GGBS/GGBFS(standard BS:6699) is a fine powder that is used in concrete as a 'cement'. The major use is in ready-mixed concrete. In the production of ready-mixed concrete, GGBS replaces a substantial portion of the normal Portland cement content, generally about 50%, but sometimes up to 70%. The higher the proportion, the better is the durability. GGBS is also used in other forms of concrete, including site-batched and precast.
 
In the production of ready-mixed concrete, GGBS replaces a substantial portion of the normal Portland cement content, generally about 50%, but sometimes up to 70% or more. The higher the proportion, the better the durability. The disadvantage of the higher replacement level is that early-age strength development is somewhat slower.
 
Ground Granulated Blast Furnace Slag(GGBS) is also used in other forms of concrete, including site-batched and precast. Unfortunately, it is not available for smaller-scale concrete production because it can only be economically supplied in bulk. GGBS is not only used in concrete: other applications include the in-situ stabilisation of soil.