Workability is an important property of concrete while mixing your concrete for construction. During the preparation of concrete, everybody should take proper measures to get high degree workability of concrete.
The workability can easily increase by adding water, but by adding more water the strength of concrete losses. Here you can use plasticizers for improving the property of concrete.
Plasticizers are one of the important admixtures for construction.
A high degree of workability should be maintained while constructing deep beams, concrete pumping, hot weather concrete etc..The required workability can easily be achieved by adding a concrete plasticizer.
The most common or conventional method used for increasing workability is improving gradation, adding cement content by adding water or increasing the higher percentage of fine aggregate. But adding more cement will also lead to increasing the heat of hydration. This occurs mainly in case of mass concrete.
You must control the heat of hydration when you construct mass concrete. This is an important criterion for the construction of mass concrete. So concrete plasticizers are also very helpful for the construction of mass concrete.
Adding extra water to concrete will reduce strength and durability of concrete. You should maintain the right amount of water with pure quality.
“Concrete Plasticizers are the substance added to concrete to increase the flexibility and plasticity of concrete while the mixing of concrete.”
What are the constituents used in concrete plasticizers you can use for concrete mixing?
There are mainly two types of constituents are there, anionic and nonionic surfactant. Anionic surfactants such as lignosulphonates and sulphonates hydrocarbons are used.
In nonionic surfactants, polyglycol esters and acids of hydroxylated carboxylic acids are used.
The amount or quantity of plasticizers used for making concrete ranges from 0.1% to 0.5% by weight of cement. Plasticizers are very useful than air entraining agents.
Disadvantages of Plasticizers in Concrete
You have studied so many advantages of plasticizers in concrete at above section. Here you are going to study various disadvantages of using plasticizers.
When adding plasticizers to concrete, they will be absorbed by cement particles and leads to the formation of a thin sheath on the surface of cement particles.
This prevents the interaction of water with cement particles and causes a decline in the rate of hydration of cement. The number of plasticizers in concrete will eventually decrease with the rate of hydration of cement.