Relationships among the chemical, mechanical and geometrical properties of basalt fibers

We investigated the chemical, mechanical and geometrical properties of basalt fibers from three different commercial manufacturers and compared the results with those from an industry standard glass fiber. The chemical composition of the fibers was investigated by X-ray fluorescence spectrometry, which showed that basalt and glass fibers have a similar elemental composition, with the main difference being variations in the concentrations of primary elements. A significant correlation between the ceramic content of basalt and its tensile properties was demonstrated, with a primary dependence on the Al ₂O ₃ content. Single fiber tensile tests at various lengths and two-way ANOVA revealed that the tensile strength and modulus were highly dependent on fiber length, with a minor dependence on the manufacturer. The results showed that basalt has a higher tensile strength, but a comparable modulus, to E-Glass. Considerable improvements in the quality of manufacturing basalt fibers over a three-year period were demonstrated through geometrical analysis, showing a reduction in the standard deviation of the fiber diameter from 1.33 to 0.61, comparable with that of glass fibers at 0.67. Testing of single basalt fibers with diameters of 13 and 17 µm indicated that the tensile strength and modulus were independent of diameter after an improvement in the consistency of fiber diameter, in line with that of glass fibers.