If you have guessed that a concrete mixer is pretty similar to a cement mixer, congratulations, you are right on the mark. These devices are designed to mix the ingredients of concrete and to keep them moving to stop them from hardening. They are powered machines that are used to mix specific quantities of sand, gravel, pebbles and water in a revolving drum. When the mix is ready to be used it is poured directly into the application or into trolleys or handcarts. Concrete mixers are used in many types of industrial settings, wherever concrete is used.
Small, portable concrete mixers are often used, but for heavy duty jobs, the concrete mixer is usually a larger drum that is attached to the back of a truck. Portable concrete mixers generally have electric motors that can plug into standard home power outlets or small gas engines. Large construction sites usually use the truck mounted mixers as they are able to mix several tons of concrete at a time. The drum is filled with the ingredients at the concrete manufacturer's location and is driven to the site where the concrete is to be used. The concrete mixer truck arrives at the construction site just before the concrete is to be poured so the mixture won't set or harden. The drum on the back of the truck slowly rotates the ingredients inside of it to ensure the concrete doesn’t become hard or set.
Most mobile concrete mixers also have a water tank and a spray hose. The concrete is poured down a folding trough device that is attached to the truck. The trough is then sprayed with water enabling the concrete to flow down it easier. The heavy, large drum on the truck doesn’t have to be tilted to pour the concrete as the inside of the drum is fitted with a spiral screw. While the truck is delivering the concrete the drum rotates in a direction which continuously forces the mixture to the bottom of the drum. When the truck reaches the job site the drum starts rotating in the opposite direction and the spiral screw forces the cement mixture upwards and out of the drum.
Concrete mixers and cement mixers are classified by their internal capacity in cubic feet and the engine rated horsepower. They are either fixed-type or portable devices. Heavy duty mixers with large capacities are usually placed in a central location and the ingredients are poured into the mixer. Rotating the mixer prepares the mixture and then the concrete mix is poured into trolleys, hoists or trucks for transport to the construction area. Concrete mixers generally run on diesel or electric power.