Study of the effects of iron tailings sand and basalt fibers on the strength of cement-based materials

Abstract

This study utilizes flexural and compressive testing, combined with microscopic characterization, to examine the effects of iron tailings sand (ITS) and basalt fiber (BF) on the mechanical strength of cement-based materials (CBMs). Results indicate that ITS exhibits low physicochemical reactivity, which inhibits cement hydration in CBMs. The inclusion of ITS and an increase in its particle size lead to higher CBM porosity and larger pore sizes, ultimately decreasing mechanical strength. When BF length is 6 mm, basalt fiber cement-based materials (BF-CBM) achieves peak flexural and compressive strengths: 28 d values increase by 39.20% and 9.25%, respectively, compared to ordinary Portland cement (OPC) specimens. Mechanistically, BFs absorb energy during bending deformation, suppressing crack propagation. They also enhance interfacial strength and matrix density, thereby improving the flexural strength of CBMs. This research provides a theoretical foundation for optimizing the design of CBMs.