Admixture

A material other than aggregates, cement, reinforcement or slag which is added to the batch to modify the properties of concrete in plastic or hardened state. The admixtures contain chlorine and if excess amount of chlorine is present in the concrete it corrodes the reinforcement which affects the durability and serviceability condition of the structure. The amount of chlorine permitted in the concrete is written in IS 456. The acceptance criteria for admixture is given in IS 9103. The different types of admixtures are:

1. Accelerating Admixture
2. Retarding Admixture
3. Water Reducing Admixture
4. Air Entertaining Admixture
5. Super Plasticizing Admixture
6. Retarding Super Plasticizing Admixture