Abstract: The mechanical properties of basalt fiber and nano-SiO₂ reinforced concrete were studied by cube compressive strength, splitting tensile strength, and flexural strength tests with basalt fiber volume fraction and nano-SiO₂ substitution rate as factors. It is found that the basalt fiber can change the failure mode of Nano-SiO₂ concrete. When basalt fiber and nano-SiO₂ are mixed, the cube compressive strength, splitting tensile strength, and flexural strength of concrete matrix are improved. The results show that the cubic compressive strength and flexural strength of basalt fiber nano-SiO₂ concrete are the best when basalt fiber volume content is 0.10% and nano-SiO₂ content is 1.0%. When the volume fraction of basalt fiber is 0.15% and the replacement rate of Nano-SiO₂ is 1.5%, the splitting tensile strength of basalt fiber nano-SiO₂ concrete is the best, which is 22.97% higher than that of plain concrete. Based on the experimental data, the cube compressive strength prediction model of basalt fiber nano-SiO₂ reinforced concrete is established.

Key words: basalt fiber, nano SiO₂, mechanical properties of concrete, strength prediction model, composites