Carbon Fibre Strengthening of Parapets

thumb_ironbridgeIronbridge is recognised as the birth place of the Industrial Revolution, and at the heart of this World Heritage site lies the Iron Bridge, the first iron bridge ever erected.

The bridge is visited by thousands of tourists each year, but fears about the safety of the parapets had necessitated the erection of barriers to protect the public. English Heritage, who manage the site, had become aware of Topbond from the work they had done on another historic cast iron bridge – Tickford Bridge near Milton Keynes, for which they had won a Historic Bridges Award. Topbond were approached to ascertain if similar sympathetic strengthening techniques could be applied to the Iron Bridge.

The technology used in both strengthening projects involved the use a carbon fibre – a product whose great strength enables repairs to be made far more discretely than using traditional methods.

The works involved shotblasting the internal faces of the posts, applying carbon fibre to the cast iron surface and finally repainting the posts with aestethically pleasing surface finish to mirror aged cast iron in texture.

Tensile testing of the materials was carried out by Oxford Brookes University to verify the effectiveness of he repairs and having established this, it has now been possible to remove the barriers and allow free access to the bridge.