Influence of metakaolin on pH of cement paste

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21110%2F21%3A00353964" target="_blank" >RIV/68407700:21110/21:00353964 - isvavai.cz</a>

Výsledek na webu

<a href="https://aip.scitation.org/doi/abs/10.1063/5.0069758" target="_blank" >https://aip.scitation.org/doi/abs/10.1063/5.0069758</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1063/5.0069758" target="_blank" >10.1063/5.0069758</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Influence of metakaolin on pH of cement paste

Popis výsledku v původním jazyce

The influence of metakaolin (MK) additive in ordinary Portland cement (OPC) paste to its pH was studied by direct pore solution pH measurement and by XRD and thermal analysis. This research program was motivated by importance of pH for reinforcement corrosion; while the steel demands the high pH for its corrosion protection, the basalt-based reinforcement elements are damaged in the high pH. The initial hypothesis thus was to reduce the concrete pH by adding of MK. The mixtures containing 0-20% of MK were prepared and characterized after 28 days. MK presence reduced the pH due to proceeding pozzolanic reaction from 12.57 to 12.39, i.e. in terms of OH- molarity from 0.0372 mol/L to 0.0245 mol/L. The pH decrease was obviously caused by pozzolanic reaction between MK and Ca(OH)2 generated in OPC hydration; it means that blended cements are more suitable for basalt elements reinforcement than OPC. There was certain difference between TGA and XRD results indicating, that part of the present Ca(OH)2 is not crystallized in form of portlandite.

Název v anglickém jazyce

Influence of metakaolin on pH of cement paste

Popis výsledku anglicky

The influence of metakaolin (MK) additive in ordinary Portland cement (OPC) paste to its pH was studied by direct pore solution pH measurement and by XRD and thermal analysis. This research program was motivated by importance of pH for reinforcement corrosion; while the steel demands the high pH for its corrosion protection, the basalt-based reinforcement elements are damaged in the high pH. The initial hypothesis thus was to reduce the concrete pH by adding of MK. The mixtures containing 0-20% of MK were prepared and characterized after 28 days. MK presence reduced the pH due to proceeding pozzolanic reaction from 12.57 to 12.39, i.e. in terms of OH- molarity from 0.0372 mol/L to 0.0245 mol/L. The pH decrease was obviously caused by pozzolanic reaction between MK and Ca(OH)2 generated in OPC hydration; it means that blended cements are more suitable for basalt elements reinforcement than OPC. There was certain difference between TGA and XRD results indicating, that part of the present Ca(OH)2 is not crystallized in form of portlandite.

Druh

D - Stať ve sborníku

CEP obor

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OECD FORD obor

20505 - Composites (including laminates, reinforced plastics, cermets, combined natural and synthetic fibre fabrics; filled composites)

Projekt

<a href="/cs/project/GA21-00800S" target="_blank" >GA21-00800S: Chemické a fyzikální interakce výztuže na čedičové bázi s cementovou matricí</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2021

Kód důvěrnosti údajů

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

Název statě ve sborníku

AIP Conference Proceedings 2429

ISBN

978-0-7354-4139-2

ISSN

0094-243X

e-ISSN

1551-7616

Počet stran výsledku

6

Strana od-do

"020012-1"-"020012-6"

Název nakladatele

AIP Conference Proceedings

Místo vydání

New York

Místo konání akce

Kazimierz Dolny

Datum konání akce

1. 9. 2021

Typ akce podle státní příslušnosti

WRD - Celosvětová akce

Kód UT WoS článku

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