Admixture which, without effecting the consistence, permits a reduction in the water content of a given concrete mix, or which, without affecting the water content increases the slump/flow or produces both effects simultaneously.
This type of admixture improves the dispersion of cement particles resulting in an increase in workability.
With a typical dosage of 0.2 – 0.8 % by weight of cement, plasticisers increase the workability at a given water/cement-ratio by between 50 and 100 mm slump with no loss of strength or durability.
Alternatively, they can be used to reduce water content in a range of 5 – 12 %. This reduction in water/cement ratio gives significant durability enhancement and strength increase for a constant cement content.
The main application of plasticisers is by ready-mix concrete producers to optimise the cost effectiveness of the mix. The environmental profile is also improved.