Question

Which of the following is not an ingredient of clinker cement?

• A. Calcium silicate
• B. Aluminium silicate
• C. Calcium aluminium silicate
• D. Gypsum

Answer 1

The correct option is D Gypsum

The four main components of clinker are:

• Alite: approximately tricalcium silicate (typically about $65\%$ of the total)
• Belite: approximately dicalcium silicate (typically about $15\%$ of the total)
• Aluminate: very approximately tricalcium aluminate (typically about $7\%$ of the total)
• Ferrite: very approximately tetracalcium aluminoferrite (typically about $8\%$ of the total)
  Thus Gypsum is not an ingredient of clinker while it is added in the cement formation process after formation of clinker.