This document provides an overview of ready mix concrete (RMC). It discusses that RMC is concrete manufactured at a central batching plant according to a customer's specifications. The key components of an RMC plant include batching plants for mixing materials, transit mixers for transporting concrete, and concrete pumps. Common materials used in RMC include aggregates, cement, fly ash, and water. RMC has applications in foundations, buildings, bridges and more. Advantages include consistent quality, reduced time and waste. Limitations include high initial investment and effective transportation requirements.
3. Contents
• Introduction
• Background
• Components
• Material used in RMC
• Application of RMC
• Advantages & Limitations of RMC
• Research paper
• Case study
• Comparison
• Conclusion
4. Introduction
• As per the Indian Standard Specification IS 4926:2003,”Concrete mixed in
a stationary mixer in a central batching and mixing plant or in a truck-
mixer and supplied in fresh condition to the purchaser either at the site or
into the purchaser’s vehicles.”
• Ready-mix concrete (RMC) is a ready-to-use material, with a
predetermined mixture of cement, sand, aggregates and water.
• RMC is a type of concrete manufactured in a factory according to a set
recipe or as per specifications of the customer, at a centrally located
batching plant.
• Most of ready mixed concrete is currently manufactured under computer
controlled operations and transported and placed at project sites using
sophisticated equipment and methods.
5. Background
• The Idea of Ready Mix Concrete (RMC) was
first introduced in Germany in 1903.
• In India RMC was first time used for
Bhakhranagal Dam Project in 1953
6. • The first concrete mixed off site and delivered
to a construction site was done in Baltimore,
United States in 1913.
• The first RMC Plant was setup in Pune, India in
1993.
7. Components of RMC Plant
• Batching Plant:
Inline Bins
oRaw materials like fine & coarse
aggregates are stored in bins called
as “INLINE BINS” where the trucks
carrying fine and coarse aggregate
can dump the material easily.
8. Silos
oCement & Fly ash are stored in an airtight
container called as “Silos”. The required
quantity of cement & fly ash is extracted by
the silos.
Screw Conveyer Belt
oCement and Fly ash are fed to holding
hopper with the help of a screw conveyer. A
heavy duty cement screw conveyor is fixed
in an inclined position to convey the
cement from Manual Feeding Hopper to
Cement Hopper.
9. Type of Batching plants
As per BIS 4926-2003
• CP 18 – 16cum/hr .
• CP 30 – 30cum/hr .
• M1 - 56cum/hr .
• M3 - 64cum/hr
10. • Transit Mixers
• Transit mixers are made to transport and mix concrete up to the
construction site. The discharge of concrete is done from rear side of the
Transit mixer.
11. • Concrete Pumps
• A concrete pump is a machine used
for transferring liquid concrete by
pumping.
• Vibrator
• A vibrator is a mechanical device to
generate vibrations to remove the air
voids in concrete and for proper
compaction of concrete.
15. Material used in RMC
• Aggregate
• Coarse Aggregate
• Fine Aggregate
• Cement
• Fly ash
• Water
16. AGGREGATE :
• Aggregates are the important materials in concrete. They give body to the
concrete, reduce shrinkage and effect economy. The mere fact that the
aggregates occupy 70-80 % of the volume of concrete
• Aggregates are divided into two categories from the consideration of size
• Coarse aggregate
• Fine aggregate
• The size of the aggregate bigger than 4.75 mm is considered as coarse
aggregate and aggregate whose size is 4.75 mm and less is considered as
fine aggregate.
17. CEMENT :
• Cement is a binder material which sets and hardens independently, and can
bind other materials together.
• Cement is made up of four main compounds,
• Daicalcium Silicate (2CaO SiO2),
• Tricalcium silicate (3CaO SiO2),
• Tricalcium aluminate (3CaO Al2O3),
• Tetra-Calcium aluminoferrite (4CaO Al2O3 Fe2O3).
• These compounds are designated as C2S, C3S, C3A, and C4AF where C stands
for calcium oxide (lime), S for silica and A for alumina, and F for iron oxide.
• Small amounts of uncombined lime and magnesia also are present, along with
alkalis and minor amounts of other elements.
18. FLY ASH :
• The coal used in plants is mainly composed of combustible elements
such as carbon, hydrogen and oxygen and non combustible impurities
(10 to 40%) usually present in the form of clay, shale, quartz, feldspar
and limestone.
• The size of fly ash ranges from 1.0 to 100 micron & the average size is
around 20 microns.
WATER :
• The pH value of water should be in between 6.0 and 8.0 according to IS
456-2000.
19. Application of RMC
• Foundation
• Building
• Highway
• Bridge
• Walkway
• Retaining
• Airport
• Tunnels
• Canals
• Pile Foundation
• Water tank
• Shear wall
• Kerb
• Dams
• Power Plant
20. Advantages of RMC
• Better quality concrete is produced.
• Elimination of storage space for basic materials at site.
• Elimination of Hiring plant and machinery
• Wastage of basic materials is avoided.
• Labour associated with production of concrete is eliminated.
• Time required is greatly reduced
• Noise and dust pollution at site is reduced.
• No wastage on site
• Environment friendly
21. Limitations of RMC
• Need huge initial investment.
• Not affordable for small projects (small quantity of concrete)
• Needs effective transportation system from R.M.C to site.
• Traffic jam or failure of the vehicle creates a problem if the proper dose of
admixture is not given.
• Labours should be ready on site to cast the concrete in position to vibrate it
and compact it.
• Concrete's limited time span between mixing and going-off means that
ready-mix should be placed within 90 minutes of batching at the plant.
22. Research Paper
Title : Manufacturing of concrete from ready mix concrete
plant
Authors : D.V.Sweta, V.V.S.Sravankumar, Dr.K.Rajashekar
Subjects : Manufacturing, Cost
Keywords : Concrete, Fly Ash, aggregates, Super Plasticizer,
durability and Compressive Strength
Publication Date: 11, November-2014
23. Abstract
• This paper summarizes the results of various physical properties conducted on the
aggregates, cement, fly ash, concrete and the effect of replacement of cement by fly
ash (15%, 20% and 30%) on the compressive strength to provide sound concrete for
the purpose of utilization in various civil engineering constructions like buildings, dams,
bridges etc. Our study includes the mix designs of fly ash blended concrete and
compressive strength test on concrete cubes to know the performance of the concrete.
• It is the material of choice where strength, durability, impermeability, fire resistance
and abrasion resistance are required. Several design mixes were prepared, cured and
tested for compressive strength properties.
• The results are analysed and compared with standard concrete and conclusions made
on how best the fly ash can be utilized to give optimum results. The results indicate
that, as the total replacement level of OPC in concrete using blend of OPC + FA
increases, the strength with respect to control mix increases up to certain replacement
level and thereafter decrease.
24. Case study
• Company : RIM Concrete PVT. Ltd., Rajkot.
• Client :Takshal Devlopers,
SHREENATHJITower,
Kalawad Road,
Rajkot.
• Work : Concreting of 75’*62’*4” Slab
RequiredTransit Miller : 14 nos.
• Duration : 1 day
25. Comparison between RMC & Site Mix Concrete
Consistent Quality- concrete is
made in high tech batching
plants in a computerized
environment.
Quality is inconsistent
because concrete is hand
mixed.
26. Construction in double quick time.
Manual mixing is time consuming.
Projects take longer time to finish.
There’s no worry about to stock materials
and watch over them.
Risk of pilferage of raw materials is high.
Housekeeping could be poor due to piles
of stocks lying at the site
27. Large quantities of concrete can be ordered.
Takes more time. Repeated mixing needs to be done for large
quantities as the mixer will be too small to handle the
requirement.
No wastage of raw materials at site. Everything is
pre-mixed at RMC plants, based on Client’s needs.
High wastage of raw materials due to manual
mixing.
28. No hassle of managing labor on site.
Involves the use of laborers for mixing the
concrete on site. Management of labor means
more time, efforts and money.
Safe work practices – no disruption in the
schedule.
Highly unsafe. Unskilled and untrained laborers may
work carelessly resulting in dangerous working
condition
29. Conclusion
• Ready Mix Concrete is a modern technique of production of concrete in
large quantities away from the actual site of placing.
• RMC is very useful in cities where demand of concrete is very high and
construction sites are in congested areas, where mixing on site is not
possible.
• The Supervisory and labour costs associated with production of RMC is less,
and the quality of concrete is high.
• RMC is suitable for huge industrial and residential projects where time plays
a vital role.