Preparation and application conductive concrete from iron tailings to the teaching reform in engineering materials courses

The conversion of iron tailings, a mining solid waste, into conductive concrete aligns with green engineering and supports the development of intelligent construction materials. This study employed a four-factor, four-level orthogonal test to investigate the effects of water-binder ratio, silica fume content, sand-binder ratio, and carbon fiber content on the density, compressive strength, and resistivity of carbon fiber-reinforced iron tailings conductive concrete (CF-ITCC). It is found that the compressive strength of CF-ITCC is linearly positively correlated with the density, and the correlation coefficient is 0.87. When the density ≥ 2300 kg/m³, the strength is generally more than 30 MPa, up to 44.7 MPa. The volume content of carbon fiber > 0.25% gives it excellent conductivity, with a minimum of 616 Ω cm. The sand-binder ratio dominates the density and strength, and the carbon fiber content dominates the resistivity, and the ratio combination of minimum density, maximum strength and optimal conductivity is determined. Microscopically, the hydration products C-S-H gel and calcium hydroxide enhance the strength, and carbon fiber and iron tailings form a conductive network to reduce the resistance. The material has the application value of solid waste resource utilization and intelligent construction, and promotes the innovative practice of engineering materials teaching through interdisciplinary experimental system. This research presents a novel approach for utilizing iron tailings and improving concrete conductivity. Additionally, a composite engineering materials experiment system integrating materials science, construction technology, and environmental engineering was developed. This system expanded traditional teaching frameworks and supported teaching reform by enhancing students' understanding of engineering materials theory and strengthening their innovative and practical abilities. The multidisciplinary paradigm demonstrates strong application value in ecological governance and engineering education reform.