Investigation of Multi-layered Mitigation Systems for Protection from 120 mm Mortar HE Top Attacks.

Abstract

This paper investigates the protection of reinforced concrete (RC) structures from Mortar 120 mm HE (high explosive) top attacks. Two multi-layered mitigation systems are proposed to be added to the roofs of RC structures to achieve full protection against the destructive effects of Mortar 120 mm (i.e., ballistic penetration and explosion). The proposed mitigation systems combine relatively high-strength materials to stop or slow down the projectile, along with lightweight porous materials to attenuate the explosion shock wave. The porous materials also serve to increase the thickness of the proposed mitigation systems, thereby increasing the explosion stand-off distance. Traditional construction materials such as steel and RC were used as cost-effective high-strength materials, while commercial rigid polyurethane foam and lightweight bricks were examined as shock wave absorbers. Two firing tests of the 120 mm bomb from cannon barrels were conducted against one-story RC structures strengthened with the proposed protection systems. A numerical simulation of the real firing tests was performed using the Autodyn hydrocode to further analyze the performance of the constituent components in mitigating the effects of the rounds. The current study demonstrates that the proposed mitigation systems, based on the concept of multi-layering, are efficient and have their merits in countering Mortar 120 mm HE attacks.
Subjects
POROUS materials; MORTAR; LIGHTWEIGHT materials; CONSTRUCTION materials; EFFECT of earthquakes on buildings; FIRE testing; DENIAL of service attacks; TRANSVERSE reinforcements; EARTHQUAKE resistant design

Description