstructure and chloride binding was highlighted by comparing the material with pure Portland-limestone cement paste. The results showed that the high Al content in metakaolin increased the chloride binding ability of the binder and Al incorporation in the C–S–H phase. Close to the surface, metakaolin admixture contributed in greater polymerization of the silicate chains of C–S–H, while larger amounts of unreacted clinker were observed, compared to deeper parts. At higher depths, chlorides bound in the form of Friedel’s salt and free chlorides, were considerably reduced, attributed to refinement of the matrix. The presence of sulfates in the exposure solution affected chloride binding by inhibiting the formation of Friedel’s salt and increasing free chlorides in the pore solution. Moreover, sulfates decreased the polymerization of the silicate chains in the C–S–H of the Portland-limestone cement – metakaolin paste and reduced the hydration of clinker in pure Portland-limestone cement paste. Workplace Institute of Theoretical and Applied Mechanics Contact Kulawiecová Kateřina, kulawiecova@itam.cas.cz, Tel.: 225 443 285 Year of Publishing 2024 Electronic address https://doi.org/10.1007/978-3-031-33187-9_88
Number of the records: 1