"Several factors... affect the mechanical properties of FRFC, namely: fresh and hardened densities, particle size distribution, percentage of ic material... and volume of chemical foam agent. ...rheological properties ...are influenced by the properties of both fibres and foam; therefore, it is necessary to apply an additional dosage of a foam agent to enhance the adhesion and cohesion between the foam agent and the cementitious filler in comparison with materials without fibres."
January 1, 1970
https://en.wikiquote.org/wiki/Foam_concrete