# Effect of Basalt Fiber Content on Mechanical Properties of Lunar Regolith Simulant Geopolymer Under Static Loading

## TL;DR

This study explores how adding basalt fibers affects the strength of a concrete-like material made from simulated lunar soil under different curing conditions.

## Contribution

The novel contribution is identifying optimal basalt fiber content and curing strategies to enhance the mechanical properties of lunar regolith simulant geopolymer.

## Key findings

- Strong alkali-activated specimens with 0.3% fibers showed optimal ductility with compressive and flexural strengths of 2.85 MPa and 0.53 MPa.
- Specimens with 0.2% fibers cured at 80 °C for 1 d achieved maximum compressive and flexural strengths of 44.76 MPa and 1.60 MPa.
- Weak alkali-activated specimens with 0.1% fibers at 80 °C for 7 d showed peak flexural strength of 3.88 MPa with good fiber-matrix synergy.

## Abstract

In-situ lunar construction technology is critical for future lunar base development, and the production of geopolymers from lunar regolith—a novel cementitious material with concrete-like properties—has become a vital approach for achieving in-situ resource utilization. This study systematically investigated the influence of basalt fiber content (0–0.4%) on the mechanical properties of lunar regolith simulant geopolymers by controlling key parameters including curing temperature (20 °C and 80 °C), duration (1 d and 7 d), and alkali activator type (strong alkaline solution: a mixture of sodium hydroxide and sodium silicate, and weak alkaline solution: sodium silicate solution). Through testing of 144 specimens, the results revealed that strong alkali-activated specimens with 0.3% fibers cured at 20 °C for 7 d showed optimal ductility with compressive strength of 2.85 MPa and flexural strength of 0.53 MPa, exhibiting characteristic flat stress-strain curves. Specimens with 0.2% fibers under high-temperature curing at 80 °C for 1 d achieved maximum compressive strength of 44.76 MPa and flexural strength of 1.60 MPa but demonstrated brittle failure behavior. Weak alkali-activated specimens containing 0.1% fibers cured at 80 °C for 7 d attained superior comprehensive performance with peak flexural strength reaching 3.88 MPa, showing excellent fiber-matrix synergy. These findings provide important theoretical foundations for optimizing lunar construction materials through customized fiber reinforcement and curing strategies.