MasterAir AE 90 is the air-entraining admix used by Salmon Bay. Entrained air is designed into a mix; where as entrapped air is a consequence of mixing concrete. MasterAir AE-90 disperses microscopic air bubbles uniformly throughout the mix improving resistance to the effects of freeze thaw cycling. It is a must in all concrete to be used for exterior flatwork in the Pacific Northwest. Additionally, in low sackage mixes, “air” will improve the ultimate strength of the concrete mix.