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MATERIAL TESTING AND EVALUTION
CEMENT
Prepared
By
Sanjeev singh
AP {CE} TEC SHAHPUR-KANDI PATHANKOT
snjv432@gmail.com
Part-II
TABLE OF CONTENT
 INTRODUCTIION OF CEMENT
 TYPES OF CEMENT
 PROPERTIES OF CEMENT
 USES OF CEMENT
Introduction of Cement:
➢ Cement is the mixture of calcareous, siliceous,
argillaceous and other substances. Cement is used as a
binding material in mortar, concrete, etc.
Chemical Composition
of cement is:
Sanjeev singh, Asst. Professor TEC
Lime 63%
Silica 22%
Alumina 06%
Iron oxide 03%
Gypsum 01 to 04%
Bogue’s Compounds
C3S & C2S PRVOIDE STRENTH & OFFERS RESISTANCE
TOWARDS THE
Suchismita Sahu, Asst. Professor KIIT University
ATTACK OF ACIDS & ALKALIES.
Name of Compound Formula Abbreviated
Formula
Tricalcium silicate 3 CaO.SiO2 C3S –hydrates rapidly;
provides early & ultimate
strength
Dicalcium silicate 2 CaO.SiO2 C2S-hydraes slowly&
provides strength after a
duration of 7 days
Tricalcium aluminate 3 CaO.Al2O3 C3A-hydrates rapidly;
provides early strength &
less ultimate strength
Tetracalcium aluminoferrite 4 CaO.Al2O3.Fe2O3 C4AF-doesn’t provide
strength but is stable than
C3A
TYPES OF CEMENT
:
Sanjeev singh
15. White Cement
1. Ordinary Portland Cement
2. Rapid Hardening Cement (or) High Early Strength
cement
3. Extra Rapid Hardening Cement
4. Sulphate Resisting Cement
5. Quick Setting Cement
6. Low Heat Cement
7. Portland Pozzolana Cement
8. Portland Slag Cement
9. High Alumina Cement
10. Air Entraining Cement
11. Supersulphated Cement
12. Masonry Cement
13. Expansive Cement
14. Colored Cement
(1) ORDINARY PORTLAND CEMENT:
SANJEEV SINGH, Asst. Professor TEC
•It is called Portland cement because on
hardening (setting) its colour resembles to rocks
near Portland in England. It was first of all
introduced in 1824 by Joseph Asp din, England.
• Most important type
•Classified into three grades, namely 33 grade,
43 grade and 53 grade.
Chemical Composition of
O.P.Cement:
SANJEEV SINGH, Asst. Professor TEC
O.P.C has the following approximate chemical
composition:
The major constituents are:
1. Lime (CaO) 60- 63%
2. Silica (SiO2) 17- 25%
3. Alumina (Al2O3) 03- 08%
Chemical Composition of O.P.Cement: Continued--
-----
SANJEEV SINGH, Asst. Professor TEC
The auxiliary constituents are:
1. Iron oxide (Fe2O3) 0.5- 06%
2. Magnesia (MgO) 1.5- 03%
3. Sulphur Tri Oxide (SO3) 01- 02%
4. Gypsum 01 to 04%
Functions of Cement
Manufacturing
Constituents
SANJEEV SINGH, Asst. Professor TEC
(i) Lime (CaO):
SANJEEV SINGH, Asst. Professor TEC
1.Lime forms nearly two-third (2/3) of the
cement. Therefore sufficient quantity of the lime
must be in the raw materials for the manufacturing
of cement.
2.Its proportion has an important effect on the
cement. Sufficient quantity of lime forms di-
calcium silicate and tri-calcium silicate in the
manufacturing of cement.
3.Lime in excess, causes the cement to expand
and disintegrate.
(ii) Silica (SiO2):
SANJEEV SINGH, Asst. Professor TEC
1.The quantity of silica should be enough to
form di-calcium silicate and tri-calcium silicate in
the manufacturing of cement.
2. Silica gives strength to the cement.
3.Silica in excess causes the cement to set
slowly.
(iii) Alumina (Al2O3):
SANJEEV SINGH, Asst. Professor TEC
1.Alumina supports to set quickly to the
cement.
2. Lowers the clinkering temperature.
3.Alumina in excess, reduces the strength
of the cement.
SANJEEV SINGH, Asst. Professor TEC
(iv) Iron Oxide (Fe2O3):
Iron oxide gives colour to the
cement.
SANJEEV SINGH, Asst. Professor TEC
(v) Magnesia (MgO):
1.It also helps in giving colour to the
cement.
2.Magnesium in excess makes the cement
unsound.
SANJEEV SINGH, Asst. Professor TEC
(vi) Calcium Sulphate (or) Gypsum (Ca
SO4) :
At the final stage of manufacturing,
gypsum is added to increase the setting of
cement.
(2) RAPID HARDENING CEMENT:
SANJEEV SINGH, Asst. Professor TEC
•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
SANJEEV SINGH, Asst. Professor TEC
(3) 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.
SANJEEV SINGH, Asst. Professor TEC
(4) 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.
(5) QUICK SETTING CEMENT:
SANJEEV SINGH, Asst. Professor TEC
• 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.
(6) LOW HEAT CEMENT:
SANJEEV SINGH, Asst. Professor TEC
•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.
(7) Portland Pozzolana
Cement:
SANJEEV SINGH, Asst. Professor TEC
• 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.
(8) Portland Slag Cement
SANJEEV SINGH, Asst. Professor TEC
• 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.
(9) HIGH ALUMINA CEMENT:
SANJEEV SINGH, Asst. Professor TEC
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
(10) AIR ENTRAINING CEMENT:
SANJEEV SINGH, Asst. Professor TEC
•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.
(11) Supersulphated Cement:
SANJEEV SINGH, Asst. Professor TEC
•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
(12) Masonry Cement:
SANJEEV SINGH, Asst. Professor TEC
• Unlike ordinary cement, it is more plastic.
• Made by mixing hydrated lime, crushed
stone, granulated slag or highly colloidal
clays are mixed with it.
• Addition of above mentioned materials
reduces the strength of cement.
(13) Expansive Cement:
SANJEEV SINGH, Asst. Professor TEC
• 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
(14) Colored Cement:
SANJEEV SINGH, Asst. Professor TEC
• Suitable pigments used to impart desired
color.
• Pigments used should be durable under
light, sun or weather.
(15) WHITE CEMENT:
SANJEEV SINGH, Asst. Professor TEC
•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.
PROPERTIES OF CEMENT
 Physical Properties of Cement
 Fineness of cement. The size of the particles of the cement is its
fineness. The required fineness of good cement is achieved through
grinding the clinker in the last step of cement production process. As
hydration rate of cement is directly related to the cement particle
size, fineness of cement is very important.
 Soundness. Soundness refers to the ability of cement to not
shrink upon hardening. Good quality cement retains its volume after
setting without delayed expansion, which is caused by excessive free
lime and magnesia.
 Consistency. The ability of cement paste to flow is consistency.
 Strength. Three types of strength of cement are measured –
compressive, tensile and flexural. Various factors affect the strength,
such as water-cement ratio, cement-fine aggregate ratio, curing
conditions, size and shape of a specimen, the manner of molding
and mixing, loading conditions and age.
PROPERTIES OF CEMENT
 Setting time. Initial set: When the paste begins to stiffen
noticeably (typically occurs within 30-45 minutes)
Final set: When the cement hardens, being able to sustain some
load (occurs below 10 hours)
 Heat of hydration. When water is added to cement, the
reaction that takes place is called hydration. Hydration generates
heat, which can affect the quality of the cement and also be
beneficial in maintaining curing temperature during cold weather.
 Bulk density. When cement is mixed with water, the water
replaces areas where there would normally be air. Because of that,
the bulk density of cement is not very important. Cement has a
varying range of density depending on the cement composition
percentage. The density of cement may be anywhere from 62 to 78
pounds per cubic foot.
PHYSICAL PROPERTIES OF CEMENT
 Specific Gravity (Relative Density). Specific gravity is
generally used in mixture proportioning calculations. Portland
cement has a specific gravity of 3.15, but other types of cement
(for example, portland-blast-furnace-slag and portland-
pozzolan cement) may have specific gravities of about 2.90.
CHEMICAL PROPERTIES OF CEMENT
 Tricalcium aluminate (C3A). Low content of C3A makes the
cement sulfate-resistant. Gypsum reduces the hydration of C3A,
which liberates a lot of heat in the early stages of hydration. C3A
does not provide any more than a little amount of strength.
Type I cement: contains up to 3.5% SO3 (in cement having more
than 8% C3A)
Type II cement: contains up to 3% SO3 (in cement having less than
8% C3A)
 Tricalcium silicate (C3S).C3S causes rapid hydration as well as
hardening and is responsible for the cement’s early strength gain
an initial setting.
 Dicalcium silicate (C2S).As opposed to tricalcium silicate,
which helps early strength gain, dicalcium silicate in cement helps
the strength gain after one week.
CHEMICAL PROPERTIES OF CEMENT
 Ferrite (C4AF).Ferrite is a fluxing agent. It reduces the melting
temperature of the raw materials in the kiln from 3,000°F to
2,600°F. Though it hydrates rapidly, it does not contribute much to
the strength of the cement.
 Magnesia (MgO) .The manufacturing process of Portland cement
uses magnesia as a raw material in dry process plants. An excess
amount of magnesia may make the cement unsound and expansive,
but a little amount of it can add strength to the cement. Production
of MgO-based cement also causes less CO2 emission. All cement is
limited to a content of 6% MgO.
 Sulphur trioxide .Sulfur trioxide in excess amount can make
cement unsound.
 Iron oxide/ Ferric oxide.Aside from adding strength and
hardness, iron oxide or ferric oxide is mainly responsible for the
color of the cement.
CHEMICAL PROPERTIES OF CEMENT
 Alkalis .The amounts of potassium oxide (K2O) and sodium oxide
(Na2O) determine the alkali content of the cement. Cement
containing large amounts of alkali can cause some difficulty in
regulating the setting time of cement. Low alkali cement, when
used with calcium chloride in concrete, can cause discoloration.
 Free lime.Free lime, which is sometimes present in cement, may
cause expansion.
 Alumina. Cement containing high alumina has the ability to
withstand frigid temperatures since alumina is chemical-resistant.
It also quickens the setting but weakens the cement.
USES OF CEMENT
 To prepare cement mortar
 To prepare cement concrete
 To build fire proof and thermal proof structures
 To build hydrographic and frost resistant structures
 To build chemical proof structures
 As a grout material
 To construct Cement concrete roads
 To manufacture precast members
 For aesthetic concrete construction
 Cement concrete is used for the construction of various
structures like buildings, bridges. water tanks, tunnels, docks,
harbours etc.
THANKS

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CEMENT

  • 1. MATERIAL TESTING AND EVALUTION CEMENT Prepared By Sanjeev singh AP {CE} TEC SHAHPUR-KANDI PATHANKOT snjv432@gmail.com Part-II
  • 2. TABLE OF CONTENT  INTRODUCTIION OF CEMENT  TYPES OF CEMENT  PROPERTIES OF CEMENT  USES OF CEMENT
  • 3. Introduction of Cement: ➢ Cement is the mixture of calcareous, siliceous, argillaceous and other substances. Cement is used as a binding material in mortar, concrete, etc.
  • 4. Chemical Composition of cement is: Sanjeev singh, Asst. Professor TEC Lime 63% Silica 22% Alumina 06% Iron oxide 03% Gypsum 01 to 04%
  • 5. Bogue’s Compounds C3S & C2S PRVOIDE STRENTH & OFFERS RESISTANCE TOWARDS THE Suchismita Sahu, Asst. Professor KIIT University ATTACK OF ACIDS & ALKALIES. Name of Compound Formula Abbreviated Formula Tricalcium silicate 3 CaO.SiO2 C3S –hydrates rapidly; provides early & ultimate strength Dicalcium silicate 2 CaO.SiO2 C2S-hydraes slowly& provides strength after a duration of 7 days Tricalcium aluminate 3 CaO.Al2O3 C3A-hydrates rapidly; provides early strength & less ultimate strength Tetracalcium aluminoferrite 4 CaO.Al2O3.Fe2O3 C4AF-doesn’t provide strength but is stable than C3A
  • 6. TYPES OF CEMENT : Sanjeev singh 15. White Cement 1. Ordinary Portland Cement 2. Rapid Hardening Cement (or) High Early Strength cement 3. Extra Rapid Hardening Cement 4. Sulphate Resisting Cement 5. Quick Setting Cement 6. Low Heat Cement 7. Portland Pozzolana Cement 8. Portland Slag Cement 9. High Alumina Cement 10. Air Entraining Cement 11. Supersulphated Cement 12. Masonry Cement 13. Expansive Cement 14. Colored Cement
  • 7. (1) ORDINARY PORTLAND CEMENT: SANJEEV SINGH, Asst. Professor TEC •It is called Portland cement because on hardening (setting) its colour resembles to rocks near Portland in England. It was first of all introduced in 1824 by Joseph Asp din, England. • Most important type •Classified into three grades, namely 33 grade, 43 grade and 53 grade.
  • 8. Chemical Composition of O.P.Cement: SANJEEV SINGH, Asst. Professor TEC O.P.C has the following approximate chemical composition: The major constituents are: 1. Lime (CaO) 60- 63% 2. Silica (SiO2) 17- 25% 3. Alumina (Al2O3) 03- 08%
  • 9. Chemical Composition of O.P.Cement: Continued-- ----- SANJEEV SINGH, Asst. Professor TEC The auxiliary constituents are: 1. Iron oxide (Fe2O3) 0.5- 06% 2. Magnesia (MgO) 1.5- 03% 3. Sulphur Tri Oxide (SO3) 01- 02% 4. Gypsum 01 to 04%
  • 11. (i) Lime (CaO): SANJEEV SINGH, Asst. Professor TEC 1.Lime forms nearly two-third (2/3) of the cement. Therefore sufficient quantity of the lime must be in the raw materials for the manufacturing of cement. 2.Its proportion has an important effect on the cement. Sufficient quantity of lime forms di- calcium silicate and tri-calcium silicate in the manufacturing of cement. 3.Lime in excess, causes the cement to expand and disintegrate.
  • 12. (ii) Silica (SiO2): SANJEEV SINGH, Asst. Professor TEC 1.The quantity of silica should be enough to form di-calcium silicate and tri-calcium silicate in the manufacturing of cement. 2. Silica gives strength to the cement. 3.Silica in excess causes the cement to set slowly.
  • 13. (iii) Alumina (Al2O3): SANJEEV SINGH, Asst. Professor TEC 1.Alumina supports to set quickly to the cement. 2. Lowers the clinkering temperature. 3.Alumina in excess, reduces the strength of the cement.
  • 14. SANJEEV SINGH, Asst. Professor TEC (iv) Iron Oxide (Fe2O3): Iron oxide gives colour to the cement.
  • 15. SANJEEV SINGH, Asst. Professor TEC (v) Magnesia (MgO): 1.It also helps in giving colour to the cement. 2.Magnesium in excess makes the cement unsound.
  • 16. SANJEEV SINGH, Asst. Professor TEC (vi) Calcium Sulphate (or) Gypsum (Ca SO4) : At the final stage of manufacturing, gypsum is added to increase the setting of cement.
  • 17. (2) RAPID HARDENING CEMENT: SANJEEV SINGH, Asst. Professor TEC •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
  • 18. SANJEEV SINGH, Asst. Professor TEC (3) 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.
  • 19. SANJEEV SINGH, Asst. Professor TEC (4) 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.
  • 20. (5) QUICK SETTING CEMENT: SANJEEV SINGH, Asst. Professor TEC • 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.
  • 21. (6) LOW HEAT CEMENT: SANJEEV SINGH, Asst. Professor TEC •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.
  • 22. (7) Portland Pozzolana Cement: SANJEEV SINGH, Asst. Professor TEC • 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.
  • 23. (8) Portland Slag Cement SANJEEV SINGH, Asst. Professor TEC • 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.
  • 24. (9) HIGH ALUMINA CEMENT: SANJEEV SINGH, Asst. Professor TEC 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
  • 25. (10) AIR ENTRAINING CEMENT: SANJEEV SINGH, Asst. Professor TEC •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.
  • 26. (11) Supersulphated Cement: SANJEEV SINGH, Asst. Professor TEC •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
  • 27. (12) Masonry Cement: SANJEEV SINGH, Asst. Professor TEC • Unlike ordinary cement, it is more plastic. • Made by mixing hydrated lime, crushed stone, granulated slag or highly colloidal clays are mixed with it. • Addition of above mentioned materials reduces the strength of cement.
  • 28. (13) Expansive Cement: SANJEEV SINGH, Asst. Professor TEC • 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
  • 29. (14) Colored Cement: SANJEEV SINGH, Asst. Professor TEC • Suitable pigments used to impart desired color. • Pigments used should be durable under light, sun or weather.
  • 30. (15) WHITE CEMENT: SANJEEV SINGH, Asst. Professor TEC •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.
  • 31. PROPERTIES OF CEMENT  Physical Properties of Cement  Fineness of cement. The size of the particles of the cement is its fineness. The required fineness of good cement is achieved through grinding the clinker in the last step of cement production process. As hydration rate of cement is directly related to the cement particle size, fineness of cement is very important.  Soundness. Soundness refers to the ability of cement to not shrink upon hardening. Good quality cement retains its volume after setting without delayed expansion, which is caused by excessive free lime and magnesia.  Consistency. The ability of cement paste to flow is consistency.  Strength. Three types of strength of cement are measured – compressive, tensile and flexural. Various factors affect the strength, such as water-cement ratio, cement-fine aggregate ratio, curing conditions, size and shape of a specimen, the manner of molding and mixing, loading conditions and age.
  • 32. PROPERTIES OF CEMENT  Setting time. Initial set: When the paste begins to stiffen noticeably (typically occurs within 30-45 minutes) Final set: When the cement hardens, being able to sustain some load (occurs below 10 hours)  Heat of hydration. When water is added to cement, the reaction that takes place is called hydration. Hydration generates heat, which can affect the quality of the cement and also be beneficial in maintaining curing temperature during cold weather.  Bulk density. When cement is mixed with water, the water replaces areas where there would normally be air. Because of that, the bulk density of cement is not very important. Cement has a varying range of density depending on the cement composition percentage. The density of cement may be anywhere from 62 to 78 pounds per cubic foot.
  • 33. PHYSICAL PROPERTIES OF CEMENT  Specific Gravity (Relative Density). Specific gravity is generally used in mixture proportioning calculations. Portland cement has a specific gravity of 3.15, but other types of cement (for example, portland-blast-furnace-slag and portland- pozzolan cement) may have specific gravities of about 2.90.
  • 34. CHEMICAL PROPERTIES OF CEMENT  Tricalcium aluminate (C3A). Low content of C3A makes the cement sulfate-resistant. Gypsum reduces the hydration of C3A, which liberates a lot of heat in the early stages of hydration. C3A does not provide any more than a little amount of strength. Type I cement: contains up to 3.5% SO3 (in cement having more than 8% C3A) Type II cement: contains up to 3% SO3 (in cement having less than 8% C3A)  Tricalcium silicate (C3S).C3S causes rapid hydration as well as hardening and is responsible for the cement’s early strength gain an initial setting.  Dicalcium silicate (C2S).As opposed to tricalcium silicate, which helps early strength gain, dicalcium silicate in cement helps the strength gain after one week.
  • 35. CHEMICAL PROPERTIES OF CEMENT  Ferrite (C4AF).Ferrite is a fluxing agent. It reduces the melting temperature of the raw materials in the kiln from 3,000°F to 2,600°F. Though it hydrates rapidly, it does not contribute much to the strength of the cement.  Magnesia (MgO) .The manufacturing process of Portland cement uses magnesia as a raw material in dry process plants. An excess amount of magnesia may make the cement unsound and expansive, but a little amount of it can add strength to the cement. Production of MgO-based cement also causes less CO2 emission. All cement is limited to a content of 6% MgO.  Sulphur trioxide .Sulfur trioxide in excess amount can make cement unsound.  Iron oxide/ Ferric oxide.Aside from adding strength and hardness, iron oxide or ferric oxide is mainly responsible for the color of the cement.
  • 36. CHEMICAL PROPERTIES OF CEMENT  Alkalis .The amounts of potassium oxide (K2O) and sodium oxide (Na2O) determine the alkali content of the cement. Cement containing large amounts of alkali can cause some difficulty in regulating the setting time of cement. Low alkali cement, when used with calcium chloride in concrete, can cause discoloration.  Free lime.Free lime, which is sometimes present in cement, may cause expansion.  Alumina. Cement containing high alumina has the ability to withstand frigid temperatures since alumina is chemical-resistant. It also quickens the setting but weakens the cement.
  • 37. USES OF CEMENT  To prepare cement mortar  To prepare cement concrete  To build fire proof and thermal proof structures  To build hydrographic and frost resistant structures  To build chemical proof structures  As a grout material  To construct Cement concrete roads  To manufacture precast members  For aesthetic concrete construction  Cement concrete is used for the construction of various structures like buildings, bridges. water tanks, tunnels, docks, harbours etc.