In recent years glass reinforced cement (GRC) has made considerable progress as an important and versatile construction material. In the main, alkali-resistant (AR) glass fibres are used in these composites. The long term properties of GRC made from ordinary Portland and high alumina and supersulphated cements and placed in different environments have been investigated at the BRE over many years and the results published. In previous papers, it was reported on the strength of commercially made AR glass fibres, similar to Cem-FIL extracted from OPC/GRC boards after various times of exposure in two different environments. Similar measurements on fibres extracted from composite boards up to 10 years old and made from OPC, HAC and SSC have been carried out and the results are described in this article.
