Calcium sulfoaluminate-belite cements: Opportunities and challenges

There has been a significant push in the direction of reducing carbon footprint of concrete through the development of alternative binders. To that end, calcium sulfoaluminate-belite (CSAB) cement is a promising alternative due to its lower carbon footprint and higher resistance against shrinkage cracking. Lower burning temperature and lesser amount of limestone requirement for CSAB cement manufacturing can provide up to 30% reduction in carbon footprint of concrete. Moreover, the porous nature of CSAB cement clinker lowers the grinding energy requirement. The main constituents of CSAB cement are ye’elimite, belite, ferrite, and calcium sulfate. Hydration of ye’elimite in presence of calcium sulfate results in the formation of ettringite, leading to early-age expansion. For shrinkage-compensating property, CSAB cement can be formulated as an expansive cement system. Nonetheless, the use of CSAB cement in concrete has been limited to niche applications. This paper reviews the manufacturing, composition, mechanical properties and durability characteristics of CSAB cement. The current challenges with respect to its wider application in concrete are also discussed. © 2020, Associated Cement Companies Ltd.. All rights reserved.