There are three types of concrete mixers: a slurry mixer, a wet mix, and a dry mix. A slurry mixer is the most common type of concrete mixer. It is a machine that mixes the two substances together. A wet mix is more like a traditional mortar and pestle. It is used to break down the clays and other materials into smaller pieces so they can be used in the construction process. A dry mix is made up of just water and sand.