European engineers have shown that urea can serve as a suitable plasticizer for concrete mortar for the construction of the future lunar base.
Colonization of the Moon is fraught with a great many difficulties and challenges: a dangerous level of radiation, extreme temperature drops, the risk of meteorites falling, and so on. All of them are completely solvable if a reliable, protected and hermetic base is built on the satellite. But for this, the main problem remains to be solved – the logistics.
Shipping every kilogram of cargo to the moon costs tens of thousands of dollars, so transporting building materials to a satellite would be too expensive. Therefore, engineers are developing technologies for building a base of lunar regolith using robotic technology and 3D printing. The find made by the team of Anna-Lena Könicksen from Estoll University College in Norway promises to further ease this task.
In an article published in the Journal of Cleaner Production, they examine the possibility of utilizing the urine of future colonists for the construction of a lunar base. According to engineers, urea isolated from it can serve as a plasticizer for cement mortar. Such an additive increases the ductility of concrete makes it easier to work with it and increases the density and resistance to deformation.
“The idea is to use what can be found on the spot: regolith and water from the ice present in many areas”, the authors explain. “Moreover, we have shown that waste such as urine from the personnel of the lunar base is also useful for the matter”. Its two main components are water and urea, whose molecules weaken hydrogen bonds and reduce the viscosity of many aqueous solutions”.
For their experiments, scientists used a lunar soil simulator created in ESA and a suitable 3D printer, with which they printed out samples, and then sent them for detailed analysis. The components printed with the addition of urea as a plasticizer underwent several cycles of freezing-thawing and heating to 80°C but retained their structural properties completely.
“We have not yet considered the process of extracting urea”, adds Anna-Lena Könicksen, “since we have not yet figured out whether other urine components can be used to add to the building mixture. Perhaps water will go into it, along with the one that can be found on the moon itself”.