Different types of concrete mixers./Classification of concrete mixers in construction.

 Concrete mixers are classified into the following  4 categories based on their,

A. Type of operation.

B. Power or fuel used.

C. Concrete mixer capacity.

D. Special purpose.

Now, let us go through the subcategories under each of these four types.

A. Type of operation:

1. Batch mixers:

This is the most common type of mixer used all over to obtain the required concrete. The concrete is prepared in batches as per the required grade. All the concrete raw materials are fed volumetrically or by weight into the drum or hopper. The concrete is prepared in part by part by following one batch after another.

These mixers are further classified as

✸. Drum mixers:  In this type of mixer, the main mixing unit is in the drum shape. 

a. Tilting drum mixer:

The raw material is fed at one side of the drum. After mixing the ingredients with water, the concrete is poured at the opposite end by tilting the drum with the help of a steering handle. 

The tilting mixer is available with or without a hopper as per the requirement.

b. Non-tilting drum mixer:

After preparing the concrete, the drum cannot be tilted to pour the mix. The mixer is lifted by the handle & inclined to pour the concrete. Usually, such mixers have a lesser capacity & are ideal for smaller construction works.

c. Reversing drum mixer:

The mixer drum contains chute-like partition blades to mix the ingredients. The material is poured into weigh batching hopper & the digital control panel shows the weight of the individual raw materials.

 The total ingredients are fed into the drum & the mixer drum is rotated in a clockwise direction. Once the concrete is ready, the drum is rotated in the anti-clockwise direction to pour out the mix at the other end. The control panel contains forward & reverse buttons to rotate the drum as desired.

✸. Pan mixer: The main mixing container is in a pan-like shape.

The mixing blades agitate the raw materials in the horizontal direction to prepare the concrete. Here, the pan is stationary & the four no. of blades do the mixing job. The ready material is poured out by opening the lock of the side door. 

The rotating blade throws out the concrete through the sweeping action. The door is closed & the process is repeated.   

2. Continuous concrete mixer:

A controlled volume of raw materials is fed into the shaft chamber through the hopper. The rotating shaft contains screw blades to prepare the mix.

 The screw pushes the mix forward & the prepared concrete is poured at the other end of the shaft. We get fresh concrete continuously without any breaks in between.

B. Power or fuel used:

a. Manual concrete mixer:

The mixer is run manually by rotating the handle. This type of mixer is used when the required volume of concrete is very low. Usually, while doing the PCC works in remote areas, such mixers are very useful.

b. Electrical concrete mixer:

The mixer is run by either single or 3-phased electrical motors. This type of mixer is used in industrial units where all the construction products like concrete blocks, RCC poles, RCC doors, etc. are manufactured.

In the electrical mixers, the drum may be either tilting or non-tilting type. The power of the electrical motor starts from 1/2 HP & it may go up to 10HP, depending upon the concrete manufacturing capability.

c. Diesel-operated concrete mixer:

This is the most common type of concrete mixer used all over construction sites. The diesel engine runs the rotation of the drum as well as the lifting operation of the hopper to feed the material.

While casting the slabs & beams we need a continuous supply of concrete. The electrical mixer stops working if there is a power outage. So, diesel mixers are the most convenient & preferred type at construction sites.   

C. Concrete mixer capacity:

a. Half-bag concrete mixer:

The capacity of the drum is between 3.5 - 5cu ft. Or in liters, the volumetric capacity ranges between 100 - 140 liters. 

The concrete volume of half a bag is produced at a time or per batch of mixing. Convenient for smaller construction works where we cannot consume larger mix volumes within the initial setting time of concrete.

b. One bag concrete mixer:

This is the widely used type of mixer to produce one bag of concrete mix per batch. The capacity of the mixer is between 7 - 10 CFT. Or we can say, the capacity is between 200 - 280 liters. 

c. Two bags of concrete mixer:

The drum is heavier having a capacity of  400 to 650 liters. These mixers are utilized for bigger construction sites or for mass concrete works.

D. Special purpose mixer:

a. Twin shaft mixer:

These mixers are ideal for the ready mix industry where we need a rapid output of concrete. They have an output capability of 2cum. to 5cum. within a short period of time due to the twin rotation of shafts. 

They have hydraulically operated discharge doors & the input is inspected by the control panels.

b. Vertical shaft mixer:

In a vertical shaft mixer, the stirring spindle revolves & the stirring planet itself rotates in the reverse direction. This system creates a superior mix of concrete of the required property.

 These types of mixers are used in larger projects where concrete quality is the priority.

To go through the articles related to the various types of construction machinery & tools, Click here.

Thank you for going through this article❤. Have a good day 😄.

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