TOP 8 INGREDIENTS OF CEMENT AND THEIR FUNCTIONS.

THERE ARE 8 MAJOR INGREDIENTS OF CEMENT AND THEY ARE GIVEN BELOW WITH THEIR PERCENTAGE IN CEMENT.


 Ingredient   (Oxides)                            

Percentage in cement

Lime (CaO)                                          60-67
Silica (SiO2)17-25
Alumina (Al2O3)3-8
Magnesia (MgO)0.5-4
Iron oxide (Fe2O3)0.5-6
Calcium Sulfate (CaSO4)0.1-0.5
Sulfur Trioxide (SO3)1-3
Alkaline 0.3-1.2



  • The function of these ingredients of an ordinary portland cement are as follows :
1. Lime : Lime is a calcium oxide or calcium hydroxide.
  • It makes the cement sound and strong.
  • In excess quantity, It makes cement unsound.
  • In excess quantity, It makes cement expand and disintegrate.
  • Deficiency of lime makes cement weaker.
2. Silica : Silicon dioxide is known as a silica.
  • It provides strength to the cement due to the formation of dicalcium and tricalcium silicates.
  • Excess quantity of silica causes the cement to set slowly.
3. Alumina : It is an aluminium oxide.
  • It provides quick setting property to the cement.
  • It behaves as a flux and reduces the clinkering temperature.
  • Excess quantity of alumina accelerate the temperature and reduces the strength of cement.
4. Magnesia : It is a magnesium oxide.
  • It provides hardness and color to the cement when present in small quantity.
  • Excess quantity of it makes cement unsound.
  • Excess quantity also reduces the strength of cement.
5. Iron oxide :
  • It imparts color, hardness and strength to the cement.
  • It acts as a flux.
  • It helps the fusion of raw materials during manufacturing process.
  • At the high temperature, Iron oxide forms tricalcium aluminoferrite by reacting with aluminium and calcium.
6. Calcium sulfate :
  • Calcium sulfate is present in cement in the form of gypsum.
  • It is responsible for the initial setting time of cement.
7. Sulfur trioxide :
  • It makes cement sound when present in very small quantity.
  • Excess quantity of it, makes cement unsound.
8.Alkalies : 
  • These should be present in small quantity. 
  • The alkalies in excess quantity will cause efflorescence.










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