Review of research on basalt fibers and basalt fiber-reinforced composites in China (I): Physicochemical and mechanical properties

This paper reviewed the research progress in China on the durability, acid and alkali corrosion resistances, thermal insulation, sound insulation, and hygroscopic properties of basalt fibers (BFs) as well as the physicochemical and mechanical properties of BF-reinforced resin composites. The acidity coefficient and pH value of BFs and glass fibers (GFs) were tested, which showed that BFs had better chemical stability. Scanning electron microscopy observations showed that the acid corrosion of BFs gradually occurred from the outside to the inside, whereas the alkali corrosion of BFs occurred nearly simultaneously both inside and outside. Moreover, the reasons for these results were analyzed from a chemical reaction perspective. BFs met the thermal conductivity and sound absorption coefficient requirements of building thermal insulation and sound absorption materials. The hygroscopicity of BFs was 1/8–1/6 that of GFs, and BFs also had a smaller dielectric loss angle. Tests confirmed that BFRC exhibited great high-temperature resistance. As the short BF content increased, the flexural strength, splitting tensile strength and impermeability of BFRC significantly improved, and an optimal fiber length and content were proposed. A comparison showed that the mechanical properties of BF-reinforced resin were generally better than those of GF-reinforced resin. Finally, this review identified some concepts to be studied in this field and prospects for possible future research directions. [Formula: see text]