Which compound imparts grey color, strength and hardness to the portland cement?
A. Iron oxide
B. Alumina
C. Magnesium oxide
D. Silica
Answer:A
Which compound imparts grey color, strength and hardness to the portland cement?
A. Iron oxide B. Alumina C. Magnesium oxide D. Silica
Explanation: Iron oxide imparts grey color, strength and hardness to the portland cement.