St Georges Bridge, Doncaster

As summer draws to a close, Derek Lewis Ltd takes a moment to look back on its involvement in the season’s biggest local project.

Doncaster’s A19 St. George’s Bridge allows 44,000 vehicles a day to make the crossing over the East Coast Main Line, the River Don and the Don Navigation Canal.With the bridge due to have its joints replaced, a decision was reached by Doncaster Council to move away from the existing porous asphalt and opt instead for a conventional binder course topped by a special thin surfacing that possesses both enhanced durability and high resistance to skidding; this aptly-named Steelflow.

Public consideration has ever been at the forefront of the Derek Lewis way of thinking, therefore, it was pleasing to be able to undertake the works at night, better facilitating traffic management and in turn minimising disruption to daytime traffic.

The works spanning a total of 5 weeks involved an initial 3 weeks of facilitating works carried out by the Civil engineering section of Derek Lewis Ltd. The key elements of this phase being:

• Traffic Management (supplied by Direct Traffic Management Ltd)

• Traffic Segregation (installation and maintenance of concrete Containment barrier)

• All Surveying and Setting out

• Carriageway realignment (Removal of existing metal vehicle barrier, Break out, Hard dig, excavation around live services, kerbing and hard landscaping works)

• Traffic Signal Ducts, chambers and NAL Socket installation

On completion of the initial 3 weeks the later 2 were taken over by the Road Surfacing section of Derek Lewis Ltd whose works entailed the removal of all existing porous bituminous material and the application of a new binder and surface course. These works comprised of the following key elements:

• Road Planing and disposal of arising’s to various depths including the formation of construction joints.

• Application of Hot Tanker applied bond coats

• Supply and application of AC 20mm Binder

• Supply and Application of 6mm Steelflow Surface course

• Supply and application of 10mm Stone Mastic Asphalt

The specified 20mm of Steelflow is approximately 5mm thicker than Steelflow was originally designed to be laid. What proved crucial to the material’s nomination was that it could be put down thin at 15mm, restoring the carriageway’s impermeability, ride quality and resistance to skidding. Not to mention its cost-effectiveness.

Over and above our initial 5 weeks on site we were then brought in as a local contractor to support the bridge joint replacement phase of the works.

Works on St. George’s Bridge are now complete, the structure standing ready for the coming winter months and beyond.