Air entrainment is the process where many tiny air bubbles are distributed into concrete to prevent the hardened concrete from rupture and scaling. These entrained air bubbles range in size from an inch to a diameter. There are literally billions of these air bubbles, and their presence dramatically changes the nature of both the fresh and hardened concrete.
Resistance to freezing and thawing With proper air entrainment, the placement of very tiny air bubbles reduces the stresses created within the concrete when water expands during its transformation to the ice during cold weather.
Resistance to chemical attack Air entrainment provides resistance in concrete against chemical and acid attacks. The air voids block and prevent the acid from invading the concrete through these canals.
Less bleeding and segregation Air entrainment in concrete enhances the friction between concrete ingredients, reducing segregation and bleeding considerably.
Light in weight In comparing the regular concrete with that of air-entrained concrete, it was found that air-entrained concrete is 5% less solid and thus light in weight.
Economical Because lightweight concrete reduces approximately 5% in the cost of cement and aggregate.
Resistance for Alkali-aggregate reaction Air entrained concrete is found to be more resistant to alkali-aggregate reaction.