Investigation of Impact Behavior of High Strength Concrete and Ultra-High Performance Steel Fiber Reinforced Concrete under Impact of Projectile

The purpose of this study is the investigation of the behavior of ultra-high performance steel fiber reinforced concrete (UHPSFRC) under the low and high velocity impacts. The behavior of two types of concrete panels made of UHPSFRC and a type of conventional high strength concrete (HSC) under low velocity impact was investigated by the drop-weight tests. Experimental results, including required number of drops to initiate the crack and ultimate failure, crack pattern and the damage state for both types of concrete panel specimens are compared. Besides, numerical simulations using the LS-Dyna software package were implemented on both type concrete panels under high velocity impacts. The experimental test results proved the HSC specimens to be brittle and exhibit low impact strength by failure under the first impact incident. However, the UHPSFRC specimens with 2% fibers resulted in ductile behavior and could undergo at least ten consecutive drops. The numerical simulations revealed the identical specimens made of HSC and UHPSFRC under similar high velocity impact conditions resulted in different level of damage in panels. While the specimen composed of HSC experienced the penetration with full perforation at the impact location, the UHPSFRC specimens underwent penetration with no perforation under the impact load.