Abstract: In order to study the influence of chopped basalt fiber on the corrosion resistance of concrete under the action of chloride salt freeze-thaw, five groups of concrete with different basalt fiber content were prepared in the experiment. The effects of basalt fiber content on concrete compressive strength, free chloride ion concentration and chloride ion diffusion coefficient were studied and analyzed, and a quantitative functional relationship model between chloride ion diffusion coefficient and fiber content was established. The results of the study show that the addition of basalt fiber improves the compressive strength of concrete and reduces the damage to the concrete compressive strength caused by freeze-thaw cycles. When the basalt fiber content is 1.2 kg·m^-3, the compressive strength is the most obvious. The appropriate amount of basalt fiber is beneficial to reduce the free chloride ion concentration and chloride ion diffusion coefficient in the concrete, and the large amount of basalt fiber will cause fiber agglomeration to form pores, resulting in rapid growth of free chloride ion in the early stage of concrete. Under the action of chopped basalt fiber, there is a good quadratic function relationship between the chloride ion diffusion coefficient of concrete and the content of basalt fiber.

Key words: basalt fiber concrete, freeze-thaw cycle, compressive strength, chloride ion, composites