Basically, there are two type of admixtures available. One is natural admixtures and another is chemical admixtures. Natural admixtures are rice husk, flour, egg mix, ghee and the chemical admixtures is GGBS, fly ash, pozzolana.
In previous time, natural admixtures were used widely but this was very expensive and not much modification was not possible in that time. On the other hand, usage of chemical admixture provides variety in the construction industry.
Types of Chemical Admixtures
1. Plasticizers
2. Superplasticizers
3. Accelerators
4. Retarders
5. Air entrainers
Plasticizers
This are used for improving the plasticity of fresh concrete to reduce water content. Workability and water cement ratio do not affect because of using plasticizer. There are few types of plasticizer available like calcium, sodium, ammonium, lignosulphonates, polyglycol esters. These are added 0.1% to 0.4% ratio.
After adding this element is absorbed on the cement particles. This element also creates expulsive force named zeta potential. This expulsive force depends upon the used amount of plasticizer.
Published By
Arka Roy
www.constructioncost.co
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