A Novel Structure to Protect Against Explosive Loads

This paper describes a novel protective structure that minimizes the possibility that small pieces of concrete debris traveling at high velocity will escape the protective structure in the event of an explosion or blast load proximate to the structure. As shown in Figures 1 and 2, the protective structure employs a membrane-like mesh structure made up of, for example, of steel wires. The mesh structure is compressible in all three dimensions, and surrounds a concrete fill material such as reinforced concrete. The size of the mesh opening is designed to retain the course aggregate constituent of concrete. In the event of an explosion, the mesh structure advantageously prevents concrete fragments produced due to disintegration of the concrete fill material from injuring people or causing property damage in the vicinity of the explosion. The protective structure is capable of undergoing large deflections in response to an explosive loading, thereby absorbing the energy associated with the blast. The structure is sacrificial in nature: its sole purpose is to mitigate the blast effect of the explosion by preventing the escape of the disintegrated concrete debris and by absorbing the energy of the blast, thereby minimizing the loss of life and damage to property. After the explosion, the damaged structure will be dismantled and replaced with a new protective structure. A number of the protective structure units can be joined together by columns or posts to create a wall of sufficient length to provide perimeter protection for a given area as well as additional ease of construction and use. The interconnecting columns or posts also employ the mesh reinforcement structure in addition to conventional steel reinforcement bars. It has been previously suggested that wire mesh may be employed on or just beneath the front and rear surfaces of the structural elements to mitigate "scabbing" (i.e. creation of craters on the target face due to a blast load) and "spalling" (i.e. separation of particles of structural element from the rear face at appropriate particle velocities) for light to moderate blats loads. However, in the protective structure of this paper, the wire mesh structure employed does not merely mitigate scabbing and spalling for light to moderate blats loads. Instead, the wire mesh structure can be designed to both prevent scabbing at large blast loads and to deflect elastically and plastically in response to the blast load to absorb the energy of the blast.