Method and apparatus for testing relative permeability of materials

• US 4,979,390 A
• Filed: 12/01/1988
• Issued: 12/25/1990
• Est. Priority Date: 12/01/1988
• Status: Expired due to Fees

• Current Assignee: Daniel Schupack, Morris Schupack
• Original Assignee: Daniel Schupack, Morris Schupack
• Inventors: Schupack, Morris, Schupack, Daniel
• Primary Examiner(s): Williams, Hezron E.
• Application Number:
  US07/278,580
• Time in Patent Office: 754 Days
• Field of Search: 73/40, 73/40.7, 73/37, 73/38
• US Class Current: 73/38
• CPC Class Codes: G01M 3/04 by detecting the presence of fluid at the leakage point
• CPC Class Codes: G01M 3/12 by observing elastic covers or coatings, e.g. soapy water
• CPC Class Codes: G01M 3/26 by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors
• CPC Class Codes: G01N 15/08 Investigating permeability, pore-volume, or surface area of porous materials
• CPC Class Codes: G01N 15/0826 and measuring fluid flow rate, i.e. permeation rate or pressure change
• CPC Class Codes: G01N 33/24 Earth materials G01N33/42 takes precedence

Abstract

An apparatus for testing the relative permeability of materials, particularly concrete structures, comprises a transparent, optically non-distorting head having a gasket, which together with the head defines a head chamber, and which allows the head to be sealed against the structure when a partial vacuum is induced in the head chamber. The decay of the vacuum may be measured, and the rate of decay provides an index of permeability. A liquid may be applied to the surface being tested and will foan to allow identification of cracks and fissures. In alternative embodiment, a fluid is introduced into a secondary chamber defined by a secondary gasket and the head, and the rate of permeation of the fluid into the structure provides a measure of permeability. The vacuum mounted test apparatus allows in-situ testing without requiring the extraction of sample cores from the structure or making invasive attachments to the structure, thus providing a quality control apparatus and method for rapid testing of construction materials.

Claims

1. Apparatus for testing relative permeability of a structure, comprising:

a transparent head, having

an optically non-distorting segment through which said structure may be observed;

primary means for resiliently sealing said head against said structure, and

a head chamber defined by said head and said primary sealing means;

means for providing a partial vacuum in said head chamber;

means for generating electrical signals representative of said vacuum in said head chamber;

means operatively connected to said vacuum signal generating means for displaying an indication of vacuum;

means for generating electrical signals representative of time;

means operatively connected to said vacuum signal generating means for determining a change in said vacuum signal and providing an electrical signal representative thereof;

means operatively connected to said time signal generating means for determining a change in said time signal and providing an electrical signal representative thereof;

means operatively connected to said vacuum change determining means and said time change determining means for dividing said vacuum change electrical signal by said time change electrical signal and generating an electrical signal representative of said divided signals; and

means operatively connected to said electrical dividing means for electrically displaying an indication of the rate of any decay of said vacuum.

2. Apparatus for testing relative permeability in accordance with claim 1, wherein said transparent head is generally circular.

3. Apparatus for testing permeability in accordance with claim 1, wherein said transparent head is generally elongated.

4. Apparatus for testing relative permeability in accordance with claim 3, wherein said transparent head comprises a curved material for testing curved surfaces.

5. Apparatus for testing relative permeability in accordance with claim 1, wherein said primary sealing means comprises an elastomeric gasket having a width from about 0.3 inch to about one inch.

6. Apparatus for testing relative permeability in accordance with claim 1, wherein said means for providing a partial vacuum comprises:

a vacuum pump;

tubing connecting said vacuum pump and said pressure gauge, and connecting said pressure gauge with said head chamber;

a valve located in said tubing connecting said vacuum pump and said pressure gauge; and

a vacuum relief valve operably connected to said head chamber.

7. Apparatus for testing relative permeability of a structure, comprising:

a transparent head, having

primary means for resiliently sealing said head against said structure comprising elastomeric gaskets having a width from about one-half inch to about one inch, and

a head chamber defined by said head and said primary sealing means;

an optically non-distorting segment through which said structure may be observed;

means for providing a partial vacuum in said head chamber comprising a vacuum pump, tubing connecting said vacuum pump and said pressure gauge and connecting said pressure gauge with said head chamber, a valve located in said tubing connecting said vacuum pump and said pressure gauge, and a vacuum relief valve operably connected with said head chamber;

secondary sealing means located inwardly of said primary sealing means for resiliently sealing said head against said structure comprising elastomeric gaskets having a width from about one-half inch to about one inch;

a secondary chamber defined by said head and said secondary sealing means;

means for providing a fluid to said secondary chamber under pressure comprising a graduated cylinder having its lower end mounted on and connecting with said secondary chamber and having a closed upper end, a fluid injection valve located in said closed upper end, a pressure gauge located to measure the pressure in said graduated cylinder, a pump operably connected to the graduated cylinder for pressurizing the graduated cylinder, and a valve located between said secondary chamber and said graduated cylinder to control the flow of fluid into said secondary chamber;

means for measuring the quantity of fluid provided to said secondary chamber; and

means for measuring the vacuum in said head chamber.

8. Apparatus for testing relative permeability in accordance with claim 7, wherein said transparent head is generally circular.

9. Apparatus for testing relative permeability in accordance with claim 7, wherein said transparent head is generally elongated.

10. Apparatus for testing relative permeability in accordance with claim 7, wherein said fluid comprises a penetrating liquid.

11. Apparatus for testing relative permeability in accordance with claim 10 wherein said penetrating liquid comprises a dye.