The explosive load is one of the dynamic loads on structures, which has been considered as an important issue in strengthening studies of structures due to increased military attacks and terrorist incidents and unexpected events in industry and traortation in recent decades. Accordingly, the first factor retrofit buildings are to apply the materials with high energy absorption and toughness. Today concrete, as the highest consumption among man-made materials, has found many applications in building structures. However the concrete has weaknesses against tensile, bending and dynamic loads including explosive. Accordingly, there are extensive researches for improving the concrete in these areas. In this context, increased energy absorption and toughness in the concrete by reinforced concrete with fibers is one of the best methods. The aim of this research is to compare the toughness, cracking and damage of concrete reinforced fiber slabs with steel, glass, polypropylene and its hybrids, under blast loading. Also, the effect of other factors such as mix design, aggregate ratio and slab thickness is measured for resistance evaluation of samples under explosive. Slab dimensions is 500 × 500 mm, with a thickness of 50 and 75 mm. water cement ratio is considered 0.45 for all samples, but the ratio of sand, gravel and cement has been selected variable. Fiber volume percent used in this work is 0.5 to 1.5 for steel fiber, 0.1 to 1.2 for polypropylene fiber and 0.2 to 1.2 for glass fiber. Apart from individual fibers, is also used in hybrid steel-polypropylene and glass-polypropylene fiber with different volume percentages.
