Pavement optimisation helps support entrepreneurs in County Durham
A flexible and reactive approach to optimising pavement design has delivered cost savings on the expansion of a science and technology park in County Durham.
Durham County Council’s £5.1m NETPark Phase 3A Infrastructure project will see construction of a new spine road and side roads which will open up 10.5ha of development land at the North East Technology Park (NETPark). The ambitious expansion plans will create additional space for research and development companies which need room to prototype and scale-up to manufacture on site.
NETPark is already home to some of the world’s most innovative companies and the latest development could lead to the creation of around 1,400 jobs.
Tensar’s Spectra Pavement Optimisation system, incorporating TriAx geogrid, has mechanically stabilised the roads’ granular layers, enabling them to be built over the site’s weak and variable ground. The system mitigates the risk of differential settlement and reduced the amount of imported materials.
“The TriAx interacted with the aggregate to create a mechanically stabilised layer, which increased flexural rigidity and allowed the total pavement thickness to be reduced,” said Tensar’s Highways Manager Craig Andrews. “The granular particles partially penetrate through the geogrid apertures, which confines and restrains the stone from moving both vertically and laterally, helping to deliver road pavements capable of carrying anticipated traffic loads.”
Tensar worked closely with Durham County Council to develop the initial pavement design for the roads, which was adjusted once actual CBRs were taken.
“Because ground conditions are so varied, we finalised the optimal pavement design as the underlying ground was exposed and tested,” Andrews said.
This approach meant that, rather than using a ‘one-size-fits-all’ design to cope with the weakest ground, thicker pavements could be used in these areas, while thinner sections could be used over stronger ground. As a result, material use was reduced and construction was faster and more cost-effective.
Andrews explained: “We used three mechanically stabilised layers above the very weak ground, reducing this to two layers over slightly improved areas. Where ground conditions were more favourable, we were able to design the capping layer out completely and only a single mechanically stabilised layer was needed.”
A total of 10,000m² of TriAx was laid by Groundwork Services (Durham) at NETPark, which was working on behalf of main contractor ESH Group.
NETPark is home to a number of innovative companies researching and developing new technologies. The project, being built by Lumsden & Carroll, part of the Esh Group for Business Durham (which manages NETPark on behalf of the council) is part of a ten year plan to attract inward investment to the region, creating 3,000 jobs.