The density of the foamed concrete is a function of the volume of foam that is added to the cement paste.
To ensure that the desired percentage air is entrained in the mixture, pre-foaming; where the foaming agent is aerated being
added to the mixture is used. The aerated foaming agent, on mixing with the cement based slurry entrains a controlled
quality of air in uniformly dispersed discreet cavities. These voids are typically spherical.