Study on the electrical conductivity, strength properties and failure modes of concrete incorporating carbon fibers and iron tailings

Abstract

This study aims to explore the feasibility of preparing conductive concrete using carbon fibers and iron tailings and its application in snow and ice melting on roads, and to solve the problem of excessive stacking of iron tailings. In addition, the effects and action mechanisms of the water-binder ratio, the content of silica fume, the sand-binder ratio, and the content of carbon fibers on the electrical conductivity, mechanical properties, and failure modes of the concrete were studied. The results show that: (1) When the volume content of carbon fibers is 1 %, Carbon Fiber - Iron Tailing Conductive Concrete (CF-ITCC) has good electrical conductivity. Its resistivity ranges from 400 to 1800 Ω cm, which meets the requirements for conductive concrete used in snow and ice melting on roads. (2) When the water-binder ratio is 0.24, the content of silica fume is 18 %, and the sand-binder ratio is 0.8, the compressive strength and flexural strength of CF-ITCC are the highest. (3) The digital image correlation (DIC) technique was used to reveal that the main failure mode of CF-ITCC is shear failure. However, specimens G18 % and I1.6 exhibit some bulging failures, accompanied by corresponding "X" and "H" type cracks. The research shows that it is feasible to prepare conductive concrete for snow and ice melting on roads and building heating using carbon fibers and iron tailings, thereby reducing the potential environmental impacts associated with iron tailings and meeting the requirements of the green development of the construction industry.