Admixture which, without effecting the consistence, permits a high reduction in the water content of a given concrete mix, or which, without affecting the water content increases the slump/flow considerably or produces both effects simultaneously
This type of admixture, like plasticizers, improves the dispersion of cement particles resulting in a large increase in workability.
With a typical dosage of 0.8 – 4.0 % by weight of cement, superplasticisers increase the workability at a given water/cement-ratio much more effectively than plasticisers, leading to a high workability and easier placing and compaction.
Alternatively, they can be used to give large reductions in water content in a range of 15 – 40 %. This reduction in water/cement ratio gives very significant durability enhancement and big strength increase at both early and later ages.
The use of superplasticiser is absolutely vital for the development of high quality / high performance concrete including high strength concrete or self-compacting concrete (SCC). Due to the steady improvement modern superplasticiser can be seen as one of the driving forces in concrete technology. They are used on all major construction projects worldwide.