Geotextiles Jae K. (Jim) Park, Professor Dept. of Civil and Environmental Engineering University of Wisconsin-Madison

Types of Geotextiles Nonwoven geotextiles Resemble felt and provide planar water flow Made from staple filaments of polypropylene fiber and are needle-punched and heat set. Roll size: 12.5’  360’ and 15’  300’ Woven geotextiles Planar textile structure Interlaced with two or more sets of strands Slit films: flat strands – strength but filtration not critical Monofilaments: round strands – strength and filtration Roll size: 12.5’  432’, 15’  360’, and 17.5’  309’ Reference: http://www.usfabricsinc.com/

Nonwoven Geotextiles An economical alternative to graded aggregate and sand filters Drainage collection system rap Asphalt overlay fabric Paver walkways or railroad track Revetment filter fabric Filter bags for dewatering Cow Carpet®, Stall Mat, and Marine Recovery Mat Resists ultraviolet and biological deterioration, rotting, naturally encountered basics and acids Stable within a pH range of 2 to 13

Woven Geotextiles Used for heavy loads and soft soils due to the use of a high strength, high modulus stabilization fabric Reduce localized shear failure in weak subsoil conditions and aid construction over soft subsoils Reduce rutting in paved or unpaved surfaces Used when both the strength and separation are needed Asphalt overlay fabric Used for shoreline rip rap application Resists ultraviolet and biological deterioration, rotting, naturally encountered basics and acids Stable within a pH range of 2 to 13

AASHTO M288 Geotextiles M288-06 covers six geotextile applications: Subsurface Drainage Separation Stabilization Permanent Erosion Control Sediment Control Paving Fabrics AASHTO M288-06 is not a design guideline. Survivability Classes: (1) most severe and (3) least severe If an elongation is not specified, in many cases a woven is the user's best options since they are typically less expensive than nonwoven geotextiles.

Geotextile Strength Requirements – AASHTO M288 Source: http://www.cflhd.gov/programs/techDevelopment/geotech/promogeoflhp/documents/05_chapter_2_review_national_guidelines.pdf

Selection Guide: AASHTO M288-06 Survivability Class Geotextile Application (Elongation) CLASS 1 CLASS 2 CLASS 3 Woven Nonwoven (<50%) (>50%)   Subsurface Drainage % Fines < 15% US 230 US 205NW US 160NW US 120NW 15% to 50% n/a US 670 >50% Stabilization US 315 US 250 US 200 Separation Permanent Erosion Control Paving Fabrics US 100P Source: http://www.usfabricsinc.com/reference/aashto-m288-06-selection-guide

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