Behavior of prestressed fiber-reinforced steel-lined concrete slabs under projectile impact

Recently, investigators have found that the application of prestressing, addition of fibers, and steel lining can improve concrete's overall performance, including its impact resistance. There is, however, no study in the available literature on the impact response of steel-lined post-tensioned fiber-reinforced concrete (PFRC). This study examines how steel-lined PFRC responds to projectile impact. The PFRC slabs with/without a steel lining on the rear face were tested against the impact of hemispherical-nosed projectiles at varied velocities using a gas-gun facility. The test results revealed that steel fiber volume increased the ballistic limit, reduced penetration and scabbing depths, and reduced ejected mass substantially from the back face. The use of steel lining on the back face caused a substantial increase in the ballistic limit and caused a significant reduction in the ejected mass. NDRC equations are modified to incorporate the effects of prestressing, steel fibers, and steel lining to predict penetration depth. Another empirical model is developed for ballistic limit prediction of the prestressed steel-lined fiber-reinforced concrete slab by incorporating the prestressing, steel fibers, and steel lining in the UKAEA formula. The models agreed well with the experimental results.