Effects of fiber clustering on fatigue behavior of steel fiber reinforced concrete beams

•The effect of fiber clustering on fatigue behavior of SFRC beams was investigated by experimental and numerical analysis.•The fiber distribution in the cross section of concrete was studied.•The fiber clustering probability increased with increasing fiber volume fraction.•An optimum fiber volume fraction existed to achieve the highest fatigue performance of SFRC beam. This paper investigated the effects of fiber clustering on fatigue behavior of steel-fiber-reinforced concrete (SFRC) beams with reinforcements by experimental and numerical analysis. The steel fiber volume fractions of beams were 0 vol%, 0.5 vol%, 1.0 vol%, and 1.5 vol%. One beam was tested under static loading, and eight beams under fatigue loading with different stress levels. Moreover, the fiber distribution in the cross section of concrete was experimentally characterized to understand the underlying mechanism. The results indicated that the fatigue life of beam increased with increasing fiber volume fraction from 0 to 1.0 vol%, and decreased from 1.0 vol% to 1.5 vol% due to a significant amount of fiber clusters for the beam with 1.5 vol% fiber volume fraction, and thus resulted in the decreased fatigue performance of the beam. Based on the statistical results of fiber distance distribution in the concrete section, fiber clustering was considered in the concrete damaged plasticity model in ABAQUS to simulate the crack patterns of SFRC beam, and validated by the experimental results.