Often referred to as cement mixers by the general public, concrete mixers are industrial machines which blend cement aggregate and water together to make concrete. In fact, a mix of concrete can be formed with nothing more complex than a shovel and a wheelbarrow to get the mixture to its desired location. Having said that, the amount of concrete that is needed on the average building site will mean that one of the four following types of mixers will be used. In addition to hand-formed concrete, portable concrete mixers are often used for relatively small jobs, such as pouring concrete to form a domestic patio. What are the industrial-scale concrete mixers used in Australia today?
Twin-Shaft Concrete Mixers
These industrial machines have two axles within them that rotate in opposite directions to one another. Each has a number of blades that extend from these revolving shafts that keep the concrete mixture moving and in a fluid state until it is needed onsite. You will find twin-shaft mixers being used for specialist applications where a highly durable form of concrete is needed, for example, to make airport runways. When the blades of a twin-shaft mixer are in operation, they form a spiral pattern to make sure all of the material is thoroughly worked. Batches of around six cubic metres of concrete can be made with this sort of industrial mixer.
Vertical-Axis Concrete Mixers
This type is often used to make large amounts of concrete and would be a common sight on a large building site. Vertical mixers allow the material to flow through and, therefore, take advantage of something as simple as gravity. The same sort of technology can be seen in grain and ceramic mixers, as well. It is commonplace to use a vertical-axis concrete mixer to create coloured and textured concrete where you want to see an even distribution of additives.
Drum Concrete Mixers
This type of concrete mixer rotates around an axis which can be lifted up and down to either keep the material inside in a liquefied state or to pour it out. Both industrial-scale and portable concrete mixers tend to be made using drums. Inside of the drum is a spiral blade which helps to prevent the concrete from going off prematurely by turning it back in on itself continually.
Truck-Based Concrete Mixers
Designed to deliver concrete to a site rather than make it locally, truck-based concrete mixers essentially have drums fitted on their backs so they can take their load anywhere. By reversing the direction of the drum, it is possible to expel the concrete from the truck at just the right time and location. They often need to be pressure-washed to keep them in mint condition.