prEN 16416

Geosynthetic clay barriers - Determination of water flux index - Flexible wall permeameter method at constant head

This European Standard describes an index test method that covers laboratory measurement of water flux through saturated clay geosynthetic barrier (GBR-C) specimens using a flexible wall permeameter at constant head.
This test method is applicable to GBR-C products with no additional sealing layers attached.
This test method provides a measurement of flux under a prescribed set of conditions that can be used for manufacturing quality control. The test method can also be used to check conformance.
The flux value determined using this test method is not considered to be representative of the in-service flux of a GBR-C.

Geosynthetische Tondichtungsbahnen - Bestimmung der Durchflussrate - Triaxialzellen-Methode mit konstanter Druckhöhe

Dieses Dokument beschreibt ein Index-Prüfverfahren, das eine Labormessung der Durchflussrate von Wasser durch gesättigte Messproben einer geosynthetischen Tondichtungsbahn (GBR-C) bei konstanter Druckhöhe unter Anwendung eines Durchlässigkeitsmessgerätes mit Triaxialzellen umfasst.
Dieses Prüfverfahren ist auf GBR-C-Produkte ohne aufgebrachte zusätzliche Dichtungsschicht (z.B. polymer oder bitumenhaltig) anwendbar.
Dieses Prüfverfahren beschreibt eine Messung der Durchflussrate unter einem vorgeschriebenen Satz von Bedingungen, die zur Qualitätsüberwachung bei der Herstellung angewendet werden kann. Das Prüfverfahren kann außerdem zur Konformitätsprüfung angewendet werden.
Der nach diesem Prüfverfahren bestimmte Wert der Durchflussrate wird nicht als repräsentativ für die Durchflussrate einer im Einsatz befindlichen GBR-C angesehen.

Barrières géosynthétiques argileuses - Détermination de l'indice eau par analyse en flux - Méthode au perméamètre à paroi flexible de charge constante

Le présent document décrit une méthode d’essai « index » relative à la mesure en laboratoire du flux d’eau au travers d’éprouvettes de géosynthétiques bentonitiques (GSB) saturés, utilisant un perméamètre à paroi flexible à charge constante.
Cette méthode d’essai est applicable aux géosynthétiques bentonitiques sans couches d’étanchéité supplémentaires liées (par exemple, polymériques ou bitumineuses).
Cette méthode d’essai permet de mesurer le flux dans un ensemble de conditions prescrites qui peut être utilisée pour le contrôle de qualité de la fabrication. La méthode d’essai peut également être utilisée pour vérifier la conformité.
La valeur du flux déterminée à l’aide de cette méthode d’essai n’est pas considérée comme étant représentative du flux en service d’un GSB.

Geosintetične glinene pregrade - Ugotavljanje indeksa vodnega pretoka - Metoda s permeametrom (merilnikom prepustnosti) z gibko steno pri konstantnem vodnem tlaku

General Information

• Status: Not Published
• ICS: 59.080.70 - Geotextiles
• ICS: 91.100.50 - Binders. Sealing materials
• Technical Committee: CEN/TC 189 - Geotextiles and geotextile-related products
• Drafting Committee: CEN/TC 189/WG 4 - Hydraulic testing
• Directive: 305/2011 - Regulation (eu) No 305/2011 of the European Parliament and of the Council of 9 march 2011 laying down harmonised conditions for the marketing of construction products and repealing council directive 89/106/eec
• Ref Project: oSIST prEN 16416:2021 - Geosynthetic clay barriers - Determination of water flux index - Flexible wall permeameter method at constant head

RELATIONS

• Revised: EN 16416:2013 - Geosynthetic clay barriers - Determination of water flux index - Flexible wall permeameter method at constant head
• Effective Date: 19-Feb-2020

Standards Content (sample)

SLOVENSKI STANDARD
oSIST prEN 16416:2021
01-oktober-2021
Geosintetične glinene pregrade - Ugotavljanje indeksa vodnega pretoka - Metoda s
permeametrom (merilnikom prepustnosti) z gibko steno pri konstantnem vodnem
tlaku
Geosynthetic clay barriers - Determination of water flux index - Flexible wall
permeameter method at constant head

Geosynthetische Tondichtungsbahnen - Bestimmung der Durchflussrate - Triaxialzellen-

Methode mit konstanter Druckhöhe

Barrières géosynthétiques argileuses - Détermination de l'indice eau par analyse en flux

- Méthode au perméamètre à paroi flexible de charge constante
Ta slovenski standard je istoveten z: prEN 16416
ICS:
59.080.70 Geotekstilije Geotextiles
91.100.50 Veziva. Tesnilni materiali Binders. Sealing materials
oSIST prEN 16416:2021 en

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
oSIST prEN 16416:2021
---------------------- Page: 2 ----------------------
oSIST prEN 16416:2021
DRAFT
EUROPEAN STANDARD
prEN 16416
NORME EUROPÉENNE
EUROPÄISCHE NORM
September 2021
ICS 59.080.70; 91.100.50 Will supersede EN 16416:2013
English Version
Geosynthetic clay barriers - Determination of water flux
index - Flexible wall permeameter method at constant
head

Barrières géosynthétiques argileuses - Détermination Geosynthetische Tondichtungsbahnen - Bestimmung

de l'indice eau par analyse en flux - Méthode au der Durchflussrate - Triaxialzellen-Methode mit

perméamètre à paroi flexible de charge constante konstanter Druckhöhe

This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee

CEN/TC 189.

If this draft becomes a European Standard, CEN members are bound to comply with the CEN/CENELEC Internal Regulations

which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.

This draft European Standard was established by CEN in three official versions (English, French, German). A version in any other

language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC

Management Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,

Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,

Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and

United Kingdom.

Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are

aware and to provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without

notice and shall not be referred to as a European Standard.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels

© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 16416:2021 E

worldwide for CEN national Members.
---------------------- Page: 3 ----------------------
oSIST prEN 16416:2021
prEN 16416:2021 (E)
Contents Page

European foreword ............................................................................................................................................ 3

1 Scope .......................................................................................................................................................... 4

2 Normative references .......................................................................................................................... 4

3 Terms and definitions ......................................................................................................................... 4

4 Apparatus ................................................................................................................................................ 4

5 Permeant water ..................................................................................................................................... 9

6 Specimen sampling and preparation ............................................................................................. 9

7 Procedure ................................................................................................................................................ 9

8 Calculation ............................................................................................................................................. 11

9 Report ..................................................................................................................................................... 11

Annex A (informative) Hydraulic conductivity calculation .............................................................. 12

Annex B (informative) Permittivity calculation ................................................................................... 13

Bibliography ....................................................................................................................................................... 14

---------------------- Page: 4 ----------------------
oSIST prEN 16416:2021
prEN 16416:2021 (E)
European foreword

This document (prEN 16416:2021) has been prepared by Technical Committee CEN/TC 189

“Geosynthetics”, the secretariat of which is held by NBN.
This document is currently submitted to CEN Enquiry.
This document will supersede EN 16416:2013.

In comparison with the previous edition, the following technical modifications have been made:

— Addition of details in Figure 1;
— Addition of details in 7.5 on the compressive stress.

This document has been prepared under a Standardization Request given to CEN by the European

Commission and the European Free Trade Association
---------------------- Page: 5 ----------------------
oSIST prEN 16416:2021
prEN 16416:2021 (E)
1 Scope

This document describes an index test method that covers laboratory measurement of water flux through

saturated clay geosynthetic barrier (GBR-C) specimens using a flexible wall permeameter at constant

head.

This test method is applicable to GBR-C products with no additional sealing layers attached (e.g.

polymeric or bituminous).

This test method provides a measurement of flux under a prescribed set of conditions that can be used

for manufacturing quality control. The test method can also be used to check conformance.

The flux value determined using this test method is not considered to be representative of the in-service

flux of a GBR-C.
2 Normative references

The following documents are referred to in the text in such a way that some or all of their content

constitutes requirements of this document. For dated references, only the edition cited applies. For

undated references, the latest edition of the referenced document (including any amendments) applies.

EN ISO 9862, Geosynthetics — Sampling and preparation of test specimens (ISO 9862)

ISO 554, Standard atmospheres for conditioning and/or testing — Specifications

ISO 11465, Soil quality — Determination of dry matter and water content on a mass basis — Gravimetric

method
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

• IEC Electropedia: available at https://www.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp
3.1
flux

volumetric flow rate per unit area normal to the plane of the product at a defined head

[SOURCE: EN ISO 10318-1:2015, 2.3.3.4]
4 Apparatus
The apparatus shall consist of the following.
4.1 Constant head hydraulic system
4.1.1 General

The system shall be capable of maintaining constant hydraulic pressures to within ± 2,5 % and shall

include means to measure the hydraulic pressures to within the prescribed tolerance. In addition, the

system shall be capable of maintaining a constant head loss across the test specimen to within ± 5 % and

shall include means to measure the head loss with the same accuracy or better.
---------------------- Page: 6 ----------------------
oSIST prEN 16416:2021
prEN 16416:2021 (E)
4.1.2 System de-airing

The hydraulic system shall be designed to facilitate rapid and complete removal of free air bubbles from

flow lines.
4.1.3 Cell pressure system

The hydraulic system shall have the capability to apply back pressure to the specimen to facilitate

saturation. The system shall be capable of maintaining the applied back pressure throughout the duration

of the test. The cell pressure system shall be capable of applying, controlling, and measuring the back

pressure to within ± 2,5 % of the applied pressure. The back pressure may be provided by a compressed

gas supply, a deadweight acting on a piston, or any other method capable of applying and controlling the

back pressure to the tolerance specified in this paragraph.

NOTE Application of gas pressure directly to a liquid will dissolve gas in the liquid. A variety of techniques are

available to minimize dissolution of gas in the back-pressure liquid, including separation of gas and liquid phases

with a bladder and frequent replacement of the liquid with de-aired water.
4.2 Flow Measurement System
4.2.1 Accuracy of inflow and outflow

Both inflow and outflow volumes shall be measured unless the lack of leakage, continuity of flow, and

cessation of consolidation or swelling can be verified by other means. Required accuracy for the flow

measured over an interval of time is ± 5 %.
4.2.2 De-airing and compliance of the system

The flow-measurement system shall contain a minimum of dead space and be capable of complete and

rapid de-airing. Rigid tubing shall be used so that volume change of the system in response to changes in

pressure is minimized.
4.3 Permeameter cell pressure system

The system for pressurizing the permeameter cell shall be capable of applying and maintaining the cell

pressure to within ± 2,5 % of the applied pressure. However, the effective stress on the test specimen

shall be maintained to the desired value with an accuracy of ± 5 %. The device for pressurizing the cell

may consist of a reservoir connected to the permeameter cell and partially filled with de-aired water,

with the upper part of the reservoir connected to a compressed gas supply or other source of pressure

(see NOTE).

NOTE De-aired water is commonly used for the cell liquid to minimize potential for diffusion of air through the

membrane into the specimen. Other liquids, such as oils, which have low gas solubilities, are also acceptable,

provided they do not react with components of the permeameter and the flexible membrane. The use of a long

(approximately 5 m to 7 m) tube connecting the pressurized cell liquid to the cell can help delay the appearance of

air in the cell liquid and to reduce the flux of dissolved air into the cell.
4.4 Permeameter Cell

An apparatus shall be provided in which the specimen and porous end pieces, enclosed by a flexible

membrane sealed to the cap and base, are subjected to controlled liquid pressures. A schematic diagram

of a typical cell is shown in Figure 1.
---------------------- Page: 7 ----------------------
oSIST prEN 16416:2021
prEN 16416:2021 (E)

The permeameter cell shall allow for observation of changes in height of the specimen, either by

observation through the cell wall using a suitable instrument or by monitoring of either a loading piston

or an extensometer extending through the top plate of the cell bearing on the top cap and attached to a

suitable measuring device.

The piston or extensometer – if used – shall pass through a bushing and seal incorporated into the top

plate and shall be loaded with sufficient force to compensate for the cell pressure acting over the cross-

sectional area of the piston where it passes through the seal. If deformations are measured, the

deformation indicator shall be graduated to 0,01 mm or better and shall have an adequate travel range.

This piston or extensometer shall not restrict the swelling of the specimen.

To facilitate gas removal, and thus saturation of the hydraulic system, four drainage lines leading to the

specimen, two each to the base and top cap, are recommended. The drainage lines shall be controlled by

no-volume-change valves, such as ball valves, and shall be designed to minimize dead space in the lines.

4.5 Top cap and base

An impermeable, rigid top cap and base shall be used to support the specimen and provide for

transmission of permeant liquid to and from the specimen. The base shall prevent leakage, lateral motion,

or tilting, and the top cap shall be designed to receive the piston or extensometer, if used, such that the

piston-to-top cap contact area is concentric with the cap.

The surface of the base and top cap that contacts the membrane to form a seal shall be smooth and free

of scratches.
---------------------- Page: 8 ----------------------
oSIST prEN 16416:2021
prEN 16416:2021 (E)
Key
1 permeameter cell 6 filter paper
2 end piece 7 back pressure system
3 porous piece 8 outflow volume measuring device
4 specimen
...