Concrete that has been air-entrained has been infused throughout with thousands of tiny air bubbles, which become part of what binds aggregate together in the concrete.
Air-entrained concrete has been part of concrete technology for over forty-five years. Early forms of air-entrained concrete were achieved with the addition of organic substances derived from animal and wood byproducts, which were found to increase the resistance of concrete to the problems brought on by repeated freeze and thaw cycles.
Freeze-Thaw Durability and Air-Entrained Concrete
Testing has proven that the formation of the many air bubbles uniformly throughout the concrete significantly improves the freeze-thaw durability of the final product. Air-entrained concrete is more workable than non-entrained concrete. The use of air-entraining agents also reduces bleeding and segregation of fresh concrete.
The majority of air-entrained concrete, up until the 1980’s, was based on salts of wood resins or neutralized Vinsol resin. Most of those concrete highway structures built during that time were air-entrained with Vinsol resin. Nowadays, a much wider variety of air-entraining agents are available on the market, competing with the previously used Vinsol resins.
It is universally acknowledged that all concrete used today should be air-entrained.