Round panel experiment research on flexural toughness of hybrid fiber shotcreting

In order to investigate the flexural toughness of hybrid fiber shotcreting, The round hybrid fiber shotcreting panel with a diameter of 800mm was placed on the pedestal, which is arranged along the circumference with three cylinders that are 120 degrees to each other, and the center point of the panel was loading with concentrated force until the deflection of center point was at least 45 mm, then the load-deflection curve and energy absorption value were obtained, the effects to the concrete slab on flexural toughness and deflection performance for hybrid fiber shotcreting were investigated, which brought by the different amount of steel fiber volume fraction,steel fiber type and the addition of the polypropylene fibers. The results show that the flexural strength and flexural toughness of shotcreting panel raising with the increased of steel fiber volume fraction. The flexural toughness and crack control ability of ultra-short microfilament steel fibers shotcreting are better than multiple anchor steel fiber shotcreting. When it comes with the hybrid fibershotcreting with 1.2% of ultra-short microfilament steel fibers and 0.11% of the polypropylene fibers, the experimental results show the best flexural toughness and the highest compressive strength.