Influence of filler effect on the sulfate requirement of blended cements

The study aims to understand the mechanism behind the impact of two SCMs, namely metakaolin and limestone, on the sulfate balance of blended cements. No significant impact of the aluminum content of these SCMs was observed. Instead, it is observed that the filler effect of the SCM, which accelerates the reaction of alite, is the main factor impacting the sulfate balance.

Relationship between heat release and gypsum content

As the rate of precipitation of C-S-H is increased, more sulfate is adsorbed by the C-S-H and consequently, the depletion of gypsum is reached earlier in time during the hydration process. A relationship between heat release at the onset of the aluminate peak and the gypsum content of the system was established.

The study is published in: Cement and Concrete Research, Volume 126, December 2019, 105918.