What Is Air Entrainment in Concrete, and Why Does It Matter for Winter Durability?

Why Air Entrainment Matters

Concrete is a solid mass formed from a mixture of gravel, sand, cement, and water. In its normal state, it doesn’t naturally contain air. However, when exposed to water—especially during winter—this lack of internal space can lead to serious damage.

Air entrainment solves this by introducing microscopic air bubbles into the concrete. These air pockets serve as pressure relief zones. When water infiltrates the concrete and freezes, it expands. Without somewhere to go, that expansion causes cracks, surface flaking (scaling), and pockmarks. But if air voids exist, the expanding ice has space to move—preventing damage.