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

Abstract

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.