Optimising pullout friction of basalt mesh geotextiles in rice husk ash-stabilised soils

This study investigates the pullout friction resistance of basalt fibre geotextiles embedded in rice husk ash (RHA)–stabilised backfill soils to optimise soil reinforcement for sustainable construction. RHA, a pozzolanic by-product rich in amorphous silica, promotes cementitious bonding within the soil matrix and enhances mechanical behaviour. Basalt mesh geotextiles with high tensile strength and durability were incorporated to evaluate soil–geotextile interaction characteristics. Four basalt mesh configurations – GX1 (1  mm × 1  mm), GX2 (5  mm × 5  mm), GX3 (10  mm × 10  mm), and GX4 (25  mm × 25  mm) – were examined to assess the influence of mesh geometry on interface shear behaviour. Pullout tests were conducted under controlled laboratory conditions using a modified direct shear apparatus. Interface performance was evaluated in terms of pullout resistance, apparent interface adhesion, and apparent interface friction angle at RHA contents of 5%, 10%, and 15%. The results indicate that GX1 exhibits the highest apparent interface friction angle, GX2 provides moderate performance, GX3 records the lowest interface parameters, and GX4 develops the highest interface adhesion, which decreases with increasing RHA content. Overall, geotextile geometry governs pullout behaviour, and combining RHA with basalt geotextiles provides an effective and sustainable ground improvement solution.