How to Make Air Entrained Concrete and Test it for Air content

Air-Enterained Concrete Test

Air entrained concrete is made by adding a commercial agent to the concrete in the quantities that each manufacturer will specify. Dilution of the agent is not recommended unless it is specifically asked for by the instructions given with the agent. Portland cement is the right cement to use, and the air content has to be controlled so that mix is uniform.


It is likely that higher concrete temperatures will require more quantity of the air-entraining agent, and this requires frequent testing of the air content. Concrete needs to be mixed for at least 1 or 2 minutes. An increase in mixing time because of the distances to pouring site may increase the quantity of agent by a percent if the time of mixing goes over 5 minutes. It can however reduce if mixing time is more than 10 minutes. Vibrating of the concrete can further reduce air content by 15 to 20 percent, and this is more pronounced when the vibration is internal and not through external form vibrators.


Concrete entrained air testing is a must for such concrete. Air content of the freshly mixed concrete can be measured by gravimetric, volumetric, or pressure methods. The pressure method is the most commonly used, and in this method a calibrated air meter is used to test a known volume of concrete that is subjected to a defined pressure.