Manufacture and Properties of Sulfur Mortar for Lunar Applications

The main constraint for lunar construction is availability of resources. Concrete is a versatile material that could be used in a variety of applications on the Moon. However, conventional concrete (aggregates, cement and water) is hard to manufacture on the lunar surface. First, water is a very scarce resource (even if polar ice deposits are confirmed); second, cement (portland or alumina) production requires a very significant amount of processing and energy consumption. Sulfur has been proposed as an alternative binding agent for concrete manufacture on the Moon, but few studies have addressed the questions related to resource exploitation, mixing procedure and mechanical properties. In this work we report on experimental studies on sulfur mortar manufacture, using a variety of aggregate types (including lunar simulant JSC-1). Results indicate that the amount of sulfur can be reduced more than 10% relative to previous works and mechanical properties (compressive and tensile strengths) are, on the average, 30% greater than those obtained in earlier experimental studies. Adequate compaction of the hot sulfur and aggregate mix is a critical issue in assuring the production of a suitable material for lunar construction. These observations impose important constraints on the utilization of sulfur concrete (or mortar) on the lunar surface.