Rheological properties of clay-containing Martian regolith simulant slurries

The rheological properties of slurries prepared from two Martian regolith simulants with different smectite contents, JEZ-1 and MGS-1C, were investigated in the context of in situ resource utilization (ISRU). Flow curve measurements revealed that both slurries exhibit yield-stress fluid behavior and anti-thixotropic hysteresis. The yield stress strongly depends on solid concentration and follows a power-law relationship. At the same solid concentration, MGS-1C showed higher stress and modulus values than JEZ-1, likely reflecting differences in mineral composition, including smectite content. Furthermore, for JEZ-1, increasing ball-milling time reduced particle size and was accompanied by a decrease in slurry hysteresis, whereas no pronounced effect of ball milling was observed for MGS-1C. From an ISRU perspective, JEZ-1 may be more suitable for slurry transport and processing due to lower stress and reduced water demand, whereas MGS-1C may have potential advantages for producing high-strength construction materials because of its stronger apparent binder effect. These results highlight the importance of optimizing regolith selection and processing conditions according to the intended application under resource-constrained Martian environments.