Question

what is cement? what is its composition?​

Answer 1

Answer:

The raw materials used for the manufacture of cement consist mainly of lime, silica, alumina and iron oxide. ... The relative proportions of these oxide compositions are responsible for influencing the various properties of cement; in addition to rate of cooling and fineness of grinding.

Answer 2

Answer:

The raw materials used for the manufacture of cement consist mainly of lime, silica, alumina

and iron oxide. These oxides interact with one another in the kiln at high temperature to form

more complex compounds. The relative proportions of these oxide compositions are responsible

for influencing the various properties of cement; in addition to rate of cooling and fineness of

grinding. Table 1.4 shows the approximate oxide composition limits of ordinary Portland

cement.

Table 1.4. Approximate Oxide Composition Limits of Ordinary Portland Cement

Oxide Per cent content

CaO 60–67

SiO2 17–25

Al2O3 3.0–8.0

Fe2O3 0.5–6.0

MgO 0.1–4.0

Alkalies ( K2O, Na2O) 0.4–1.3

SO3 1.3–3.0

The identification of the major compounds of cement is largely based on Bogue’s equations

and hence it is called “Bogue’s Compounds”. The four compounds usually regarded as major

compounds are listed in table 1.5.

Table 1.5. Major compounds of cement

Name of Compound Formula Abbreviated Formula

Tricalcium silicate 3 CaO.SiO2 C3S

Dicalcium silicate 2 CaO.SiO2 C2S

Tricalcium aluminate 3 CaO.Al2O3 C3A

Tetracalcium aluminoferrite 4 CaO.Al2O3.Fe2O3 C4AF

It is to be noted that for simplicity’s sake abbreviated notations are used. C stands for CaO, S

stands for SiO2, A for Al2O3, F for Fe2O3 and H for H2O