THERMAL INSULATION COMPOSITE BLOCKS BASED ON GEOPOLYMER

Thermal insulation composite blocks consisted from two types of different geopolymer boards with different properties. One board was a foamed geopolymer with low bulk density and thermal conductivity and second board, also based on a geopolymer binder, was characterized by high bulk density and excellent mechanical properties. The composite block was prepared by pouring a geopolymer containing a foaming agent onto a prefabricated compact board prepared by pressing a mixture of a refractory filler with a geopolymer binder. The function of the pressed board is the mechanical protection of the foamed board. The basic mechanical and thermal insulation properties of both cast and pressed boards were determined. The thermal insulation properties of composite blocks were investigated using a high-temperature gas chamber. It was verified that the composite blocks had comparable thermal insulation properties as a commercial thermal insulation board (polycrystalline mullite/alumina wool).