Concrete is an all-purpose construction material that has been around for thousands of years. It’s a mixture of aggregate, water, sand and cement. Concrete is used in everything from building foundations to sidewalks. The type of concrete mixer you use will depend on the size of your project and what it entails. There are three primary types: batch mixers, central mixers and continuous mixers.
1. Batch mixers
are used for small projects and are usually operated by hand. These mixers can be on wheels or on a pedestal and can make up to 400 pounds of concrete at a time.
Batch mixers use less cement, which means that the water-to-cement ratio is lower than with central mixers. When this ratio is low, the resulting concrete is less strong and durable. However, batch mixers are more efficient than central mixers.
Batch mixers that are on wheels can be moved to different points in your project as you need them. They also make it easier for you to move the concrete into place after it’s mixed.
Bath mixers are categorised as drum mixer type and pan mixer type.
2. Drum mixer type
The drum mixer type is the most primitive concrete mixer. It has two rotating barrels on a common vertical axis. There are three different types of drum mixers: paddle, plough and tilt-drum mixers which are operated by hand in order to rotate the barrel. The amount of aggregate is limited in this type of concrete mixer due to its limited capacity.
- Tilting Drum mixer
The tilting drum mixer can be either ‘’T-shaped’’ or ‘’H-shaped.’’ This type of concrete mixer has a capacity of about twice that of the paddle, plough and tilt-drum mixers. The tilting drums are covered with mesh screens to help prevent clogging from the wet mixture. This type of mixer can be either stationary or mobile. Mobile mixers are more commonly used in construction projects because of their versatility and flexibility. Also, mobile concrete mixers have a greater capacity than the conventional central drum mixers because they are on wheels and can deliver up to 2 cu yd (1.25 m3) of concrete at once.
- Non-Tilting Drum mixer
This type of concrete mixer is also called a stationary mixers. It has a slightly different design compared to the tilting drum mixer because it does not have tilted drums.
This type of concrete mixer is designed to be stationary and has a capacity of up to 8 cu yd (5 m3).
- Reversing Drum mixer
This is a special type of concrete mixer that has two drums, of different capacities. While one drum has the largest capacity at about 7 cu yd (4.5 m3), the other one can accommodate 10 cu yd (6 m3). The reversing drum mixers are usually stationary and therefore have a limited usage range.
3. Pan mixer type
The pan mixer is also called the “paddle-wheel” concrete mixer and represents a great improvement over the drum mixer types in that it has less friction between floats and inner walls of the mixing chamber, thus making the mixing process more efficient. However, this kind requires an additional power source.
It consists of a mixing chamber, with an axis parallel to the ground and is usually mounted on wheels or wooden legs for easy movement. The pan mixer has two vertical steel blades which traditionally are propelled by hand; however, more recently other types were developed with engines attached for mechanical power. This type of concrete mixer can mix small to large batches and is used in many countries to produce construction materials, not only concrete.
4. Central mixers
The central mixer is considered to be the most efficient and productive type of concrete mixer because it can mix the highest volume with minimal effort. A central mixer has a drum that rotates inside or outside a stationary vessel containing water. It usually consists of three parts:
1) Housing – The housing provides support for other components of the mixer, and acts as a frame for the vessel.
2) Vessel – The rotating vessel typically has an inside diameter that ranges between 5 ft (1.5 m) to 10 ft (3 m), with a height of about 8 ft (2.4 m).
3) Batching Hopper – The drum is mounted on top of the vessel, and is driven by a motor over a circular track or via shafts, which are connected to the vessel. The drum is lifted up and delivered into position with the aid of heavy duty chains or cables as it rotates inside the stationary vessel.
4.1. 3 ways to operate central mixers :
1) Belt & drag mixer – It depends on the rotation of a large vertical fly-wheel attached to a belt and pulley system to deliver concrete in one direction along the fixed vessel. Consequently, after delivery of concrete into the mixing chamber, it is drawn back by another drum mechanism through the opposite end.
2) Reverse action mixer – It works on similar principles as that of a belt-drag mixer, except that the drum is rotated in the opposite direction. Generally, it enables better performance of the machine to produce larger batches of concrete.
3) Pull action mixer – It is a unique type of central mixer which uses pulleys and cables system to pull forward or backward the rotating drum as required by the batching hopper. The pulling action enables better performance of the machine to produce larger batches of concrete.
4.2 Types of central mixers :
+ Horizontal mixer
In this type, the vessel can be horizontal or vertical. They are most popular in small businesses where they are used to make a wide range of construction materials such as adobe blocks, sand and cement blocks, and also for plastering.
+ Vertical mixer
Vertical mixers are popular in large building projects such as high rises buildings, where they can be used to make concrete pillars or a number of vertical walls at the same time.
+ Elevated drum mixer
The elevated drum type is specifically designed to suit large volume production of concrete. It uses an elevated mixing drum with a long shaft overhead to make the entire operation more efficient and cost effective. This type is generally used in large-scale building projects such as foundations for buildings, roads and canals.
+ Planetary mixer
The planetary mixer is also commonly called the continuous mixers or the planetary concrete mixer. It is a high-performance self-contained machine that can produce three times more concrete in a given period. Since its introduction, the planetary mixer has revolutionized the construction industry and made it easier to construct buildings and other structures of almost any size.
The planetary assembly consists of an outer drum with grooves on the surface for mixing concrete. It is positioned on a turntable which is mounted below the hopper. The turntable can be rotated by a motor, and as it rotates, concrete delivered to the drum through an inlet gate slides down along the grooves towards the center of the drum. When it reaches the center region, the action of centrifugal force throws the concrete outward towards the outer surface of the drum. As it emerges from the outer groove, the concrete moves to an outlet gate near the rim of the drum where it is discharged into a place for further processing.
+ Screw mixer
The screw type mixer operates on the same principles as that of a planetary mixer, except that instead of a revolving drum, the machine uses a rotating screw mechanism to mix the concrete. The basic difference between a planetary mixer and a screw mixer is that the planetary mixer has an external mixing groove on the surface of its drum, whereas a screw mixer rotates inside a stationary vessel containing material to be mixed.
5. Continuous mixers
Continuous mixers are used in large construction projects, where concrete is required in a continuous flow. Since the introduction of concrete batching plants, which can produce concrete at rates faster than most commercial central mixers or site-mixed concrete, continuous mixers have virtually replaced all other types of central mixer for large jobs.
The continuous mixer can produce a greater amount of concrete in a shorter time than a batch batching plant. It mixes quickly and continuously, enabling it to complete the job in a few hours, whereas site-mixed concrete will take close to one or two days if the concrete is produced by hand.
While central mixers are mostly stationary on construction sites, concrete batching plants can be mobile and are easily transported from one place to another.
Advantages of continuous mixers include:
Continuous mixers can also produce a wide range of other materials including mortar, grout, screed and render depending on the drum used. Most central mixers have mixing drums that can produce both concrete and mortar, but continuous mixers usually have separate drums for each purpose.
A wide variety of drum designs are available, with a selection of inlet type and outlet type gates including side-inlet/wide-mouthed discharge gates. The drum can also be continuously rotated from front to back, top to bottom or a combination of both.
Continuous mixers are used for the production of large volumes of concrete and masonry products such as screed, render or other materials which require a high degree of fluidity. They can be mounted in either a trailer for field placements or stationary plant installations with mechanical drive systems.
Most continuous mixers can be equipped with dual drum configurations to allow two separate product mixes to be manufactured simultaneously. Dual drum systems are most commonly installed in large-scale projects where the same concrete batch will contribute to multiple sections of a construction site.
What makes the best concrete mixer?
The most important factor in choosing a reliable and sturdy cement mixer is to seek experience. The more years on the market, the better experience of building materials it will gain.
A good one should be able to make exactly what you are asking for - and that is what matters.
Look at the various options available on Amazon and make sure you are comfortable with a brand name before buying. Takes time, but if you do your homework properly, then you should be happy and it will serve you well for years!
Where can I get a concrete mixer?
To buy a concrete mixer, you will need to go to the nearest hardware shop or do an online search for the best cement mixer on Amazon .
How can I determine the cost of purchasing a concrete mixer?
It depends on what type and size you want. Cement mixers prices start from a few hundred dollars.
What are the handy features of a concrete mixer?
The best concrete mixers have additional features that make them more convenient to use and store, including tilt back support for easy dumping, lightweight design for easy transport and foldable handles for compact storage.
What size concrete mixer should I buy?
The standard way to measure the pour rate of a cement mixer is in cubic feet per minute (cfm), which is how many cubic feet of concrete can be poured in a minute. The pour rate you require will depend on the size of your project and the type of concrete mix you're working with, but a few guidelines: If there are more than two people mixing, look for a model with at least 125 cfm. If only one person is mixing, look for a model with at least 180 cfm. If you're mixing concrete for small projects, such as driveway slabs or patios, then any cement mixer that can make anywhere from one to three cubic yards per batch should do the trick.
How big of a concrete mixer do I need for my project?
If you're pouring a foundation, patio, driveway slab or other small job that requires the standard three cubic yards of concrete, then any good commercial cement mixer will do. On the other hand, if your project involves larger volumes of concrete -- like a swimming pool deck or garage floor -- you'll need to purchase a larger model that can make up to nine cubic yards of concrete at a time. For any mixers exceeding the nine cubic yards per batch capacity, get in touch with a professional mixer manufacturer as they are likely meant for construction sites and may require special add-ons for safe use.
In conclusion, you really need to think about the size of your project, the amount of people that will be mixing, and time. Everything else is just icing on the cake when buying a concrete mixer for small residential projects. If you are on a budget, look for something priced around $200 but if you have the extra cash lying around, then go all out and get a more expensive one.