DOI: 10.1002/cepa.70851 ISSN: 2509-7075
Comparison of different methods for ettringite synthesis – influence on crystal length
Lukas Koops, Christiane Rößler, Horst‐Michael LudwigAbstract
For realistic results the correct morphology of synthetic ettringite is an essential part in rheological measurements of cement model systems. Most of the time synthetic ettringite is made by the combination of two clear solutions of calcium hydroxide and aluminium sulphate. Because of the poor solubility of calcium hydroxide, the supersaturation of ettringite is comparatively low. Thus, the ettringite crystallises in thin long prisms of up to several μm in length. Other synthesis methods seem more effective to produce nano‐ettringite, which is found in early age cementitious systems. This work aims to compare different methods to produce ettringite to get the crystal morphology comparable to those in Portland‐cement systems.