Quantitative Rietveld analysis of the decomposition of hardened rapid sulphoaluminate cement after exposure to elevated temperatures

• Published in: Archives of Civil and Mechanical Engineering 2021-08, Vol.21 (3), p.119, Article 119
• Main Authors: Tchekwagep, Jean Jacques Kouadjo, Chen, Dangui, Mukhopadhyay, Anol K., Wang, Shoude, Huang, Shifeng, Cheng, Xin
• Format: Article
• Language: English
• Subjects: Cement; Cement paste; Civil Engineering; Concrete; Decomposition; Dehydration; Engineering; High temperature; Hydration; Mechanical Engineering; Original Article; Packaging; Porosity; Portland cements; Structural Materials; Structural stability; Sulfoaluminate cement; Temperature
• ISSN: 1644-9665; 2083-3318; 1644-9665
• DOI: 10.1007/s43452-021-00265-9

Concrete made from rapid sulphoaluminate cement is widely used today, especially in China. It is likely to continue gaining popularity since its manufacture produces less CO 2 than the process of manufacturing ordinary Portland cement. Elevated temperatures are among the most serious threats to the structural stability of this product. In the present study, laboratory tests were carried out, through Rietveld analysis and other systematic testing, on samples of hardened rapid sulphoaluminate cement paste exposed to six different temperatures. As the temperature increased, the content of minerals that contribute to rapid sulphoaluminate cement strength was reduced. There was also an increase in porosity. The results show that the chemical dehydration of rapid sulphoaluminate cement after exposure to elevated temperatures is great enough to increase the local pores’ absorption, a change that can be fatal to rapid sulphoaluminate cement concrete’s strength. This understanding could help us characterize strength reduction in a more effective manner, not just in laboratory samples but also in actual structures containing rapid sulphoaluminate cement that has been exposed to elevated temperatures.