geosynthetic clay liners (gcls) advances in gcls herlin… · 2017-03-24  · ® geosynthetic clay...

Geosynthetic Clay Liners (GCLs) Advances in GCLs

Bruno Herlin, P.Eng. Bentofix Product Manager bherlin@terrafixgeo.com

Geosynthetic Clay Liners (GCLs) Advances in GCLs

Bruno Herlin, P.Eng. Bentofix Product Manager bherlin@terrafixgeo.com

Geosynthetic Clay Liners (GCLs) Advances in GCLs

Bruno Herlin, P.Eng. Bentofix Product Manager bherlin@terrafixgeo.com

What is a GCL?

Bentonite sandwiched between two layers of textiles GCL = 3 ft of CCL (Compacted Clay Liner).

What is a GCL?

Not every GCL is alike

- Different types for different applications: - Slopes (different textiles used). - Application (ponds vs landfill vs mine site vs base liner vs cap). - Leachate compatibility (bentonite and/or enhanced polymers). - Soil conditions (ion exchange?).

- Different types of bentonites: - Wyoming based bentonite. - Bentonite from overseas (Activated/Soda Ash).

Where to use GCLs:

Geosynthetic Clay Liner

Where to use GCLs:

Geosynthetic Clay Liner

Geosynthetic Clay Liner

Where to use GCLs:

Geosynthetic Clay Liner

Geosynthetic Clay Liner Hydration?

Wyoming based bentonite in direct contact with a Hazardous Leachate

Flux vs time Date Time Flux (m3/m2)/s • March 24, 2017 10:43 AM 8.70E-07 11:15 AM 8.20E-07 12:10 PM 5.10E-07 • March 27, 2017 11:45 AM 7.70E-07 1:19 PM 6.40E-07 12:10 PM 5.10E-07 • March 28, 2017 1:50 PM 7.70E-07 2:02 PM 7.65 E-07 2:12 PM 6.40 E-07

Dry Wyoming bentonite

Wyoming based bentonite in direct contact with a Hazardous Leachate

Enhanced Polymer with a Wyoming Based Bentonite

Foreign based bentonite in direct contact with a Hazardous Leachate

?

Foreign based bentonite in direct contact with a Hazardous Leachate

?

Foreign based bentonite in direct contact with a Hazardous Leachate

?

Foreign based bentonite in direct contact with a Hazardous Leachate

Plate Absorbtion Test – update to ASTM

Time to rename GCLs?

GWCL: Geosynthetic Wyoming Clay Liners GFCL: Geosynthetic Foreign Clay Liners GDL: Geosynthetic Dirt Liners

Over 4+ decades of Wyoming Clay Research Foreign Clay – along for the ride!

Where to use GCLs:

Geosynthetic Clay Liner

Where to use GCLs:

GCL Research / Recent findings

GCLs that are not scrim-reinforced

GCLs that are not scrim-reinforced

Non-Wowen

Bentonite

GCL Cross-Section GCL that is NOT Scrim-Reinforced

Non-Wowen

Woven

Non-Wowen

Bentonite

GCL Cross-Section Scrim-Reinforced GCL

Contains a Scrim (woven)

Non-Wowen

GCL Research / Recent findings GCLs that were Scrim-Reinforced did not Shrink

Benefits of a Scrim-Reinforced GCL

Non-Wowen

Bentonite

Non-Wowen

Benefits of a Scrim-Reinforced GCL

Non-Wowen

Bentonite

Non-Wowen

Woven

Golf Course Pond done with a double nonwoven GCL

Internal Erosion

Why?

USE A THICKER TEXTILE GCL OR BETTER YET – COVER IT UP AS RECOMMENDED!

Coated GCL facing up > No Internal Erosion for 2 yrs in an Exposed Liner Site.

Wrickles of the HDPE

Switch to White HDPE instead of Black HDPE

LessWrinkles = Less Damage during coversoil operations. Less Wrinkes = a lower transmissivity between HDPE/GCL.

Specifying a GCL? Do not use Tradenames

Specifications BENTOFIX ® NSL Thermal Lock® Geosynthetic Clay Liners Bentofix Thermal Lock® NSL Geosynthetic Clay Liner (GCL) is a needlepunched, thermally reinforced composite comprised of a core of natural sodium Wyoming bentonite clay between two durable geotextile layers to form a low permeability hydraulic barrier. The top layer is a staple fiber nonwoven (NW) geotextile while the bottom layer is a woven (W) geotextile. The product is intended for moderate to steep slopes and moderate to high load applications where increased internal shear strength is required.

REMOVE ALL PRODUCT NAMES ASK FOR A TECHNICAL DATA SHEET IN WORD FORMAT

Specifying a GCL? List all the ASTM values

Property ASTM Test Method Frequency Value Imperial Units Value

Metric Units

Typical Geotextile Properties

• Top / Cap Nonwoven • Scrim Reinforced Nonwoven

Bottom Fabric

D 5261

D 5261

200,000 sq ft

( 20,000 m2)

6.0 oz./yd2 MARV

6.0 oz./yd2 MARV

200 g / m2 MARV(1)

200 g / m2 MARV

Bentonite Properties (SI Units Only)

• Swell Index • Moisture Content • Fluid Loss • Smectite (Montmorillonite)

D 5890 D 4643 D 5891

XRD

100,000 lbs. (50,000 kg) 100,000 lbs.

Periodic

24 ml/ 2 g min 12 % max 18 ml max 90% min

24 ml/ 2 g min 12 % max 18 ml max 90% min

Finished GCL Properties

• Bentonite Mass/Unit Area2 • Tensile Strength3 • Peel Strength • Permeability5 • Index Flux5 • Internal Shear Strength6

D 5993

D 6768

D 6496

D 5887

D 5887

D 6243

40,000 ft2 (4,000 m2)

40,000 ft2 (4,000 m2)

40,000 ft2 (4,000 m2)

Weekly

Weekly

Periodic

0.75 lbs/ft2 MARV

45 lb/in MARV

3.5 lbs/in min

5 x 10-9 cm/s max

1 x 10-8 m3/m2/s max

500 psf Typical

3.66 kg/m2 MARV

7.8 kN/m MARV

610 N/m min

5 x 10-9 cm/s max

1 x 10-8 m3/m2/s max

24 kPa Typical

Specifying a GCL? Do not use GRI-GCL3 – which one?

Specifying a GCL? Please don’t go on vacation

before tender closing !

Specifying a GCL? Please don’t go on vacation

before tender closing !

OK … which one do you think he/she will be provided?

4.10.2 GCL Liner: (1) Shall be a needle-punched reinforced composite consisting of two durable geotextile outer layers with a uniform core of natural sodium bentonite clay to form a hydraulic barrier.

Geosynthetic Clay Liner

w=47%

7% initial moisture

Photo: Courtesy of Queens University

GCL Base – 54 weeks HDPE-GCL no cover

w=36%

24% initial moisture

Photo: Courtesy of Queens University

GCL Base – 54 weeks HDPE-GCL no cover

GEOPIPE/GEOTUBES

You can get anything you want

- List all ASTM values and items you want. - DO third party testing (from site samples) … papers mean nothing. - Protect yourself via Third Party Testing.

New products every year – be receptive !

Great new product ! No need for Sandbags/Ballast.

Membership – stay connected.

Thank you for your time …

Bruno Herlin, P.Eng. Product Manager – Terrafix VP Board of Directors, IGS-NA