The statement used in the article 'Keeping damage under wraps' from a representative of Sika managed to convey the impression that when it comes to selecting a fibre material for bridge wrapping, it is simply a matter of balancing 'the extra cost of the carbon fibre itself against the savings in time against glass fibre'. Aramid fibres are dismissed out of hand.
It is important that as engineers we should not be shortsighted in deciding what fibres to use in any given situation. Costs are important, but so are a whole range of technical, aesthetic and installation criteria. For example, in a bridge wrapping context, the ease of installation and the inherent resistance to impact of the fibre or fibre combinations used has to be a major consideration. For this, aramid fibres offer the best fracture resistance and are especially proof against repeated impacts. They are also easy to apply as the fibres are 'very soft, pliable and kind to hands'.
David Wilson (M), 5 Martin Close, Buckingham MK18 7HB.