Mechanical Properties and Additive Manufacturing of Alkali-Activated Lunar Regolith in Artificial Lunar Environments

Lunar base construction has become a cutting-edge and multi-disciplinary research issue worldwide. The development of sustainable lunar infrastructure is essential for future exploration and a major challenge for constructing on the Moon is the availability of suitable building materials. In this regard, the research on alkali-activated lunar regolith simulants (AALRS) is a significant breakthrough. In this paper, the mechanical properties and additive manufacturing of AALRS are investigated with reference to the lunar environments. The study has shown that the type of alkali, curing temperature and vacuum exposure have a prominent effect on the solidification behaviour of AALRS. Furthermore, the acceptable long-term properties of silicate-based AALRS were also revealed after undergoing several lunar diel temperature cycles. The scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) analysis have indicated the presence of two solidification mechanisms, geopolymerization and dehydration, within AALRS, which have contributed to its microstructure stability. The development of an innovative 3D printer for AALRS is a crucial step towards the future construction of a lunar base. Several conceptualized printers that can extrude, compress, and deposit treated lunar regolith will be presented. Additive manufacturing of lunar regolith has the potential to reduce the cost and increase the efficiency of building on the Moon.