Experimental study of calcium sulfoaluminate cement-based self-leveling compound exposed to various temperatures and moisture conditions: Hydration mechanism and mortar properties

The hydration mechanism and mortar properties of CSA cement-based SLC under various temperatures and moisture conditions have been investigated experimentally. The phase assemblage and hydration process were examined by XRD and DSC-TG analysis. Morphology and microstructure of hardened mortars were observed by SEM. Mortar properties including flowability, setting time, strength and dimensional change were measured. The results indicate that elevated temperatures accelerate the hydration process, leading to phase assemblage variation and heterogeneous microstructure. Despite of worse flowability and shorter setting time, strength is increased and dimensional change is reduced by increasing temperature. At each individual temperature, water curing has little influence on the long-term hydration process. It degrades the strength but is beneficial to small absolute dimensional change. Contrary to air-cured samples, all water-cured samples swell instead of shrinking. The compressive strength has a positive relation to the AFt/AFm.