Concrete mixer
Encyclopedia : C : CO : CON : Concrete mixer
A concrete mixer (sometimes erroneously called a cement mixer) is a device that homogeneously combines cement, aggregate such as sand or gravel, and water to form concrete. A typical concrete mixer uses a revolving drum to mix the components. For smaller volume works portable concrete mixers are often used so that the concrete can be made at the construction site, giving the workers ample time to use the concrete before it hardens. An alternative to a machine is mixing concrete or cement by hand. This is usually done in a wheelbarrow; however, several companies have recently begun to sell modified tarps for this purpose.
Industrial mixers
Today's market increasingly requires consistent homogeneity and short mixing times for the industrial production of ready-mix concrete, and more so for precast/prestressed concrete. This has resulted in new technologies for concrete production. Worldwide, therefore, twin-shaft batch mixers are becoming more important for high-quality concrete production. They introduce very high turbulence into the mix and achieve about 95% homogeneity at only around 30 seconds mixing time per batch.
Concrete transport truck
Special concrete transport trucks are made to transport ready-mix concrete from a factory/plant to the construction yard. Because of the difficulty in tipping a large drum attached to the back of a concrete truck, the interior of the drum on a concrete truck is fitted with a spiral blade. In one rotational direction, the concrete is pushed deeper into the drum. This is the direction the drum is rotated while the concrete is being transported to the building site. When the drum rotates in the other direction, the Archimedes screw-type arrangement forces the concrete out of the drum, and then optionally onto slides to guide the viscous concrete, or a concrete pumper.
Stephen Stepanian filed a patent application for the first truck mixer in 1916 [link].
Trucks weigh 20–30,000 pounds (9–13.5 tonnes), and can carry roughly 40,000 pounds (18 tonnes) of concrete.
External links
- [Cement Concrete Mixer Resource] Enter the Cement & Concrete Mixer Resource. Discover info, articles, and more on cement & concrete mixers.
From Wikipedia, the Free Encyclopedia. Original article here. Support Wikipedia by contributing or donating.
All text is available under the terms of the GNU Free Documentation License See Wikipedia Copyrights for details.