Repeated penetration and different depth explosion of ultra-high performance concrete

• Increasing of the penetration depth of UHPC subjected to repeated penetration.
• The damage of UHPC after each time of impact by the ultrasonic wave velocity method.
• The penetration process of UHPC observed by the high-speed camera.
• The damage and fracture of UHPC with TNT explosive embedded at different depths.
• The explosion process and pressure of UHPC simulated by the finite element method.

Ultra-high performance concrete (UHPC) was prepared and its dynamic behavior was researched under repeated penetration and different depth explosion using 14.5 mm bullets and TNT explosives. The penetration depth of UHPC was measured on different number of penetrations. The damage of UHPC was measured by the ultrasonic wave velocity method and the penetration process of UHPC was observed by the high-speed camera. The explosion damage of UHPC with TNT explosive embedded at different depths was measured and the explosion process was simulated by the finite element method. Results show that UHPC resistance to repeated penetration and different depth explosion is improved significantly by hybrid reinforcement of steel and basalt fibers. The second penetration depth of UHPC with basalt coarse aggregates is decreased and the damage of UHPC with basalt coarse aggregates is more than that of UHPC without basalt coarse aggregates. The mass and the placing depth of explosive have important effects on the damage of UHPC.