Evaluation of industrial byproduct iron ore tailings and carbon fiber cement-based materials under sulfate freeze-thaw cycles: Durability, piezoresistivity, and microscopic mechanism

Abstract

This study investigated the feasibility of utilizing industrial byproduct iron ore tailings and carbon fiber cement-based materials (ICCM) in sulfate freeze-thaw (F-T) environments. The effects of carbon fiber (CF) and iron ore tailing (IOT) on the sulfate F-T resistance, piezoresistivity, and pore distribution were tested. The results revealed that CF (0.6 vol%) and IOT (30%) significantly improved the compressive strength (51.6 MPa) and resistance to sulfate F-T of ICCM. The stress sensitivity was obviously enhanced to 1.389 %·MPa−1. Furthermore, the stress sensitivity is closely related to the sulfate F-T environment. After the sulfate F-T cycles, the fractional change in resistivity (FCR) and compressive stress agreed with a first-order exponential decay relationship. Replacement with IOT compensated for the degradation in piezoresistivity by formation of balanced pore distribution over 200 F-T cycles. The combination of IOT and CF in cement material yields excellent performance in terms of stress sensing, cost, and environmental impact (EI). This approach is expected to be developed for self-sensing in extreme environments with a recycled conductive filler.