Section 714 — Geosynthetic Material

714.01Geotextile. Provide geotextile conforming to the following physical properties based on intended use of the geotextile:

(a)Separation geotextile. Conform to AASHTO M 288 Table 1, Class 1 and Table 3. Separation geotextiles can be in either the <50 percent elongation category (woven) or the ≥50 percent elongation (non-woven) category.

(b)Stabilization geotextile. Conform to AASHTO M 288 Table 1, Class 1, <50 percent elongation (woven) only, and AASHTO M 288 Table 5. (c) Geotextile filter. Conform to AASHTO M 288 Table 1, Class 1 and Table 6 for riprap, special rock embankment, rock buttress, and other high survivability applications. Conform to AASHTO M 288 Table 1, Class 2 and Table 2 for underdrains and other subsurface drainage applications. Geotextile filter can be in either the <50 percent elongation categ ory (woven) or the ≥50 percent elongation (non- woven) category.

(d)Paving geotextile. Provide geotextile conforming to AASHTO M 288, Table 8. Do not use woven slit film geotextile. 714.02 Geocomposite Drain. Provide a prefabricated geocomposite drain composed of a drainage core and a nonwoven geotextile that allows in- flow from both sides. Geocomposites that only allow in- flow from one side may only be used directly against a concrete surface. Provide geotextile conforming to AASHTO M 288 and drainage core ma nufactured from long chain synthetic polymers composed of at least 95 percent by mass of polypropylene, polyester, polyamide, PVC, polyolefin, or polystyrene. Build the core up in thickness by columns, cones, nubs, cusps, meshes, stiff filaments, or other configurations. Fabricate the core in sheets, panels, or rolls of adequate strength to resist installation stresses and long -term loading conditions. Firmly attach the encapsulating geotextile to the core at the manufacturing plant, so that folding, wrink ling, or other movement cannot occur during handling or after placement. Use a nonwater- soluble adhesive, heat sealing, or other methods recommended by the geotextile manufacturer. Do not use adhesive on areas of the geotextile where flow is intended to occur. If heat sealing is used, do not weaken the geotextile below the required strength values. Extend the geotextile beyond the core length on all sides sufficiently to encapsulate the core and collector pipe. Conform to Table 714-1. Table 714-1

Geocomposite Drain Requirements

Property Test Method Units Specifications(5)

Sheet Drain Strip Drain

Type 1 Type 1 Type 2

Transmissivity

(flow rate)(1) ASTM D4716 Gal/min/ft 5.0 15.0 20.0

Compressive strength

at yield ASTM D1621 psi 100 50 50

Applied normal

compressive stress ASTM D4716(4) psi 14.5 1.45 1.45 Hydraulic gradient ASTM D4716(2),(3),(4) dimensionless 1.0 0.1 0.1 Fungi resistance ASTM G21 − No visible growth

(1)If core construction separates the flow channel into two or more discrete sections, only the flow rate on one in- flow face is considered in determining the core’s acceptability.

(2)14 -inch-long specimen.

(3)100- hour seating period.

(4)Rubber membrane between platens and geocomposite.

(5)The property values in this Table are specified as minimum average roll value (MARV) in the weakest principal direction as described in ASTM D4759, except for fungi resistance.

714.03Stabilization Geogrid. Provide biaxial geogrid conforming to AASHTO M 288, Table 12, Class 4C.

714.04Reinforcement Geotextile and Geogrid . Provide reinforcement geotextile and geogrid conforming to AASHTO M 288 Tables 9 and 10, and Table 714-2. The minimum allowable long -term strength ( 𝑇𝑇𝑀𝑀𝑀𝑀) for each layer of reinforcement geotextile or geogrid is based on: 𝑇𝑇𝑀𝑀𝑀𝑀 =𝑇𝑇𝑐𝑐𝑀𝑀𝑀𝑀 𝑅𝑅𝑃𝑃 where: Tult = Ultimate tensile strength of the reinforcement geotextile or geogrid RF = Reduction Factors = RF ID × RF CR × RF D. Provide manufacturer test data for 𝑅𝑅𝑃𝑃𝐼𝐼𝐼𝐼, 𝑅𝑅𝑃𝑃𝐶𝐶𝐶𝐶, and 𝑅𝑅𝑃𝑃𝐼𝐼values by evaluation of independent test results by Highway Innovative Technology Evaluation Center (HITEC), AASHTO Product Evaluation & Audit Solutions , Innovations, Developments, Enhancement and Advancements (IDEA), or an equivalent third- party report. 835 Table 714-2 Reinforcement Geotextile and Geogrid Strength Requirements

Property Test

Method

ASTM Units Minimum Specifications(1),(2) Type 1 Type 2 Type 3 Type 4 Type 5 Type 6

Allowable

long-term strength (T al) D4595 or D6637(3),(4) lb/ft 1000 1500 2000 2500 3000 4000

(1)For reinforcement geotextile, also meet the Class 1 strength requirements in AASHTO M 288 Table 1 and the ultraviolet stability requirements of AASHTO M 288 Table 10.

(2)The specified strength is in the principal direction of reinforcement, perpendicular to the wall or slope face and based on MARV.

(3)ASTM D4595 is for reinforcement geotextile and ASTM D6637 is for geogrid.

(4)See the nominal long-t erm strength (T al) formula above.

714.05Geomembrane. Provide geomembrane that consists of textured (roughened) surface polyvinyl chloride, HDPE , or linear low density polyethylene with a thickness of 28.5 to 31.5 mils. Glue or weld seams of the geomembrane to prevent leakage. Conform to Table 714-3. Table 714-3

Geomembrane Requirements

Geomembrane Type Test Method

Polyvinyl chloride (PVC) ASTM D7176(1) HDPE GRI Test Method GM13(2) Linear low density polyethylene (LLDPE) GRI Test Method GM17(2)

(1)The minimum average asperity height is 10 mils. Ensure 8 of 10 readings are greater than or equal to 7 mils and the lowest individual reading is greater than or equal to 5 mils.

(2)Geosynthetic Research Institute.

714.06Geosynthetic Reinforced Soil Reinforcement Geosynthetic. Provide reinforcement geotextile or geogrid conforming to AASHTO M 288, Tables 9 and 10, and Table 714-4. Table 714-4 GRS Reinforcement Geotextile and Geogrid Strength Requirements

Property Test Method

ASTM Units Minimum

Specifications(1)

Ultimate tensile

strength(2) (Tult) D4595 lb/ft 4800 Tensile strength at 2% strain (T 2%) D4595 lb/ft 1320

(1)The specified strength is in the principal direction of reinforcement perpendicular to the wall or slope face.

(2)Based on MARV.