Sulfate optimization in ettringite rich cements by SO3/Al2O3 molar ratio: A comparative study of calcium sulfoaluminate and aluminate cements
Source abstract
Abstract
The hydration process of calcium sulfoaluminate (CSA) and aluminate cement (CAC) is influenced by their composition and calcium sulfate sources. Increasing the calcium sulfate content promotes ettringite generation; however, exceeding the optimal threshold may cause volume instability. This study aims to optimize sulfate levels in CSA and CAC by adjusting the SO 3 /Al 2 O 3 molar ratios. Contour maps were used to analyze how different sulfate sources and calcium sulfate levels affect strength development, ettringite formation, and volume stability. Both gypsum and anhydrite similarly improved compressive strength in CAC and CSA at equivalent SO 3 /Al 2 O 3 ratios. However, gypsum caused more significant expansion than anhydrite at equivalent SO 3 /Al 2 O 3 ratios, as indicated by the higher expansion values in gypsum-rich regions. The SO 3 /Al 2 O 3 molar ratio is crucial for regulating ettringite formation, enhancing compressive strength, and ensuring volume stability in CSA and CAC systems. Maintaining this ratio below 1.0 enabled the addition of sufficient calcium sulfate to achieve optimal performance. • Calcium sulfate of CSA and CAC optimized by modifying the SO 3 /Al 2 O 3 molar ratio. • Gypsum caused greater expansion than anhydrite at equivalent SO 3 /Al 2 O 3 ratios. • The threshold of SO 3 /Al 2 O 3 molar ratio lower than 1.0 was recommended.
Source: openalex_inverted_index · Quality: baseline
Research context
OpenAlex topics: Concrete and Cement Materials Research · Building materials and conservation · Ferroelectric and Piezoelectric Materials
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
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