Sensor-enabled geosynthetic material and method of making and using the same

• US 8,752,438 B2
• Filed: 04/13/2011
• Issued: 06/17/2014
• Est. Priority Date: 01/16/2009
• Status: Active Grant

• Current Assignee: The Board of Regents of the University of Colorado (University of Colorado System)
• Original Assignee: The Board of Regents of the University of Colorado (University of Colorado System)
• Inventors: Hatami, Kianoosh, Grady, Brian
• Primary Examiner(s): Kirkland, III, Freddie
• Application Number:
  US13/086,231
• Publication Number:
  US 20120090400A1
• Time in Patent Office: 1,161 Days
• Field of Search: 737/60, 737/88, 737/95
• US Class Current: 73/788
• CPC Class Codes: E02D 17/202 with flexible securing means
• CPC Class Codes: G01B 7/18 using change in resistance
• CPC Class Codes: G01L 1/20 by measuring variations in ohmic resistance of solid materials or of electrically-conductive fluids of piezo-resistive materials G01L1/18; by making use of electrokinetic cells, i.e. liquid-containing cells wherein an electrical potential is produced or varied upon the application of stress
• CPC Class Codes: G01L 1/205 using distributed sensing elements
• CPC Class Codes: G01M 5/0083 by measuring variation of impedance, e.g. resistance, capacitance, induction
• CPC Class Codes: G01N 2203/0016 Tensile or compressive
• CPC Class Codes: G01N 2203/0244 Tests performed "in situ" or after "in situ" use
• CPC Class Codes: G01N 2203/0617 Electrical or magnetic indicating, recording or sensing means
• CPC Class Codes: G01N 2203/0664 using witness specimens
• CPC Class Codes: H01B 1/24 the conductive material comprising carbon-silicon compounds, carbon or silicon

Abstract

The present invention is directed to a sensor-enabled geosynthetic material for use in geosynthetic structures and geosyntapes, a method of making the sensor-enabled geosynthetic material and the geosyntapes, and a method of measuring geometric strains of a geosynthetic product made from the sensor-enabled geosynthetic material. The sensor-enabled geosynthetic material includes a polymeric material and an electrically conductive filler. The polymeric material and an electrically conductive filler are combined to provide a sensor-enabled geosynthetic material. The sensor-enabled geosynthetic material having a predetermined concentration of the electrically conductive filler so as to provide the sensor-enabled geosynthetic material with an electrical conductivity and a strain sensitivity within the percolation region or slightly above it.

Claims

1. A method of measuring geometric strains of a structure, comprising the steps of:

selecting a measuring location of a structure to measure a geometric strain in the structure, wherein the structure is selected from the group consisting of geogrids, geomembranes, geotextiles, geonets, geosynthetic clay liners, geofoams, and geocomposites and is fabricated from a sensor-enabled geosynthetic material; and

determining the geometric strain of the structure at the measuring location.

2. The method of claim 1 wherein conductive leads are attached to the structure to provide conductivity data;

and

manipulating the conductivity data to provide the geometric strain applied to the structure.

3. The method of claim 1 wherein the sensor-enabled geosynthetic material comprises:

a polymeric material; and

an electrically conductive filler combined with the polymeric material, the sensor-enabled geosynthetic material having a predetermined concentration of the electrically conductive filler so as to provide the sensor-enabled geosynthetic material with an electrical conductivity and a strain sensitivity within a percolation region.

4. The method of claim 3 wherein the polymeric material is a polyolefin.

5. The method of claim 4 wherein the polyolefin is selected from the group consisting of polypropylene, polyethylene, and combinations thereof.

6. The method of claim 3 wherein the electrically conductive filler is selected from the group consisting of metal powders, conductive carbon black, carbon fiber, carbon nanotubes, and combinations thereof.

7. The method of claim 3 wherein the predetermined concentration of the electrically conductive filler in the sensor-enabled geosynthetic material is the maximum concentration that places the sensor-enabled geosynthetic material within the percolation region.

8. The method of claim 3 wherein the predetermined concentration of the electrically conductive filler in the sensor-enabled geosynthetic material is in a range of from about 0.01 wt % to about 30 wt %.

9. The method of claim 3 wherein the predetermined concentration of the electrically conductive filler in the sensor-enabled geosynthetic material is a concentration that places the piezoresistivity in the upper concentration portion of the percolation region.

10. The method of claim 1 wherein a plurality of measuring locations of the structure are selected to measure their geometric strains.

11. The method of claim 10 wherein the geometric strains of the plurality of measuring locations are measured simultaneously.

12. A structure constructed from a sensor-enabled geosynthetic material, comprising:

a sensor-enabled geosynthetic material constructed from (1) a polymeric material and (2) an electrically conductive filler combined with the polymeric material, the sensor-enabled geosynthetic material having a predetermined concentration of the electrically conductive filler so as to provide the sensor-enabled geosynthetic material with an electrical conductivity and a strain sensitivity within its percolation region, and wherein the structure is selected from the group consisting of geogrids, geomembranes, geotextiles, geonets, geosynthetic clay liners, geofoams, and geocomposites.

13. The structure of claim 12 wherein the polymeric material of the sensor-enabled geosynthetic material is a polyolefin.

14. The structure of claim 13 wherein the polyolefin of the sensor-enabled geosynthetic material is selected from the group consisting of polypropylene, polyethylene, and combinations thereof.

15. The structure of claim 12 wherein the electrically conductive filler of the sensor-enabled geosynthetic material is selected from the group consisting of metal powders, conductive carbon black, graphite fiber, carbon nanotubes, and combinations thereof.

16. The structure of claim 12 wherein the predetermined concentration of the electrically conductive filler in the sensor-enabled geosynthetic material is the maximum concentration that places the sensor-enabled geosynthetic material within the percolation region.

17. The structure of claim 12 wherein the predetermined concentration of the electrically conductive filler in the sensor-enabled geosynthetic material is in a range of from about 0.01 wt % to about 30 wt %.

18. The structure of claim 12 wherein the predetermined concentration of the electrically conductive filler in the sensor-enabled geosynthetic material is a concentration that places the piezoresistivity in the upper concentration portion of the percolation region.

19. A method of making a sensor-enabled structure, comprising the steps of:

combining a polymeric material and an electrically conductive filler to form a sensor-enabled geosynthetic material, the sensor-enabled geosynthetic material having a predetermined concentration of the electrically conductive filler so as to provide the sensor-enabled geosynthetic material with an electrical conductivity and a strain sensitivity within a percolation region; and

forming a sensor-enabled structure from the sensor-enabled geosynthetic material, the sensor-enabled structure selected from the group consisting of geogrids, geomembranes, geotextiles, geonets, geosynthetic clay liners, geofoams, and geocomposites.

20. The method of claim 19 wherein the polymeric material is a polyolefin.

21. The method of claim 20 wherein the polyolefin is selected from the group consisting of polypropylene, polyethylene, and combinations thereof.

22. The method of claim 19 wherein the electrically conductive filler is selected from the group consisting of metal powders, conductive carbon black, graphite fiber, carbon nanotubes, and combinations thereof.

23. The method of claim 19 wherein the predetermined concentration of the electrically conductive filler in the sensor-enabled geosynthetic material is the maximum concentration that places the sensor-enabled geosynthetic material within the percolation region.

24. The method of claim 19 wherein the predetermined concentration of the electrically conductive filler in the sensor-enabled geosynthetic material is in a range of from about 0.01 wt % to about 30 wt %.

25. The method of claim 19 wherein the predetermined concentration of the electrically conductive filler in the sensor-enabled geosynthetic material is a concentration that places the piezoresistivity in the upper concentration portion of the percolation region.

26. A method of measuring a geometric strain in a geosynthetic product, comprising the steps of:

selecting a measuring location of a geosynthetic product to measure a geometric strain in the geosynthetic product, wherein the geosynthetic product has a sensor-enabled geosynthetic material attached to the measuring location thereof, and wherein the geosynthetic product is selected from the group consisting of geogrids and geomembranes; and

determining a geometric strain in the geosynthetic attached at the measuring location.

27. The method of claim 26 wherein conductive leads are attached to the sensor-enabled geosynthetic material to provide conductivity data.

28. The method of claim 26 wherein the sensor-enabled geosynthetic material comprises:

a polymeric material; and

an electrically conductive filler combined with the polymeric material, the sensor-enabled geosynthetic material having a predetermined concentration of the electrically conductive filler so as to provide the sensor-enabled geosynthetic material with an electrical conductivity and a strain sensitivity within a percolation region.

29. The method of claim 28 wherein the polymeric material is a polyolefin.

30. The method of claim 29 wherein the polyolefin is selected from the group consisting of polypropylene, polyethylene, and combinations thereof.

31. The method of claim 28 wherein the electrically conductive filler is selected from the group consisting of metal powders, conductive carbon black, carbon fiber, carbon nanotubes, and combinations thereof.

32. The method of claim 28 wherein the predetermined concentration of the electrically conductive filler in the sensor-enabled geosynthetic material is the maximum concentration that places the sensor-enabled geosynthetic material within the percolation region.

33. The method of claim 28 wherein the predetermined concentration of the electrically conductive filler in the sensor-enabled geosynthetic material is in a range of from about 0.01 wt % to about 30 wt %.

34. The method of claim 28 wherein the predetermined concentration of the electrically conductive filler in the sensor-enabled geosynthetic material is a concentration that places the piezoresistivity in the upper concentration portion of the percolation region.

35. The method of claim 26 wherein a plurality of measuring locations of the geosynthetic product are selected to measure their geometric strains.

36. The method of claim 35 wherein the geometric strains of the plurality of measuring locations of the geosynthetic product are measured simultaneously.

37. A geosynthetic product, comprising:

a sensor-enabled geosynthetic material comprising (1) a polymeric material, and (2) an electrically conductive filler combined with the polymeric material, the sensor-enabled geosynthetic material having a concentration of the electrically conductive filler which provides the sensor-enabled geosynthetic material with an electrical conductivity and a strain sensitivity within its percolation region, wherein the geosynthetic product is a geogrid or a geomembrane.

38. The geosynthetic product of claim 37 wherein the polymeric material of the sensor-enabled geosynthetic material is a polyolefin.

39. The geosynthetic product of claim 38 wherein the polyolefin of the sensor-enabled geosynthetic material is selected from the group consisting of polypropylene, polyethylene, and combinations thereof.

40. The geosynthetic product of claim 37 wherein the electrically conductive filler of the sensor-enabled geosynthetic material is selected from the group consisting of metal powders, conductive carbon black, graphite fiber, carbon nanotubes, and combinations thereof.

41. The geosynthetic product of claim 37 wherein the concentration of the electrically conductive filler in the sensor-enabled geosynthetic material is the maximum concentration that places the sensor-enabled geosynthetic material within the percolation region.

42. The geosynthetic product of claim 37 wherein the concentration of the electrically conductive filler in the sensor-enabled geosynthetic material is in a range of from about 0.01 wt % to about 30 wt %.

43. The geosynthetic product of claim 37 wherein the concentration of the electrically conductive filler in the sensor-enabled geosynthetic material is a concentration that places the piezoresistivity in the upper concentration portion of the percolation region.

44. A method of measuring a geometric strain in a geosynthetic product associated with a geosynthetic structure for monitoring a mechanical behavior in the geosynthetic structure, comprising the steps of:

selecting a measuring location of the geosynthetic product, wherein the geosynthetic product is selected from the group consisting of geogrids, geomembranes, geotextiles, geonets, geosynthetic clay liners, geofoams, and geocomposites and comprises a sensor-enabled geosynthetic material fabricated from (1) a polymeric material, and (2) an electrically conductive filler combined with the polymeric material, the sensor-enabled geosynthetic material having a concentration of the electrically conductive filler which provides the sensor-enabled geosynthetic material with an electrical conductivity and a strain sensitivity within a percolation region; and

measuring the geometric strain at the measuring location of the geosynthetic product to monitor a mechanical behavior of the geosynthetic structure.

45. The method of claim 44 wherein the geosynthetic product comprises conductive leads attached thereto.

46. The method of claim 44 wherein the polymeric material of the sensor-enabled geosynthetic material is a polyolefin.

47. The method of claim 46 wherein the polyolefin of the sensor-enabled geosynthetic material is selected from the group consisting of polypropylene, polyethylene, and combinations thereof.

48. The method of claim 44 wherein the electrically conductive filler of the sensor-enabled geosynthetic material is selected from the group consisting of metal powders, conductive carbon black, carbon fiber, carbon nanotubes, and combinations thereof.

49. The method of claim 44 wherein the concentration of the electrically conductive filler of the sensor-enabled geosynthetic material is the maximum concentration that places the sensor-enabled geosynthetic material within the percolation region.

50. The method of claim 44 wherein the concentration of the electrically conductive filler of the sensor-enabled geosynthetic material is in a range of from about 0.01 wt % to about 30 wt %.

51. The method of claim 44 wherein the concentration of the electrically conductive filler in the sensor-enabled geosynthetic material is a concentration that places the piezoresistivity in the upper concentration portion of the percolation region.

52. The method of claim 44 wherein a plurality of geometric strains at a plurality of measuring locations are measured in the geosynthetic product simultaneously.