Admixtures are of following five types with their examples are 1. Plasticizers or water reducers: I t allows a reduction in water content for the given workability. For examples- Lignosulphonates, esters, acid of hydroxylated carboxylic acids and their derivatives. 2. Super plasticizers: They are chemically different from normal plasticisers. Types of Superplasticizers are Sulphonatedmalanie formal dehyde (SMF), Sulphonated naphthaleneformaldehyde (SNF) and Modified lignosul-phonates (MLS) 3. Retarder: It slows down the chemical process of hydration so that concrete remains plastic and workable for a longer time. For examples Gypsum and Calcium Sulphate, starches, sugars etc. 4. Accelerators: it increase the rate of early strength development . Accelerating compounds are calcium chloride, Silicates. 5. Air entraining agent: In cement, very small quantities of air-entraining materials are added as the clinker is being ground during manufacturing. Concrete contains tiny, welldist ribut ed and completely separated air bubbles. The air bubbles provide space for freezing water to expand without damaging the concrete. Compounds used as an air entrained are Natural wood resins, olive oil and stearic and oleic acids, sulphonic acids, hydrogen peroxide and aluminium powder.