What can be used to slow the hardening of concrete (give example?) Why would slowing this process be desirable?

To slow the hardening of concrete we will use Sugar or other materials. Sugar can be added to the concrete to retard hardening. For example, if the concrete needs to be transported a long distance, then a retarding admixture would be required.

Retarder type admixtures can be used to slow down the concrete hardeing. It can be used, where you need more time to pour the concrete especially in hot weather 

Moisten it with blankets in it surface, 

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