With two projects, alternative and sustainable materials are being tested to protect waterbanks in the Netherlands. The Dutch Department of Waterways and Public Works has placed waterbank protection poles made from roadside clippings to replace wooden ones. Additionally, planks of recycled fibre reinforced composite, used to make boats and windmill blades, protect the waterside in Almere (NL).

Usually, water bank protection poles and dam walls are made from tropical wood. This wood has several disadvantages, as trees have to be cut down and the long-term exposure to water causes it to rot.

Roadside clippings
Using waste materials to make useful products is an integral part of the circular economy. Roadside clippings are currently not being used for anything, and thus a waste material.

The poles made with roadside clippings were developed by Dutch company Millvision (link in Dutch). The poles are currently being tested at the waterside in Middelburg, the Netherlands, to see if they hold up against the wooden poles.

Fibre-reinforced plastic
Fibre reinforced composite is not easy to recycle, yet there is in the Netherlands alone annually a residual stream of 4,500 tonnes. Most of this waste material comes from the hull of boats, followed by rotor blades of windmills.

Researchers from Windesheim University of Applied Sciences (link in Dutch) in the Netherlands developed a new method to reuse this material. The researchers cut the material into strips or shred it into pieces. Combining de strips and/or pieces with polyester resin, they use vacuum injection to create a new material that looks like hard wood. The resin that is currently being used is not biobased, but could in the future be replaced by biobased resin.

The material is currently being tested in Almere, the Netherlands. It is expected that the material will outlast wooden poles. The project is a collaboration between Reimert Bouw en Infrastructuur, Demacq Recycling, CompoWorld, Provincie Flevoland, PolyProducts, Hogeschool Windesheim, Bootjessloperij ‘t Harpje, Waterschap Zuiderzeeland and Werkbedrijf Lelystad.

Photos: Millvision / Waterschap Scheldestromen / Rudy Visser / Windesheim