Concrete Mixers |Types of Concrete Mixers | Volumetric Concrete Mixer
What is a Concrete Mixer?
Concrete mixers are machines that combine cement, aggregates, and water to create a concrete paste or slurry. To mix the components, a standard concrete mixer uses a spinning drum.
Concrete mixers are frequently utilized so that the concrete can be prepared on-site, allowing the workers plenty of time to use the concrete before it hardens.
A good concrete mixture should not only mix the elements uniformly, but it should also discharge the mix without altering its consistency. The homogeneous consistency and color of the slurry are indicators of this.
Concrete can also be mixed manually in the absence of concrete mixers. However, this only applies to modest amounts of concrete.
Furthermore, employees are prone to mixing concrete incorrectly and, in many cases, over-mixing it. As a result, it is preferable to employ machine mixers to mix concrete materials.
To mix the ingredients, a standard concrete mixer employs a spinning drum. Portable concrete mixers are frequently used for low volume jobs so that the concrete can be prepared on the construction site, providing the workers plenty of time to use the concrete before it hardens.
Hand mixing concrete is an alternative to using a machine. Normally, this is done in a wheelbarrow, but several companies have recently begun to sell customized tarps for this purpose.
Types of Concrete Mixers
Industrial Concrete mixers
Industrial Concrete Mixers are a type of industrial machine that has been designed to mix mixtures of aggregates with cement and water. The machines come in all shapes and sizes, depending on the construction project.
Most Industrial Concrete Mixers can be driven with electricity but some may have different power sources, like gas or diesel engines or even an internal combustion engine.
The most common and the most used mixes for concrete are referred to as Mortar, concrete, and asphalt. They are usually composed of aggregates (sand, gravel, crushed rock) and cement.
The mixture is usually mixed by using a mechanical mixer which uses blades to drive the materials into a homogeneous state where it can be used in construction.
Concrete machines are used in the field of road construction, railways as well as other industrial sites like warehouses or hospitals.
The concrete mixer is most commonly used in construction to make concrete. It can be easily and quickly transported to any construction site or warehouse, because of its portability.
It can also be used as a mobile mixing unit and this makes it easy to get the material on the construction site for immediate use.
These machines are also very useful when it comes to working with large amounts of materials at one time, especially when used in factories that produce more than 100 cubic yards of concrete per day.
Concrete Transport Trucks
Concrete transport trucks (in-transit mixers) are specially designed to mix concrete and transport it to construction sites. They can be charged with both dry and wet materials, with the mixing taking place during travel.
They can also be loaded from a “central mix” plant, where the material has already been mixed before being loaded.
The concrete mixing transport truck keeps the material in a liquid state by agitating it, or turning the drum until it is delivered. A spiral blade is installed inside the drum of a concrete mixing truck. The concrete is pushed deeper into the drum in one rotational direction.
This is the direction in which the concrete drum is rotated while being delivered to the construction site. This is referred to as “charging” the mixer.
The Archimedes’ screw-type mechanism “discharges,” or drives the concrete out of the drum, when the drum rotates in the opposite direction. It may then be transferred to chutes, which will route the viscous concrete directly to the job site.
If the truck cannot get close enough to the site to use the chutes, the concrete can be released into a concrete pump, which is attached to a flexible hose, or onto a conveyor belt that can be stretched some distance (typically ten or more meters).
A pump allows the material to be moved to specific areas, multi-story buildings, and other long-distance places. Concrete is also placed using buckets suspended by cranes.
The drum has typically been made of steel, however, on some contemporary trucks, fiberglass has been utilized as a weight-saving strategy.
Trucks weigh between 20,000 and 30,000 pounds (9,070 and 13,600 kg) and can transport approximately 40,000 pounds (18,100 kg) of concrete, while many other types of mixer trucks are now in use. 8 cubic yards is the most typical truck capacity (6.1 m3).
Concrete mixers rarely travel far from their facility since the concrete begins to solidify as soon as it enters the truck.
Many contractors demand that the concrete be poured within 90 minutes of being loaded. If the truck breaks down or the concrete hardens in the truck for any other reason, employees may need to enter the barrel with jackhammers.
Volumetric Concrete Mixer
A volumetric concrete mixer also referred to as a volumetric mobile mixer, is a concrete mixer that is mounted on a truck or trailer and has compartments for sand, stone, cement, and water.
Metered concrete trucks contain concrete ingredient ingredients and water that are mixed on the truck at the job site to produce and distribute concrete in the required amount.
On the site job, materials are combined to make the exact amount of concrete required. Volumetric mixers are primarily used to distribute specialty high-early strength concrete that sets too quickly for traditional rotating-drum “agitators,” and they have also been used in the construction of airfield pavements.
If quantities and schedules are not fully known, some concrete providers offer general-purpose concrete batched in a volumetric mixer as a feasible alternative to ready-mix, in order to avoid waste and prevent premature stiffening of the mix.
Furthermore, standard batch plant opening fees for after-hours operations do not apply.
Advantages And Disadvantages of Volumetric Concrete Mixer
- By supplying correct quantities, it reduces waste and associated costs.
- There is no risk of premature hardening of concrete if delays occur.
- Allows for the delivery of lesser volumes of concrete.
- Nighttime operations do not necessitate the reopening of a concrete batch facility.
- The ability to switch between several concrete mixes as needed for the application.
Batch Concrete Mixers
Batch concrete mixers are the most common form of mixer used in the production of concrete. Batch mixers, as opposed to continuous mixers, mix and discharge concrete in batches, one after the other.
Batch mixers are made up of revolving drums with blades within. All of the ingredients are fed into the drum or pan in the proper proportions in this mixer, and the drum is spun at a constant pace.
The resulting mixture is discharged and put to use. When the first batch is finished, the drum must be refilled. The materials are combined and then discharged in order to make another batch. This process is repeated until the necessary amount of concrete is produced.
Tilting Drum Mixer
Tilting drum mixers work by mixing the ingredients by inducing the concrete to move in a circular motion inside the drum. The drum is then tilted so that the concrete can be discharged. They are widely used for ready mixed concrete.
Tilting drum mixers have gotten more common in use because of their lower production costs and liquid-saving technologies, which require only half of a standard amount of water to produce an equivalent amount.
Non-Tilting Drum Mixer
Non-tilting drum mixers are the most basic form of concrete mixer, but it is still widely used in the construction industry. The drum is rotated by a pump and the ingredients are mixed in the proper proportion.
It works similarly to a batch mixer, with only one difference: there are no motors and no cleaning of the components between batches.
Reversing Drum Mixer
Reversing drum mixers are also called “hole-in-the-drum” mixers. This mixer delivers materials into the concretes in the correct proportions, in a continuous and uniform manner.
They are more expensive than non-tilting drum mixers, but they provide greater precision to the output of concrete and improve material quality by ensuring that components are discharged at exactly the right concentration.
Pan Type Concrete Mixer
This type of mixer is the most common type used in the construction industry. The mix will be delivered into large plastic boxes, and a rotating drum will feed the concrete mixture into the box, one after another.
The final product is discharged to a spreading device (belt or roller) for distribution to the job site.
Pneumatic Concrete Mixer
Pneumatic concrete mixers are usually used for smaller projects and in specialty situations, especially where there is no need for long-distance transportation of concrete materials.
They can be used for a variety of applications, such as concrete flatwork.
Pneumatic concrete mixers are also used to transport concrete materials from one location to another. They are smaller and lightweight, which helps operators keep the truck on the road where it is needed most.
Pneumatic concrete trucks come in various shapes and sizes, depending on the application; they nearly always have a vibratory motor as a prime source of power to mix and blend the concrete.
These mixers can be used in almost any type of application, including in the building of highways and roads. These mixers are approved for use on highways and roads by the American Association of State Highway and Transportation Officials (AASHTO), so they are one option for highway construction.
They are also more appropriate for smaller projects such as foot paths, bike paths, basketball courts, stadium floors, or parking lots.
These concrete mixers can be equipped with other tools and functions, such as asphalt spreaders or water tanks for pumping coolant.
Concrete Batching Plants
These are big structures, which are used to produce concrete materials in large quantities. They are often used in public works projects that need large amounts of concrete.
Concrete batching plants generally have a production capacity of up to several cubic yards per hour of ready-mixed concrete.
A typical concrete batch plant might have 7-8 concrete mixing stations (3-4 top, 2-3 bottom)
and a number of mixers such as roller mills, piston mixers, and vibratory mixers.
The largest batching plants have a volume of up to 30,000 cubic meters.