Glass-fibre-reinforced cement is a composite material consisting of ordinary Portland cement, silica sand and water, mixed with alkali-resistant glass fibres. It has been described by Young (1980) as an ‘ideal marriage between brittle materials, cement, sand and glass, to produce a tough composite’. At that time, the most common percentage constitution of the material by weight was as follows:
Portland cement 40% Water 20% Sand 40% Glass fibre 5% (for spray techniques)
3-4% (for premix) Later formulations included 0-5 % acrylic polymer.