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Geotextile Fabrics
Geotextile
Fabrics
are
man made or synthetic fabric used in the control of soil erosion.
The fabric is available in roles of various widths and lengths, (color
standards are usually white, black or gray) and usually vary from one
manufacturer to the other. Various specifications are available for
varying soil types and applications. The product is sometimes referred
to as "filter fabric", and can also be defined as "woven" or
"non-woven".
MCCA uses
synthetic geotextile fabrics extensively as an underlying stabilizing,
filtration, and separation barrier. Many applications exist
including:
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Erosion
prevention along stream, river, lake, bay, and ocean front.
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Stormwater
drainage systems filtration to prevent clogging and extend the life of the
drainage system.
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Road bed
separation and stabilization.
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Riprap and
seawalls
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Types
and Uses of Synthetic Geotextile Fabrics
Many varieties of
synthetic geotextile fabrics exist to serve various needs. Three
prominent types are:
US Fabrics is one of the
leading world producers of geotextile fabrics. There products are featured
below and are representative of the types of material MCCA typically uses
for its erosion control project design requiring a synthetic geo-fabric
solution. Various
woven, non-woven, light-weight, and heavyweight, geotextile fabrics are
typically utilized depending on the specific design
application and project objective.
Nonwoven Needlepunched
Geotextile Fabric
Made from 100%
polypropylene staple filaments, lightweight fabrics such as US 80 NW is
typically used as filters in drainage applications. For use under
riprap and for separators under pavement, medium fabrics like US 160NW up
to US 205NW are typically specified. For use under railroad tracks and
cushions for geomembranes, heaver fabrics like US 270NW, US 300NW, or US
380NW are typically required.
The following
characteristics apply to the product indicated. Values listed are
minimum average role values.
| |
DRAINAGE |
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SEPARATION/
RIPRAP |
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GEO-MEMBRANE CUSHION/
RAILROAD SEPARATOR |
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Properties
Test Method |
US
80 NW |
US
90 NW |
US
105 NW |
US
120 NW |
US
160 NW |
US
180 NW |
US
205 NW |
US
160 NW |
US
180 NW |
US
205 NW |
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Tensile strength (lbs.)
ASTM-D-4632 |
80 |
90 |
105 |
120 |
160 |
180 |
205 |
270 |
300 |
380 |
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Elongation @ Break
ASTM D-4632 |
50 |
50 |
50 |
50 |
50 |
50 |
50 |
50 |
50 |
380 |
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Mullen
Burst (psi)
ASTM-D-4833 |
150 |
185 |
210 |
230 |
310 |
320 |
350 |
450 |
600 |
750 |
Puncture Strength
(lbs.)
ASTM-D-4533 |
50 |
55 |
65 |
65 |
90 |
90 |
115 |
150 |
175 |
235 |
Trapezoidal Tear
(lbs.)
ASTM-D-4751 |
30 |
40 |
45 |
50 |
65 |
70 |
80 |
100 |
115 |
140 |
AOS - US Std. Sieve
ASTM-D-4491 |
70 |
70 |
70 |
70 |
80 |
80 |
80 |
100 |
100 |
100 |
Permittivity (Sec
-1)
ASTM-D-4491 |
2.0 |
2.0 |
1.8 |
1.5 |
1.3 |
1.3 |
1.2 |
.8 |
.8 |
.7 |
UV Resistance (%
500hrs.)
ASTM-D-4355 |
70 |
70 |
70 |
70 |
70 |
70 |
70 |
70 |
70 |
70 |
Flow Rate (gal/min/sf)
ASTM D-4491 |
150 |
150 |
140 |
120 |
95 |
85 |
85 |
65 |
65 |
50 |
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US90NW Geotextile used in a used in a drainage
application.
<click photo to enlarge> |
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US210NW
Geotextile fabric installed beneath riprap.
<click drawing to enlarge> |
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US210NW Geotextile installed as separation beneath
roadbed.
<click drawing to enlarge> |
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Woven Filtration Geotextiles
Woven monofiliment geotextile fabrics
provide immediate and long term solutions for most drainage and filtration
applications. The combination of high strength and excellent
hydraulic characteristics make monofiliment the fabric of choice behind
bulkheads and under riprap. Percent open area, a property most often
associated with 100% monofilament geotextiles, offer both water and
particles a direct path through the geotextile. Nonwoven fabric,
slitfilms, and combination fabrics have little or no percent open area,
and often trap soil particles with the thickness of the fabric, clogging
the geotextile.
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Properties |
Test Method |
US 670 |
US 1040 |
US 1540 |
US 3040 |
US 840 |
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Tensile strength (lbs.) |
ASTM-D-4632 |
370x250 |
265x255 |
365x200 |
325x200 |
430x360 |
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Elongation @ Break (%) |
ASTM-D-4632 |
15 |
15 |
15 |
15 |
15 |
| Mullen
Burst (psi) |
ASTM-D-3786 |
480 |
500 |
480 |
400 |
700 |
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Puncture Strength (lbs.) |
ASTM-D-4833 |
135 |
125 |
105 |
115 |
170 |
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Trapezoidal Tear (lbs.) |
ASTM-D-4833 |
100x60 |
80x75 |
115x75 |
90x50 |
150x140 |
|
Percent Open Area |
COE-022125 |
4-6 |
10 |
15 |
20-30 |
8 |
| AOS -
US Std. Sieve |
ASTM-D-4751 |
70 |
40 |
40 |
40 |
40 |
|
Permittivity (Sec -1) |
ASTM-D-4491 |
.28 |
.95 |
1.36 |
2.14 |
1.05 |
| Flow
Rate (gal/min/sf) |
ASTM-D-4491 |
18 |
70 |
100 |
145 |
73 |
| UV
Resistance (% 500hrs.) |
ASTM-D-4355 |
90 |
90 |
90 |
90 |
90 |
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Woven stabilization fabrics provide
strength and separation needed for paved or unpaved application.
High tensile strength at low elongation will reduce rutting in both paved
and unpaved surfaces. The fabrics separate the base course while
reinforcing the adjacent soft soil.
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Properties |
Test Method |
US 100 |
US 150 |
US 180 |
US 200 |
US 315 |
US 400 |
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Tensile strength
(lbs.) |
ASTM-D-4632 |
100 |
150 |
180 |
200 |
315 |
400 |
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Elongation @ Break
(%) |
ASTM-D-4632 |
15 |
15 |
15 |
15 |
15 |
10 |
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Wide Width Tensile
(lbs/ft) |
ASTM-D-3786 |
N/A |
N/A |
N/A |
1800 |
2160 |
4800 |
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Mullen Burst (psi) |
ASTM-D-4833 |
220 |
250 |
305 |
400 |
600 |
1200 |
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Puncture Strngth
(lbs.) |
ASTM-D-4533 |
60 |
75 |
80 |
100 |
145 |
190 |
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Trapezoidal Tear
(lbs.) |
ASTM-D-4751 |
45 |
65 |
70 |
75 |
115 |
18 |
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AOS - US Std. Sieve |
ASTM-D-4491 |
50 |
50 |
50 |
40 |
40 |
30 |
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Permittivity (Sec
-1) |
ASTM-D-4491 |
.02 |
.07 |
.07 |
.07 |
.02 |
.40 |
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UV Resistance (%
500hrs.) |
ASTM-D-4355 |
90 |
90 |
90 |
90 |
90 |
90 |
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US 670
Geotextile fabric installed behind bulkhead.
<click drawing to enlarge> |
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US
670 Geotextile installed beneath riprap.
<click drawing to enlarge> |
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