Energy absorption capacity of prestressed and reinforced concrete slabs subjected to multiple impacts

The dynamic response of prestressed and reinforced concrete slabs has been investigated under a freely falling steel hammer. The prestressed and reinforced concrete slabs has equivalent span of 0.8 m × 0.8 m and thickness 100 mm. The target concrete slabs were prepared using concrete of same design mix having unconfined compressive strength, 48 N/mm2. All the four edges of the target slabs were clamped using steel fixtures. All slabs were then hit at the center of the span by freely dropping a steel mass of 243 kg under gravity from a height of 500 mm. The residual load carrying capacity and energy absorption capacity of the damaged concrete slabs were further explored by repeatedly dropping the steel mass from the same height. The impact force and deflection response for both prestressed and reinforced concrete slabs were measured under each repeated impact and the energy absorption capacity was compared. Prestressed concrete slab has shown superior performance and subjected to relatively smaller displacement under multiple impacts. The energy absorption capacity of prestressed concrete slab has found to be higher than that of identical reinforced concrete slab.