- Matthias Maurer researches the hardening of concrete in zero gravity.
- Climate protection through more efficient use of raw materials.
- Experiments in space provide data for technical developments on earth.
- Cooperation DLR with the universities of Cologne and Duisburg-Essen.
- The experiment is part of the Cosmic Kiss mission.
COLOGNE, Germany (DLR PR) — How does freshly poured concrete behave in zero gravity? And how can this contribute to environmental protection on Earth? In early February 2022, the German ESA astronaut Matthias Maurer searched for answers to these questions on the International Space Station experiment “MASON/Concrete Hardening” is a joint project of the German Aerospace Center (DLR), the University of Cologne and the University Duisburg-Essenand takes place as part of the Cosmic Kiss mission.
Global carbon dioxide (CO₂) emissions are around 38 gigatonnes (38,000,000,000 tons). Three gigatonnes of this are generated in the manufacture of cement alone. Cement, in turn, is the essential component of concrete, currently the most important building material. If it is possible to optimize the use of concrete through modern processes, this will contribute to improving the climate balance.
“Concrete as a material has been known to mankind for thousands of years and still holds a lot of mysteries for us. We want to clarify some of these questions with Matthias Maurer on the ISS,” says Prof. Matthias Sperl from the DLR Institute of Materials Physics in Space.
Why Concrete is Researched on ISS
Concrete is not a material associated with space travel. However, due to the permanent weightlessness, space travel on board the ISS opens up insights into the behavior of materials that are only possible to a very limited extent in laboratories on earth.
In addition to the mixing ratio and reinforcements (reinforcement), the hardening of the material is decisive for the strength of concrete. The curing process determines the arrangement of the components inside the concrete and the distribution of trapped air bubbles.
Hardening is strongly influenced by gravity on Earth. It is therefore of great interest for materials research to investigate how this mixture of sintered limestone and clay plus sand and water behaves without this influence. This allows a better understanding of chemical and physical processes. These findings can be used for optimized mixing ratios, which ultimately save valuable resources.
The hardening and drying process of the concrete can take weeks and months. This is why research on the International Space Station ISS is so important, because only here do the same conditions of zero gravity (G) prevail over the long term.
The data obtained from Matthias Maurer’s experiments also provide the basis and reference values for further investigations in earthly laboratories. Here, artificial weightlessness is created in so-called “clinostats” for a short period of time.
“If we succeed in simulating weightlessness, a large number of tests could be carried out more quickly, easily and cost-effectively in the future,” explains Prof. Martina Schnellenbach-Held from Institute for solid construction (IfM) at the University of Duisburg-Essen. She and her team made the experiment possible: by developing a special concrete mixer that meets the strict safety requirements for the ISS. This is just the size of a hand – the concrete is mixed manually.
How to Build on the Moon and Mars
MASON (materials research in weightlessness on concrete) has a cosmic component despite the earthly applications. If humanity realizes its plans to establish a permanent presence on the moon or Mars, the stations must be built of solid material. This primarily serves to protect against small meteorites and cosmic radiation.
The formulas used for construction projects on earth to calculate the statics of buildings always assume the force of gravity of 1 G. On the moon, however, gravity is a sixth lower and it is not certain that a simple conversion would lead to a stable structure. Therefore, the data obtained as part of MASON is an important building block in the truest sense of the word.
Essential components of concrete are not available on the Moon and Mars, so astronaut Maurer also examines samples made of artificially produced moon dust.
The German Space Agency at DLR is using funds from the Federal Ministry of Economics and Climate Protection (BMWK) to support the scientific work at the University of Cologne and the University of Duisburg-Essen.