Environmental impact

Rijk Blok, project leader of the Dutch partners and researcher at TU Eindhoven: “Cement production releases a lot of CO₂. Additionally, the large amount of sand and gravel needed has a significant environmental impact. Concrete is therefore an important material to take a closer look at if we want to make construction more sustainable.”

TU/e researcher Patrick Teuffel, co-project leader of the Dutch project, continues: “You want to reuse the materials at the highest possible level, so don’t grind them into granules first. If we want to use fewer fossil materials, we really need to start looking at improving reuse.”

Quality assurance

But that’s not so easy. Older buildings don’t have quality marks to tell you the grade of the concrete. Rebar which was the norm 40 years ago might not pass the latest requirements today.

Furthermore, elements can be damaged during disassembly, which could further reduce their quality. It goes without saying that the municipality wants to have a formal record that it meets all requirements. Blok: “Structural safety is and remains an essential requirement, of course.”

And even if the quality is perfect, a concrete column that supported one floor in the old building would not be able to support more floors in the new building. Blok: “During the design process of a new building in particular, you have to take into account the elements that are available for reuse.”

Determining preconditions

Then there are the higher costs you incur for careful disassembly and storage, for example, which means that the cost-benefit analysis is not necessarily favorable. Teuffel: “Quite simply, new cement is cheaper right now. But it may not be in the future, such as if a climate tax or higher CO₂ tax is levied on concrete.” Yet the researchers remain optimistic. Blok: “Problems are there to be overcome. If we want to become more sustainable, we have to investigate the preconditions now.”