Concrete mixer and its origin

A concrete mixer (often colloquially known as a cement mixer) is a device that uniformly mixes cement, aggregates (such as sand or gravel), and water to form concrete.A typical concrete mixer uses a rotating drum to mix the components.For smaller volume projects, portable concrete mixers are often used so that the concrete can be made on the construction site, allowing workers ample time to work with the concrete before it hardens. An alternative to a machine is to mix the concrete by hand.This is usually done on a wheelbarrow; however, several companies have recently started selling modified tarps for this purpose.The concrete mixer was invented by Gebhard Jaeger, an industrialist in Columbus, Ohio.

Origin

In 1900, T.L.developed the first concrete mixer. Smith in Milwaukee.The mixer already exhibits the still common basic structure, with a tiltable conical drum with blades (double cone at the time).In 1925, at least two mixers built 25 years earlier are still in use (serial numbers 37 and 82).The Smith Mascot essentially has the same construction as the small mixers used today. In the 1920s, the T.L. Smith Company of Milwaukee built the world's largest concrete mixer. Use the company's blender e. g.Used in the construction of the Wilson Dam (six 2-yard and two 4-yard mixers, at the time the largest single installation of the largest concrete mixer in the world), Ohio State University's first stadium and the Exchequer Dam.

Industrial mixers

• Consistent homogeneity and short mixing times are increasingly required in today's market for industrial production of ready-mixed concrete, especially for precast/prestressed concrete.This led to improvements in mixing technology for concrete production.Different styles of stationary mixers have been developed, each with their inherent advantages and suitable for different segments of the concrete production market.The most commonly used mixers today fall into three categories:

• Twin-shaft mixer, known for its high intensity mixing and short mixing times.These mixers are typically used for high strength concrete, RCC and SCC and are typically in batches of 2-6 m3 (2.6-7.8 yd3).

•  Vertical axis mixers,most commonly used for precast and prestressed concrete.This type of mixer cleans well between batches and is suitable for colored concrete,smaller batches (typically 0.75-3 cubic meters or 0.98-3.92 cubic yards) and multiple discharge points.In this category, pan mixers are gradually being replaced by more efficient planetary (or countercurrent) mixers,as the additional mixing action helps produce more critical concrete mixes (color consistency, SCC, etc.

• Drum mixers (inverting drum mixers and inclined drum mixers) for high-volume production (batch sizes of 3–9 cubic meters or 3.9–11.8 cubic yards).This type of mixer is capable of high throughput.All console styles have their inherent advantages and disadvantages, and are all used around the world with varying degrees of popularity.