| 摘要 |
A building element structure, in particular a window frame, comprising a hollow, preferably extruded, shell (42) formed from a first material defining at least one internal chamber (44, 46) filled with a geopolymer material (62). The geopolymer material (62) is formed from a mixture of alumino silicate metakaolin, mixed with mica and/or graphite (or other lamellar material), and an aqueous alkali metal silicate solution comprising an alkali metal hydroxide solution. The curable mixture comprises by weight as compared to 3 parts by weight of the aluminosilicate metakaolin from at least 1 up to 5 parts of Mica and/or graphite; from 0 up to 4 parts of an alkali metal silicate, and/or from 0 to 2 parts silica; from at least 0.2 up to 3 parts of an alkali metal hydroxide and/or oxide; and from at least 1 up to 6 parts of water. The mixture is mixed and then cured within the at least one chamber (44, 46). Preferably the geopolymer material (62) is a foam material, and may be formed by adding a blowing agent, for example from 0.1 to 0.6 parts of 100Vol hydrogen peroxide per 8 part of the mixture, prior to filling the at least one chamber (44, 46). The first material forming the shell (42) is a plastic material, for example PVC. The geopolymer mineral foam material (62) strengthens the structure, in particular in a fire, maintaining structural integrity of the window fame, while the extruded plastic material shell (42) protects the geopolymer (62) and provides the required surface finish and appearance. |
