what is concrete Admixture & types of admixture

Admixture : 

 
 It is defined as a material other than cement, water, and aggregates that are used as an ingredient of concrete and is added to the batch immediately before and during mixing. It is used to modify the properties of ordinary concrete so as to make it more suitable for any situation.

 Types of Admixture :

•  Air entertaining agents -AEA.
• Water reducers.
• Plasticizes
• Super plasticizes.
• Retarders.
• Accelerators.