Air-Entrained Concrete

Air-Entrained Concrete

Air-Entrained concrete is defined as the air intentionally incorporated by means of a suitable agent. other Definition is 
Air-Entrained concrete contains billions of microscopic air cells per cubic foot. These air pockets relieve internal pressure on the concrete by providing tiny chambers for water to expand into when it freezes.
Air-entrained concrete is produced using air-entraining portland cement, or by the introduction of air-entraining agents






Air-Entrained agents are:

• Animal and vegetable fats 
• oils and their fatty acids.
• Natural wood resins, which react with lime in cement to form a soluble resinate.
• Wetting agents such as alkali salts of sulfate
• sulphonated organic compound.

The air-entraining agents can be dispensed either as an admixture, (a material added to the mix when the ingredients are fed into the concrete mixer) or else as an addition to the cement, in which the agent is interground with the cement in fixed proportion. The air entraining agents represent between 0.005 to 0.05 percent of the weight of the cement. But to facilitate the dispensing operation, a solution of the agent in water is usually made up.