Question

The approximate percentage of silica in cement is:

• A. 5 - 10%
• B. 15 - 20%
• C. 20 - 25%
• D. 25 - 30%

Answer 1

Answer: (C)

20 - 25%

Answer 2

The approximate composition of cement is : Lime ${(CaO)}$ = 50 - 60% Silica ${(SiO2)}$ = 20 - 25 % Alumina ${(Al2O3)}$ = 5 - 10 % Magnesia ${(MgO) }$= 2 - 3% Ferric oxide ${(Fe2O3)}$ = 2 - 3%