Preparing foamed concrete for wall backfillings, comprises forming cement paste comprising cement, water and network agent by mixing of the components in planet mixer, forming a foam by foam generator, and mixing the paste and the foam

摘要

The preparation method comprises forming a cement paste comprising cement, water, and a network agent, which is a mixture of negatively charged, inorganic and/or organic material with amide groups with counter ions (cations), and optionally an additive, by mixing of the components in a planet mixer (1), forming a foam comprising water, air and a protein-based foaming agent from nonpolar and polar amino acids a foam generator (2), mixing the cement paste and the foam in the mixer and/or in a concrete mixer (3), and drying the foamed concrete. The preparation method comprises forming a cement paste comprising cement, water, and a network agent, which is a mixture of negatively charged, inorganic and/or organic material with amide groups with counter ions (cations), and optionally an additive, by mixing of the components in a planet mixer (1), forming a foam comprising water, air and a protein-based foaming agent from nonpolar and polar amino acids a foam generator (2), mixing the cement paste and the foam in the mixer and/or in a concrete mixer (3), and drying the foamed concrete. The foam comprises a density of 80 g/l. The network agent is LithoFoam NWF S(RTM: Protein based foaming agents) with a nitrogen content of 1 mass% and density of 1.2-1.35 g/ml. A stabilizer is dosed in the preparation method. The addition of the stabilizer as aqueous suspension to water takes place before the formation the cement paste. The stabilizer is a sugar polymer with molecular attached inorganic silicate-active elements, where the sugar polymer consists of glucose units with a molecular weight of 125000-150000 Dalton, and LithoFoam MRF 2000-S(RTM: Protein based foaming agents) with a drying bulk density of 0.1-0.5 g/ml. The working pressure of the foam generator is 1 bar. Silicone oil (5 kg) is admitted with molecular weight of 2-4 kg per cubic meter cement paste for the hydrophobisation process of the dry foamed. The additive is limestone flour and building lime is used as hydraulic binder. The mixer is present with or without wirbler. The water of the cement paste, the water for the foam formation and the water of the stabilizer suspension before the mixing step are treated with a direct current of 25 mA per liter and minute.