| 摘要 |
<p>Sheet material, which may be flat or of profiled (e.g. corrugated) cross-section, suitable for use as building panels, e.g. roofing slates, is formed of a fibre-reinforced cement composition comprising, in weight percentages:- Ordinary Portland cement 50 to 71% Pulverised fuel ash 14 to 40% Volatilised silica (containing at @@least 86% SiO2 5 to 12% Filamentised chopped glass fibre strands 2 to 7% these components constituting at least 90% by weight of the composition, the material having a minimum average modulus of rupture of 16 N.mm<-2> and a minimum density of 1.3 g.cm<-3>. The balance of the composition may include up to 4% by weight cellulose pulp and up to 5% of a plasticiser such as ball clay, bentonite or talc, together with small quantities of known dispersing agents and flocculating agents.</p> |
