In depth: Embracing innovation in concrete road replacement projects

We completed the ￡37m A14 J47A-49 Concrete Roads reconstruction project in Summer 2024. In this article, we look at how our team embraced innovative techniques to ensure the project finished on time and under budget.

The scheme, in Suffolk near Bury St. Edmunds, was located on a heavily trafficked section of this major dual carriageway, with average annual daily flows of around 65,000 vehicles.

The major challenge was not replacing the design-life expired concrete surface itself, but the poor subgrade encountered. From the outset, there was a shared focus to create a solution that would not only solve the subgrade problem on this scheme, but which was transferrable to future schemes, becoming ‘business as usual’.

Our team together with Ramboll, Norse Highways, Combined Soil Stabilisation and National Highways collaborated to identify alternative options to provide programme reassurance during the winter months to enable the westbound carriageway to be constructed. The eastbound carriageway was re-constructed in 2023 but issues with failing subgrade hindered the project.

Developing and delivering the pioneering solution ultimately saw a step-change from ‘replace’ to ‘renew’. This was in the forefront of the team’s mind. Rather than simply replacing the failing subgrade, they were determined to find a solution that could work with the existing material.

In doing so, the team have also clearly demonstrated alignment with the values of our partners, National Highways. They took ownership of the problem, demonstrated passion by developing an ambitious, innovative solution outside of standards and demonstrated teamwork, collaborating with many parties and openly sharing the successes and lessons from the eastbound carriageway construction.

Aside from the subgrade, there was much more to the project. An example included the removal of 7km of failing, design-life expired concrete pavement and replacing it with a modern, flexible, asphalt pavement.

The final solution delivered cost savings, programme surety and minimised CO2 emissions. It also supported the National Highways Innovation and Research Strategy. The scheme was ultimately delivered ahead of schedule on 29 June 2024.

Looking back at the scheme, Michael Widdicks, Regional Director at Sisk, commented: “The A14 J47A-49 scheme was a great example of innovation and collaboration between National Highways, our teams, and our sub-contractors. Coming up with a solution for the original failing subgrade took a lot of effort and we achieved it, delivering cost and carbon savings whilst maintaining our Construction programme. I’m proud of everyone involved.”

We are specialists in projects within the Concrete Roads Framework and you can see a similar project that we undertook on the A12 in this short video: