Fibre reinforced gypsum binder composite, its microstructure and durability

The effect of E-type glass fibre on the strength and durability of gypsum binder composites was studied under different climatic conditions and by accelerated methods. After 50 cycles of wetting and drying at 60 degrees C an irregular deposition of gypsum binder products was found at the surface of glass fibres. Durability of E-type glass (borosilicate) fibres employed as reinforcement in the gypsum binder composites was examined after immersion into aqueous extract of gypsum binder at temperature 27 degrees to 60 degrees C. The exposed glass fibres were studied by scanning electron microscope and by weight loss determination. Deterioration off-type glass fibres was observed at 50 degrees and 60 degrees C on exposure to aqueous gypsum binder extract which is directly related to the durability of gypsum binder composites. It is concluded that gypsum binder composites should be used under 50 degrees C.