Strength comparison for lunar concrete

A recent European study sponsored by ESA showed that urea, the main organic compound found in our urine, would make the mixture for lunar concrete more malleable before hardening into a final, sturdy shape for future lunar habitats.

Researchers found that adding urea to the lunar geopolymer mixture, a construction material similar to concrete, worked better than other common plasticisers, such as naphthalene or polycarboxylate to reduce the need for water.

The mix coming out of a 3D printer proved to be stronger and retained a good workability – a fresh sample could be easily moulded and retained its shape with weights up to 10 times its own on top of it.