Hydration Behavior of Calcium Alumina Cements with Different Amounts of Impurities

• Published in: Interceram Vol. 65; no. 6-7; pp. 250 - 254
• Main Authors: Shang, Xuejun, Ye, Guotian, Zhai, Pengtao, Wang, Qingfeng, Zhang, Chuanyin
• Format: Magazine Article
• Language: English
• Published: Wiesbaden Springer Fachmedien Wiesbaden 01-12-2016
• Subjects: Ceramics; Chemistry and Materials Science; Composites; Glass; Materials Science; Natural Materials; Refractories; impurity; setting time; hydration; calcium aluminate cement
• ISSN: 0020-5214; 2523-8957
• DOI: 10.1007/BF03401177

The influence of impurities such as SiO
2
and F
2
O
3
on the hydration behavior of calcium aluminate cement (CAC) was studied in this work. The hydration of the cement was characterized by the exothermic profile of cement pastes, and the dissolution-precipitation rate of the cement aqueous suspension was evaluated by electrical conductivity measurement. In order to analyze the resulting hydration products, the cement hydration was terminated via the freeze-vacuum drying method at the designated times. Then the phase development and microstructure evolution during cement hydration were investigated by XRD and SEM, respectively. The results indicate that the hydration rate is faster when the cement contains a higher amount of impurities. It is proposed that the higher hydration rate of the cement is probably related to the lattice imperfection of the main calcium aluminates in CAC.