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− | Material specifications should conform to [http://www.raqsb.mto.gov.on.ca/techpubs/OPS.nsf/0/2ccb9847eb6c56738525808200628de1/$FILE/OPSS%201860%20Apr12.pdf Ontario Provincial Standard Specification (OPSS) 1860 for Class II geotextile fabrics].
| + | [[File: Geotextile-GSI.JPG|thumb|The properties of geotextiles vary widely.]] |
− | *Fabrics should be woven monofilament or non-woven needle punched. Woven slit film and non-woven heat bonded fabrics should not be used as they are prone to clogging.
| + | See [[Clogging]] for notes on their application in LID structures. |
− | <p>Primary considerations are:
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− | <ol>
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− | <li>Maximum forces that will be exerted on the fabric (i.e., what tensile, tear and puncture strength ratings are required?);</li>
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− | <li>Load bearing ratio of the underlying native soil (i.e. is the geotextile needed to prevent downward migration of aggregate into the native soil?);</li>
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− | <li>Texture (i.e., grain size distribution) of the overlying fill material; and</li>
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− | <li>Permeability of the native soil</li>
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− | <li>Suitable apparent opening size (AOS) for non-woven fabrics, or percent open area (POA) for woven fabrics, to maintain water flow even with sediment and microbial film build-up;</li>
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− | </ol>
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| | | |
− | <table class = "table-responsive">
| + | Geotextiles can be used to prevent downward migration of smaller particles in to larger aggregates, and slump of heavier particles into finer underlying courses. |
− | <table class="table table-striped">
| + | The formation of biofilm on geotextiles has also been shown to improve water quality: |
− | <caption><strong>Recommended criteria for selection of geotextile fabric</strong></caption>
| + | *By degrading petroleum hydrocarbons<ref>Newman AP, Coupe SJ, Spicer GE, Lynch D, Robinson K. MAINTENANCE OF OIL-DEGRADING PERMEABLE PAVEMENTS: MICROBES, NUTRIENTS AND LONG-TERM WATER QUALITY PROVISION. https://www.icpi.org/sites/default/files/techpapers/1309.pdf. Accessed July 17, 2017.</ref> |
− | <tr class="success"><th>Percent media passing 0.075 mm (#200 sieve)</th><th>Non-woven fabric apparent opening size (AOS, mm)</th><th>Woven fabric percent open area (POA, %)</th><th>Permittivity (sec<sup>-1</sup>)</th></tr> | + | *By reducing organic pollutant and nutrient concentrations <ref>Paul P, Tota-Maharaj K. Laboratory Studies on Granular Filters and Their Relationship to Geotextiles for Stormwater Pollutant Reduction. Water. 2015;7(4):1595-1609. doi:10.3390/w7041595.</ref> |
− | <tr><td align="center" valign="middle">>85</td><td align="center" valign="middle">≤ 0.3</td><td align="center" valign="middle">-</td><td align="center" valign="middle">0.1</td></tr>
| + | *When installing geotextiles an overlap of 150 - 300 mm should be used. |
− | <tr><td align="center" valign="middle">50 - 85</td><td align="center" valign="middle">≤ 0.3</td><td align="center" valign="middle">≥ 4</td><td align="center" valign="middle">0.1</td></tr>
| + | Material specifications should conform to OPSS 1860 for Class II geotextile fabrics |
− | <tr><td align="center" valign="middle">15 - 50</td><td align="center" valign="middle">≤ 0.6</td><td align="center" valign="middle">≥ 4</td><td align="center" valign="middle">0.2</td></tr>
| + | <ref>ONTARIO PROVINCIAL STANDARD SPECIFICATION METRIC OPSS 1860 MATERIAL SPECIFICATION FOR GEOTEXTILES. 2012. http://www.raqsb.mto.gov.on.ca/techpubs/OPS.nsf/0/2ccb9847eb6c56738525808200628de1/$FILE/OPSS%201860%20Apr12.pdf. Accessed July 17, 2017</ref>. |
− | <tr><td align="center" valign="middle">5 - 15</td><td align="center" valign="middle">≤ 0.6</td><td align="center" valign="middle">≥ 4</td><td align="center" valign="middle">0.5</td></tr>
| + | *Fabrics should be woven monofilament or non-woven needle punched. |
− | <tr><td align="center" valign="middle">≤ 5</td><td align="center" valign="middle">≤ 0.6</td><td align="center" valign="middle">≥ 10</td><td align="center" valign="middle">0.5</td></tr>
| + | *Woven slit film and non-woven heat bonded fabrics should not be used, as they are prone to clogging. |
− | </table>
| + | In choosing a product, consider: |
| + | #The maximum forces that will be exerted on the fabric (i.e., what tensile, tear and puncture strength ratings are required?), |
| + | #The load bearing ratio of the underlying native soil (i.e. is the geotextile needed to prevent downward migration of aggregate into the native soil?), |
| + | #The texture (i.e., grain size distribution) of the overlying and underlying materials, and |
| + | #The suitable apparent opening size (AOS) for non-woven fabrics, or percent open area (POA) for woven fabrics, to maintain water flow even with sediment and microbial film build-up. |
| | | |
| + | {|class="wikitable" |
| + | |- |
| + | |+Recommended criteria for selection of geotextile fabric |
| + | |- |
| + | !Percent soil/filter media passing 0.075 mm (#200 sieve) |
| + | !Non-woven fabric apparent opening size (AOS, mm) |
| + | !Woven fabric percent open area (POA, %) |
| + | !Permittivity (sec<sup>-1</sup>) |
| + | |- |
| + | |>85||≤ 0.3||-||0.1 |
| + | |- |
| + | |50 - 85||≤ 0.3||≥ 4||0.1 |
| + | |- |
| + | |15 - 50||≤ 0.6||≥ 4||0.2 |
| + | |- |
| + | |5 - 15||≤ 0.6||≥ 4||0.5 |
| + | |- |
| + | |≤ 5||≤ 0.6||≥ 10||0.5 |
| + | |} |
| + | ===Performance research=== |
| + | http://www.mdpi.com/2073-4441/7/4/1595/htm |
| + | ---- |
| [[category:materials]] | | [[category:materials]] |