The A303 in Wiltshire is one of the best-known roads in the South of England and deals with a heavy usage of traffic, resulting in general wear and tear, which has led Highways England to consider plans to upgrade the road.
In particular, FM Conway were commissioned to resurface the section between Winterbourne Stoke and Amesbury, as in some places the entire depth of the road pavement was damaged and had to be replaced.
FM Conway’s Business Development Director, Nick Burman, said:
“The main treatment was the replacement of 50mm surface course across the whole scheme. But within that, there were areas where there was structural damage to the pavement, and here we had to reconstruct to different depths to provide a stable base for the surface course.”
In total, the team were required to apply 14 different pavement treatments, varying in solution depending on the nature and severity of the structural failure and location. These ranged from planing 50mm off the existing surfacing and replacing it with a new thin surface course, through to complete 180mm reconstruction of base course, binder course and surfacing.
“In an ideal world, we would have planed 50mm off the whole area, then gone deeper where we needed to, before laying all the new material,” explains Nick. “But we had to do all the work during night-time closures between 10pm and 6am. Whatever section we worked on had to be completed in time to reopen it in the morning.”
To deliver a more efficient way of working, FM Conway used innovative materials such as lower temperature asphalt to speed the whole procedure up. This new type of asphalt was used throughout the reconstruction and surfacing, enabling the materials to cool faster and increase the speed of the laying process.
“By using lower temperature asphalt, we reduced the programme by two days,” says Nick. “It enabled us to do larger areas each night, which had a major impact on the availability of the network.”