Development of waterless extra-terrestrial concrete using Martian regolith

Human colonization on Martian land is gaining significant attention in space exploration activities that demand in-situ resource utilization in the development of construction and building materials for human habitation. This research explores the utilization of Martian regolith simulant and sulfur to create extra-terrestrial concrete (ETC) with a property suitable for constructing human habitat on Mars. The primary objective of the study is to maximize the utilization of Martian regolith simulant to achieve the desired compressive strength of 25 MPa (average compressive strength specified for concrete used in residential buildings on Earth). Mechanical properties, phase transition, and microstructural characteristics of Martian regolith based-ETC under varied temperature conditions (0 °C, 40 °C, and 50 °C) on Mars were investigated. The optimal mixture proportion of ETC had 70% (by wt.) of Martian regolith and exhibited an average compressive strength of 27 MPa. The formulated ETC could retain up to 25 MPa of compressive strength at 40 ℃ and 50 ℃, and could reach up to 35 MPa at 0 ℃ temperature conditions. The change in compressive strength was attributed to the sulfur sublimation and pore closure brought about by freezing at extreme temperatures, respectively