Geopolymer and Lunamer Binders as Radioactive Shielding Materials for Space Applications

Geopolymers are inorganic cementitious binders produced by polymeric reaction between an aluminosilica rich material and an alkali metal hydroxide/silicate liquid, forming a binding gel, which can be used to encapsulate fine and coarse aggregates to produce concrete. While earth-based applications utilize commonly available materials, such as metakaolin, fly ash, or even rice husk, researchers at Louisiana Tech have reproduced lunar regolith to make geopolymer concrete specimens ('Lunamer') by activating the regolith with alkali liquid. Geopolymer binder technology presents superior mechanical and thermal performance, and has been shown to be compatible with an abundantly available lunar resource (lunar regolith).