CREAKING bridges could be made stronger by spraying on a coating of fibres
embedded in plastic. The coating is now being field-tested in Canada.
Engineers already use fibre-reinforced plastic sheets to help strengthen old
bridges. The wallpaper-like sheets, about a millimetre thick, contain long
fibres of glass or carbon lying side by side. When glued to a concrete bridge
deck, say, the plastic transfers stress to the fibres, which can be as strong as
steel.
But fibre sheets are awkward to use near bolts or support cables, and few
bridges offer clean, flat surfaces. So Nemkumar Banthia, an engineer from…
