Research on the mechanical properties and electrical conductivity of cement mortar based on recycled nano-iron boride

Traditional cement-based materials are being gradually replaced by nanomodified cement-based materials because the traditional materials cannot meet the production needs of modern society. Nano-iron boride (nano-FeB) is a high-performance nanomaterial prepared from waste iron powder during construction. Its one-dimensional structure is similar to that of carbon nanotubes, which makes it a potential candidate for nano-reinforcement materials. In this paper, the effects of different contents of recycled nano-FeB (0%, 0.05%, 0.075%, and 0.1 wt.%, based on cement weight) on the mechanical properties and electrical conductivity of cement mortar were studied. The results showed that the mechanical properties of the composite cement mortar were improved with the addition of nano-FeB. When the content of nano-FeB was 0.075%, the 28 d compressive strength and flexural strength of the composite cement mortar increased by 60.2% and 42.1%, respectively. In addition, a 0.075% nano-FeB content favorably improved the conductivity of cement mortar. Compared with that of the control group, the volume resistivity of the composite cement mortar decreased by one order of magnitude.