Experimental study on direct tensile fatigue performance of basalt fiber reinforced concrete

Conducting research on the fatigue performance of concrete materials is of great significance for the anti fatigue design of concrete structures. Currently, indirect tensile or compressive strength tests are commonly used to study the fatigue performance of basalt fiber reinforced concrete, but there is little research on its fatigue performance under direct tensile conditions. Using a fatigue testing machine and a self-developed concrete axial tensile device, direct tensile fatigue tests of basalt fiber reinforced concrete were conducted under different fiber content and stress levels. Based on fatigue test data, the entire fatigue tensile process of basalt fiber reinforced concrete was analyzed, and the effects of fiber content and stress level on the fatigue life of concrete specimens were explored. Strain fatigue life curves of concrete with different fiber content were plotted. The experimental results indicate that the failure mode of basalt fiber reinforced concrete under cyclic loading is brittle failure; with the increase of basalt fiber content, the fatigue life of concrete first increases and then decreases. When the fiber content is 0.3%, the fatigue life of basalt fiber concrete is the highest compared to the benchmark concrete. When the fiber content is the same, the fatigue life of concrete decreases with the increase of stress level. The fatigue deformation process of basalt fiber reinforced concrete can be divided into three stages: the stage of fast strain growth, the stage of uniform strain growth, and the stage of rapid strain growth.