The right concretening

How that counts

For spoken words, it is not only the facts that count, but also the way in which a conversation is structured. The tone of voice of a statement determines whether the other person accepts what is said. In turn, emphasis plays an essential role in expressing emotions and what is said. This “how” in combination with the “what” is not only important when conveying messages. Research often does not change the actual use of the product, but the way in which something is produced or put together.

But what does this have to do with construction? The spin-off Rement wants to focus on a sensible emphasis in the construction industry. Here, the right concreting in terms of ecological aspects plays an important role for future construction projects. The construction industry is booming and around 1.2 million square kilometers of the earth are now covered in concrete, and the trend is rising. Even if this only amounts to just under one percent of the earth's land, the consequences are devastating. “Almost 30 billion tons of fossil material are used for concrete production every year. The amount of man-made materials such as concrete, plastic and textiles is growing exponentially, so that the proportion of man-made mass has now exceeded the Earth's biomass,” explains Robert Schleinhege, co-founder of Rement. In addition to the use of fossil materials, the environmental impact of cement production is also a problem. Around eight percent of global CO2 emissions are attributable to the cement industry. “An end to the construction boom is not in sight, it is not realistic to do without the building material globally and the use of recycled material in concrete is not yet widespread. We need to find other ways to make the construction industry more sustainable,” adds Felix Baur, another co-founder of Rement. Together, the team has developed a concrete upcycling approach that aims to make the use of raw materials more sustainable.

Building the future

The idea is convincing. The founders were able to beat off the competition in GROW, Germany's largest student start-up competition. “We used the funding to equip our first laboratory and have been fully focused on developing the technology ever since. We have carried out a lot of laboratory research and built the first prototype,” reports Baur. With the EXIST research transfer successfully applied for at the end of 2024, the founders are currently in the process of piloting the prototype. “We are currently working intensively on setting up a pilot system in container format. Once completed, this will allow us to test it flexibly in a real environment on the premises of interested application groups in order to gather important feedback for the subsequent construction of a fully scaled system,” says Schleinhege, describing the young company's next steps.

They are already in talks with potential users: “We have already discussed our idea with a number of companies and taken away initial requirements for later implementation. Some companies are already interested in further cooperation,” Schleinhege continues. The Rement process is particularly interesting for two target groups: on the one hand, for construction material recycling companies and, on the other, for cement producers. The latter generate high carbon dioxide emissions, which could be reduced by feeding them directly into cement plants. This not only protects the environment, but also the budget: on the one hand, cement producers would have to pay less costs for the European emissions trading system and, on the other hand, could include the calcium carbonate produced during recycling in their product portfolio. In contrast, building material recycling companies do not have such fossil point sources and therefore no need for emissions trading. The potential here lies in the supply of liquid, biogenic carbon dioxide, which is introduced into cement plants and bound during recycling. Companies with ambitious climate targets can purchase carbon dioxide removal certificates to improve their carbon footprint, creating a new revenue stream for the building materials recycling company - a win-win situation with a positive impact on the climate.

Commissioning of the pilot plant is planned for the end of 2025. The aim is then to carry out trial production runs with industrial partners in order to generate new findings and prepare for the construction of the fully scaled plant. In the long term, Rement would like to offer its customers a complete solution based on a license model, from consulting to the plant. “Our focus is on fundamentally redesigning value chains and bringing the necessary partners together. With our technological expertise, we support and contribute together to discarding outdated ways of thinking and rethinking the foundations of the construction industry,” explains Schleinhege. An approach that shows that the “how” of concreting is essential in order to make the construction industry more resource-efficient and sustainable in the future. It can decide how the relationship between biomass and man-made mass develops in the future.