Basalt fiber offers excellent tensile strength and impact resistance, similar to mid-range carbon fibers. While its tensile modulus is lower than that of carbon fiber, basalt fibers outperform in high-temperature stability, chemical resistance, and cost-effectiveness.

Basalt fiber has a high thermal resistance and maintains its mechanical properties in temperatures up to 800°C (1472°F) for short durations. Its continuous use temperature is typically around 500°C (932°F), making it ideal for heat-resistant composites.

Surface treatments like silane coupling agents or acid etching improve the interfacial bonding between basalt fibers and polymer matrices. These treatments increase composite performance in terms of strength and durability by enhancing fiber-matrix adhesion.

Basalt fiber is naturally hydrophobic and absorbs minimal moisture. However, prolonged exposure to highly humid conditions can slightly affect its mechanical properties. Protective coatings or matrix encapsulation can mitigate this effect in composites.

Basalt fiber reinforcement offers superior crack resistance, higher tensile strength, and corrosion resistance compared to traditional steel reinforcements. It also reduces the overall weight of the structure while enhancing its durability and lifespan.

Key challenges include ensuring consistent quality of basalt raw material, controlling fiber diameter during production, and optimizing fiber-matrix bonding for specific applications. Additionally, basalt fiber requires specialized equipment for spinning and composite fabrication.