Flexural fatigue behavior of hooked-end steel fibres reinforced concrete using centrally loaded round panel test

In this study, a centrally loaded round panel test was used to investigate the flexural fatigue behavior of steel fibre reinforced concrete (SFRC) considering three influencing factors, such as stress level, steel fiber type and steel fibre content. The results show that the fatigue life of all specimens at different stress levels followed the two-parameter Weibull distribution with a statistical correlation coefficient greater than 0.90. The predicted double logarithmic fatigue equations were also developed, which enables designers to predict fatigue life according to the required reliability and stress level in actual engineering. Due to the geometrical characteristics of hooked-end steel fibres, the SFRC specimens with 3D and 5D hooked-end steel fibres exhibited higher compressive strength, flexural toughness and flexural fatigue performance, showing more effective macrocracks control and higher energy absorption capacity. In addition, a developed analytical model for hooked-end fibers shows that the peak pull-out load of the 5D fiber is 30% higher than that of the 3D fiber, taking into account snubbing and matrix spalling effects. This finding results in the SFRC-5D specimens having the best flexural fatigue performance.