Ballistic and Heat Resistance of Hybrid-Fiber Reinforced Reactive Powder Concrete

The influence of hybrid fiber reinforcement on the ballistic and heat resistance of reactive powder concrete was evaluated through an experimental program. Prismatic and cylindric test specimens were cast using different binary combinations of steel, polypropylene, polyvinyl alcohol, glass and aramid fibers. The resistance to elevated temperatures was evaluated by determining the residual strength after exposure to 200, 400, 600 and 800 ℃ (2 h isothermic dwell time). The ballistic resistance of hybrid fiber-reinforced cylindric samples was investigated experimentally by the DoP test. Specimens were subjected to the 7.62 × 54 R B32 API projectile impact load using the striking velocity of 850 m/s. The influence of different hybridization concepts on the projectile impact resistance represented by differential efficiency factor (DEF), height of impact crater and damaged surface area was evaluated. It was found that by appropriate hybridization of the fiber reinforcement, superior ballistic and heat resistance of RPC can be achieved compared to only steel fiber-reinforced RPC. Steel and PVA mix (3:1 Vol.) was found the most effective combination to achieve a high level of dual heat and ballistic protection.