chaitra-1.pptx fake news detection using machine learning
CEMENT.pptx
1. Cement
• Cement is a Binding Material.
• First cementing materials were used by Egyptians.
• Portland cement was developed in England by bricklayer Jos
Aspdin in early1800’s
• We use word “Portland” because concrete made wit
resembled natural stone from the Portland
• In India Portland cement was
South
first
India
manufactured in 1904 by
Industrial Ltd.
2. 1) Consistency
• Percentage of water
require to produce
standard cement
paste.
• It is measured
by Vicat apparatus.
2) Setting Time
• Require time to set the
cement when water
is added.
• Initial setting time
• Final setting time
Initial setting time
• At which time cement paste
start to losing its plasticity.
Final setting time
• At which time cement
paste loss complete
plasticity.
Properties Of Cement.................. Physical
3. 3) Soundness
• Soundness refers to the ability
of cement to not undergo any
appreciable change in volume.
Le Chatelier's test.
• Unsoundness due to excess
lime is measured by this test.
Autoclave Test
• Unsoundness due to
excess MgO and lime
measured by this test.
4. 4) Fineness
permeability
a)By sieving
• In this method take 100gm
sample on IS sieve no. 9.(90µ)
Sieve the sample.
b) By blain air permeability
• Due to this property of cement •
has grater surface area and
faster development of strength.
• Fineness of cement expressed•
in two way: a) By sieving
b) By blain-air
Given volume of air pass
through a prepare sample
definite density.
It can be use for measuring
the specific surface area of
cement.
• Surface area is denoted by
cm2/gm.
5. 5) Compressive Strength
• Compressive strength is
important property of
cement.
• Make mould by proper
gauging.
• Put it into curing tank
after 24 hour.
• Measure its ultimate
strength after 28 days.
6. 6) Heat of hydration
• Reaction of cement with water
is exothermic, Which liberated
a considerable quantity of heat.
• It create problem in mass
concrete work, like dam.
• Test of heat of hydration carried
out by vacuum flask method
for Low heat cement.
7. 7) Specific gravity
• It is ratio of volume of cement
to same volume of kerosene.
• Specific gravity of cement measured
by Le Chatelier’s Flask method.
8. Properties of cement…………….chemical
1) Tricalcium aluminate-C3A
• Less C3A makes the cement sulphate-resistant.
• C3A does not provide more amount of strength.
• Heat liberate about 1350J/gm.
2) Tricalciumsilicate-C3S
• C3S causes rapid hydration as well as hardening.
• Responsible for the cement’s early strength gain.
3) Dicalcium silicate-C2S
• C2S in cement helps the strength gain after one week.
• Heat liberate about 260J/gm.
9. 4) Tetra calcuim Aluminate FerriteC4AF
• It is a fluxing agent.
• Though it cement hydrates rapidly, It does not contribute much
to the strength of the cement.
5) Magnesia- MgO
• A little amount of magnesia in cement provides strength.
• An excess amount of magnesia may make the cement
unsound and expansive.
6) Oxides
a) Sulphur trioxide
of Sulphur trioxide can make cement
• Excess amount
unsound.
b) Iron oxide
• Iron oxide is mainly responsible for the Color of the cement.
10. 7)Alkalis
• Large amounts of alkali can cause some difficulty in the
setting time of cement.
8) Free lime
• Free lime, which is sometimes present in cement, may cause
expansion in crakes.
9) Alumina
• It quickens the setting but weakens the cement.
11. Types of Cement
GREY CEMENT
OPC -53/43/33
Rapid hardening
Extra rapid hardening
Sulphate resisting
Quick Setting
Expansive cement
Low heat cement
Air Entraining cement
High alumina cement
Hydrophobic cement
WHITE / Color CEMENT
Portland Pozzolana
Cement (PPC)
Portland Slag Cement
Super Sulphated Cement
OPC CEMENT BLENDED CEMENT
12. (1) RAPID HARDENING CEMENT:
•Also known as early gain in strength of cement. This
cement contains more %age of C3S and less %age of C2S, high
proportion of C3S will impart quicker hydration
•The high strength at early stage is due to finer grinding, as
fineness of cement will expose greater surface area for the action of
water.
•The strength obtained by this cement in 03 days is same as
obtained by O.P.C in 7 days.
•Initial and final setting times are same as OPC.ie. 30mins and 10
hrs.And soundness test by Le-Chatielier is 10mm and Autoclave is
0.8%.
• Greater lime content than OPC
13. (2) EXTRA RAPID HARDENING CEMENT:
•It is obtained by intergrinding Cacl2 with rapid
hardening cement.
•Addition of Cacl2 should not exceed 2% by weight of the
rapid hardening cement.
•Concrete made by using this cement should be
transported, placed, compacted & finished within about 20
minutes.
•Strength is higher than 25% than that of rapid hardening
cement at 1 or 2 days.
14. (3) SULPHATE RESISTING CEMENT:
•It is modified form of O.P.C and is specially
manufactured to resist the sulphates.
•This cement contains a low %age of C3A and high
%age of C3S
•This cement requires longer period of curing.
•It develops strength slowly, but ultimately it is as
strong as O.P.C.
15. (4) QUICK SETTING CEMENT:
• This cement is manufactured by adding small
%age of aluminum sulphate (Al2SO4) which
accelerates the setting action.
• Gypsum content is reduced.
• Sets faster than OPC.
•Initial setting time is 5 minutes. Final setting time
is 30 minutes.
16. (5) LOW HEAT CEMENT:
•Low percentage of tri-calcium aluminates (C3A) and
silicate (C3S) and high %age of di-calcium silicate (C2S)
to keep heat generation low.
•Very slow rate of developing strength as rate of C3S
Content is low.
•Heat evolved @ 7 days-66 cal/g and 28 days-75 cal/g
•initial set time-1 hr, final set time-10 hrs
•Better resistance to chemical attack than OPC.
17. (6) Portland Pozzolana
Cement:
• OPC clinker and Pozzolana (Calcined Clay,
Surkhi and Fly ash) ground together.
Produces less heat of hydration and offers great
resistance to attacks of Sulphates.
• Used in marine works and mass concreting.
• Ultimate strength is more than OPC.
• Low shrinkage on drying
• Water tightness.
18. (7) Portland Slag
Cement:
• Produced by mixing Portland cement clinker,
gypsum and granulated blast furnace slag
which shall not exceed 65%
• blackish grey in color.
• Lesser heat of hydration.
• Suitable for marine works, mass concreting.
• Offers good resistance to the attack of
sulphate.
19. (8) HIGH ALUMINA CEMENT:
Different from OPC
Characterised by its dark colour, high heat of hydration
and resistance to chemical attack.
Initial setting time of 4 hrs and final setting time of 5
hrs.
Raw materials used are limestone and bauxite
20. Suchismita Sahu, Asst. Professor KIIT
University
(9) HIGH ALUMINA CEMENT:
Different from OPC
Characterised by its dark colour, high heat of hydration
and resistance to chemical attack.
Initial setting time of 4 hrs and final setting time of 5
hrs.
Raw materials used are limestone and bauxite
21. (9) AIR ENTRAINING CEMENT:
•OPC with small quantity of air entraining materials
(oils, fats, fatty acids) ground together.
•Air is entrained in the form of tiny air bubbles which
enhances workability and reduces seggregation and
bleeding.
•It increases sulphate water resistance of concrete.
22. Suchismita Sahu, Asst. Professor KIIT
University
(10) Supersulphated
Cement:
•Ground blast furnace slag + OPC +CASO4.
Heat of hydration which is considerably lower.
•
•
It is also resistant to Sulphate attack.
Used in a) Marine Structures, b) Mass concrete works
23. Suchismita Sahu, Asst. Professor KIIT
University
(11) Expansive
Cement:
• The main difference in this cement is the increase
in volume that occurs when it settles.
• Used to neutralize shrinkage of concrete made
from ordinary cement so as to eliminate cracks. A
small percentage of this cement with concrete will
not let it crack. It is specially desirable for
hydraulic structures.
• In repair work, it is essential that the new concrete
should be tight fitting in the old concrete. This can
be done by using this cement
24. Suchismita Sahu, Asst. Professor KIIT
University
(12) Colored
Cement:
• Suitable pigments used to impart desired
color.
• Pigments used should be durable under
light, sun or weather.
25. Suchismita Sahu, Asst. Professor KIIT
University
(13) WHITE CEMENT:
•OPC with pure white color produced with white chalk or
clay free from iron oxide.
•As iron oxide gives the grey colour to cement, it is
therefore necessary for white cement to keep the content
of iron oxide as low as possible.
• Instead of coal, oil fuel is used for burning.
26.
27.
28. Manufacturing of the
cement Process
•Wet process easiest to control chemistry &better
for moist rawmaterials.
•Wet process high fuel requirements - fuel needed
to evaporate 30+% slurrywater.
• Dry process kilns less fuelrequirements
•Preheater/Precalciner further enhancefuel
efficiency & allow for high productionrates.
29.
30.
31. 1. BLASTING
quarry
crushing
conveyor
3. CRUHING & TRANSPORTATION
1.BLASTING : The raw materials that are used to manufacture cement (mainly limestone and
clay) are blasted from the quarry.
2. TRANSPORT : The raw materials are loaded into a dumper.
3. CRUSHING AND TRANSPORTATION : The raw materials, after crushing, are transported to the
plant by conveyor. The plant stores the materials before they are homogenized.
dump
er
plant
loader
Quarry
2. TRANSPORT
storage
at the
face
32. THE CEMENT MANUFACTURING PROCESS
1. RAW GRINDING
Raw grinding and burning
conveyor Raw mix
kiln
preheating
cooling
clinke
r
2. BURNING
1. RAW GRINDING : The raw materials are very finely ground in order to produce the raw mix.
2.BURNING : The raw mix is preheated before it goes into the kiln, which is heated by a flame
that can be as hot as 2000 °C. The raw mix burns at 1500 °C producing clinker which, when it
leaves the kiln, is rapidly cooled with air fans. So, the raw mix is burnt to produce clinker : the
basic material needed to make cement.
storage
at the
plant
Raw mill
33. 2. STORAGE, PACKING, DISPATCH
1.GRINDING : The clinker and the gypsum are very finely ground giving a “pure cement”.
Other secondary additives and cementitious materials can also be added to make a blended
cement.
2. STORAGE, PACKING, DISPATCH :The cement is stored in silos before being dispatched
either in bulk or in bags to its final destination.
clinker
storage
THE CEMENT MANUFACTURING PROCESS
Grinding, storage, packing, dispatch
Gypsum and the secondary
additives are added to the clinker.
1. GRINDING
silos
dispatch
bags
Finish
grinding