Engineered cementitious contaminant barriers and their method of manufacture

• US 5,169,566 A
• Filed: 11/28/1990
• Issued: 12/08/1992
• Est. Priority Date: 05/18/1990
• Status: Expired due to Term

• Current Assignee: E. Khashoggi Industries, LLC
• Original Assignee: E. Khashoggi Industries, LLC
• Inventors: Stucky, Galen, Hodson, Simon K., Jennings, Hamlin M.
• Primary Examiner(s): Hunt, Brooks H.
• Assistant Examiner(s): JENKINS, DANIEL J
• Application Number:
  US07/619,317
• Time in Patent Office: 741 Days
• Field of Search: 252/625, 252/627, 252/628, 252/629, 252/633, 252/626, 376/272, 52/310
• US Class Current: 264/255
• CPC Class Codes: B28B 1/00 Producing shaped prefabricated articles from the material using presses B28B3/00; shaping on moving conveyors B28B5/00; producing tubular articles B28B21/00 ; producing articles with embedded elements B28B23/00
• CPC Class Codes: B28B 11/24 for curing, setting or hardening processes for influencing or modifying the setting or hardening ability of mortars, concrete or artificial stone compositions, in general C04B40/00
• CPC Class Codes: B28B 11/245 Curing concrete articles B28B11/242 takes precedence
• CPC Class Codes: B28B 23/0087 Lightweight aggregates for making lightweight articles
• CPC Class Codes: B28B 7/342 which are at least partially destroyed, e.g. broken, molten, before demoulding; Moulding surfaces or spaces shaped by, or in, the ground, or sand or soil, whether bound or not; Cores consisting at least mainly of sand or soil, whether bound or not
• CPC Class Codes: C04B 14/047 Zeolites
• CPC Class Codes: C04B 2111/00775 the composition being used as waste barriers or the like, e.g. compositions used for waste disposal purposes only, but not containing the waste itself
• CPC Class Codes: C04B 22/002 Water
• CPC Class Codes: C04B 28/02 containing hydraulic cements other than calcium sulfates
• CPC Class Codes: C04B 40/0035 Processes characterised by the absence of a mechanical mixing step, e.g. "no-mix" processes
• CPC Class Codes: C04B 40/0616 preformed, e.g. bandages
• CPC Class Codes: C04B 40/0675 Mortars activated by rain, percolating or sucked-up water; Self-healing mortars or concrete
• CPC Class Codes: C04B 7/527 obtaining cements characterised by fineness, e.g. by multi-modal particle size distribution
• CPC Class Codes: G21F 9/304 Cement or cement-like matrix compositional aspects C04B
• CPC Class Codes: G21F 9/34 Disposal of solid waste

Abstract

Novel cementitious contaminant barriers are formed by positioning a hydraulic cement composition into a predetermined configuration and then hydrating the cement composition. The contaminant barriers of the present invention include at least one liquid, gas, or ion getter capable of binding with or absorbing liquids, ions, or gases which may penetrate the barrier. The contaminant barriers of the present invention may be engineered to include mixtures of different getters, single and multiple layers of different getters, multiple layers of cement and getters, and a host of different getter, cement, mixture, and layer combinations.

Novel waste containers are advantageously prepared utilizing contaminant barriers within the scope of the present invention. The waste containers may be prepared by surrounding waste material with at least one getter and with a powdered hydraulic cement composition and then compressing the cement and getter around the waste material. Preformed waste containers may also be prepared within the scope of the present invention. Use of reinforcing fibers and aggregates to improve the mechanical properties of the hazardous waste container is disclosed.

Claims

1. A method for preparing a contaminant barrier from a hydraulically bonded cement composition, the method comprising the steps of:

(a) deliberately positioning a powdered hydraulic cement composition and at least one getter into a near net final position substantially corresponding to a desired contaminant barrier shape, said getter being capable of preventing passage of a contaminant through the barrier; and

(b) hydrating the powdered hydraulic cement composition without substantial mechanical mixing of the cement and water.

2. A method for preparing a contaminant barrier as defined in claim 1, wherein the at least one getter includes an ion getter.

3. A method for preparing a contaminant barrier as defined in claim 1, wherein the at least one getter includes a liquid getter.

4. A method for preparing a contaminant barrier as defined in claim 1 wherein the at least one getter includes a gas getter.

5. A method for preparing a contaminant barrier as defined in claim 1, wherein the powdered hydraulic cement composition is hydrated by contacting the powdered hydraulic cement composition with gaseous water.

6. A method for preparing a contaminant barrier as defined in claim 1, wherein the powdered hydraulic cement composition is hydrated in a controlled gaseous environment including carbon dioxide.

7. A method for preparing a contaminant barrier as defined in claim 1, wherein the powdered hydraulic cement composition is hydrated by contacting the powdered hydraulic cement composition with an aqueous solution.

8. A method for preparing a contaminant barrier as defined in claim 1, wherein the powdered hydraulic cement composition has a predetermined polymodal size distribution.

9. A method for preparing a contaminant barrier as defined in claim 1, further comprising the step of deliberately positioning an aggregate within the powdered hydraulic cement composition prior to hydrating the cement.

10. A method for preparing a contaminant barrier as defined in claim 9, wherein the aggregate comprises a plurality of aggregate particles having a predetermined polymodal size distribution.

11. A method for preparing a contaminant barrier as defined in claim 9, wherein the aggregate includes a plurality of fibers.

12. A method for preparing a contaminant barrier as defined in claim 1, wherein the powdered hydraulic cement composition and the at least one getter are compressed into the near net final position by isostatic compression in a mold.

13. A method for preparing a contaminant barrier as defined in claim 1, wherein the powdered hydraulic cement includes a mixture of chemically different hydraulic cements.

14. A method for preparing a contaminant barrier as defined in claim 1, wherein the powdered hydraulic cement includes a Portland cement.

15. A method for preparing a contaminant barrier as defined in claim 1, wherein the contaminant includes a radioactive waste.

16. A method for preparing a contaminant barrier as defined in claim 1, wherein the contaminant includes a heavy metal ion.

17. A method for preparing a contaminant barrier as defined in claim 1, wherein the contaminant includes a gas generator.

18. A method for preparing a contaminant barrier as defined in claim 1, wherein the contaminant includes both radioactive and hazardous waste.

19. A method for preparing a contaminant barrier as defined in claim 1, wherein the at least one getter includes a zeolite.

20. A method for preparing a contaminant barrier as defined in claim 1, wherein the at least one getter includes a mixture of different zeolites.

21. A method for preparing a contaminant barrier as defined in claim 1, wherein the at least one getter includes a layered clay.

22. A method for preparing a contaminant barrier as defined in claim 1, wherein the at least one getter includes a mixture of layered clays.

23. A method for preparing a contaminant barrier as defined in claim 1, wherein the at least one getter includes a mixture of at least one zeolite and at least one layered clay.

24. A method for preparing a contaminant barrier as defined in claim 1, wherein the at least one getter includes a mixture of different getters.

25. A method for preparing a contaminant barrier as defined in claim 1, wherein the powdered hydraulic cement composition includes a water-containing compound, such that at least a portion of the water necessary for hydrating the powdered hydraulic cement is capable of being provided by the water-containing compound.

26. A method for preparing a contaminant barrier as defined in claim 1, wherein a portion of the powdered hydraulic cement composition remains substantially unhydrated.

27. A method for preparing a contaminant barrier as defined in claim 1, wherein the powdered hydraulic cement composition and the at least one getter are deliberately positioned in substantially separate layers.

29. A method for preparing a contaminant barrier as defined in claim 1, wherein the desired contaminant barrier shape is in the form of a waste container.

28. A method for preparing a contaminant barrier as defined in claim wherein the powdered hydraulic cement composition and the at least one getter are deliberately positioned as a mixture.