Cement Ingredients
| INGREDIENTS | PERCENTAGE | AVERAGE |
| LIME (CaO) | 60 To 67% | 62 |
| SILICA (SiO2) | 17 To 25% | 22 |
| ALUMINA (Al2O3) | 3 To 8% | 5 |
CALCIUM SULPHATE (CaSO4) | 3 To 4% | 4 |
| IRON OXIDE (Fe2O3) | 0.5 To 6% | 3 |
| MAGNESIA (MgO) | 0.1 To 4% | 2 |
| SULPHUR TRIOXIDE (SO3) | 1 To 3% | 1 |
ALKALIS 'OR' SODA & POTASH (Na2 + K2O) | 0.5 To 1.3 % | 1 |
Chemical Compounds in Manufacturing of cement.
C3S (45-65%) Tricalcium silicate (3 CaO. SiO2)
C2S (15-35%) Dicalcium silicate (2 CaO. SiO2)
C3A (4-14%) Tricalcium Aluminate (3CaO. Al2O3)
Functions of Different Ingredients of Cement.
LIME: Lime is called calcium oxide or calcium hydroxide.Deficiency in Lime reduces the strength of cement.
SILICA: Silica or silica dioxide is second largest quantity of cement.It helps in maintaining the consistency & workability of cement.
ALUMINA: Aluminum or aluminum oxide it imparts quick setting property to cement.
CALCIUM SULPHATE: Present in form of gypsum in cement.It increase initial setting time of cement.
IRON OXIDE: It provides hardness & strength to the cement.It also grant colour to cement.
MAGNESIA: Magnesia or magnesia oxide give colour to the cement.Excess of magnesia makes cement sound.
SULPHUR: Sulphur or sulphur trioxide present in small quantity & make cement sound.
ALKALIES: Soda & Potash not present more than 1%.Excess quantity causes efflorescence.
