Short Notes: Cement | Short Notes for Civil Engineering - Civil Engineering (CE) PDF Download

 Page 1


Cement                                                                                      
  
CHAPTER -3 
CEMENT 
 
Cement in its broadest term means any substance which acts as a 
binding agent for materials natural cement (Roman Cement) is obtained 
by burning and crushing the stones containing clay, carbonates of lime 
and some amount of carbonate of magnesia. The clay content in such 
stones is about 20 to 40 percent. Natural cement resembles very closely 
eminent hydraulic lime. It is not strong as artificial cement, so it has 
limited use in practice. 
  
Artificial cement is obtained by burning at very high temperature 
a mixture of calcareous and argillaceous materials in correct proportion. 
Calcined product is known as clinker. A small quantity of gypsum is 
added to clinker and it is then pulverized into very fine powder is known 
as cement. Cement was invented by a mason Joseph Aspdin of leeds in 
England in 1824. The common variety of artificial cement is known as 
normal setting cement or ordinary cement or Portland cement. 
 
3.1 Ingradeints – Functions 
 Ordinary Portland cement contains two basic ingredients, 
namely argillaceous and calcareous. In argillaceous materials, 
clay predominates and in calcareous materials, calcium carbonate 
predominates. Good ordinary cement contains following 
ingradients.  
1. Lime (cao)    ………. 62% 
Page 2


Cement                                                                                      
  
CHAPTER -3 
CEMENT 
 
Cement in its broadest term means any substance which acts as a 
binding agent for materials natural cement (Roman Cement) is obtained 
by burning and crushing the stones containing clay, carbonates of lime 
and some amount of carbonate of magnesia. The clay content in such 
stones is about 20 to 40 percent. Natural cement resembles very closely 
eminent hydraulic lime. It is not strong as artificial cement, so it has 
limited use in practice. 
  
Artificial cement is obtained by burning at very high temperature 
a mixture of calcareous and argillaceous materials in correct proportion. 
Calcined product is known as clinker. A small quantity of gypsum is 
added to clinker and it is then pulverized into very fine powder is known 
as cement. Cement was invented by a mason Joseph Aspdin of leeds in 
England in 1824. The common variety of artificial cement is known as 
normal setting cement or ordinary cement or Portland cement. 
 
3.1 Ingradeints – Functions 
 Ordinary Portland cement contains two basic ingredients, 
namely argillaceous and calcareous. In argillaceous materials, 
clay predominates and in calcareous materials, calcium carbonate 
predominates. Good ordinary cement contains following 
ingradients.  
1. Lime (cao)    ………. 62% 
2. silica (Sio2)   ………. 22%  
3. Aluminca(Al2 u3)   ………. 5% 
4. Calcium sulphate (CaSo4)  ……….  4% 
5. Iron Oxide (Fe2 O3)   ………. 3%  
6. Magnescia (Mgo)   ………. 2% 
7. Sulphur   ………. 1% 
8. Alkalies   ………. 1% 
 
Functions of Ingradients: 
1. Lime: Lime is the important ingredient of cement and its proportion is 
to be maintained carefully. Lime in excess makes the cement unsound 
and causes the cement to expand and disintegrate. On the other hand, if 
lime is in deficiency the strength of the cement is decreased and it causes 
cement to set quickly 
 
2. Silica: This also an important ingredient of cement and it gives or 
imparts quick setting property to imparts strength to cement. 
 
3.Alumina: This ingredient imparts quick setting properly to cement. 
Express alumina weakens the cement.   
 
4. Calcium Sulphate: This ingredient is in the form of gypsum and its 
function is to increase the initial setting time of cement. 
 
5. Magnesia: The small amount of this ingredient imparts hardness and 
colour to cement. 
 
Page 3


Cement                                                                                      
  
CHAPTER -3 
CEMENT 
 
Cement in its broadest term means any substance which acts as a 
binding agent for materials natural cement (Roman Cement) is obtained 
by burning and crushing the stones containing clay, carbonates of lime 
and some amount of carbonate of magnesia. The clay content in such 
stones is about 20 to 40 percent. Natural cement resembles very closely 
eminent hydraulic lime. It is not strong as artificial cement, so it has 
limited use in practice. 
  
Artificial cement is obtained by burning at very high temperature 
a mixture of calcareous and argillaceous materials in correct proportion. 
Calcined product is known as clinker. A small quantity of gypsum is 
added to clinker and it is then pulverized into very fine powder is known 
as cement. Cement was invented by a mason Joseph Aspdin of leeds in 
England in 1824. The common variety of artificial cement is known as 
normal setting cement or ordinary cement or Portland cement. 
 
3.1 Ingradeints – Functions 
 Ordinary Portland cement contains two basic ingredients, 
namely argillaceous and calcareous. In argillaceous materials, 
clay predominates and in calcareous materials, calcium carbonate 
predominates. Good ordinary cement contains following 
ingradients.  
1. Lime (cao)    ………. 62% 
2. silica (Sio2)   ………. 22%  
3. Aluminca(Al2 u3)   ………. 5% 
4. Calcium sulphate (CaSo4)  ……….  4% 
5. Iron Oxide (Fe2 O3)   ………. 3%  
6. Magnescia (Mgo)   ………. 2% 
7. Sulphur   ………. 1% 
8. Alkalies   ………. 1% 
 
Functions of Ingradients: 
1. Lime: Lime is the important ingredient of cement and its proportion is 
to be maintained carefully. Lime in excess makes the cement unsound 
and causes the cement to expand and disintegrate. On the other hand, if 
lime is in deficiency the strength of the cement is decreased and it causes 
cement to set quickly 
 
2. Silica: This also an important ingredient of cement and it gives or 
imparts quick setting property to imparts strength to cement. 
 
3.Alumina: This ingredient imparts quick setting properly to cement. 
Express alumina weakens the cement.   
 
4. Calcium Sulphate: This ingredient is in the form of gypsum and its 
function is to increase the initial setting time of cement. 
 
5. Magnesia: The small amount of this ingredient imparts hardness and 
colour to cement. 
 
Cement                                                                                      
  
6. Sulphur: A very small amount of sulphur is useful in making sound 
cement. If it is in excess, it causes the cement to become unsound. 
 
7. Alkalies: Most of the alkalies present in raw material are carried away 
by the flue gases during heating and only small quantity will be left. If 
they are in excess in cement, efflorescence is caused.  
 
3.2  Types of Cement 
 In addition to ordinary cement, the following are the other 
varieties of  cement. 
a. Acid Resistance Cement : This is consists of acid 
resistance aggregates such as quartz, quartzite’s, etc, 
additive such as sodium fluro silicate (Na
2
SiO
6
) and 
aqueous  solution of sodium silicate. This is used for acid- 
resistant and heat resistant coating of installations of 
chemical Industry. By adding 0.5 percent of unseed oil or 
2 percent of ceresil, its resistance to water is increased 
and known as acid water resistant cement. 
b. Blast Furnace Cement: For this cement slag as obtained 
from blast furnace in the manufacture of pig iron and it 
contains basic elements of cement, namely alumina, lime 
and silica. The properties of this cement are more or less 
the same as those of ordinary cement and prove to be 
economical as the slag, which is waste product, is used in 
its manufacture. 
c. Coloured Cement: Cement of desired colour may be 
obtained by intimately mixing mineral pigments with 
Page 4


Cement                                                                                      
  
CHAPTER -3 
CEMENT 
 
Cement in its broadest term means any substance which acts as a 
binding agent for materials natural cement (Roman Cement) is obtained 
by burning and crushing the stones containing clay, carbonates of lime 
and some amount of carbonate of magnesia. The clay content in such 
stones is about 20 to 40 percent. Natural cement resembles very closely 
eminent hydraulic lime. It is not strong as artificial cement, so it has 
limited use in practice. 
  
Artificial cement is obtained by burning at very high temperature 
a mixture of calcareous and argillaceous materials in correct proportion. 
Calcined product is known as clinker. A small quantity of gypsum is 
added to clinker and it is then pulverized into very fine powder is known 
as cement. Cement was invented by a mason Joseph Aspdin of leeds in 
England in 1824. The common variety of artificial cement is known as 
normal setting cement or ordinary cement or Portland cement. 
 
3.1 Ingradeints – Functions 
 Ordinary Portland cement contains two basic ingredients, 
namely argillaceous and calcareous. In argillaceous materials, 
clay predominates and in calcareous materials, calcium carbonate 
predominates. Good ordinary cement contains following 
ingradients.  
1. Lime (cao)    ………. 62% 
2. silica (Sio2)   ………. 22%  
3. Aluminca(Al2 u3)   ………. 5% 
4. Calcium sulphate (CaSo4)  ……….  4% 
5. Iron Oxide (Fe2 O3)   ………. 3%  
6. Magnescia (Mgo)   ………. 2% 
7. Sulphur   ………. 1% 
8. Alkalies   ………. 1% 
 
Functions of Ingradients: 
1. Lime: Lime is the important ingredient of cement and its proportion is 
to be maintained carefully. Lime in excess makes the cement unsound 
and causes the cement to expand and disintegrate. On the other hand, if 
lime is in deficiency the strength of the cement is decreased and it causes 
cement to set quickly 
 
2. Silica: This also an important ingredient of cement and it gives or 
imparts quick setting property to imparts strength to cement. 
 
3.Alumina: This ingredient imparts quick setting properly to cement. 
Express alumina weakens the cement.   
 
4. Calcium Sulphate: This ingredient is in the form of gypsum and its 
function is to increase the initial setting time of cement. 
 
5. Magnesia: The small amount of this ingredient imparts hardness and 
colour to cement. 
 
Cement                                                                                      
  
6. Sulphur: A very small amount of sulphur is useful in making sound 
cement. If it is in excess, it causes the cement to become unsound. 
 
7. Alkalies: Most of the alkalies present in raw material are carried away 
by the flue gases during heating and only small quantity will be left. If 
they are in excess in cement, efflorescence is caused.  
 
3.2  Types of Cement 
 In addition to ordinary cement, the following are the other 
varieties of  cement. 
a. Acid Resistance Cement : This is consists of acid 
resistance aggregates such as quartz, quartzite’s, etc, 
additive such as sodium fluro silicate (Na
2
SiO
6
) and 
aqueous  solution of sodium silicate. This is used for acid- 
resistant and heat resistant coating of installations of 
chemical Industry. By adding 0.5 percent of unseed oil or 
2 percent of ceresil, its resistance to water is increased 
and known as acid water resistant cement. 
b. Blast Furnace Cement: For this cement slag as obtained 
from blast furnace in the manufacture of pig iron and it 
contains basic elements of cement, namely alumina, lime 
and silica. The properties of this cement are more or less 
the same as those of ordinary cement and prove to be 
economical as the slag, which is waste product, is used in 
its manufacture. 
c. Coloured Cement: Cement of desired colour may be 
obtained by intimately mixing mineral pigments with 
ordinary cement. The amount of colouring may vary from 
5 to 10 percent and strength of cement if it is exceeds 10 
percent. Chromium oxide gives brown, red or yellow for 
different proportions. Coloured cements are used for 
finishing of floors, external surfaces, artificial marble, 
windows       
d. Expanding Cement : This type of cement is produced by 
adding an expanding medium like sulpho – aluminate and 
a  stabilizing agent to ordinary cement. Hence this cement 
expands where as other cement shrinks. Expanding 
cement is used for the construction of water retaining 
structures and also for repairing the damaged concrete 
surfaces. 
e. High alumina Cement: This cement is produced by 
grinding clinkers formed by calcining bauxite and lime. 
The total content should not be less than 32 percent and 
the ratio by weight of alumina to lime should be between 
0.85 and 1.30. 
Advantages 
1. Initial setting time is about 31/2 hours therefore, allows more time 
for mixing and placing operations. 
2. It can stand high temperatures. 
3. It evolves great heat during setting therefore not affected by frost. 
4. It resists the action of acids in a better way. 
5. It lets quickly and attains higher ultimate strength. 
 
Page 5


Cement                                                                                      
  
CHAPTER -3 
CEMENT 
 
Cement in its broadest term means any substance which acts as a 
binding agent for materials natural cement (Roman Cement) is obtained 
by burning and crushing the stones containing clay, carbonates of lime 
and some amount of carbonate of magnesia. The clay content in such 
stones is about 20 to 40 percent. Natural cement resembles very closely 
eminent hydraulic lime. It is not strong as artificial cement, so it has 
limited use in practice. 
  
Artificial cement is obtained by burning at very high temperature 
a mixture of calcareous and argillaceous materials in correct proportion. 
Calcined product is known as clinker. A small quantity of gypsum is 
added to clinker and it is then pulverized into very fine powder is known 
as cement. Cement was invented by a mason Joseph Aspdin of leeds in 
England in 1824. The common variety of artificial cement is known as 
normal setting cement or ordinary cement or Portland cement. 
 
3.1 Ingradeints – Functions 
 Ordinary Portland cement contains two basic ingredients, 
namely argillaceous and calcareous. In argillaceous materials, 
clay predominates and in calcareous materials, calcium carbonate 
predominates. Good ordinary cement contains following 
ingradients.  
1. Lime (cao)    ………. 62% 
2. silica (Sio2)   ………. 22%  
3. Aluminca(Al2 u3)   ………. 5% 
4. Calcium sulphate (CaSo4)  ……….  4% 
5. Iron Oxide (Fe2 O3)   ………. 3%  
6. Magnescia (Mgo)   ………. 2% 
7. Sulphur   ………. 1% 
8. Alkalies   ………. 1% 
 
Functions of Ingradients: 
1. Lime: Lime is the important ingredient of cement and its proportion is 
to be maintained carefully. Lime in excess makes the cement unsound 
and causes the cement to expand and disintegrate. On the other hand, if 
lime is in deficiency the strength of the cement is decreased and it causes 
cement to set quickly 
 
2. Silica: This also an important ingredient of cement and it gives or 
imparts quick setting property to imparts strength to cement. 
 
3.Alumina: This ingredient imparts quick setting properly to cement. 
Express alumina weakens the cement.   
 
4. Calcium Sulphate: This ingredient is in the form of gypsum and its 
function is to increase the initial setting time of cement. 
 
5. Magnesia: The small amount of this ingredient imparts hardness and 
colour to cement. 
 
Cement                                                                                      
  
6. Sulphur: A very small amount of sulphur is useful in making sound 
cement. If it is in excess, it causes the cement to become unsound. 
 
7. Alkalies: Most of the alkalies present in raw material are carried away 
by the flue gases during heating and only small quantity will be left. If 
they are in excess in cement, efflorescence is caused.  
 
3.2  Types of Cement 
 In addition to ordinary cement, the following are the other 
varieties of  cement. 
a. Acid Resistance Cement : This is consists of acid 
resistance aggregates such as quartz, quartzite’s, etc, 
additive such as sodium fluro silicate (Na
2
SiO
6
) and 
aqueous  solution of sodium silicate. This is used for acid- 
resistant and heat resistant coating of installations of 
chemical Industry. By adding 0.5 percent of unseed oil or 
2 percent of ceresil, its resistance to water is increased 
and known as acid water resistant cement. 
b. Blast Furnace Cement: For this cement slag as obtained 
from blast furnace in the manufacture of pig iron and it 
contains basic elements of cement, namely alumina, lime 
and silica. The properties of this cement are more or less 
the same as those of ordinary cement and prove to be 
economical as the slag, which is waste product, is used in 
its manufacture. 
c. Coloured Cement: Cement of desired colour may be 
obtained by intimately mixing mineral pigments with 
ordinary cement. The amount of colouring may vary from 
5 to 10 percent and strength of cement if it is exceeds 10 
percent. Chromium oxide gives brown, red or yellow for 
different proportions. Coloured cements are used for 
finishing of floors, external surfaces, artificial marble, 
windows       
d. Expanding Cement : This type of cement is produced by 
adding an expanding medium like sulpho – aluminate and 
a  stabilizing agent to ordinary cement. Hence this cement 
expands where as other cement shrinks. Expanding 
cement is used for the construction of water retaining 
structures and also for repairing the damaged concrete 
surfaces. 
e. High alumina Cement: This cement is produced by 
grinding clinkers formed by calcining bauxite and lime. 
The total content should not be less than 32 percent and 
the ratio by weight of alumina to lime should be between 
0.85 and 1.30. 
Advantages 
1. Initial setting time is about 31/2 hours therefore, allows more time 
for mixing and placing operations. 
2. It can stand high temperatures. 
3. It evolves great heat during setting therefore not affected by frost. 
4. It resists the action of acids in a better way. 
5. It lets quickly and attains higher ultimate strength. 
 
Cement                                                                              
  
Disadvantages: 
1. It is costly 
2. It cannot be used in mass construction as it evolves great heat and as 
it sets soon. 
3. Extreme care is to taken to see that it does not come in contact with 
even traces of lime or ordinary cement. 
 
f. Hydrophobic Cement: This type of cement contains admixtures, 
which decreases the wetting ability of cement grains. The usual 
hydrophobic admixtures are acidol napthene soap, oxidized 
petrolatum etc when hydrophobic cement is used, the fire pores 
in concrete are uniformly distributed and thus the frost resistance 
and the water resistance of such concrete are considerably 
increased. 
 
g. Low Heat Cement: Considerable heat is produced during the 
setting action of cement. In order to reduce the amount of heat, 
this type of cement is used. It contains lower percentage of tri 
calcium aluminates C
3
A and higher percentage of dicalcium 
silicate C
2
s. This type of cement is used for mass concrete works 
because it processes less compressor strength.  
 
h. Pozzuolona Cement: Pozzuolona is a volcanic powder and the 
percentage should be between 10 to 30. 
Advantages 
1. It attains compressive strength with age. 
2. It can resist action of sulphates.