The adaptability of foam concrete to planned applications is enormous. Each variable has a significant impact on the properties of the final material.
a) Ratio of Slurry to Foam – Changing the slurry/foam ratio affects the density of the foam concrete, which has a significant impact primarily on thermal insulation, strength, rigidity, and water absorption of the material. The density of foam concrete ranges from 400 to 14600 kg/m³.
b) Cement/Water/Aggregate Ratio – Changing the cement content or the amount of water at a given density affects strength and rigidity. Increasing the content of aggregates or fillers at a given density reduces shrinkage and sensitivity to cracking and can improve the binding process.
c) Foaming Agent – Synthetic and organic foaming agents are available. The latter provides foam concrete with better hydrophobic properties. The quality of the foam (and consequently the quality of the foam concrete) is influenced by its density, the dilution ratio of the agent, the foam generation process, and the process of adding and mixing with the slurry. This quality manifests in the stability of the foam concrete and subsequently the strength and rigidity of the installed material.
d) Hydration Speed – The speed of hydration can be influenced by using specific types of cement (such as Portland cement with ultra-high early strength), by using very fine fillers, by using insulating formwork, increasing the ambient temperature, using accelerators, or reducing the water/cement ratio. The advantages of increasing the hydration speed are high early strength values (formwork can be removed faster) and less stringent stability requirements for the foam concrete slurry.
e) Workability of Foam Concrete – That is, its fluidity, depends on the water and foam content. The possibilities range from almost complete self-leveling to a material that allows for shaping slopes up to 5%.
f) Using Foam Concrete – Foam concrete has excellent fire-resistant properties, good acoustic properties, high impact energy absorption capacity, and the finished foam concrete can be easily processed with saws, nails, or drills.