Composition of Ordinary Portland Cement
Composition of Ordinary Portland Cement
The chief chemical components of ordinary Portland cement are:
- Calcium
- Silica
- Alumina
- Iron
Calcium is usually derived from limestone, marl or chalk while silica, alumina and iron come from the sands, clays & iron ores. Other raw materials may include shale, shells and industrial byproducts.
Basic Composition:
|
Contents
|
%
|
|
CaO
|
60-67
|
|
SiO2
|
17-25
|
|
Al2O3
|
3-8
|
|
Fe2O3
|
0.5-6.0
|
|
MgO
|
0.5-4.0
|
|
Alkalis
|
0.3-1.2
|
|
SO3
|
2.0-3.5
|
The chief compound which usually form in process of mixing:
- 1-triclcium silicate (3CaO.SiO2)
- 2-Dicalcium silicate (2CaO.SiO2)
- 3-tricalcium aluminates (3CaO.Al2O3)
- 4-tetracalcium aluminoferrite (4CaO.Al2O3.Fe2O3)
