Self-dispensing bullet trap buffer block

• US 20050006849A1
• Filed: 08/04/2004
• Published: 01/13/2005
• Est. Priority Date: 12/02/2002
• Status: Active Grant

• Current Assignee: U.S. Government
• Original Assignee: U.S. Government
• Inventors: Malone, Philip G., Larson, Steven L., Weiss, Charles A. Jr., Fransen, Edward J., Tom, Joe G.
• Granted Patent: US 7,111,847 B2
• Time in Patent Office: Days
• US Class Current: 273/410
• CPC Class Codes: F41J 11/02 Safety means therefor
• CPC Class Codes: F41J 13/00 Bullet catchers

Abstract

An additive for buffering a projectile trapping medium and spent projectiles trapped therein is a buffering compound formed as a low density foamed concrete block that will self-dispense via fragmentation or pulverization when subjected to incoming fire. The block combines at least one dry component selected from the group consisting of low solubility phosphate compounds, low solubility aluminum compounds, iron compounds, sulfate compounds, and calcium carbonate with a cementing material, water, and an aqueous based foam in substantially stoichiometric amounts. The aqueous based foam is added in a quantity sufficient to adjust the density of the resulting block to be non-buoyant without sinking in the projectile trapping medium. The additive may be employed in a projectile trapping medium to chemically stabilize the medium and environmentally stabilize projectiles trapped therein.

Claims

1. An additive for stabilizing and passivating a projectile trapping medium and spent projectiles trapped therein, said additive comprising a buffering compound formed as a low density, self-dispensing, foamed concrete block.

2. The additive according to claim 1, wherein said low density, self-dispensing, foamed concrete block comprises:

one or more dry components selected from the group consisting of low solubility phosphate compounds, low solubility aluminum compounds, iron compounds, sulfate compounds, and calcium carbonate;

a cementing material;

water; and

a quantity of aqueous based foam sufficient to yield a density of said block sufficiently high to prevent said block from being buoyant and sufficiently low to prevent said block from sinking in the projectile trapping medium;

wherein said one or more dry components, said cementing material, and said water are provided in substantially stoichiometric amounts.

3. The additive according to claim 2, wherein said quantity of aqueous based foam is sufficient to yield a density of said block between about 65 and 90 lb/ft³.

4. The additive according to claim 2, wherein said low solubility phosphate compounds are selected from the group consisting of monobasic calcium phosphate, dibasic calcium phosphate, tribasic calcium phosphate, monobasic magnesium phosphate, dibasic magnesium phosphate, tribasic magnesium phosphate, zinc phosphate, aluminum phosphate, and any combination thereof.

5. The additive according to claim 2, wherein said low solubility aluminum compounds are selected from the group consisting of aluminum phosphate, aluminum metaphosphate, aluminum silicate, aluminum hydroxide, aluminum oxide, and any combination thereof.

6. The additive according to claim 2, wherein said iron compounds are selected from the group consisting of iron oxide, iron phosphate, iron silicate, calcium iron carbonate, and any combination thereof.

7. The additive according to claim 2, wherein said sulfate compounds are selected from the group consisting of calcium sulfate, iron sulfate, potassium aluminum sulfate hydrate, and any combination thereof.

8. The additive according to claim 2, wherein said one or more dry components, said cementing material, and said water are provided in substantially stoichiometric amounts according to a formula comprising:

about 1 part by mass low solubility phosphate compound;

about 1 part by mass cementing material; and

about 0.4 parts by mass water.

9. The additive according to claim 2, wherein said one or more dry components, said cementing material, and said water are provided in substantially stoichiometric amounts according to a formula comprising:

about 1 part by mass low solubility phosphate compound;

about 0.7 parts by mass low solubility aluminum compound;

about 1 part by mass cementing material; and

about 0.4 parts by mass water.

10. The additive according to claim 2, wherein said one or more dry components, said cementing material, and said water are provided in substantially stoichiometric amounts according to a formula comprising:

about 1 part by mass low solubility phosphate compound;

about 1.4 parts by mass iron compound;

about 1 part by mass sulfate compound;

about 1 part by mass cementing material; and

about 0.4 parts by mass water.

11. The additive according to claim 1, wherein said low density, self-dispensing, foamed concrete block is substantially circular and has a diameter between about 1 and 6 inches.

12. A method of forming an additive for stabilizing and passivating a projectile trapping medium and spent projectiles trapped therein, comprising the steps of:

selecting one or more dry components from the group consisting of low solubility phosphate compounds, low solubility aluminum compounds, iron compounds, sulfate compounds, and calcium carbonate;

selecting a cementing material;

mixing substantially stoichiometric amounts of the dry components, the cementing material, and water to make a workable paste;

adding a quantity of an aqueous based foam to the paste to form a slurry, wherein the quantity is sufficient to yield a density of the additive sufficiently high to prevent buoyancy of the additive and sufficiently low to prevent the additive from sinking in the projectile trapping medium;

casting the slurry in a mold; and

curing the slurry to yield a low density, self-dispensing, foamed concrete block of buffering compound.

13. The method according to claim 12, wherein said step of mixing substantially stoichiometric amounts of the dry components, the cementing material, and water comprises mixing about 1 part by mass low solubility phosphate compound, about 1 part by mass cementing material, and about 0.4 parts by mass water.

14. The method according to claim 12, wherein said step of mixing substantially stoichiometric amounts of the dry components, the cementing material, and water comprises mixing about 1 part by mass low solubility phosphate compound, about 0.7 parts by mass low solubility aluminum compound, about 1 part by mass cementing material, and about 0.4 parts by mass water.

15. The method according to claim 12, wherein said step of mixing substantially stoichiometric amounts of the dry components, the cementing material, and water comprises mixing about 1 part by mass low solubility phosphate compound, about 1.4 parts by mass iron compound, about 1 part by mass sulfate compound, about 1 part by mass cementing material, and about 0.4 parts by mass water.

16. The method according to claim 12, further comprising the step of employing the low density, self-dispensing, foamed concrete block in a projectile trapping medium.

17. The method according to claim 12, wherein the quantity of aqueous based foam is sufficient to yield a density of the additive between about 65 and 90 lb/ft³.

18. A method of dispensing compounds for stabilizing and passivating a projectile trapping medium and spent projectiles trapped therein, comprising the steps of:

providing at least one low density, self-dispensing, foamed concrete block of buffering compound in contact with the projectile trapping medium and subject to incoming fire; and

pulverizing the at least one low density, self-dispensing, foamed concrete block of buffering compound by subjecting it to incoming fire.

19. The method according to claim 18, wherein said step of providing at least one low density, self-dispensing, foamed concrete block of buffering compound comprises mixing the at least one low density, self-dispensing, foamed concrete block of buffering compound within the projectile trapping medium.

20. The method according to claim 18, wherein said step of providing at least one low density, self-dispensing, foamed concrete block of buffering compound comprises disposing the at least one low density, self-dispensing, foamed concrete block of buffering compound over at least a portion of an upper surface of the projectile trapping medium.

21. The method according to claim 20, wherein a density of the at least one low density, self-dispensing, foamed concrete block of buffering compound is selected such that the at least one low density, self-dispensing, foamed concrete block neither floats nor sinks in the projectile trapping medium.

22. The method according to claim 18, wherein said low density, self-dispensing, foamed concrete block of buffering compound comprises:

one or more dry components selected from the group consisting of low solubility phosphate compounds, low solubility aluminum compounds, iron compounds, sulfate compounds, and calcium carbonate;

a cementing material;

water; and

a quantity of aqueous based foam sufficient to yield a density of said block between about 65 and 90 lb/ft³;

wherein said one or more dry components, said cementing material, and said water are provided in substantially stoichiometric amounts.