Ready mix concrete

2. Ready mix concrete

6. The idea of ready mix concrete (RMC) was first
introduced by Architect Heinrich ,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 . so this gave rise
to a concrete which is made in the off site.
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 and in 1933, first
specification on RMC was published in united
kingdom.

7.  In India RMC was first initially was used in 1950
during the construction sites of dams like KOYNA at
the construction the transportation of concrete is
done by either manually or mechanically using
ropeways and buckets or conveyor system.
 RMC at PUNE in the year 1991. However, due to
various pit falls and problem this plant did not
survive for long and was closed. Within a couple of
months in the year , 1993, two RMC plant were set up
in the MUMBAI to commercially sell RMC to the
projects where they were installed .

8. 1) AGGREGATE: Aggregate are the important They give
body to the concrete , reduce shrinkage and effect
economy . earlier , aggregates were considered were as
chemically inert materials but
Now it has been recognized that some of the aggregates.
Constituents in concrete.

9. Cement is binder material which sets and
hardness independently ,and can bind other material
together . cement is made up for main compounds.
 Dacalcium silicate (2CaOSiO2),
 Tricalcium silicate (3CaOSiO2),
 Tricalcium aluminates (3CaOSiO2)

10.  The coal used is mainly composed of elements such
as carbon , hydrogen and oxygen and non
combustible impurities (10 to 40%) usually in the form
of clay , shale and limestone.
 The size of fly ash ranges from 1.0 to 100 micron and
the average size is around 20 microns.

11.  Ready mix concrete (RMC) is a type of concrete which
is manufacturing in a cement factory, or specifically
known as the batching plant, according to given set of
properties, and then delivered to a work site, by truck
mounted with mixers. This results in precise mixture,
allowing specialty concrete mixtures to be developed
and implemented sites.

13. 1.Batching plant
 Inline Bins
Raw material like fine and coarse aggregates are
stored in bins called as “INLINE BINS” where the
trucks carrying fine and coarse aggregates can
dump the material easily.

14. 2. Silos
 Cement and fly ash are stored in an airtight
container called as “Silos” of cement and fly ash is
extracted by the silos.

15. 3. Screw conveyer belt
 Cement and fly ash are fed to holding hopper
with the help of 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.

16.  Almost all imported production plants offer
automatic system for control function . these are
required for better quality control higher economy
and superior working conditions. Fully automatic
plant control systems with multiple inputs for up
to 120 mixes or template control system are
usually housed in a container or control room of
the plant. Microprocessor controlled production
plants

18.  Better quality concrete is produced.
 Elimination of storage space for basic materials at
site.
 Elimination hiring of plant and machinery.
 Wastage of basic materials is avoided.
 Labors associated with production of concrete is
eliminated.
 Noise and dust pollution at site is reduced.
 Time required is greatly reduced.

19.  The plants are located in areas zoned for industrial
use and yet the delivery trucks can service
residential
Districts or inner cities . site – mix trucks have the
same capabilities.
 Better quality concrete is produced .site mix can
produce higher compression strength with less
water than standard batching methods.

21. 1) Cement:-

22. 2) Aggregate:-

23.  GRADE OF CONCRETE ASSUMED DEVIATION
N/sq.mm
 M 10
 M 15
 M 20
 M 25
 M 30
 M 35
 M 40
 M 45
 M 50.