Heat of hydration in clays stabilized by a high-alumina steel furnace slag

Abstract

This investigation utilized isothermal calorimetry (IC) to quantify the heat of hydration of steel furnace slag (SFS)-stabilized clays to assess the chemical aspects of the stabilization. Specifically, kaolin and bentonite clays were each blended with 40% of SFS by mass at water-to-binder ratios ranging from 1.0 to 1.5. The hydration properties of stabilized mixtures using lime (CaO) or portland cement (PC) were also tested for comparison at the same experimental conditions. The obtained thermal power and total heat curves of stabilized mixtures could contribute to confirming that there is a hydration process taking place in clay stabilized by SFS. Relative to lime and PC, the SFS performed similarly in terms of hydration heat behavior. When blended into clays, SFS provided a more significant hydration heat behavior than cement, but that was much milder than lime. X-ray diffraction (XRD) and thermogravimetric analysis (TGA) were also employed to qualitatively analyze the mineralogy of the stabilized mixtures.

Keywords

• Steel furnace slag (SFS)
• Kaolin
• Bentonite
• isothermal calorimetry (IC)
• X-ray diffraction (XRD)
• thermogravimetric analysis (TGA)