Converting a quarry dust to a potential SCM through calcination

The present work dealt with a by-product from quarry industry named as “blue clay” that was typically not reused in the past. Preliminary research found that this blue clay has muscovite, a common component of raw clays, indicating a great potential for it to be used as a SCM. In this study, we calcined the blue clay under different temperatures. Raw and calcined blue clay at four different temperatures were investigated on the following properties: amorphous silica content, specific surface area, heat flow and reactivity. Results show that calcination improves the amorphous silica content of the system thereby enhanced the chemical reactivity towards pozzolanic reaction. When used at a cement replacement rate of 20% by mass, the measured calcium hydroxide content decreased compared to the control sample, indicating the enhancement in the reactivity of the pozzolanic reaction.