Impact resistance of multi-layer slabs made with (HPSCC) reinforced by hybrid fibers under drop weight impact

In this research, the robust strength slabs made of concrete, self-compacting, multi-layer reinforced steel and nylon fibers and a combination them under the influence of impact load is investigated. To achieve this goal, 30 concrete slabs one layer and three layers with dimensions 40*40*7.5 cm are made. The slabs come from 10 different types, one type of non-fibrous as a control, and other slabs all have a fixed volume 1% fiber, hence the type and percentage of fiber varies in the layers. The impact weight loss test was performed on the made slabs. In this test, steel ball weighing 5.8 kg at a distance 1.5 m repeatedly hit and The number of blows to make the first crack and the destruction recorded. The results the test indicate a very high effect steel fibers and the slight impact nylon fibers on the slab resistance the slabs. Multi-layered slabs in the first-cracks are the same as the slabs a uniform laminate layer, but the resistance to the destruction and absorption the final energy these slabs increases compared to one-layer samples, which can be due to an increase in the percentage fiber in the outer layers and the layered layout the fibers.