Influence of barrier material and barrier shape on blast wave mitigation

• The effect of complex shape of a barrier on blast wave propagation is discussed.
• Thanks to rough surface, the same level of safety is achieved with smaller barrier.
• Rough surface reduces blast effects without compromising fragment absorption.
• Ultra high performance self-compacting concrete subjected to blast performed well.

This paper investigates means for increasing the effectiveness of a blast barrier using various types of surfacing. It builds on previous research on the blast effect mitigation properties of rigid concrete blast barriers. Previous research has studied barriers with a smooth surface. The effectiveness of rigid smooth barriers in reducing shock wave overpressure has been proven to be low. Their main contribution is in absorbing flying debris or shrapnel created by an explosion, and thereby reducing the risk of injury to the occupants of a building. This paper suggests ways to achieve greater safety by increasing the blast mitigation properties of barriers. It studies the influence of various materials and shapes on the effectiveness of a barrier, and proposes methods for providing increased overpressure reduction while keeping the same overall dimensions. A barrier of this kind provides additional security for the occupants of a building without disrupting the functionality of the interior with a massive obstacle. The use of a deformable porous material is compared with the use of rigid durable ultra-high performance fibre-reinforced self-compacting concrete (UHPFRSCC), developed by the authors especially for application in blast-resistant structures. The results of an original experimental program are used to determine the influence of barrier shape and barrier material on blast wave mitigation. The effect of uneven barrier surfacing on a shock wave is demonstrated on a finite element numerical model calculated using LS-DYNA. Results of the analysis proved that the use of uneven surface has a positive effect on blast mitigation properties of a barrier without affecting its shrapnel absorption capabilities. All experiments and FEM models consistently proved that a barrier has significant overpressure reduction effect in the area directly behind the barrier. The comparison of experimental measurements of rigid and deformable barrier material showed no drastic increase in mitigation properties of deformable barrier.