The document provides information about ready-mix concrete (RMC), including: 1. It discusses the key raw materials used to produce RMC - aggregates (obtained from quarries), cement, fly ash, additives/admixtures, and water. Tests conducted on aggregates and their purposes are outlined. 2. Fly ash is described as a supplementary cementitious material (SCM) that contributes to hardened concrete properties through hydraulic or pozzolanic activity. 3. Additives are chemicals that can improve hardened concrete durability or reduce water content to shorten setting times. 4. The amount of water controls many fresh and hardened concrete properties like workability, strength, permeability, durability

1. RMC
READY-MIX
CONCRETE
• VISHAL
HIRWANI
• DHRUPAD

2. CONTENTS
1.RMC
2.HISTORY
3.GRADES OF CONCRETE
4.ADV. AND LIM.
5.EQUIPMENTS
6.MANUFACTURING PROCESS
7.RMC PLANT
8.SAMPLING AND TESTING

3. RMC (READY MIX CONCRETE)
Ready-mix concrete (RMC) is a type of concrete which is
manufactured in a cement factory, or specifically known as the
batching plant, according to a given set of proportions, and then
delivered to a work site, by truck mounted with mixers. This results
in a precise mixture, allowing specialty concrete mixtures to be
developed and implemented on construction sites.

4. IS-4926,
the definition of Ready mixed concrete is:
“Concrete delivered at site or in to the purchaser’s vehicle in
a plastic condition and requiring no further treatment before
being placed in position in which it is to set and harden”

5. READY MIX VS SITE MIX
READY MIX
1. Consistent Quality- concrete is made in high tech
batching plants in a computerized environment.
2. Construction in double quick time.
3. Raw materials are chosen after strict quality checks
4. Large quantities of concrete can be ordered. This allows
you to upgrade yourself and handle projects of any size.
5. No wastage of raw materials at your site. Everything is
pre-mixed at our plants, based on your needs.
6. No hassle of managing labor on site. We supply ready-to-
use concrete. well-equipped technical crew will handle the
pouring and patching of concrete at the site.
7. Safe work practices – no disruption in your schedule
8. You don’t have to stock materials and watch over them.
There’s no worry about pilferage as the concrete is directly
supplied to your site when you need it.
SITE MIX
1. Quality is inconsistent–because concrete is hand mixed.
2. Manual mixing is time consuming. Projects take longer
time to finish.
3. Quality of raw materials is manually checked. Or not
checked at all.
4. Takes more time. Repeated mixing needs to be done for
large quantities as the mixer will be too small to handle the
requirement
5. High wastage of raw materials due to manual mixing.
6. Involves the use of laborers for mixing the concrete on
site. Management of labor means more time, efforts and
money.
7. Highly unsafe. Unskilled and untrained laborers may work
carelessly resulting in dangerous working conditions
8. Risk of pilferage of raw materials is high. Housekeeping
could be poor due to piles of stocks lying at the site

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

7. RMC PLANTS IN INDIA
COMPANY PLANTS ACROSS INDIA
UltraTech - Ready Mix Concrete (RMC) Plants 103
LAFARGE 68
ACC LIMITED 92
RMC Ready-mix India 50
Relcon Infra Projects Ltd -
RDC -
Apollo Inffratech Private Limited -
The Ramco Cements Limited -
Wonder Ready-mix Concrete -
TOTAL IN INDIA 9000+ PLANTS

8. READY MIX CONCRETE - GRADES OF
CONCRETECLASSIFICATION GRADE APPLICATION RATIO
ORDINARY M10 PCC (Plain Cement Concrete) e.g. Levelling course, bedding for footing, concrete roads etc. 1:3:6
M15 PCC e.g. Levelling course, bedding for footing, concrete roads etc. 1 : 2 : 4
M20 RCC (Reinforced Cement Concrete) e.g. Slabs, beams, columns, footing etc. (for mild
exposure)
1 : 1.5 : 3
STANDARD M25 RCC (Reinforced Cement Concrete) e.g. Slabs, beams, columns, footing etc. 1 : 1 : 2
M30 RCC e.g. Slabs, beams, columns, footing etc.
M35 RCC e.g. Slabs, beams, columns, footing etc.
M40 RCC e.g. Pre-stressed concrete, slabs, beams, columns, footing etc.
M45 RCC e.g. Runways, Concrete Roads (PQC), Prestressed Concrete Girders, beams, RCC
Columns
M50 RCC e.g. Runways, Concrete Roads (PQC), Prestressed Concrete Girders, beams, RCC
Columns
M55 RCC e.g. Prestressed Concrete Girders & Piers
HIGH-
STRENGTH
M60-
M80
RCC work where compressive strength is required such as high rise building, long span
bridges, ultra-thin white topping etc and constructions in aggressive e.g. Spilways of dams
coastal construction

9. ADVANTAGE OF READY-MIX CONCRETE
•Better quality concrete is produced in lesser time.
•Elimination of storage space for basic materials at site.
•Elimination of Procurement / Hiring of plant and machinery
•Wastage of basic materials is avoided.
•Labor associated with production of concrete is eliminated.
•Time required is greatly reduced.
•Noise and dust pollution at site is reduced.
•Organization at site is more streamlined.

10. LIMITATIONS OF READY-MIX CONCRETE
• As the Ready Mixed Concrete is not available for placement immediately after
preparation of concrete mix, loss of workability occurs. In addition, there are chances
of setting of concrete if transit time involved is more. Therefore, generally admixture
like plasticizers/ super plasticizers and retarders are used. Addition of retarders may
delay the setting time substantially which may cause placement problems. In addition,
it may also affect the strength of concrete. Therefore, it is necessary that the
admixtures i.e. plasticizers and super plasticizers/ retarders used in Ready
Mixed Concrete are properly tested for their suitability with the concrete. In case loss
of strength is observed, the characteristic strength may have to be enhanced so that
after loss of strength, required characteristic strength is available.
• Because of large quantity of concrete available in short span, special placing and form
work arrangement are required to be made in advance.

11. EQUIPMENTS (RMC)
• THE STORAGE SYSTEM
This System Stores The Cement, Fine Aggregates(sand), Coarse Aggregates(gravel, Limestone, Gypsum) And Also Generally Has A Tank
For Storing Compressed Air For Cleaning And Another Tank For Storing Chemical Additives For The Concrete Mix.
1. BIN TYPE:
Consists Of A Metal Structure With Partitions Inside For Storing The Materials Except The Chemicals, Air And The Cement. Depending On
The Type Of The Batching Plant, The Bins Greatly Vary In Size. They Drop Materials Onto A Conveyor Belt Or Directly Into A Movable
Bucket( Called Skip Bucket/Charger Box) Via Pneumatically Or Electrically Operated Gates That Open For Specific Time Periods So
That Appropriate Amounts Of Materials Are Added For Different Concrete Recipes. They Are Common In Large Capacity Plants(ie
Plants With Capacities Over 60 Cu M Per Hour). The Bins May Be Arranged In-line Or Side-by-side.

12. EQUIPMENTS (RMC)
• THE STORAGE SYSTEM
2. STAR TYPE:
This system consists of the materials(except cement) stored in the open with partitions between the materials. The
aerial view roughly resembles half a star so hence the name. The partitions are made of metal, concrete blocks or
bricks. They are fed into a bucket for transporting to the mixer by means of a scraper( the long arm attached to the
cabin) which has a bucket attached and is controlled by an operator in the cabin. The number of partitions
depends on the requirement but is generally at least four.

13. EQUIPMENTS (RMC)
• THE STORAGE SYSTEM
3. COMPARTMENT BINS:
Very Similar To The Bins Mentioned Above But The Difference Is That While The Bins Generally Feed Onto A Conveyor
That Feeds The Skip Bucket, The Compartment Bins Feed Directly Into The Skip-bucket. They Are More Common In
Small Capacity And Vertical Plants.

14. EQUIPMENTS (RMC)
• SILOS (Cement and Cement Supplement)
UNLOADING OF CEMENT OR CEMENT SUPPLEMENT INTO ELEVATED
STORAGE SILOS FROM TRUCK, RAIL OR BARGE. DUE TO THE
SENSITIVITY OF CEMENT AND THE CEMENT SUPPLEMENT TO
MOISTURE, THIS IS ALWAYS AN ENCLOSED SYSTEM. THE
EMISSIONS THAT ARE GENERATED BY THIS PROCESS ARE
GENERALLY PASSED THROUGH A BAGHOUSE LOCATED ON TOP OF
THE STORAGE SILO, OR THROUGH A CENTRAL BAGHOUSE. THE
DNR RECOMMENDS THE EMISSIONS FROM EACH SILO BE MODELED
AS A POINT SOURCE USING THE STACK CHARACTERISTICS OF THE
BAGHOUSE THAT CONTROLS IT.
• Diameter of Silo Diameter is 2800/3200/3500 mm.
• Shell Thickness 5 mm Premium Quality Plate Grade IS 2062-B.
• Bottom Cone Section 6 mm Thick Premium Quality Plate Grade
IS 2062-B.
• Top Shell in 5 mm Thick Premium Quality Plate Grade IS 2062-
B.

15. EQUIPMENTS (RMC)
• TRANSIT MIXER (IS 5892-2004)
The purpose of producing well mixed concrete is lost if concrete
loses its strength during transportation. Therefore, efficient
transit mixers constitute an integral part of the RMC plants as
well as concrete batching plant units.
• The geometrical volume of a 4 cum capacity mixer is around
8,000 liter and 10,500 liter for a 6 cum capacity mixer.
Therefore, a 5 cum capacity mixer should have about 8,700
liter capacity. Filling volumes vary from 50 per cent to 60 per
cent
• Mixer drum The transit mixers are made of sturdy, high wear
resistance grade steel. Normally, the chrome and nickel
content of steel should be more than normal.
• The thickness of drum should be more at the bottom than at
the sides. A bottom thickness of 6 mm and shell thickness of 4
mm can be considered normal.

16. EQUIPMENTS (RMC)

17. EQUIPMENTS (RMC)
• CONVEYANCE UNIT
1. SKIP-BUCKET/CHARGER-BOX:
This is a large steel box that receives the aggregates and transports it to the mixer for mixing. The box runs on rails pulled by 1 or 2 metal
cables which are attached to a motor or two motors. The box has steel rails to run along the track but polyurethane wheels are increase
becoming popular due to their longer life and quieter operation.
2. CONVEYOR BELTS:
Made of Buna-S or EP rubber they are used to convey materials from the bins to the skip-bucket or to the mixer. A modified form of
the conveyor belt is called a dip-bucket and it is used to carry materials to the mixer in place of the charger box. The dip-bucket
consists of two protective rubber layers at the sides to prevent spillage and the belt is partitioned to ensure correct quantities
are batched.
3. SCREW CONVEYORS:
Screw conveyors are used to carry cement from the silos to the mixer.
4. OTHERS:
A batching plant also has a network of pipes to carry air-suspended oil droplets for circulation and for operating the various
pneumatic systems like batching gates etc. A water pump for adding water. Admixture pump for adding the chemical additives
from the admixture tank.

18. EQUIPMENTS (RMC)
SKIP-BUCKET/CHARGER-
BOX
.
CONVEYOR BELTS SCREW CONVEYORS OTHERS
1. 2. 3. 4.

19. 1
Aggregates, Which Make Up Roughly 60% To 75% Of Ready-mix Concrete’s
Volume, Are Obtained From Quarries And Aggregate Banks.
AGGREGATES
• GRADING :- Grading refers to the determination of the particle-size distribution for
aggregate. Grading limits and maximum aggregate size are specified because these
properties affect the amount of aggregate used as well as cement and water requirements,
workability, pump ability, and durability of concrete.
• SPECIFIC GRAVITY :- It is the ratio of the mass of a substance to the mass of a reference
substance for the same given volume.
• WATER ABSORPTION :- This test helps to determine the water absorption of coarse
aggregates as per IS: 2386 (Part III) – 1963.
• MOISTURE CONTENT :- Water content or moisture content is the quantity of water
contained in a material.
• ORGANIC IMPURITIES :- The Organic Impurities Test is used to determine the presence of
injurious organic compounds in sand to be used in cement mortar or concrete
RAW
MATERIAL
USED TO
PRODUCE
CONCRETE
FINE AGG. TEST
•GRADING
•SPECIFIC GRAVITY
•WATER ABSORPTION
•MOISTURE CONTENT
•ORGANIC IMPURITIES (IS 383 &2386
COARSE AGG. TEST
•GRADING
•SPECIFIC GRAVITY
•WATER ABSORPTION
•MOISTURE CONTENT
•IMPACT VALUE
•CRUSHING VALUE
•ABRASION VALUE (IS 383 & 2386

20. 1
Aggregates, Which Make Up Roughly 60% To 75% Of Ready-mix Concrete’s
Volume, Are Obtained From Quarries And Aggregate Banks.
AGGREGATES
• IMPACT VALUE :-The aggregate impact value is a measure of resistance to sudden impact
or shock, which may differ from its resistance to gradually applied compressive load.
PROCEDURE: The test sample consists of aggregates sized 10.0 mm 12.5 mm. Aggregates
may be dried by heating at 100-110° C for a period of 4 hours and cooled.
• CRUSHING VALUE :- This test helps to determine the aggregate crushing value of coarse
aggregates as per IS: 2386 (Part IV) – 1963. The apparatus used is Cylindrical measure and
plunger, Compression testing machine, IS Sieves of sizes – 12.5mm, 10mm and 2.36mm.
• ABRASION VALUE (IS 383 & 2386) :- The test sample and the abrasive charge should be
placed in the Los Angles abrasion testing machine and the machine rotated at a speed of 20
to 33 revolutions/minute for 1000 revolutions. At the completion of the test, the material
should be discharged and sieved through 1.70mm IS Sieve.
RAW
MATERIAL
USED TO
PRODUCE
CONCRETE
FINE AGG. TEST
•GRADING
•SPECIFIC GRAVITY
•WATER ABSORPTION
•MOISTURE CONTENT
•ORGANIC IMPURITIES (IS 383 &2386
COARSE AGG. TEST
•GRADING
•SPECIFIC GRAVITY
•WATER ABSORPTION
•MOISTURE CONTENT
•IMPACT VALUE
•CRUSHING VALUE
•ABRASION VALUE (IS 383 & 2386)

21. 2
The Reason Cement Is One Of The Most Common Construction Ingredients
Among Other Is Its Ability To Hold The Structure Together
CEMENT
3 Fly Ash Is Used As A Supplementary Cementitious Material (SCM) In The
Production Of Portland Cement Concrete. A Supplementary Cementitious
Material, when Used In Conjunction With Portland Cement, contributes To
The Properties Of The Hardened Concrete Through Hydraulic Or Pozzolanic
Activity, or Both.(The pozzolanic activity is a measure for the degree of
reaction over time or the reaction rate between a pozzolan and Ca2+
or
Ca(OH)2 in the presence of water.)
The major utilization areas of FLY ASH areas under:
•Manufacture of Portland Pozzolana Cement & Performance improver in
Ordinary Portland Cement(OPC).
•High volume fly ash concrete.
FLY ASH
RAW
MATERIAL
USED TO
PRODUCE
CONCRETE

22. 4
Additives Are Solid Or Liquid Chemical Substances That Can Be Added To Rmc
Before Or During Preparation. Most Commonly Used Additives Either Improve A
Hardened Concrete’s Durability Or Reduce A Concrete’s Water Content In An
Effort To Shorten Setting Times . EX-CHRYSO PLAST CRX
ADDITIVES/ADMIXTURES
5
The Amount Of Water In Concrete Controls Many Fresh And Hardened
Properties Of Concrete Including Workability, Compressive Strengths,
Permeability And Water tightness, Durability And Weathering, Drying
Shrinkage And Potential For Cracking
WATER
6
A Concrete Mixer Is Often Referred To As A Cement Mixer. The Function Of
A Concrete Mixer Is To Combine Cement With Aggregates Including Sand Or
Gravel, And Water To Form Concrete. The Most Common Type Of Concrete
Mixer Uses A Revolving Drum To Mix The Cement, Aggregates And Water
CONCRETE MIXING
RAW
MATERIAL
USED TO
PRODUCE
CONCRETE

23. MANUFACTURING OF CONCRETE
STEP1: IMPLEMENTING THE PRODUCT RECEIVED
• Receiving facilities for aggregates make it possible for trucks to unload their goods directly into a hopper (large funnel-like
device) which feeds the product through a conveyor belt.
•The cement is delivered by tanker trucks that unload their cargo in silos via pneumatic pipes under compressed air pressure.
STEP 2: STORAGE OF AGGREGATES
•Aggregates are stored in silos, in hoppers, or on the ground. The storage of aggregates allows the batch plant to have several
days worth of storage.
STEP 3: ADJUVANTS (ADDITIVES)
•Admixtures or additives are added at the time of manufacturing to obtain fluidity, and to accelerate or delay setting time…
STEP 4: STORAGE OF CEMENT
•Cement is stored in silos equipped with a dust collection venting system. There are as many silos as there are types of
cement.
STEP 5: MIXING
•The mixer blends the cement, sand, gravel and adjuvants supplied by the PLC (Programmable Logic Controller). A mixer must
contain up to 3 m3
.
•The time and the quality of the mixing are important factors so as to produce a good product. They are controlled by a
programmer.

24. MANUFACTURING OF CONCRETE
STEP 6: CONTROL STATION
•The batch plants are all equipped with PLC’s to
automate control production. They allow for
better selection with rigorous standards, of a
formulation adapted to the concrete ordered by
clients, and according to the dosage in water
corresponding to the hygrometry of aggregates.
•Cement, sand, gravel, water and adjuvants are
dosage (measured) and weighed with extreme
precision
STEP 7: DELIVERY
•Fresh concrete is brought to the site via mixer-
trucks with a capacity of 6 to 8 m3, in which it is
generally mixed before delivery to clients. Delivery
logistics constitute an essential part of the process
because of cement’s setting time which is limited.

27. SAMPLING AND TESTING OF CONCRETE
SLUMP TEST
This is a site test to determine the workability of the ready mixed concrete just before its placing to final
position inside the formwork, and is always conducted by the supervisor on site.
1. Ensure the standard Slump Cone and associated equipment are clean before test and free from hardened concrete.
2. Wet the Slump Cone and drain away the superfluous water.
3. Request the mixer or concrete truck to well mix the concrete for additional 5 minutes.
4. Place the Slump Cone on one side ( i.e. not in middle ) of the base plate on leveled ground and stand with feet on the foot-
pieces of cone .
5. Using a scoop and fill the cone with sampled concrete in 3 equal layers, each of about 100mm thick.
6. Compact each layer of concrete in turn exactly 25 times with a Slump Rod, allowing the rod just passes into the underlying
layer.
7. While tamping the top layer, top up the cone with a slight surcharge of concrete after the tamping operation.
8. Level the top by a “sawing and rolling” motion of the Slump Rod across the cone.
9. With feet are still firmly on the foot-pieces, wipe the cone and base plate clean and remove any leaked concrete from
bottom edge of the Slump Cone.
10. Leave the foot-pieces and lift the cone carefully in a vertical up motion in a few seconds time.
11. Invert the cone on other side and next to the mound of concrete.
12. Lay the Slump Rod across the inverted cone such that it passes above the slumped concrete at its highest point.
13. Measure the distance between the underside of rod and the highest point of concrete to the nearest 5mm.
14. This reading is the amount that the sampled concrete has slumped.
15. If the concrete does not show an acceptable slump, repeat the test with another sample.
16. If the repeated test still does not show an acceptable slump, record this fact in the report, or reject that load of concrete.

28. SLUMP TEST

29. SAMPLING AND TESTING OF CONCRETECOMPRESSION TEST
The Compression Test is a laboratory test to determine the characteristic strength of the concrete but the making of
test cubes is sometimes carried out by the supervisor on site. This cube test result is very important to the
acceptance of insitu concrete work since it demonstrates the strength of the design mix.
The procedure of making the test cubes is as follows: –
1. 150 mm standard cube mold is to be used for concrete mix and 100 mm standard cube mold is to be used for grout mix.
2. Arrange adequate numbers of required cube molds to site in respect with the sampling sequence for the proposed pour.
3. Make sure the apparatus and associated equipment ( see Fig 7 – 6 ) are clean before test and free from hardened concrete and
superfluous water .
4. Assemble the cube mold correctly and ensure all nuts are tightened.
5. Apply a light coat of proprietary mold oil on the internal faces of the mold.
6. Place the mold on level firm ground and fill with sampled concrete to a layer of about 50 mm thick.
7. Compact the layer of concrete thoroughly by tamping the whole surface area with the Standard Tamping Bar. (Note that no less than 35
tamps / layer for 150 mm mold and no less than 25 tamps / layer for 100 mm mold).
8. Repeat Steps 5 & 6 until the mold is all filled. (Note that 3 layers to be proceeded for 150 mm mold and 2 layers for 100 mm mold).
9. Remove the surplus concrete after the mold is fully filled and trowel the top surface flush with the mold.
10. Mark the cube surface with an identification number (say simply 1, 2, 3, etc) with a nail or match stick and record these numbers in
respect with the concrete truck and location of pour where the sampled concrete is obtained.
11. Cover the cube surface with a piece of damp cloth or polythene sheeting and keep the cube in a place free from vibration for about 24
hours to allow initial set .
12. Strip off the mold pieces in about 24 hours after the respective pour is cast. Press the concrete surface with the thumb to see any
denting to ensure the concrete is sufficiently hardened, or otherwise de-molding has to be delayed for one more day and this occurrence
should be stated clearly in the Test Report.
13. Mark the test cube a reference number with waterproof felt pen on the molded side, in respect with the previous identification number.
14. Place the cube and submerge in a clean water bath or preferably a thermostatically controlled curing tank until it is delivered to the
accredited laboratory for testing

30. SAMPLING AND TESTING OF CONCRETE
COMPRESSION TEST

31. AMPLING AND TESTING CONCRETE

32. AMPLING AND TESTING CONCRETE

33. THE END