Air entraining refers to the deliberate introduction of air bubbles into concrete through the use of air-entraining agents (AEAs) during the mixing process. This practice enhances the workability and durability of concrete, particularly in environments prone to freeze-thaw cycles. The tiny, uniformly distributed air voids act as internal cushions, allowing concrete to expand and contract without causing significant damage. The technique was developed in the 1930s and has since become a critical component in the production of durable concrete structures, especially in cold climates where the risk of frost damage is high.