What role do entrained air percentages play in concrete mixtures?

Entrained air percentages in concrete mixtures primarily influence the control of water volume within the concrete mix. When air-entraining agents are included in the mixture, they create tiny air bubbles that improve the concrete’s resistance to freeze-thaw cycles by allowing space for water to expand when it freezes. This incorporation of air affects the overall water-to-cement ratio, helping to ensure that the mixture remains workable and properly proportioned.

While air-entraining agents can contribute indirectly to aspects such as workability and durability, their primary purpose is not to decrease drying time or enhance color but to modify the concrete's behavior and performance in terms of water volume and freeze-thaw resistance. This makes the understanding of entrained air percentages crucial for achieving optimal concrete durability and stability, especially in varying environmental conditions.