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

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68378297%3A_____%2F23%3A00573017" target="_blank" >RIV/68378297:_____/23:00573017 - isvavai.cz</a>

Result on the web

<a href="https://doi.org/10.1007/978-3-031-33187-9_88" target="_blank" >https://doi.org/10.1007/978-3-031-33187-9_88</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1007/978-3-031-33187-9_88" target="_blank" >10.1007/978-3-031-33187-9_88</a>

Result language

angličtina

Original language name

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

Original language description

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.

Czech name

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Czech description

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Type

D - Article in proceedings

CEP classification

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OECD FORD branch

20501 - Materials engineering

Project

<a href="/en/project/GC21-35772J" target="_blank" >GC21-35772J: Microstructural changes in Portland-limestone cement pastes under the combined effect of sulfate and chloride ions</a><br>

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2023

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Article name in the collection

International RILEM Conference on Synergising Expertise towards Sustainability and Robustness of Cement-based Materials and Concrete Structures. SynerCrete’23

ISBN

978-3-031-33186-2

ISSN

2211-0844

e-ISSN

2211-0852

Number of pages

8

Pages from-to

966-973

Publisher name

Springer

Place of publication

Cham

Event location

Milos Island

Event date

Jun 14, 2023

Type of event by nationality

WRD - Celosvětová akce

UT code for WoS article

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