Superplasticizers(SP’s), also known as high range water reducers, are additives used in making high strength concrete. Plasticizers are chemical compounds that enable the production of concrete with ca. 15% less water content. Superplasticizers allow reduction in water content by 30% or more. These additives are employed at the level of a few weight percent. Plasticizers and superplasticizers retard the curing of concrete.
SPs are used where well-dispersed particle suspension is required to improve the flow characteristics (rheology) of suspensions such as in concrete applications. Their addition to concrete or mortar allows the reduction of the water to cement ratio without negatively affecting the workability of the mixture, and enables the production of self-consolidating concrete and high performance concrete. They greatly improve the performance of the hardening fresh paste. The strength of concrete increases when the water to cement ratio decreases.
The addition of SP in the truck during transit is a fairly modern development within the industry. Admixtures added in transit through automated slump management systems, such as Verifi, allows concrete producers to maintain slump until discharge without reducing concrete quality.
Plasticizers and superplasticizers retard the curing of concrete.
Plasticizers indirectly add strength to hardened concrete by enhancing workability of a concrete mix during its mixing and placing thereby allowing reduction in water-cement(W/C) ratio… Superplasticizers are the improved chemical admixtures over Plasticizers with highly effective Plasticizing effects on wet concrete.
Superplasticizers transform stiff, low-slump concrete into flowing, pourable, easily placed concrete. They can improve workability, speed finishing, increase strength, conserve cement and help reduce shrinkage and thermal cracking.
A polycarboxylate superplasticizer, which presents excellent performances in slump retaining and water-reducing, can significantly improve the plasticity index of fresh concrete, and enhance the pumping and construction performance of concrete at the same time, and greatly increases concrete strength.
The superplasticizer contains a surface-active substance, which is one of the commonly used admixtures for concrete. It can enable the concrete to introduce a large number of uniformly closed small bubbles from the atmosphere during the mixing process, so that the concrete contains a certain amount of air. A good active substance can introduce as many as 1 billion air bubbles into the concrete, and the pore size is usually 0.05 to 0.2 mm. It is generally a discontinuous closed sphere with uniform distribution and good stability. This can significantly improve the frost resistance of concrete. Durability. Especially in artificial aggregates or natural sands with coarser particles, poor gradation, and better use in lean cement concrete, it can improve the bleeding and segregation of concrete, reduce concrete permeability, and improve the erosion resistance of concrete .