High-ductility basalt fiber reinforced cement composite with low CO2 emission by interface property transformation: Hydrogen bond transformed into covalent bond

Despite the beneficial features and reduced carbon footprint afforded by basalt fibers, the widespread use of basalt fiber-reinforced cement composite (BFRCC) has issues linked to decreased compressive strength beyond 28 days and insufficient toughness. This study aims to address these constraints by changing the chemical bonding between basalt fibers and the cement matrix from hydrogen bonds to covalent bonds via the use of a surface modification. In accordance with the results, a concentration of 2.5 % of the modifier yields the greatest improvement. The 2.5 % modified BFRCC has a compressive strength 1.88 times that of unmodified BFRCC and an elastic modulus 2.02 times that of unmodified BFRCC. Tensile strength and peak tensile strain are improved by 1.95 times and 2.99 times, respectively. The increased threshold for fracture initiation and the increased energy required for crack propagation are both attributable to the more uniform strain distribution within the improved BFRCC, which allows for higher load sharing. The weakening of the chemical bonds aids in reducing "Z"-type fiber failure. In comparison with conventional BFRCC, the use of modified BFRCC contributes to reducing reductions in cement consumption and greenhouse gas emissions.