ARC21: This is Copper - Studio ThusThat

The goal of This Is Copper is the development, promotion and implementation of a more sustainable alternative to ordinary cement. This project addresses both the depletion of (virgin) resources as well as the emission of greenhouse gasses by the construction sector. Copper slag, the waste by-product of the copper production, is transformed into a so called geopolymer that outperforms OPC in terms of strength and durability, yet its CO2 footprint is up to 80% lower.

Toelichting Studio ThusThat

We chose furniture objects to showcase the research into alternative building materials, namely geopolymer concretes. Harnessing the power of design and storytelling we aim to complement the academic approach and bring color and beauty to this new narrative of a more sustainable future. The existing work with this material was mainly on a lab scale and concerned with performance parameters. Therefore we had to come up with new ways of production as well as material mixes.

The contribution of the construction sector to both global CO2 emissions (8%) as well as resource depletion (e.g. scarcity of river sand) are well known issues today. In order to build a more sustainable, more healthy and more socially just society we must ensure the preservation of human habitat as we know it. Tacking these wicked problems through the utilization of waste streams plays a key role in achieving these ambitious goals.


Geopolymerisation is an innovative technology that uses common inorganic compounds to create high-performance alternatives to standard cement. Because the slag has already gone through the high-temperature smelting process, it is reactive and ready to be used as a binder. It replaces the need for cement entirely.Additionally, coarser forms of slag can be used as aggregate in the place of sand. The result is a very strong black concrete-like body made from slag, with about 77% less CO2 than OPC.

We experimented with various processes and techniques in order to explore the different aspects and characteristics of the material. For instance, the individual parts of their ​Molten ​chair are joined together with molten copper, exploiting the materials' unusually high resistance to heat and thermal shock. Another example is the ​Sparkly Black ​chair that was cast directly into a pile of coarse copper slag, using the raw material itself as formwork. The process is inspired by the sand casting.


Collaboration and playing off each other's strength lies at the heart of this project. Scientists are fantastic at solving problems and developing new, better technologies. Design and architecture on the other hand have the ability to tell stories, change public perception and stimulate change on a societal level. Showcasing the academic research of KU Leuven through the means of designed objects has proven an effective way to communicate with various stakeholders from the construction sector.

Lees ook:



Sinds 2007 werkt Astrid de Wilde als (web)redacteur op de redactie van de Architect.
Naast het schrijven van het dagelijks (architectuur)nieuws, artikelen en een incidentele blog op de maakt zij ook de Whitepapers en is zij betrokken bij de printedities van de Architect.
Hiervoor was zij werkzaam bij onder andere Detail in Architectuur en Architectuur & BOUWEN.