Air-entraining admixtures are used to improve freeze-thaw durability and what else?

• A. Increase workability.
• B. Reduce scaling.
• C. Color the surface.
• D. Speed up curing.

Answer: (B)

Air-entraining admixtures create a network of tiny, evenly distributed air voids in the concrete. These voids act as relief pockets for water that freezes, so internal pressures during freeze-thaw cycles are reduced. That preservation of the surface also helps prevent the outer layer from flaking or scaling, which is common when freeze-thaw damage occurs. While air-entraining admixtures can influence workability a bit, they don’t color the surface or speed up curing. The prominent additional benefit aligned with the question is reduced scaling.