what is difference between Cement Retarder and Cement Accelerator

Difference between Cement Retarder and Cement Accelerator

Retarding admixtures : Generally used in HOT Weather.
Chemicals : Sodium Gluconate, Gypsum,sugar,strach etc

Retarding admixtures helps and work as water reducing agent and Cemenrt retarder keep concrete workable during placement and delay the initial set of concrete. Chemically retarder slow the setting rate of concrete, are used to counteract the accelerating effect of hot weather on concrete setting. High temperatures often cause an increased rate of hardening which makes placing and finishing difficult. Retarders keep concrete workable during placement and delay the initial set of concrete. Most retarders also function as water reducers and may entrain some air in concrete. Retarder use for increase setting time of cement.

Accelerating admixtures : Generally used in COLD Weather.
Chemicals : Refined silicates, Aluminium sulfate and synthetic plasticizer, calcium chloride etc.

Accelerators make concrete set faster rapidly after mixing with concrete. This product can be added to a concrete batch either immediately before or during mixing to kick the set time of a batch of concrete into high gear and initiate setting time one to three times faster than normal mortar and concrete. On the other hand Accelerating admixtures increase the rate of early strength development, reduce the time required for proper curing and protection, and speed up the start of finishing operations.  Chloride Free and Accelerating Compund for Concrete and Mortar. Accelerator is use for reduce setting time.

Accelerating admixtures are especially useful for modifying the properties of concrete in cold weather.