Ready mix concrete

AVINASH KUMAR GUPTA
CCW AIR
NEW DELHI

1. READY MIX PLANT
AK GUPTA
EE (TRAINING)
DATE 14/02/2017

2. INTRODUCTIONINTRODUCTION
Ready-mix concrete (RMC) is a ready-to-use material,
with predetermined mixture of Cement, sand, aggregates
and water.
 The Idea of Ready Mix Concrete (RMC) was first
introduced by Architect Jurgen Heinrich Magens, he got his
patent of RMC in Germany in 1903.
In 1907, he discovered that the available time for
transportation could be prolonged not only by cooling
fresh concrete but also by vibrating it during
transportation.

3. The first concrete mixed off site and delivered to a The first concrete mixed off site and delivered to a
construction site was effectively done in Baltimore, construction site was effectively done in Baltimore,
United States in 1913, just before the First World War.United States in 1913, just before the First World War.
The first concept of transit mixer was also born in 1926 The first concept of transit mixer was also born in 1926
in the United States. In 1939, the first RMC plant was in the United States. In 1939, the first RMC plant was
installed in United Kingdom and in 1933.installed in United Kingdom and in 1933.
Between the years 1950 and 1980 considerable growth Between the years 1950 and 1980 considerable growth
of RMC took place in the United States.of RMC took place in the United States.
In India RMC was first initially was used in 1950 during In India RMC was first initially was used in 1950 during
the construction sites of Dams like Bhakra Nangal, the construction sites of Dams like Bhakra Nangal,
Koyna. Koyna.

4. • The increasing availability of special transport vehicles,
supplied by the new and fast growing automobile industry,
played a positive role in the development of RMC industry.

5. OBJECTIVEOBJECTIVE
Better quality concrete is produced.
Elimination of storage space for basic
materials at site.
Elimination of Procurement / Hiring of plant
and machinery.
Wastage of basic materials is avoided.

6. MATERIALS REQUIRED FOR RMC MATERIALS REQUIRED FOR RMC
1.AGGREGATE :
Aggregates are the important constituents in
concrete. They give body to the concrete, reduce
shrinkage and effect economy. The mere fact that the
aggregates occupy 70-80 per cent of the volume of
concrete.

7. AggregatesAggregates

8. Aggregates are divided into two categories from the Aggregates are divided into two categories from the
consideration of size 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.

9. 2. 2. CEMENT : 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,
 dicalcium Silicate (2CaO SiO2),
tricalcium silicate (3CaO SiO2),
 tricalcium acuminate (3CaO Al2O3),
tetra-calcium aluminoferrite (4CaO Al2O3 Fe2O3).
these compounds are designated as C2S, C3S,
C3A, and C4AF.

10. 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.

11. 3. 3. ADMIXTURE:ADMIXTURE:
• Air-entraining admixtures (mainly used in
concrete exposed to freezing)
• Water-reducing admixtures, plasticizers (reduce
the dosage of water while maintaining the
workability)
• Retarding admixtures (mainly used in hot weather
to retard the reaction of hydration)

• Accelerating admixtures (mainly used in cold
weather to accelerate the reaction of hydration)

12. • Super plasticizer or high range water-reducer
(significantly reduce the dosage of water while
maintaining the workability)
• Miscellaneous admixtures such as corrosion
inhibiting, shrinkage reducing, coloring, pumping etc.

13. FLY ASH: FLY ASH:
Fly ash is a by-product from coal-fired
electricity generating power plants.
The fly ash is generally used in the concrete in
the following ways.
As partial replace for cement.
As partial replacement for sand.
As simultaneous replacement for both
cement and sand.

14. FLY ASHFLY ASH

15. WATER :WATER :
The pH value of water should be in
between 6.0 and 8.0 according to IS
456-2000.

16. RIcE HUSk / HULL ASH (RHA) RIcE HUSk / HULL ASH (RHA)
Today, rice is grown and harvested on every
continent except Antarctica.
 The majority of all rice is produced in India,
China, Japan, Indonesia, Thailand, Burma, and
Bangladesh. Asian farmers’ accounts for 92-
percent of the world's total rice production.
 More than 550 million tons of rice is
produced annually around the globe.
That rice husk are used in RMC to increase
the strength.

17. EQUIPMENTS REQUIRED: EQUIPMENTS REQUIRED:
Storage of materials - Silos, containers and
bins
Batching arrangement
Measuring and recording equipment
Mixing equipment
Control systems
Electrical, hydraulic and pneumatic drives
Conveying systems (belt / screw
conveyors)

18. SilosSilos

19. Aggregate Feeding Belt Aggregate Feeding Belt
Conveyors:-Conveyors:-

20. Manual Batching plantManual Batching plant

21. Semiautomatic Batching Semiautomatic Batching
Plant:-Plant:-

22. Automatic Batching Plant:-Automatic Batching Plant:-

23. MIXING PROCESS:MIXING PROCESS:
Thorough mixing of the materials is essential for
the production of uniform concrete. The
mixing should ensure that the mass becomes
homogeneous, uniform in colour and
consistency. There are three methods adopted
for mixing Ready Mix Concrete.
Following are the three types of mixing
process of RMC
1. Transit Mixed (or "truck-mixed") Concrete
2. Shrink Mixed Concrete
3. Central Mixed Concrete

24. Flow Chart of Manufacturing Flow Chart of Manufacturing
Process:-Process:-

25. MIXING PROCESSMIXING PROCESS

26. TRANSIT MIXED (OR "TRUCK-TRANSIT MIXED (OR "TRUCK-
MIXED") CONCRETE:- MIXED") CONCRETE:-
While ready mixed concrete can be delivered to the point
of placement the overwhelming majority of it is brought to
the construction site in truck-mounted, rotating drum
mixers.
Truck mixers have a revolving drum with the axis inclined
to the horizontal.
Inside the shell of the mixer drum are a pair of blades or
fins that wrap in a helical (spiral) configuration from the
head to the opening of the drum.
The concrete is loaded and mixed, it is normally hauled to
the job site with the drum turning at a speed of less than 2
rpm.

27. TRANSIT MIXER TRANSIT MIXER

28. NEEDS TO BE SPECIFIED BY CONSUMER NEEDS TO BE SPECIFIED BY CONSUMER
FOR RMC FOR RMC
Characteristic strength or grade (N/mm2)
Target workability or slump in mm required at
site
Exposure conditions for durability
requirements
Maximum water to cement ratio
 Minimum cement content
 Maximum aggregate size
 Type of cement
 Mineral admixture and its proportion (Kg/m3)

29. CHECKS BY CONSUMER BEFORE CHECKS BY CONSUMER BEFORE
ORDERING THE RMCORDERING THE RMC
Calibrations of all measuring devices and their
accuracy.
Mode of operation of plant should preferably
be fully automatic and not manual.
Quality of materials proposed to be used.
Adequacy of quantity of materials used.

30. INSPECTION OF CONSUMER INSPECTION OF CONSUMER

31. Merits of Ready-Mix ConcreteMerits of Ready-Mix Concrete
· A centralized concrete batching plant can serve a wide area. Site
Mix trucks can serve a larger area including remote locations that
standard trucks cannot.
· The plants are located in areas zoned for industrial use, and yet
the delivery trucks can service residential districts or inner cities.
· Better quality concrete is produced. Site Mix can produce higher
compression strength with less water than standard batching
methods.
· Elimination of storage space for basic materials at site. Standard
Batch plant need more room for their operation than Site Mix
trucks.
·

32. Merits Continued Merits Continued
Elimination of procurement / hiring of plant and machinery
· Wastage of basic materials is avoided. With a Site Mix truck, there is
less waste and washout. This is better for the environment.
Labor associated with production of concrete is eliminated. It takes
more people to operate a standard batch plant than a Mobile Mix
truck.

· Time required is greatly reduced..

33. Demerits of RMCDemerits of RMC
The materials are batched at a central plant, and the mixing begins at that
plant, so the travelling time from the plant to the site is critical over
longer distances. Some sites are just too far away, though this is usually a
commercial rather than technical issue.
· Generation of additional road traffic; furthermore, access roads, and site
access has to be able to carry the weight of the truck and load. Concrete
is approx. 2.5tonne per m³.
· This problem can be overcome by utilizing so-called 'minimix' companies,
using smaller 4m³ capacity mixers able to access more restricted sites.
· Concrete's limited time span between mixing and going-off means that
ready-mix should be placed within 10 minutes of batching at the plant.
· Modern additives modify precisely that time span however, the amount
of additive added to the mix is very important.

34. CONClUSION:CONClUSION:
The concrete quality produced in RMC
plant is highly consistent with low deviation
order.
It provides a high degree of overall strength
of hardened concrete and the performance
of the structure at a later date.
 RMC operations are highly mechanized and
fully controlled through electronic controls
and hence reduce the probability of errors
in various operations.

35. REFERANCE:
• Concrete technology
•www.rdcconcrete.com
•www.scribd.com
•www.wikipedia.org/

36. THANK YOUTHANK YOU