There are many types of concrete admixtures that can be used for a variety of applications. They are classified based on various tests and characteristics. However, they all have a common characteristic of enhancing the properties of the concrete.

Concrete admixtures come in five major classes. These include gas-forming admixtures, corrosion inhibiting admixtures, water proofing admixtures, grouting admixtures and surface hardening admixtures. Each type of admixture is designed to achieve specific goals, such as reducing the amount of air needed in the mix or increasing the strength of the concrete.

The chemical admixtures are one of the most important innovations of the 20th century. Admixtures are inorganic or organic substances that are added to concrete in order to improve its quality. Depending on the application, the admixtures may also help to overcome some of its drawbacks.

The mineral admixtures are finely divided materials that are usually added to the concrete in 20 to 100 percent of the Portland cement. They are mainly employed to make the concrete workable, durable and more resistant to freezing and thawing.

Water reducing admixtures, sometimes known as plasticizers, reduce the water content of the concrete mix. Although most water reducing agents entrain air, some of them actually eliminate the need for additional water.

Retarding admixtures help to slow the setting time of the cement paste in the concrete. This is especially useful for placing concrete at high temperatures.

Another kind of admixture is a super plasticizer. It can raise the slump of the concrete from 75 mm to 200 mm. When mixed with an appropriate w/c ratio, the super plasticizer increases the workability of the concrete.