Shock Compression of Porous Concrete.
Final rept. Oct 68-Apr 72,
ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MISS
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The mechanism of attenuation of pressure waves in cellular concrete has been studied previously from the rigid mechanical point of view which is applicable for the lower rates of loading. For loading rates sufficiently rapid that wave mechanics influence the behavior of the material, the mechanism of attenuation may be appreciably altered. Wave propagation experiments with cellular concrete have indicated the shock structure of cellular concrete to consist of an elastic precursor followed by a slower crushing wave. The pressure associated with the elastic precursor is a function of the input pressure of the incident wave and is observed to exceed the static yield strength of the cellular concrete for high impact velocities. This indicates that this material prior to locking may transmit stresses to a structure in excess of the elastic yield stress. Data are presented relating to wave propagation velocities, width of the transition zone for a step pressure input, and apparent rate of decay of stress waves in cellular concrete. The basis for an equation of state model is recommended from theoretical work and the results of experiments conducted on cellular concrete. Such a model should account for the increase in yield strength with pressure or energy input. Author
- Ceramics, Refractories and Glass