Quantitative in situ X-ray diffraction analysis of early hydration of belite-calcium sulfoaluminate cement at various defined temperatures

Maruša Borštnar (Avtor), Christian L. Lengauer (Avtor), Sabina Kramar (Avtor)

Povzetek

The influence of temperature on the early hydration of belite-calcium sulfoaluminate cements with two different calcium sulfate to calcium sulfoaluminate molar ratios was investigated. The phase composition and phase assemblage development of cements prepared using molar ratios of 1 and 2.5 were studied at 25, 40 and 60 ◦C by in situ X-ray powder diffraction. The Rietveld refinement method was used for quantification. The degree of hydration after 24 h was highest at ambient temperatures, but early hydration was significantly accelerated at elevated temperatures. These differences were more noticeable when we increased the temperature from 25 ◦C to 40 ◦C, than it was increased from 40 ◦C to 60 ◦C. The amount of calcium sulfate added controls the amount of the precipitated ettringite, namely, the amount of ettringite increased in the cement with a higher molar ratio. The results showed that temperature also affects full width at half maximum of ettringite peaks, which indicates a decrease in crystallite size of ettringite at elevated temperatures due to faster precipitation of ettringite. When using a calcium sulfate to calcium sulfoaluminate molar ratio of 1, higher d-values of ettringite peaks were observed at elevated temperatures, suggesting that more ions were released from the cement clinker at elevated temperatures, allowing a higher ion uptake in the ettringite structure. At a molar ratio of 2.5, less clinker is available in the cement, therefore these differences were not observed.

Ključne besede

in situ rentgenska difrakcija;hidratacija;temperatura;cement;rietveldova analiza;odprti dostop;in situ X-ray diffraction;hydration;temperature;rietveld analysis;open access;

Podatki

Jezik:	Angleški jezik
Leto izida:	2021
Tipologija:	1.01 - Izvirni znanstveni članek
Organizacija:	ZAG - Zavod za gradbeništvo Slovenije
Založnik:	MDPI AG
UDK:	620.1/.2
COBISS:	54931459
ISSN:	2075-163X
Št. ogledov:	6
Št. prenosov:	0
Ocena:	0 (0 glasov)
Metapodatki:

Ostali podatki

Sekundarni jezik:	Slovenski jezik
Sekundarne ključne besede:	in situ rentgenska difrakcija;hidratacija;temperatura;cement;rietveldova analiza;
Komentar vira:	Nasl. z nasl. zaslona; Opis vira z dne 12. 3. 2021;
Strani:	str. 1-21
Letnik:	ǂVol. ǂ11
Zvezek:	ǂno. ǂ3
Čas izdaje:	Mar. 2021
DOI:	10.3390/min11030297
ID:	19394479