The major use of GGBS is in ready-mixed concrete, and it is utilised in the majority of UK ready-mix deliveries.
Specifiers are well aware of the technical benefits, which GGBS imparts to concrete, including:
- Considerable sustainability benefits
- Lower early-age temperature rise, reducing the risk of thermal cracking in large pours
- Minimizes the risk of damaging internal reactions such as Alkali Silica Reaction (see factsheet) and Delayed Ettringite Formation (see factsheet)
- High resistance to chloride ingress (see factsheet) thus reducing the risk of steel reinforcement corrosion
- High resistance to attack by sulphates and other chemicals (see factsheet)
- Better workability, making placing and compaction easier
- Pleasing off-white colour
In the production of ready-mixed concrete, GGBS replaces a substantial portion of the Portland cement component, generally about 50%, but sometimes up to 70%.
The higher the proportion, the better is the durability. The disadvantage of the higher replacement level is that early-age strength development is somewhat slower.
Other forms of concrete
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.
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construction materials