We are working on developing geopolymers based on Lunar regolith for construction on the moon. Since it is very expensive to bring materials from earth to the moon, we are aiming at making geopolymer construction materials based on local Lunar resources. The main ingredient of the geopolymers are lunar regolith (moon dust). This is mixed with water and NaOH to form geopolymer concrete. Since water is scarce on the moon, there is a need to reduce the amount of water needed in the geopolymer mixture. However, the flow properties of the pre-set geopolymers should still remain suitable for 3D-printing. We have discovered that by utilizing urea (which can be recovered from astronaut urine) we can reduce the water needed with more than 50 %:
Shima Pilehvar, Marlies Arnhof, Ramón Pamies, Luca Valentini, Anna-Lena Kjøniksen
Utilization of Urea as an Accessible Superplasticizer on the Moon for Lunar Geopolymer Mixtures
Journal of Cleaner Production, (2020), 247, 119177.
DOI: 10.1016/j.jclepro.2019.119177
We are now working on utilizing basalt fibers to make the geopolymer concrete stronger, and to examine how well the geopolymers can withstand the severe temperature fluctuations of a Lunar day/night cycle. We are also planning to test effect of 3D-printing the geopolymers in a vacuum, and the radiation shielding properties of the geopolymers.
The project is in collaboration with the European Space Agency (ESA).