Fly ash and ground granulated blastfurnace slag (GGBFS) are used as cement constituents world wide. The use of these products when blended with Portland cement is helpful in improving the durability of concrete mixes.
- Fly Ash is a by-product of the remains of molten shale which is used in coal-fired power stations.
- Slag is by-product from the blast furnaces used to make iron.
The properties of each are similar but have slightly different charactistics. However the result when blended with Portland cement generally produces the same outcome depending on the blended ratio.
In Western Australia the obvious choice is GGBFS due to it’s accessibility and not Fly Ash due to the lack of coal fired power stations in the region.