the use of superplasticizers as admixture is an innovative way to produce a strong and workable concrete. The admixtures reduce water content and increase strength by reducing cement content while maintaining the same workability as the original mix design.
They are also used to improve the concrete’s fresh properties and retard setting time. A typical water-reducing admixture reduces the required water content by 5 to 12 percent.
When added to the concrete, superplasticizers are designed to produce a stronger, more workable concrete that is less susceptible to shrinkage and thermal cracking. They can also be used to conserve cement, save time on finishing and speed up production.
The effects of the admixture are usually measured by a Marsh Cone Test, which is used to determine the dose required for a given concrete mixture. Dosages range from 1 to 3 liters per cubic meter of concrete.
They can reduce the slump of a concrete mix by 15% while retaining its workability. This is a dramatic improvement in concrete construction and has become the most popular admixture in recent years.
Dosages of plasticizers vary depending on the type of admixture, the strength requirement and the application. A typical dosage is from 1 to 3 liters of liquid plasticizer per cubic meter of concrete.
These admixtures reduce the thixotropic index of the concrete to very low values. This is due to electrostatic pressure or steric hindrance. They do not cause segregation in the concrete.