Limestone is a sedimentary rock made up of shells of dead sea creatures that built up over millions of years. Limestone can be soft like chalk, comparatively hard like limestone, or hardest like marble. Lime mortar is made by mixing lime and sand or surkhi with water. It is used for above ground construction and has lower strength and water resistance than cement mortar. Lime has various uses including in masonry mortars, plaster, whitewash, and production of masonry blocks. Cement is made by crushing limestone and other materials, mixing them in wet or dry processes, grinding, burning at high temperatures to form clinkers, and further grinding. The ingredients and their proportions

1. LIME AND CEMENT
Done By
Saran.p
Nandha college of
technology

2. What is Limestone?
Sedimentary rock
Made up of the shells of millennia old dead
sea creatures
Layers of these built up over millions of years,
and were squashed together until they formed
limestone

3. Limestone
Chalk
(Soft)
Limestone (CaCO3)
(Comparatively
hard)
Marble
(Hardest)

4. Lime mortar:
•The paste is prepared by mixing lime and sand or
surkhi in suitable proportions in addition to water.
•If surkhi is to be added in lime mortar the equal
proportions of sand and surkhi should be mixed with
lime.
•These mortars are inferior to cement mortars in
strength as well as water tightness.
•These mortars should not be used for underground
works as they set in the presence of carbon dioxide
and break up in damp conditions.
•This type is used for construction work above ground
level i.e. exposed positions.

5. In producing masonry mortars
Plaster mortars – sets slower than gypsum
White-wash
In production of masonry blocks – slaked lime
+ sand under pressure
Uses Of Lime

6. CEMEN
T

7. FUNCTIONS OF INGREDIENTS IN CEMENT :
1. Lime – most important ingredient of the cement . its proportion have to be
carefully maintained; in excess it causes cement to expand and disintegrate, on
the other hand, if lime is less then the strength of the cement is greatly
decreased and it causes cement to set quickly.
2. Silica – it imparts strength to the cement due to the formation of dicalcium and
tricalcium silicates. If silica is present in excess the strength increases but
setting time is prolonged.
3. Alumina – it imparts quick setting properties to the cement, however in excess
it weakens the cement. It also lowers the clinkering temperature.
4. Calcium sulphate – this ingredient increases the initial setting time of cement.
5. Iron oxide – it imparts colour, hardness and strength to the cement.
6. Magnesia – in small amount helps in hardness and colour but excess makes
cement unsound.
7. Sulphur – only a very small quantity is allowable for strength.

8. Grades Of Cement
 33 grade –General Construction like plastering,
finishing works etc, where strenth is not required.
 43 grade –Useful for structural works,
precast items etc, Strength development is faster
than 33 grade.
 53 grade–Used for multi-storey buildings, precast
pre-stressed items, bridges, tall structures,etc.
Develops very fast strength and speeds up
construction.


9. • Crushing
• Mixing (Wet Process)
• Mixing (Dry Process)
• Grinding (Ball Mill and Tube
Mill)
• Storage of Ground Materials
• Burning
– Drying Zone
– Calcination Zone
– Clinkering Zone
• Grinding
– Retarder
– Dispersing Agent
– Water Proofing
• Packaging
MANUFACTURE OF PORTLAND CEMENT

10.  This is the first step in the manufacture
of Portland Cement.
 Jaw crushers of various sizes are
employed for the crushing purpose.
 Raw materials are crushed by crushers
till the size of the raw material reduces
to ¾ of an inch.
 It is than send for either Wet process or
Dry process. Wet process is universally
employed.
CRUSHING

11.  Wet process
 Calcareous materials are crushed, powdered and stored in bins.
 Argillaceous materials is mixed with water and washed. This removes
any adhering organic impurities.
 Powdered Calcareous and Washed Argillaceous materials are mixed in
proper proportions to get a slurry.
 Chemical composition is analyzed and corrected if necessary by addition
of the deficient materials.
 This slurry is then fed into the rotary klin.
MIXING PROCESS
Dry process
Hard raw materials like cement rock or blast furnace slag are first crushed
to 50mm pieces in ball mill, then dried and stored.
Crushing is done by gyratory crushers and drying is done by rotary driers.
Separate powdered ingredients are mixed in required proportions to get
the raw mix which is then fed to rotary klins.

12.  The ground materials containing 30 – 40% of water is
stored in separate tanks equipped with agitators.
 This step is followed by process of burning.
STORAGE OF GROUND MATERIALS

13.  Slurry is burnt in rotary klin where actual chemical changes takes place.
 Klin is long steel cylinder 30-40 meter in length, 2-4 meter in diameter,
lined by refractory bricks. It is inclined at gradient of 0.5-0.75 inch and
can be rotated at the desired speed.
 The material is introduced in the klin from the upper end as the klin
rotates material passes slowly towards the lower end.
 Klin is heated by burning pulverized coal or oil and temperature is
maintained at about 1400-1500°C. At clinkering temperature actual
chemical reactions takes place.
BURNING

14. Grinding can be done in two stages
Ball Mill
 Consists of cast iron drum containing iron and
steel balls of different sizes. The principle used
in ball mill s impact and shear produced by
large no. of tumbling and rolling balls.
Tube Mill
 Ball mill grinding is followed by tube mill
grinding. Tube mill is conical at the discharge
end with separate inlet and outlet.
 Slower is the feeding speed finer is the product
coming out of the tube mill.
GRINDING

15. PACKAGING
The ground powder is packed by
automatic machines in a bag.
This is then dispatched to the
markets where it is sold.

16.  When water is added to initiate dry mixtures of cement and
sand, hydration of cement starts and it will binds sand particles
as well as the surrounding surfaces of masonry and concrete.
 The proportion of cement and sand will decide the strength of
mortar.
 A richer mix than 1:3 proportion is prone to shrinkage.
 Solid surface are provided by well proportioned mortar.
 A leaner mix is not able of closing the voids in sand.
Characteristics of cement

17.  Building (floors, beams, columns, roofing, piles, bricks,
mortar, panels, plaster).
 Transport (roads, pathways, crossings, bridges, sleepers,
viaducts, tunnels, stabilization, runways, parking).
 Water (pipes, culverts, kerbing, drains, canals, weirs, dams,
tanks, pools).
 Civil (piers, docks, retaining walls, silos, warehousing, poles,
pylons, fencing).
 Agriculture (buildings, processing, housing, feedlots,
irrigation).
Common applications of cement

18. Advantages:
Cement is very strong.
It can create large structures quickly.
It conforms to different shapes (arcs and circles, etc).
It has high thermal mass (moderates temperature).
Disadvantages:
Cement is subjected to cracking.
It is very difficult to provide idoneous curing conditions.
It is not ideal for situation when settlement is expected.
Advantages and disadvantages

19. Thank you