Modifications in the properties of gypsum construction element via addition of expanded macroporous silica granules

The present study is focused on the production of light weight silicate based macroporous filler for hardened gypsum and its effect on the product properties. Highly porous, durable foam like silica granules were produced from the relatively low cost material of silica gel desiccant. Swelling behaviour and mineralogical structure of the granules after swelling were examined. Different sample series were produced by replacing gypsum by expanded silica gel. Physical properties of the hardened gypsum were improved by the addition of expanded silica gel granules. Thermal conductivity of the gypsum decreased significantly when the expanded silica gel granules introduced into the gypsum. Expanded silica gel addition also improved the high temperature durability of gypsum. Much better integrity was observed after the testing of samples at 700 °C when compared to control series.

► Macroporous, foam like, durable, low bulk density filler granules were produced.
► Thermal conductivity of the gypsum product decreased by adding expanded granules.
► Bulk density of gypsum reduced considerably but very little strength loss measured.
► Properties of the porous filler caused improvements in the physical properties.
► High temperature durability were improved by adding porous filler granules.