Concrete — a mixture of aggregates (fine or coarse), cement and water — is an essential building material widely used in modern-day construction because of its strength, durability, and versatility. Depending on the ratio of its constituent ingredients, concrete can be produced in a wide range of compressive strength or grades. Typically grades of concrete vary in the range of M5 to M70. M5 grade concrete has a compressive strength of 5 MPa whereas M70 whereas M70 grade concrete has a compressive strength of 70 Mpa. Concrete of grade M5 to M20 are generally used for applications that don’t require high strength, concrete of grade in between M25 and M45 are used for reinforced concrete applications or construction requiring standard strength and high strength applications use concrete with grade M50 to M70. These days, concrete is used in the construction of houses, bridges, high rises, canals, roads, tunnels, and several other structures.
Traditionally, concrete mixtures were prepared manually which consumed a lot of time as well as lacked precision. With growing demand and advances in technology, now, concrete mixture, even in small scale applications, is prepared using concrete mixers. Concrete mixers are devices capable of preparing concrete mixtures of varying strength precisely as well as quickly. Some concrete mixers are even capable of dispensing the concrete mixture directly on the location of the construction. Depending on the requirement of the application, concrete mixers of various sizes and types are available. Portable concrete mixers can be used in small and medium-sized applications whereas for large scale applications concrete batching plants can also be built at the construction site.
Needless to say, just like the requirements of various applications, types of concrete mixers commonly used are also quite versatile. Here’s a list of some of the most commonly used types of concrete mixers and their applications in various construction works.
Concrete mixers can be divided into two broad categories:
Now, let’s discuss these two categories in further detail and understand them.
As the name suggests, this type of mixer produces concrete one batch at a time. Batch mixers either have a drum or a pan, consisting of blades, which when rotated prepares the concrete mix. The speed of rotation, angle of the blades and in some cases the angle of inclination of the drum can be controlled. These are the most commonly used concrete mixers and are highly preferable to be used in small and medium-sized construction sites.
Batch mixers can be further divided into two types:
These mixers consist of a double conical frustum shaped drum. Depending on its type, the drum either has a single set of a blade or multiple sets of blades that are used to mix, prepare and discharge the concrete mixture. Now, drum mixers are of three different types:
In this type of drum mixer, the drum is capable of tilting upwards or downwards until a certain angle. This allows the mixer to prepare concrete more effectively by tilting upwards and to pour the concrete mix out by tilting downwards once it is prepared. The drum in these mixers is closed from one end. Tilting drum mixers are most suitable for preparing concrete with low workability and a large size of aggregates. These mixers are highly preferable for large construction sites or applications where construction work is carried out intensively.
These drum mixers come with a non-tilting drum which rotates on its horizontal axis to produce concrete. They have openings at both ends. The ingredients required to produce the mix are fed from one end and the mix is collected from the other. The mix is collected by attaching a chute to the opening of the drum. The blades in these mixers also help in the extraction process. non-tilting drum mixers are not suitable for preparing concrete with very large-sized aggregates and for applications where the rapid discharge of concrete is required. This type of drum mixer is generally used in small construction sites.
Quite similar to non-tilting drum mixers, these mixers also have openings at both ends and the constituents of the concrete mix are poured in from one end and the final mix is collected from the other. The factor that differentiates reversing drum mixers from non-tilting drum mixers is that these mixers have two sets of blades. One set of blade facilitates the mixing process while the drum is rotating in a certain direction and the other set of blade facilitates the discharge process of the mix while the drum is rotating in the opposite direction. Reversing drum mixers are most suitable for preparing dry mix concrete.
This type of mixer has a cylindrical pan instead of a drum in which concrete is prepared. Just like drum mixers, these mixers also have blades that facilitate the process of mixing. These blades are generally shaped like a star to ensure optimum efficiency. They also have scrapers attached to avoid sticking of mortar to the surface of the pan. Commonly used pan mixers have two different modes of operation:
Pan mixers are considered to be the most efficient type of concrete mixers. No matter how the mixer operates, both types of mixers are equally efficient. The concrete mix is generally collected from an opening at the bottom of the pan. These mixers are most suitable for preparing stiff and lean concrete mixes.
These concrete mixers work without any interruption and keep producing concrete continuously as long as work is going on. They are fed raw materials continuously and the concrete is discharged and collected by construction workers as soon as the mix is ready. Continuous mixer systems are generally set up in the construction site itself. They have a separate feeder unit for the intake of constituent materials, a mixer unit for mixing concrete and a discharge mechanism for dispensing the concrete mix. These mixers are deployed while constructing very large structures such as bridges, tunnels for roads, dams, etc
Virtue Industries uses concrete mixers that can dispense the concrete mixture directly on the location of the construction. For more details on building material supply and construction projects, contact us.