The Effect of Basalt Fiber on Concrete Performance under a Sulfate Attack Environment

To enhance the sulfate attack resistance performance of concrete, Sulfate erosion test was carried out on basalt fiber concrete with different contents, selecting a concentration of 5% sulfate solution and using a dry−wet cycle mechanism attack of basalt fiber-reinforced concrete (BFRC). Every 15 dry−wet cycles, the mass, compressive strength, splitting tensile strength, and relative dynamic elastic modulus of BFRC were tested, and the SO4 2− concentration was measured. This work demonstrates that the mass, relative dynamic elastic modulus, compressive and splitting tensile strength of BFRC reveal a trend of climb up and then decline with the process of the dry−wet cycle. Basalt fiber can enhance the sulfate corrosion resistance of concrete by delaying the erosion of concrete induced by SO4 2− and increasing the bearing and anti-deformation capacities of concrete by improving its internal structure. Additionally, when mixing 0.2% basalt fiber into concrete, the strength deterioration rate will be reduced when the peak values of splitting tensile and compressive strength appear at 60 and 75 times the alternating dry−wet cycles, respectively. Adverse effects will occur when the fiber volume fraction exceeds 0.2%. The research in this paper can provide a foundation for the engineering applications of basalt fiber concrete.