Cure Composites (Yandina, Queensland) won the contract to produce the giant pair of tennis shoe soles by Laing 0’Rourke the main contractor for the bridge. Although fibreglass bridge claddings are often produced as single skin components using chopper gun technology, Cure Composites proposed a solution based on sandwich composites and infusion moulding. To create the tread pattern the company produced a series of chevron mouldings that were up to 5.5 meters wide and 550 mm deep (18 ft. x 21.6 in.). The combination of sandwich composites and infusion technology would ensure that these components would meet the stiffness and strength requirements of the application while being around half the weight of single skin laminates.
In addition infusion moulding has enabled Cure Composites to achieve greater component consistency and a superior surface finish. The use of DIAB foam core instead of flow media ensured that consumable costs are reduced, less resin is used and the end result is a lighter, stiffer product. It also resulted in reduced time taken to complete the project.
With a sandwich laminate Cure Composites could achieve a consistent wall thickness – an important consideration as a sub frame was fitted in all the sandwich composite components.
Cure Composites also maintain that the infused sandwich composites approach will provide better storm and hailstone resistance. During the project, engineers working for the main contractor expressed the view that for future footbridge projects a complete composite solution could be the way forward in order to substantially reduce the overall weight of the bridge thereby speeding installation and reducing the size and cost of the lifting equipment.