29Si NMR investigation of the effect of acetic and oxalic acids on Portland-limestone cement hydration

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68378297%3A_____%2F22%3A00563761" target="_blank" >RIV/68378297:_____/22:00563761 - isvavai.cz</a>

Výsledek na webu

<a href="https://doi.org/10.4028/p-73l5m1" target="_blank" >https://doi.org/10.4028/p-73l5m1</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.4028/p-73l5m1" target="_blank" >10.4028/p-73l5m1</a>

Jazyk výsledku

angličtina

Název v původním jazyce

29Si NMR investigation of the effect of acetic and oxalic acids on Portland-limestone cement hydration

Popis výsledku v původním jazyce

The use of carboxylic acids in mix design alters the hydration process of cement, the resulting pore structure of the obtained cement paste, and, consequently, the mechanical properties of concrete. All these changes are directly related to the structure of the calcium silicate hydrate phase. In the present study, the effect of acetic acid and oxalic acid on the hydration of Portlandlimestone cement was monitored using solid state 29Si NMR spectroscopy. The results showed thatnacetic acid facilitated alite and belite hydration, however, the formation of polymerized silicate chains, incorporating Q2p species, begun later than in pure cement paste. Oxalic acid accelerated the polymerization, but slowed down alite and belite hydration. Such behaviors may correspond to decreased porosity (acetic acid addition) and increased strength (oxalic acid addition). Both acids accelerated belite hydration, compared to the pure paste, likely due to an increased acidity of the pore solution. The findings provide structural information about C─S─H phase, to be considered for thaumasite sulfate attack investigations on Portland-limestone cement pastes containing carboxylic acids.

Název v anglickém jazyce

29Si NMR investigation of the effect of acetic and oxalic acids on Portland-limestone cement hydration

Popis výsledku anglicky

The use of carboxylic acids in mix design alters the hydration process of cement, the resulting pore structure of the obtained cement paste, and, consequently, the mechanical properties of concrete. All these changes are directly related to the structure of the calcium silicate hydrate phase. In the present study, the effect of acetic acid and oxalic acid on the hydration of Portlandlimestone cement was monitored using solid state 29Si NMR spectroscopy. The results showed thatnacetic acid facilitated alite and belite hydration, however, the formation of polymerized silicate chains, incorporating Q2p species, begun later than in pure cement paste. Oxalic acid accelerated the polymerization, but slowed down alite and belite hydration. Such behaviors may correspond to decreased porosity (acetic acid addition) and increased strength (oxalic acid addition). Both acids accelerated belite hydration, compared to the pure paste, likely due to an increased acidity of the pore solution. The findings provide structural information about C─S─H phase, to be considered for thaumasite sulfate attack investigations on Portland-limestone cement pastes containing carboxylic acids.

Druh

D - Stať ve sborníku

CEP obor

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OECD FORD obor

20501 - Materials engineering

Projekt

<a href="/cs/project/GC21-35772J" target="_blank" >GC21-35772J: Změny mikrostruktury směsných cementových past s vápencem na základě kombinovaného vlívu síranových a chloridových iontů</a><br>

Návaznosti

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

Rok uplatnění

2022

Kód důvěrnosti údajů

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

Název statě ve sborníku

Materials Science Forum

ISBN

978-3-0364-0186-7

ISSN

1662-9752

e-ISSN

—

Počet stran výsledku

6

Strana od-do

247-252

Název nakladatele

Trans Tech Publications

Místo vydání

Baech

Místo konání akce

Brno

Datum konání akce

2. 12. 2021

Typ akce podle státní příslušnosti

WRD - Celosvětová akce

Kód UT WoS článku

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