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GRC cladding panels

I have been told that the cladding panels on the building I manage are manufactured from GRC. What is this material?

Answer

Glass fibre reinforced cement (GRC) is a composite building material developed in the early 1970s. The matrix in GRC normally consists of Portland cement and fine sand reinforced with alkali-resistent glass fibres. Other materials including Fly ash, also known as pulversided fuel ash (pfa), may replace the sand. Alkali-resistant glass fibres are used as standard silicate glass fibres are normally degraded in the highly alkaline environment of hydrated cements. Properties of the finished product are influenced by the proportion of glass fibres and the length and orientation of the fibres.

Cladding has been one of the main uses for GRC because it offers a lightweight construction combined with an apparent freedom of panel shape and the choice of a wide range of durable finishes. Other uses include permanent formwork for cast in-situ concrete, sheet materials for roofing and stock products such as street furniture and cable ducting.

Acknowledgement: The Concrete Society

Other references:BRE Digest 331 GRC