Ceramics-Silikáty 59, (1) 10 - 16 (2015)

The so called water procedure was used to prepare foam concrete samples with bulk density below 150 kg∙m⁻³. Direct foaming method was applied by using of protein based foaming agent. The amount of Portland cement was decreased gradually along with the water-cement ratio maintenance. Degradation of foams occurred with reducing of cement content to 30 % of its original quantity regardless of water procedure included or not in the preparation procedure. Stability of the foam concrete samples prepared only from 30 % of cement was achieved after microwave and ultrasonic treatment of protein based foaming agent. The so prepared foam concretes were stable also after water procedure and exhibited final bulk density of 95 kg∙m⁻³.