Fabric (woven – knitted – or nonwoven textile or cloth – etc.) – Nonwoven fabric – Including strand or fiber material precoated with other than...
Reexamination Certificate
1997-12-03
2001-01-09
Weisberger, Richard (Department: 1774)
Fabric (woven, knitted, or nonwoven textile or cloth, etc.)
Nonwoven fabric
Including strand or fiber material precoated with other than...
C442S366000, C442S367000, C442S381000, C442S387000, C442S388000, C442S391000, C405S015000, C405S036000, C405S107000, C405S229000
Reexamination Certificate
active
06171984
ABSTRACT:
FIELD OF THE INVENTION
This invention relates generally to novel geosynthetic materials which can be used in a broad variety of erosion control and earthen reinforcement applications, and more specifically to a novel reinforced soil composite which includes a soil material in combination with the geosynthetic material of the present invention.
BACKGROUND OF THE INVENTION
The phrase “geosynthetic material” is broadly used to refer to a large class of engineered products that are used in a variety of geostructural applications including soil stabilization, support for earthworks, erosion barriers and retaining walls, among others. The phrase “geosynthetic material” may refer to structures or to the basic components of structures. The phrase “geosynthetic materials” as used herein does not include materials employed in the construction of buildings or materials used as an interlayer in the construction of concrete and/or asphalt roadways or roadway patch materials, as these are not geostructures, i.e. earthen structures or structures used to control or reinforce earthen structures.
The applications where geosynthetic materials are often employed may be broadly classified into six major functions: reinforcement of soil; separation of soil layers; soil filtration; controlled drainage; erosion control; and providing moisture barriers in or about soil. Soil reinforcement refers generally and broadly to increasing tensile and/or shear strength of earth or particulate structures, such as in retaining wall structures, steep grades and other applications that compel tensile and/or shear strength enhancement of particulate substrate properties. Some of the types of geosynthetic materials that perform these functions include: 1) geotextiles (also known as “geotextile fabrics” or “geofabrics”, which include interwoven, non-interwoven or nonwoven fabric-like materials generally for separation/reinforcement); 2) geogrids (sometimes considered a subclass of geotextiles and which include grid-like structures having relatively large grid openings therein, generally for soil reinforcement); 3) geomembranes (sheet-like materials having little or no permeability to moisture, generally for moisture barrier applications); 4) geosynthetic clay liners (liners often consisting of a layer of bentonite or other very low permeability material supported by geotextiles, geogrids or geomembranes generally for moisture barrier applications); 5) erosion control products (any number of fabric-like, grid-like or sheet-like materials used to restrain the movement of soil or other components of particulate substrates, whether by wind, water or otherwise); and 6) specialty geosynthetics (generally referring to geosynthetics not otherwise classified).
The presently available geosynthetic materials, particularly geotextiles and geogrids, are predominately formed from polymeric materials. For example, several polymeric geogrids are available from Strata Systems, Inc. of Cumming, Ga., as described in technical sales brochures entitled:
Strata Systems. Inc., A Better Way to Build; STRATAGRID
100;
STRATAGRID
200;
STRATAGRID
300;
STRATAGRID
400;
STRATAGRID
500;
STRATAGRID
600 and
STRATAGRID
700. The Strata Systems, Inc. geogrids are manufactured from polyester yarns knitted by warp knit weft insertion into a grid-like structure having a uniform network of apertures and providing tensile reinforcement in one principal direction. A polymeric coating, (e.g. a polyvinyl chloride coating) provides additional mechanical as well as chemical and ultraviolet radiation degradation protection.
Also for example, U.S. Pat. No. 5,669,796 discloses a geogrid comprised of bicomponent fibers comprising a polyethylene terephthalate core within a sheath of a polyolefin and including carbon black for ultraviolet (UV) stabilization. The grid is a warp knit, weft inserted geogrid in which the fibers are knit into a fabric and heat bonded together. The bicomponent fibers are described as providing an improved resistance to creep. The grid is not topcoated with coatings such as polyvinyl chloride (PVC) topcoats. Avoiding the topcoating process is described therein as beneficial in reducing manufacturing costs and reducing potential environmental problems.
Also for example, U.S. Pat. Nos. 4,421,439, 4,837,387 and 5,187,004 describe a supporting fabric, primarily for supporting soil materials. The fabric is a tri-layered non-coplanar grid of synthetic warp and weft yarns having limited fabric elongation or, in the case of U.S. Pat. No. 5,187,004, an ability to support chemically aggressive materials, particularly soil materials. The warp yarns are described as being formed of polyester and polyethylene terephthalate. Other polymeric yarns are listed as acceptable alternatives. The references describe the weft yarns as being made of the same material as the warp yarns or of a different material. An example is given of the combination of polyester warp yarns with polypropylene weft yarns.
As a further example, U.S. Pat. Nos. 4,960,349 an 5,091,247 describe an interwoven geotextile grid. The grid is formed of a plurality of spaced apart polymeric pick yarn bundles interwoven with a plurality of spaced-apart polymeric warp yarn bundles. A plurality of pairs of leno yarns parallel to the warp yarns add additional strength to the fabric, as do polymeric locking yarns. The grid is coated with a suitable PVC or other plastic coating such as latex, urethane or polyethylene coatings.
An erosion control mat which includes a grid-like scrim having a web of unconsolidated fibers disposed thereon is disclosed in U.S. Patent Nos. 5,249,893 and 5,358,356. The scrim and web are described as being formed of polypropylene, polyester, nylon, rayon, polyethylene, cotton or combinations of any two or more thereof.
U.S. Pat. No. 4,472,086 discloses a fabric which includes a grid composed of a first group of synthetic threads arranged substantially transversely to a second group of synthetic threads, wherein the first and second groups of threads are bonded to each other by knit yarn stitch bonds. According to the reference, because the fabric does not include an adhesive found in many fabrics, the basic yarn elongation is the only factor affecting fabric elongation, so that fabric elongation is precisely controllable. At column 4, lines 10-12, the reference states that the preferred synthetic material is a polyester or polypropylene. The fabric of the reference is used as an intermediate between a cracked road surface and an asphalt patch to be placed over the crack, wherein the fabric operates to prevent reflective racks from reflecting from the cracked road surface and into and through the asphalt patch.
Additional examples of polymeric based geosynthetic materials may be found in U.S. Pat. Nos. 4,374,798, 4,610,568, 4,662,946, 4,756,946, 4,851,277, 5,156,495, 5,419,659, 5,567,087, and 5,651,641.
One important limitation common among polymerically based geosynthetic materials, particularly geogrids, is that such materials are subject to substantial strain. Strain refers to the elongation of the geosynthetic material under tensile load, generally normalized with respect to cross-sectional area. Depending upon the orientation of the tensile load with respect to the geosynthetic material, the strain may occur along the longitudinal, transverse or both directions of the geosynthetic material. Strain resulting in 5 to 30 percent or more elongation of polymeric geosynthetic material is not uncommon, even at tensile loads which are only about 20 to 50 percent of the short term ultimate strength of the polymeric geosynthetic material. Another limitation common among polymerically based geosynthetic materials, particularly geogrids, is that such materials are subject to creep. Creep refers to the elongation of the geosynthetic material under a sustained tensile load. Yet another drawback of many polymeric based geosynthetic materials is that they deteriorate when subjected to ultraviolet radiation, either limiting the durability of such materials or requiring add
Girgis Mikhail M.
Neubauer Jeffrey A.
Paulson John N.
Raghupathi Narasimhan
PPG Industries Ohio Inc.
Siminerio Andrew C.
Weisberger Richard
LandOfFree
Fiber glass based geosynthetic material does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Fiber glass based geosynthetic material, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Fiber glass based geosynthetic material will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2452821