Seashell – Concrete



STV was selected to participate in the ‘What If Lab…’, a design-driven intervention program of the Dutch Design Foundation. In this program, designers are deployed to provide answers to complex issues. In this edition, ProRail, together with their partners, asked us to work on a sustainable train station. For this assignment, STV investigated how local buildings can be upgraded into circular building materials. Tjeerd Veenhoven assumed purely organic raw materials that are present in and around the track.

For ProRail, STV developed a sandwich panel made of reed from the Weerribben, a biological composite veneer of natural pigments and bulrush fiber and a concrete substitute for mussel shells from Zeeland. In order to be able to apply these materials, STV has entered into a partnership with Welling Architects, who applied them in The Natural Station. STV sees the cooperation with ProRail as an excellent opportunity to introduce sustainable materials into our daily lives, as we all travel by train at some point. It goes without saying that a building with such an important social function is a forerunner in circular construction, with extra attention for water and biodiversity.



Concrete is an indispensable product if you are going to build a train station. It is strong, reliable and will last a very long time. For example, the wall of the platform is always made of concrete so that the train can pass close to it without any risk. But concrete is a difficult material to recycle and the production of concrete accounts for no less than 5% of total CO2 emissions worldwide. It goes without saying that you should not use concrete if it is not really necessary. STV has developed an alternative for ProRail for these less demanding, non-structural applications.

As a raw material STV selected the mussel. This tasty crustacean is brought ashore by the cutters in Yerseke to be processed into a healthy delicacy. In the processing process, the mussel shell is a voluminous by-product for which there are few applications. However, this shell is very suitable as a raw material for our concrete substitute. The shell is mechanically broken into small pieces and dried. This granule is then mixed with a biobased binder that makes it possible to cast the whole into a mold. After drying you get a strong, solid product that is suitable to replace some applications that are currently made of concrete. This concrete substitute has been used for ProRail to make the seating objects at stations in the Netherlands, which are currently still made of concrete.

Materials, Research