Geotextile_Material_Spec_592_Jan_2014.pdf

Chapter 3 National Standard Material Part 642

Specifications National Engineering Handbook

Material Specification 592—Geotextile

1. Scope This specification covers the quality of geotextile, including geotextile for temporary silt fence.

2. General requirements Fibers (threads and yarns) used in the manufacture of geotextile shall consist of synthetic polymers composed of a minimum of 85 percent by weight polypropylenes, polyesters, polyamides, polyethylene, polyolefins, or polyvinylidene-chlorides. They shall be formed into a stable network of filaments or yarns retaining dimensional stability relative to each other. The geotextile shall be free of defects, such as holes, tears, and abrasions. The geotextile shall be free of any chemical treatment or coating that significantly reduces its porosity. Fibers shall contain stabilizers, inhibitors, or both to enhance resistance to ultraviolet light. Geotextile other than for temporary silt fence shall conform to the requirements in tables 592–1 or 592–2, as applicable. Geotextile for temporary silt fence shall conform to the requirements in table 592–3.

Thread used for factory or field sewing shall be of contrasting color to the fabric and made of high strength polypropylene, polyester, or polyamide thread. Thread shall be as resistant to ultraviolet light as the geotextile being sewn.

3. Classification Geotextiles shall be classified based on the method used to place the threads or yarns forming the fabric. The geotextiles will be grouped into woven and nonwoven types. Geotextile for temporary silt fence may be either woven or nonwoven. Slit film woven geotextile may not be used except for temporary silt fence.

Woven—Fabrics formed by the uniform and regular interweaving of the threads or yarns in two directions.

Woven fabrics shall be manufactured from monofilament yarn formed into a uniform pattern with distinct and measurable openings, retaining their position relative to each other. The edges of fabric shall be selvedged or otherwise finished to prevent the outer yarn from unraveling.

Nonwoven—Fabrics formed by a random placement of threads in a mat and bonded by needle punching, heat-bonding, or resin-bonding. Nonwoven fabrics shall be manufactured from individual fibers formed into a random pattern with distinct, but variable small openings, retaining their position relative to each other when bonded by needle punching, heat-, or resin-bonding. The use of heat-or resin-bonded nonwovens is restricted as specified in note 2 of table 592–2.

4. Sampling and testing The geotextile shall meet the specified requirements (tables 592–1, 592–2, or 592-3, as applicable) for the product type shown on the label. Product properties as listed in the latest edition of the "Specifiers Guide," Geosynthetics, (Industrial Fabrics Association International, 1801 County Road B, West Roseville, MN 55113-4061 or at http://www.geosindex.com) and that represent minimum average roll values, are acceptable documentation that the product style meets the requirements of these specifications.

For products that do not appear in the above directory or do not have minimum average roll values listed, typical test data from the identified production run of the geotextile will be required for each of the specified tests (see table 592–1, 592–2, or 592-3, as applicable) as covered under clause AGAR 452.236-76.

5. Shipping and storage The geotextile shall be shipped and transported in rolls wrapped with a cover for protection from moisture, dust, dirt, debris, and ultraviolet light. The cover shall be maintained undisturbed to the maximum extend possible before placement.

Each roll of geotextile shall be labeled or tagged to clearly identify the brand, class, and the individual production run in accordance with ASTM D 4873.

Material Specification 592 Geotextile (continued)

(210-VI-NEH, January 2014) 592–2

Table 592–1 Requirements for woven geotextiles 1/

Property Test Method Units Class I Class II Class III Class IV

Grab Tensile Strength ASTM D 4632 pounds

247 min. 180 min. 180 min. 315 min.

Elongation at Failure ASTM D 4632 percent

< 50 <50 <50 <50

Trapezoidal Tear Strength ASTM D 4533 pounds

90 min. 67 min. 67 min. 112 min.

Puncture Strength ASTM D 6241 pounds

495 min. 371 min. 371 min. 618 min.

Ultraviolet Stability (retained strength)

ASTM D 4355 percent

50 min. 50 min. 50 min. 50 min.

Permittivity ASTM D 4491 sec-1 as specified

Apparent Opening Size

(AOS) 2/

ASTM D 4751 mm as specified

Percent Open Area (POA) USACE

CWO-02215

percent as specified

1/ All values are minimum average roll values (MARV) in the weakest principal direction, unless otherwise noted.

2/ Maximum average roll value.

Note: CWO is a USACE reference.

Table 592–2 Requirements for nonwoven geotextiles 1/

Property Test Method Units Class I 2/ Class II 2/ Class III 2/ Class IV 2/

Grab Tensile Strength ASTM D 4632 pounds

202 min. 157 min. 112 min. 202 min.

Elongation at Failure ASTM D 4632 percent

Trapezoidal Tear Strength

ASTM D 4533 pounds

79 min. 56 min. 40 min. 79 min.

Puncture Strength ASTM D 6241 pounds

433 min. 309 min. 223 min. 433 min.

Ultraviolet Stability (retained strength)

ASTM D 4355 percent

0.7 min. or as specified

Apparent Opening Size

(AOS) 3/

ASTM D 4751 mm 0.22 max. or as specified

1/ All values are minimum average roll values (MARV) in the weakest principal direction, unless otherwise noted.

2/ Needle punched geotextiles may be used for all classes. Heat-bonded or resin-bonded geotextiles may be used for classes III and IV only. They are particularly well suited to class IV.

3/ Maximum average roll value.

Material Specification 592 Geotextile (continued)

(210-VI-NEH, January 2014) 592–3

Table 592-3 Requirements for Temporary Silt Fence 1/

Property

Test Method

Units

Requirements, Supported Silt Fence 2/

Requirements, Unsupported Silt Fence 2/

Woven Geotextile (Elongation < 50% 3/)

Nonwoven Geotextile (Elongation > 50% 3/)

Maximum Post Spacing ft

4 6.5 4

Grab Tensile Strength: ASTM D 4632 pounds

Machine Direction

90 124

X-Machine Direction

90 101

0.05 0.05

Apparent Opening Size (AOS) 4/

ASTM D 4751 mm 0.60 0.60

Ultraviolet Stability (retained strength)

ASTM D 4335 % 70% after 500 hours of exposure

70% after 500 hours of exposure

1/ All values are minimum average roll values (MARV) in the weakest principal direction, unless otherwise noted.

2/ Silt fence support shall consist of 14-gage steel wire with a mesh spacing of 6 inches each way or prefabricated polymeric mesh of equivalent strength.

3/ As measured in accordance with ASTM D 4632.

4/ Maximum average roll value.