Concrete is a mixture of Portland cement, water, and coarse & fine aggregates mixed at the site. RMC as opposed to site concrete is mixed in a central batching or a mixing plant which is then transported in a truck-mixer and supplied in fresh condition to the site. RMC has the same composition & proportion as traditional concrete, since it is manufactured in a plant it has the added advantage of mixing concrete in precise proportions. This improves the concrete mix and standardizes the quality. This concrete mix is supplied in terms of cubic meters.

1. What are the Different Types of Ready
Mix Concrete?
https://arkihive.com/

3. The construction industry has seen unprecedented growth in the use of Ready-Mix
Concrete, however, the first use of RMC dates to 1903 which then progressed only
to mega projects in India until the 1950s. The last two decades have seen
tremendous use of RMC in residential & other infrastructure projects. If the term
RMC is new and you are wondering about its use, application let us get to the basics
of RMC!
What is Ready Mix Concrete?
Concrete is a mixture of Portland cement, water, coarse & fine aggregates mixed at
the site.

4. RMC as opposed to site concrete is mixed in a central batching or a mixing plant
which is then transported in a truck-mixer and supplied in fresh condition to the site.
RMC has the same composition & proportion as traditional concrete, since it is
manufactured in a plant it has the added advantage of mixing concrete in precise
proportions. This improves the concrete mix and standardizes the quality. This
concrete mix is supplied in terms of cubic meters.
When will you need RMC?
Concrete is a useful and crucial material for any form of construction or renovation.
Nevertheless, inexperienced users of concrete, in general, find it incredibly difficult to

5. To secure suitable results for any task involving concrete is a risk. This poses one of
the main reasons why ready-mix concrete is popular today. Secondly, when the
concrete requirement is immediate or when needed in small quantities, mixing on-
site is trouble, with RMC making small scale projects easily commissionable. RMC
proves its advantages with ease of site handling at the site with minimal labor cost
and low material wastage. Since the site condition & surroundings will not be harmed
at large it is environmentally friendly.

6. Since RMC is manufactured in a plant. Now, how can RMC be transported?
The concrete must be transported from the mixer to the site maintaining the
workability of the mix without segregation, loss of any constituents or ingress of
foreign matter. It must be immediately used at the site to avoid rehandling or moving
the concrete horizontally. The full load of concrete must be discharged within 30mins
of the arrival at the site as specified by IS Code. However, RMC is available in
different grades and value addition which may specify a different time and care for
casting.

7. Are there different types?
Pioneering efforts of several manufacturers have bought in the various product range
of RMC, these specialized ranges include lightweight concrete, high strength
concrete, self-compacting concrete, Fiber Reinforced and several others which will
be described in detail in the next blog. Watch this space!
Advantages of RMC?
Quality of Concrete - For one thing, the quality of concrete matters! In a traditional
on-site concrete mix, quality control is a major concern.

8. Manual labor and on-site equipment usually do not maintain an ideal water-cement
ratio and grade of aggregates to precise quantity. Do not do you agree it’s a tricky
job? With ready mix concrete, batch mixing can always guarantee an accurate
proportion of all constituents since it is manufactured in a remote plant using state-of-
the-art technology, engineering, and equipment with minimal manual labor.
Environmentally Friendly - Let us understand how RMC proves to be
environmentally friendly and how the site will not be harmed. Secondly, pre-mixed
concrete eliminates the storage of materials required at the site causing minimal or
no harm to the site and its surrounding.

9. Cost-Effective - Since ready mix concrete is premixed and available to use
immediately it reduces the labor and contracting charges required at the site &
reduces a ton of money. The batching plant has control over the production and use
of raw materials, the mechanized process reduces material wastage and overhead
costs at the site.
Time Optimized Solution - RMC offers speedy construction, reduces problems
associated with the site. Increased supervision & mechanized controls at
manufacturing plants keep the delivery of concrete time-bound. An immediate
requirement of a project can be met without pre planning buying of materials and
managing equipment at the site.

10. For what are they used?
Ready-mix concrete can be used for all concrete works like traditional concrete
works, it only needs additional care during transportation. Any concrete-based job
such as foundational works, framed construction of columns & beams, laying or
resurfacing pavement, walkways, driveways or even roadway can be quickly
undertaken and completed without any obstruction to continued activities.
Now, are there any limitations to the use of RMC?
Well, of course, any material or service has its pros and cons. In this consideration,

11. Setting Time - Concrete manufactured at the batching plant is mixed with
admixtures or retarders that delay the setting time allowing the material to be
transported to the site. RMC must arrive at the site with an optimum dose of
admixtures that does not involve undue delay in its setting.
Good Formwork - The formwork cast at the site needs to be sturdy to withstand the
load of the fresh concrete since RMC needs speedy pouring on site. The formwork
needs to sustain the placement of speed concrete. IS code specifies the concrete to
be cast within 30minutes of arrival at the site.

12. Slump & Stiffness of Concrete - Concrete supplied from the plant can either be stiff
or more slumpy. The addition of water at the site will compromise the workability and
pumping of concrete. Technical supervision at the site is necessary while discharging
the concrete for any recommendation for re-handling concrete if necessary!
Types of Ready-Mix Concrete
Here’s what we are going to talk about the types of Ready-Mix concrete determined
by the specific mix and constituents of the ingredients.

13. What are the three types of Ready-Mix Concrete?
● Shrink Mixed Concrete
● Transit Mixed Concrete
● Central Mixed Concrete
1. Shrink Mixed Concrete - The concrete is partially mixed in the batching or
manufacturing plant to a specific consistency allowing further mixing of concrete
while the mix is in transit. The secondary or continued mixing is carried out in
the mountain drum of the transit truck mixer.

14. The amount of mixing required during transit is determined by the amount of
premixing completed at the batching plant. A slump test or necessary test is taken to
determine the amount of mixing required during transit is best advised.
2. Transit Mixed Concrete - Transit mixed concrete is also known as dry-batched
concrete. Ready- Mix concrete of this type includes mixing of all ingredients in the
transit truck mixer as the name indicated. All the basic constituents including water
are combined during the transit. When the truck is loading initially with all the
ingredients, the mountain drum of the mixer rotates quickly at a very high speed
eventually reducing the speed of the drum to slow rotations to an agitating normal
speed.

15. Now the Transit mixer concrete is also available in three variations:
● Mixed at Job Site: During the transport, this variant of RMC revolves in the
mountain drum at a slow speed. Approximately 2 rotations of every minute, 2
rpm. When the mix reaches the construction site before the mix is being
removed from the truck, the drum rotates about 70 – 100 revolutions at a
maximum speed of 12-15 rotations per minute (12-15 rpm). This helps the
concrete mixture to attain a smooth texture.
● Mixed in Transit: As the name suggests, the concrete is completely mixed
during the transit. During the transit, the mix is under a continual rotation of
approximately 8 rpm is about 70 revolutions approximately.

16. After achieving 70 revolutions, the rotation of the drum is slowed to an agitating
speed. The speed of the drum is then about 2 rpm until the concrete reaches the
site and is finally discharged.
● Mixed in Yard: The mix is complete when the concrete reaches the site. During
transit, the RMC is kept at slow agitation to keep the mix in a stable texture
without forming lumps. Once the truck reaches the site, the mountain drum will
rotate at a speed of 12-15 rpm at roughly 50 revolutions until the mixture is
ready to be discharged.

17. 3. Central Mixed Concrete - Central mixed concrete is also referred to as wet batch
concrete or premix plants or even central batching plant concrete. The concrete is
mixed in a stationary unit in the plant before being transferred to the transit truck.
During transit, the mountain drum primarily acts as an agitator. Central mixed
concrete has a faster production rate than transit mix RMC. The quality of the RMC
is higher, and the consistency is improved due to the stationary mixer unit. The
intensity of the plant mixer tends to produce higher strength concrete because of
thoroughly blended ingredients.

18. Value Added Ready-Mix Concrete
1.High Strength Concrete - HS concrete offers superior workability, high durability
& compressive strength of 65 Mpa and above. The use of high strength concrete
reduces concrete volume by 45% by reducing structural column/beam size. Used for
Long span infrastructure, Structural elements, Column, Beam, Shaft.
2. Self-Compacting Concrete - High-performance concrete with properties like self-
levelling and self-compacting is achieved with special admixtures. Reduced noise
during casting, gives a smooth surface finish with high workability and reduced cost.

19. Especially preferred for congested reinforcement sections where it’s difficult to
vibrate sections while concrete placement. A generic application like slabs, beams,
foundation & columns.
3. Fiber Reinforced Concrete - Fiber Reinforced concrete contains fibrous material
which increases structural integrity & tensile strength compared to normal concrete.
The fiber content in the concrete mix controls shrinkage cracks that occur during
hydration. FRC can be an RMC mixed with additives or can be mortar mixed onsite,
care must be taken to evenly mix the fiber content. The fibrous content of the
concrete varies concerning the application.

20. Depending on the structural design the fibers can replace steel rebars or reduce the
usage of steel thereby lowering the cost of construction.
4. Steel Fiber concrete is used for road pavement, construction of bridges, decks &
pavement for airfield structures.
5. Glass Fiber concrete – GFRC is a lightweight concrete mix used for creating
structures with high aesthetic value. Commonly seen it's used in fluidic construction.
Even used as façade cladding.
6. Synthetic Fiber Concrete is made of two fibrous types either microfiber or macro

21. Macro fiber is used for obtaining high tensile strength. Commonly used for
Sidewalks, curbs & driveways.
7. Lightweight Concrete - Lightweight concrete is 50% to 75% lighter in weight than
normal concrete. It has improved thermal insulation, lesser structural loading &
higher resistance to fire. Generally used for floor screed for noise cancellation
transferring through the floor slab. Construction of light weighs partitions, filler slabs,
decks, bridges & piers.
8. Green Concrete - Sustainable alternative to concrete with lower embodied
carbon. Green concrete meets sustainable goals with reduced use of ordinary

22. Every cubic meter of Green Concrete saves about 10-13% of Co2 emission. Green
concrete controls sulfate & ion ingress, reduces hydration therefore best suited for
marine & coastal structures.