Permeable Moisture Sensor for Concrete, and Other Moisture Sensors, Moisture Sensing Methods and Construction Methods

• US 20070126433A1
• Filed: 06/02/2006
• Published: 06/07/2007
• Est. Priority Date: 06/03/2005
• Status: Abandoned Application

• Current Assignee: Virginia Tech Intellectual Properties, Inc.
• Original Assignee: Virginia Tech Intellectual Properties, Inc.
• Inventors: Theophanous, Theophanis, Case, Scott, Lesko, John
• Application Number:
  US11/421,887
• Publication Number:
  US 20070126433A1
• Time in Patent Office: Days
• US Class Current: 324/690
• CPC Class Codes: G01N 27/225 by using hygroscopic materials
• CPC Class Codes: G01N 33/383 Concrete, cement

Abstract

Non-invasive moisture-sensing within concrete (such as concrete buildings, bridges, etc.) or a polymeric material may be accomplished by a capacitor structure comprising a porous material built inside the concrete or polymeric material. The capacitance measurements change based on the amount of moisture in the porous material. Moisture-sensing can be monitored remotely (including for submerged and other structures), relatively non-invasively, and in a repeatable and reversible fashion without intermediate conditioning or resting.

Claims

1. A method of constructing a moisture sensor, comprising:

into concrete or into a polymeric material that is to be measured for moisture, constructing a capacitor structure comprising a porous material.

2. The method of claim 1, wherein the capacitor structure constructing step is performed before the concrete is fully formed.

3. The method of claim 1, wherein the capacitor structure constructing step is after the concrete is formed.

4. The method of claim 1, wherein the constructing step includes providing a quantity of cement paste, a first electrode and a second electrode disposed together form a capacitor structure.

5. The method of claim 4, wherein the first electrode comprises a first stainless steel wire mesh and the second electrode comprises a second stainless steel wire mesh.

6. The construction method of claim 1, comprising:

to the capacitor structure, connecting a read-out device where capacitance measures for the capacitor structure are readable.

7. The construction method of claim 1, including connecting a signal-measuring device to the capacitor structure, and connecting a read-out device to the signal-measuring device.

8. A method of sensing moisture in a concrete material or a polymeric material, comprising:

in the concrete material or the polymeric material, making at least one point measurement of capacitance.

9. The moisture sensing method of claim 8, including making the least one point measurement of capacitance via a capacitor comprising a porous material, said capacitor being disposed within the concrete or the polymeric material.

10. The moisture sensing method of claim 9, wherein the capacitor within the concrete is remote from where the capacitance measurement is read.

11. The moisture sensing method of claim 8 wherein the point capacitance measurement is electrically transmitted to a remote device.

12. The method of claim 11, wherein the capacitor in the concrete or the polymeric material comprises a pair of stainless steel wire meshes.

13. The moisture sensing method of claim 8, wherein the concrete material or the polymeric material being sensed for moisture is submerged.

14. The moisture sensing method of claim 8, including expressing the point capacitance measurement as an electrical signal and transmitting the electrical signal to a read-out device.

15. A moisture sensor, comprising:

a capacitor that takes point capacitance measurements in concrete or a polymeric material and/or takes flux measurements in concrete or the polymeric material.

16. The moisture sensor of claim 15, wherein the capacitor is built into the concrete or the polymeric material.

17. The moisture sensor of claim 15, wherein the capacitor comprises cement, a first electrode and a second electrode.

18. The moisture sensor of claim 17, wherein the first electrode is a first steel mesh and the second electrode is a second steel mesh.

19. The moisture sensor of claim 17, comprising a porous material.

20. The moisture sensor of claim 17, comprising a remote read-out device connected to the capacitor, wherein capacitance measurements are transmitted to the remote read-out device.

21. A construction method for a concrete structure or a polymeric structure, comprising:

within the concrete or the polymeric material, constructing a point capacitance capacitor into the concrete or polymeric material.

22. The construction method of claim 21, wherein the capacitor comprises a porous material.

23. The construction method of claim 21, including forming a quantity of cement paste, a first electrode and a second electrode in a capacitor configuration.

24. The construction method of claim 23, wherein the first electrode comprises a first steel mesh and the second electrode comprises a second steel mesh.

25. The construction method of claim 21, including forming a concrete structure.

26. The construction method of claim 21, including forming a polymeric structure.

27. The construction method of claim 21, including connecting a signal measurement device to the capacitor, and connecting the signal measurement to a read-out device.