Vestre Alle, Denmark
The Citygreen® modular Stratacell™ system was the perfect choice of system for the redevelopment of Vestre Alle in Denmark.
In the last couple of years, the system has become the main choice of suspended pavement system for tree pits in various urban development projects in Denmark, Sweden and Scandinavia.The project started in October 2010, with the tree installation part being completed in December 2010.
The project started in October 2010, with the tree installation part being completed in December 2010.
Project manager Bjarke Rolfing, from Danjord, says the Vestre Alle project was about remodeling the road, making new pavements, new bike roads, building bus stops, improving the sewage system and planting trees.
There is no other product like the Stratacell in Denmark, making it the most favoured system for urban development. Rolfing says they’ve worked with Citygreen many times in the past and the products “are working according to what they say so we had no questions regarding using them again”.
The Stratacells come in modular units, which can then be assembled to form a skeletal matrix that supports pavement and traffic loads. The Stratacell system features almost five times more available growing media compared to the traditional rock/soil method, therefore facilitating healthy root growth.
“The advantage with the Stratacell is that it can carry the weight of the road. You can actually put the area for the roots directly under the asphalt. So we have the buses parking next to the trees and there’s no risk of the road collapsing due to bad foundation because the Stratacell can carry it. That went quite well and nothing’s happened so far,” Rolfing said.
As recently proven in a laboratory test in Edmonton, Canada, the Citygreen Stratacell system’s structural integrity can sustain the weight of an ASV PT-50 multi terrain loader. An assembled Stratacell matrix has been FEA tested to 550kPa vertical load. The modules feature extremely high compressive strength and the unique, globally patented, interlocking feature provides correct dispersion of wheel loads throughout the matrix.
Rolfing says there weren’t any problems with installing the Stratacells especially given the amount of support and guidance that was provided to them.
“No there weren’t any issues, it’s very simple. It’s obvious. When you put it down, there’s only one way to assemble it. It’s like putting a box on top of each other and clipping them up together,” he says.
Rofling also said the trees are growing very well and looking symmetrical, as they expected. The Vestre Alle project is being used as a trial for the redevelopment of the harbour in the next two years. At the moment, Rofling says they are bidding on the tender for the harbour redevelopment, and if they get the job, they are going to be using the Stratacell on that project as well.
Wyatt Harding, from Milford, Denmark, supplies the Stratacells system in Denmark, Sweden and Scandinavia.
The company helps with the installation and provides back up support to their clients. They go to the site and help with the first tree pit, answering questions from clients on using the numbering and colour coding on the Stratacells. Harding says their clients are often quite surprised at how easy it is to install the Stratacells.
Although the rock soil matrix is a more common alternative in Scandinavia, Sweden and Denmark, Harding believes there is quite a big risk involved when a contractor installs it incorrectly, unlike when using the Stratacells. Harding also says they are seeing a continuous uptake of Stratacells over the rock soil matrix.
Harding says that by using the Citygreen Stratacell system, engineers and architects won’t have to contend with the spatial issues, which is a common problem in European cities.
“People use it because they don’t want to move cables and pipes and services so they’re optimising the space that’s available with Stratacells because the rock matrix only has about 30 per cent soil volume while the Stratacell has over 90 per cent so you get three times as much soil.”
The Citygreen Stratacell’s interconnected skeletal matrix provides over 94 per cent void space for filling with soil media, or storing/detaining storm water. Aside from having a very high strength capacity, the modules are also recyclable and are manufactured from 100 per cent recycled polymer. As there are no steel compone