ABSTRACT
Ground Granulated Blast Furnace Slag (GGBS) is known to improve the chloride ingress resistance of concrete when used in combination with Portland cement. However, the nature of the ore, composition of the limestone flux, coke consumption and the type of iron being made are factors which affect its chemical composition. There are standards which regulate the use of GGBS. For example, BS EN 197-1:2011stipulates that for GGBS the (CaO + MgO)/SiO2 ratio by mass must exceed 1 (EN197-1:2011). However, work done by several authors has shown that these oxide (basicity) ratios may not be an accurate predictor of slag reactivity and performance. For example, a study carried out by (Mantel, 1994) investigating the hydraulic activity of five different slags concluded that there was no clear correlation between the basicity ratios and the properties of the slags.
