Which of the following is NOT an example of blended cement?

• A. Combination of silica fume and chlorine fluoride
• B. Combination of fly ash and cement
• C. Cement with slag
• D. Cement with silica fume

Answer: (A)

Blended cement is Portland cement mixed with supplementary cementitious materials to improve concrete performance. Materials like fly ash, slag, and silica fume are classic additives that participate in chemical reactions to enhance strength, durability, and reduced permeability. The combinations with fly ash, slag, or silica fume are typical examples of blended cement because they involve legitimate cementitious or pozzolanic additions that contribute to the binder. The pairing of silica fume with chlorine fluoride isn’t a recognized cement blend; chlorine fluoride is not a cementitious material and isn’t used to form a usable concrete binder. Therefore, that option is not an example of blended cement.