Every seven years, each waterway in the Netherlands is dredged. By extracting, drying and sieving the dredged substance, Waterweg creates a new product – tiles! The substance mixed with a binder becomes a hardened tile by using a special pressing technique. The tiles are water-passing — unlike many other tiles — allowing rainwater to sink into the ground, thus also providing a climate-adaptive function.
These stones are made from dredged material from Dutch waterways, combined with a some cement. In the near future, Waterweg expects to be able to use a more sustainable binder, based on waste streams.
- All waterways in the Netherlands are dredged
- The dredged material that is extracted is later matured (natural drying process) and sieved to remove unwanted particles such as plastic and glass
- After that the dredge is mixed with cement
- The dredge is then pressed into a tile after which it has to harden
Dredge turns out to be more valuable than you might think
The water passing tile is the first application of this material. In the future, the material could be seen as an alternative to concrete. However, Waterweg prefers to use their material to support nature.
- The open structure of this water-passing tile contributes to a climate-adaptive city. The tiles allow water to pass through. In this way, sewers are not overloaded, but rainwater can sink into the soil.
- The pressing technique ensures an energy-saving process compared to firing bricks, as we know from conventional bricks. On a large scale, this can save up to 50% compared to the MKI (Environmental Cost Indicator) of concrete paving stones.
- A residual flow, namely dredge, is given a high-quality destination.
- A clinker or tile made of dredge is lighter than a conventional brick or concrete, so there is less CO2 emissions during transport and is therefore also more suitable for locations that suffer from soil subsidence.
- The material is not yet certified.
- At the moment the tile still contains a little cement, the intention is to replace this with a circular binder.
- Waterweg is scaling up production, for which they are still looking for production partners.