Admixtures are used in concrete (often in combination) to impact specific qualities to the fresh or hardened concrete. Some admixtures make the concrete set faster or slower, or make it denser, or make it stronger or more durable. Admixtures are incorporated into the concrete design to assist with the concrete consistency.

The most common are:

• Water-reducing admixtures - They help produce a medium slump, workable concrete, requiring less mixing water
• Air-entraining agents - which develop millions of tiny air bubbles in the concrete are often used to improve durability and workability.
• Superplasticiers or High Range Water Reducers - can greatly increase slump with a relatively small dose, once added to the concrete this slump increase will last up to two hours, with the concrete eventually returning to its original slump.