Plasticisers and superplasticisers can be applied when:
For the same level of workability, plasticisers can reduce the required water content of the concrete mix by around 5-10% and superplasticisers can reduce it by 12-30%. Therefore, with a plasticiser a workable concrete is achieved, but also a lower water / cement ratio can be kept to provide a high strength concrete.
Plasticisers are an expensive concrete additive and superplasticisers can be multiple times more expensive than regular plasticisers (per kg of concrete).
Adding 1-2% plasticiser per unit weight of concrete is usually enough to achieve the desired effect whereas this value can be a lot lower for superplasticiser.
Some superplasticisers can entrain unwanted air in a concrete mixture; therefore it is important to be careful when using them in conjunction with an air-entraining agent or in a floor which is to be power trowelled. F