Which of the following is NOT a component of the paste used in cementitious mixes?

• A. Water
• B. Cement
• C. Fine aggregate
• D. Air Entrainment

Answer: (D)

The paste in cementitious mixes is made from cement and water—the binder that holds the mix together. Fine aggregate is not part of the paste; it’s the solid particles embedded in the paste to form the concrete. Air entrainment, on the other hand, isn’t a chemical ingredient of the paste’s composition. It’s an admixture technique that creates microscopic air voids within the paste to improve workability and durability. Because it’s not a constituent that becomes part of the binder itself, air entrainment is not a component of the paste.