Investigation on the interfacial bond and shrinkage performance of basalt fibre reinforced cement-based materials

The interfacial bond between basalt fibre and cementitious matrix is critical for fibre-reinforced cement-based materials. This study systematically investigates the bond behaviour considering water-to-cement (w/c) ratio, fly ash content, curing temperature, age, and fibre embedded length, and examines subsequent effects of fibre length and volume content on mechanical properties, drying shrinkage, and plastic cracking of basalt fibre-reinforced mortar (BFRM). The enhancement mechanism on shrinkage and cracking is elucidated from interfacial perspective. Principal component analysis optimises the mix proportion. Results show that increasing w/c reduces contact angle and surface tension of cement paste, favouring shrinkage reduction. Pull-out peak load decreases with higher w/c, fly ash, and curing temperature. Debonding toughness first increases then decreases with embedded length; 12 mm gives highest pull-out work. For fibre lengths 6–24 mm, strengths and shrinkage reduction rate first increase then decrease with fibre content. Fiber contents 0.06%–0.08% with lengths 12–24 mm improve mechanical and anti-shrinkage performance. Fibre delays cracking and enlarges crack dimensions. Best anti-cracking performance at 18 mm and 0.08%.