Journal
MINERALS
Volume 11, Issue 3, Pages -Publisher
MDPI
DOI: 10.3390/min11030297
Keywords
in situ X-ray diffraction; hydration; temperature; cement; Rietveld analysis
Funding
- Slovenian Research Agency [1000-181502, BI-AT/18-19-014]
- Austrian Agency for International Cooperation in Education and Research (OeAD) [SI-16-2018]
Ask authors/readers for more resources
The study investigated the influence of temperature on the early hydration of belite-calcium sulfoaluminate cements, finding that higher temperatures significantly accelerated hydration reactions and affected the potential crystallite size.
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 degrees 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 degrees C to 40 degrees C, than it was increased from 40 degrees C to 60 degrees 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.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available