05 December 2003
05 December 2003
Scott Bader’s urethane acrylate adhesive has been used in the construction of Ireland’s longest cable-stay bridge – the Boyne Bridge.
Situated near Drogheda in Southern Ireland, the bridge carries traffic from the M1 motorway, across the River Boyne, linking Dublin and Belfast. The bridge officially opened this summer, with a cross section of 28 metres and an overall length of 350 metres. The south end of the bridge is of cable stay construction with a main span of 170 metres. The supporting pylon is an inverted ‘Y’ rising over 90 metres above the river.
The bridge deck is of steel construction with a concrete deck. Steel stays support the main span. The bridge steelwork consists of two longitudinal girders up to 2.4 metres deep supporting cross girders every 3.33 metres along the length of the bridge.
All of the structural steelwork of the bridge is enveloped within a pultruded glass reinforced plastic enclosure. It is these GRP sections that are bonded with Scott Bader’s urethane acrylate adhesive, Crystic Crestomer Advantage 30. Crestomer is used to bond ‘J’ sections onto the GRP panels. They are bonded in pairs and adhered to a flat panel, then curved to shape under the bridge.
Conditions inside the enclosure are similar to those that would prevail indoors. This means the steelwork is protected from the elements, avoiding the need for regular re-painting and maintenance, and provides a safe access platform for the inspection of the steelwork, deck soffit, drainage systems etc.
To be approved for the project a great deal of technical work had to be carried out. Scott Bader technical personnel spent many hours in the lab and on site with the designers and construction engineers ensuring Crestomer was ‘fit for purpose’ and being used on site in the correct manner. “One of the most important aspects Scott Bader had to prove was that Crestomer bondings could withstand a load up to 1500 kgs (which represents the ultimate limit when the panel is curved to its nominal radius)” said Tony Wood, Scott Bader’s technical expert for the project.
The Boyne Valley is one of the most historically significant sites in Ireland. The ancient monuments of Newgrange, Knowth and Dowth lie within 3-5 km of the crossing. The three main Williamite crossings of the river at the battle of the Boyne in 1690 took place adjacent to the bridge location.
The bridge was designed by Dorman Long Technology, a Cleveland Bridge Company, and constructed by a Joint Venture of SIAC Construction Limited and Cleveland Bridge UK Limited.
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