Foamed concrete is produced either by adding a quantity of preformed foam to a mortar or cement paste directly into a truck mixer or via a special in-line mixer using ready-mixed mortar or cement paste. Typically only plastic density is routinely measured together with cube strength (note 150mm cubes should be used due to the low strength of foamed concrete).

For further information see;

MCHW Series 2600 (Clause 2608 and NG 2608 Foamed Concrete for Non-Structural use in Structures)