Title: Synergetic Effect of Combined Converter Steel Slag and Metakaolin Hydration
Author(s): Winnie Franco Santos, Katrin Schollbach, Sieger van der Laan, and H.J.H.Brouwers
Publication: Symposium Paper
Appears on pages(s): 466-478
Keywords: converter steel slag; metakaolin, mineralogy, reactivity
Converter steel slag exhibits very low hydration activity compared to ordinary portland cement. To increase its reactivity, a mixture with metakaolin (Al2O3·2SiO2) was designed to increase the binding capacity. Metakaolin was used for its purity and high pozzolanic reactivity, owing to its high alumina and silica content. Two systems were prepared, metakaolin and portlandite as a reference, and the second system was composed of converter slag and metakaolin. Reactivity was assessed by measuring the heat release of the hydration reactions by isothermal calorimetry. Calorimetry results show the cumulative heat of converter slag increases when metakaolin is added. Furthermore, new hydration products were identified. Large area phase mapping based on SEM/EDX spectral imaging was done to investigate the reactions between the components.