Patrick J Stephens

US Patent:

6415824, Jul 9, 2002

Filed:

Jan 2, 2001

Appl. No.:

09/753394

Inventors:

Patrick J. Stephens - Bellingham WA 98225

International Classification:

F16L 55164

US Classification:

138 98, 138 97, 138140, 264269

Abstract:

A method and composition for grouting a water-flooded cavity. Water and portland cement are combined to form a fluid cement slurry, the slurry being substantially free of sand or other aggregate material, and the slurry is then colloidally mixed so as to achieve an ultra-fine mixing thereof. An anti-washout admixture is mixed with the slurry in a predetermined amount, and a superplasticizing agent is also preferably included, both the anti-washout admixture and the superplasticizer agent being substantially free of defoaming agents. Finished foam is then mixed with the slurry to form a stable foamed cement grout which is injected into the water-flooded cavity. The anti-washout admixture is preferably a modified cellulose ether solution.

US Patent:

20020015619, Feb 7, 2002

Filed:

Oct 15, 2001

Appl. No.:

09/978374

Inventors:

Patrick Stephens - Bellingham WA, US

International Classification:

E02D017/00
E02D003/02
E02D005/00
E02D019/00

US Classification:

405/129300, 405/287100

Abstract:

A method for filling a void using an aggregate material, such as mine tailings, the fill material being pumped from a site which is located remote from the void. A fluid, aerated material is formed by mixing the particulate solid material with finished foam. The aerated material may also include cement or another binder for applications requiring structural strength. The bubble structure which results from incorporating the foam constituent in the fill material renders this much more fluid and pumpable, thereby allowing the use of much higher solids-to-water ratios than would otherwise be possible while still being able to pump the material over significant distances. This reduces the possibly of fluidic collapse of the material in the void, and produces other advantages as well.

US Patent:

57950601, Aug 18, 1998

Filed:

May 17, 1996

Appl. No.:

8/650921

Inventors:

Patrick J. Stephens - Bellingham WA

International Classification:

B28C 508
B28C 704

US Classification:

366 2

Abstract:

An apparatus for high capacity production of high-fluidity, colloidally mixed cement slurry. Water and cement dust are combined at metered rates by a premixing assembly which discharges into a mixing tub. The high-speed, high-shear pump recirculates the material through the tub to produce the colloidally-mixed slurry. The high-fluidity slurry may be provided to a second pump, preferably of the positive-displacement, progressive-cavity, rotor-stator type, for supplying the slurry at a metered rate. Finished foam material may also be provided to the slurry metering pump at the metered rate, so the materials are mixed to form a foamed cement grout in which the weight and quality of the material is precisely adjustable.

US Patent:

61679127, Jan 2, 2001

Filed:

Nov 25, 1998

Appl. No.:

9/199394

Inventors:

Patrick J. Stephens - Bellingham WA

International Classification:

F16L 55164

US Classification:

138 98

Abstract:

A method and composition for grouting a water-flooded cavity. Water and portland cement are combined to form a fluid cement slurry, the slurry being substantially free of sand or other aggregate material, and the slurry is then colloidally mixed so as to achieve an ultra-fine mixing thereof. An anti-washout admixture is mixed with the slurry in a predetermined amount, and a superplasticizing agent is also preferably included, both the anti-washout admixture and the superplasticizer agent being substantially free of defoaming agents. Finished foam is then mixed with the slurry to form a stable foamed cement grout which is injected into the water-flooded cavity. The anti-washout admixture is preferably a modified cellulose ether solution.

US Patent:

60463740, Apr 4, 2000

Filed:

Oct 6, 1998

Appl. No.:

9/167526

Inventors:

Patrick J. Stephens - Bellingham WA

International Classification:

G21F 900

US Classification:

588 3

Abstract:

A method for forming a radiation-absorbing barrier around a radioactive component by flowing a radiation-absorbing cement grout into a container which encloses the component. The radiation-absorbing cement grout comprises a cement slurry, a finished foam material, a bentonite gel, and a radiation-absorbing metal constituent.

US Patent:

58191860, Oct 6, 1998

Filed:

Apr 25, 1997

Appl. No.:

8/842949

Inventors:

Patrick J. Stephens - Bellingham WA

International Classification:

G21F 900

US Classification:

588 3

Abstract:

A method for forming a radiation-absorbing barrier around a radioactive component by flowing a radiation-absorbing cement grout into a container which encloses the component. The radiation-absorbing cement grout comprises a cement slurry, a finished foam material, a bentonite gel, and a radiation-absorbing metal constituent.

US Patent:

57913781, Aug 11, 1998

Filed:

Jun 27, 1995

Appl. No.:

8/495346

Inventors:

Patrick J. Stephens - Bellingham WA

International Classification:

F16L 5518

US Classification:

138 98

Abstract:

A pumpable cement grout and method for use thereof for grouting liner pipes. The pumpable cement grout is a mixture of a hydraulic cement, water in an amount sufficient so that the water-to-cement ratio of the grout is from about 0. 60 to about 1. 00 by weight, and pregenerated aqueous foam in an amount sufficient to adjust the wet density of the grout to a value of from about 48 to about 72 pounds per cubic foot. The pressure at which the grout is injected into the cavity is maintained at or below a predetermined maximum pressure, so as to avoid collapsing the liner pipe.

US Patent:

51413639, Aug 25, 1992

Filed:

Apr 2, 1991

Appl. No.:

7/679524

Inventors:

Patrick J. Stephens - Bellingham WA

International Classification:

E21D 1110

US Classification:

4051501

Abstract:

A mobile train for mixing foamed cement grout within a tunnel and injecting the grout into the annular cavity between the tunnel bore and liner. Cement slurry is suppled to the train through a conduit from a remote mixing plant, and finished foam is formed by a foam generator on the train and mixed with the cement slurry to form the fooamed cement grout. The train is movable longitudinally through the tunnel so that the liner can be grouted in segments while at the same time avoiding the need to pump the foamed cement grout over excessively long distance. The train is made up of several wheeled cars which are pulled through the tunnel by a tractor.