Superflexible yet robust functionalized carbon nanotube fiber reinforced sulphoaluminate cement-based grouting materials with excellent mechanical, electrical and thermal properties

Fiber-reinforced cement-based grouting material has triggered strong interest owing to its promising application in coal mining . However, how to enable a combined feature of great robustness, exceptional electrical and thermal behaviors, which is crucial for high-performance realization, still remains a significant challenge. Herein, an effective and facile strategy to address the issue was proposed by manufacturing functionalized carbon nanotube (CNT) fibers featuring prominent flexibility, excellent water dispersibility , superior tensile strength and electrical conductivity . Benefiting from the chemical bonds generated between cement hydration product and CNT-COOH fiber effectively embedded into cement matrix , the obtained fiber-cement hybrid with water-cement ratio of 0.8 and 0.5% fiber content was integrated into a whole, with flexural strength (4.8 MPa) and compressive strength (27 MPa) increased by 50% and 30%, respectively, compared to control sample after curing for 28 days. Meanwhile, attributing to the formation of interconnected network architecture built by CNT-COOH fibers in the cement matrix, the hybrid featured a significantly enhanced performance in heat transfer and electrical conductivity, which was further improved under loading. This work has shed light on new strategies for manufacturing carbon-based fiber reinforced cement-based grouting materials with great robustness, prominent electrical and thermal behaviors toward future uses.