This document provides an overview of concrete technology. It discusses the composition of concrete including cement, water, and aggregates. It also describes the process of making concrete including batching, mixing, transporting, placing, compacting, curing, and finishing. Batching can be done by volume or weight, with weight batching being more precise. Concrete is mixed either by hand or using stationary mixers and is transported using various methods before being placed, compacted to remove air, and cured to allow further hydration. Finishing operations are the last steps to achieve the required surface.

1. CONCRETECONCRETE
TECHNOLOGYTECHNOLOGY
By
Preethi.R
Assistant professor
Dept of Civil Engg
SKCT

2. TABLE OF CONTENTS
 Concrete
 Composition of concrete
 Making of Concrete

3. CONCRETE
• A building
material(mixture of
broken stone or
gravel, sand , cement
and water)
• Composite material
• Can be spread or
poured into moulds
and forms

4. COMPOSiTiON OF CONCRETE
Cement
Water
Admixtures

5. CONCRETE TYPES(STATE)
Fresh concrete
Hardened concrete

6. MAKiNG OF CONCRETE

7. BATCHING
Batching is the process of measuring concrete mix ingredients by
either mass or volume and introducing them into the mixer .
 Volume batching
 Weight batching
 Volume batching
• Adopted for small jobs .
• Measures the fine and
coarse aggregate.

9. WEiGH BATCHiNG
Batching by weight
Preferable to volume batching
It’s equipment falls into 3 general categories :
I.Manual,
II.Semi automatic,
III.Fully automatic.

10. MixiNG
The mixing should ensure that the mass becomes
Homogeneous , uniform in colour and consistency .
Methods of Mixing :
1.Hands(using hand shovels)
2.Stationary Mixers
3.Ready mix concrete

11. Hand Mixing

12. Stationary MixerS
Concrete is sometime mixed at jobsite in a
These mixers may be of :
1.Tilting type ,
2.Non-Tilting type ,

13. tilting type Mixer
• Conical drum
• Inclined one
• Charging and discharging
done by the opening

14. non tilting type Mixer
Drum is cylindrical
Opened on both sides

15. tranSporting
1) Mortar Pan

16. tranSporting
2) Wheelbarrows and Buggies : Short flat
hauls

17. tranSporting
3) Belt Conveyors : Conveying concrete
horizontally for higher/lower level.

18. tranSporting
4) Cranes and Buckets

19. tranSporting
5) Pumps : Conveying
concrete from central
discharge point to
formwork.

20. tranSporting
6) Transit Mixer : used for transporting the
concrete over long distance particularly in
RMC plant .

21. PLACING
• Placed in systematic manner
• Within earth mould
• In formwork
• Steel shuttering
• Underwater

22. ComPACtIoN of CoNCrete
• Expelling the entrapped air from the concrete
• In the process of mixing , transporting and
placing of concrete air is likely to get entrapped
in the concrete .
• It has been found from the experimental
studies that 1% air in the concrete
approximately reduces the strength by 6%.

23. methods of CoNCrete
ComPACtIoN
1) Hand Compaction
Rodding
Ramming
Tamping
2) Compaction by Vibration
Internal vibrator
Formwork Vibrator
Table Vibrator
Platform vibrator
Surface vibrator .

24. hANd ComPACtIoN
Used for ordinary works
Rodding
Method of poking with 2m
long, 16 mm dia.
The thickness of layers for
rodding should be 15 to
20 cm.

25. Ramming
Compaction on ground in
plain concrete.
It is not used either in RCC
or on upper floors.
Tamping
Top surface is beaten by
wooden cross beam of cross
section 10 cm x 10 cm.

26. ComPACtIoN by VIbrAtIoN
By mechanical means
Causes temporary liquefaction so that air bubbles
come on to the top and expelled ultimately
Internal Vibration
It is most commonly used technique of concrete vibration.
Vibration is achieved due to eccentric weights attached
to the shaft.

28. exterNAL VIbrAtIoN
This is adopted where internal vibration can’t be
used due to either thin sections or heavy
reinforcement.

29. tAbLe VIbrAtIoN
It is mainly used for laboratories where concrete is
put on the table

30. PLAtform VIbrAtIoN
Similar to table vibrators-Large scale

31. CURING
• Making satisfactory moisture content &
favourable temperature in concrete
• Hydration will continue
Types:
– Water curing
– Membrane curing
– Application of heat

32. WATER CURING
• Slab-Immersion, water tank
• Roof slab- Ponding, Filled with water
• Concrete wall-Spraying,Water spray, gunny
bags

33. MEMBRANE CURING
• By plastic membrane
• In less water availability conditions
• Plastic sheets
• Reduces evaporation

34. APPLICATION OF HEAT
• Spraying of steam
• Provides heat and moisture
• Temperature- Accelerates hydration
• Early strength
• Only for precast structures
• Speed construction

35. FINISHING
• Last operation
• Required in roads, airport, home floor
• Formwork finishing
• Surface treatment
• Applied finishes

37. REFERENCES
• Google.com
• Concrete technology by M.S.
Shetty.
• www.civilblog.org
• www.civilenggforall.com › theory