EN 17096:2018

SLOVENSKI STANDARD
01-februar-2019
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Geosynthetics - Test method for the determination of the strain hardening modulus of
HDPE geosynthetic barriers
Geokunststoffe - Prüfverfahren für die Bestimmung des Kaltverfestigungsmodus von
HDPE-Kunststoffdichtungsbahnen
Géosynthétiques - Méthode d'essai pour la détermination du module d'écrouissage des
Géomembranes HDPE-HD
Ta slovenski standard je istoveten z: EN 17096:2018
ICS:
59.080.70 Geotekstilije Geotextiles
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 17096
EUROPEAN STANDARD
NORME EUROPÉENNE
November 2018
EUROPÄISCHE NORM
ICS 59.080.70
English Version
Geosynthetics - Test method for the determination of the
strain hardening modulus of PE-HD geosynthetic barriers
Géosynthétiques - Méthode d'essai pour la Geokunststoffe - Prüfverfahren für die Bestimmung des
détermination du module d'écrouissage des Dehnverfestigungsmodul von HDPE-
Géomembranes HDPE Kunststoffdichtungsbahnen
This European Standard was approved by CEN on 15 July 2018.

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. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists 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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2018 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 17096:2018 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 4
4 Principle . 6
5 Apparatus . 6
5.1 Tensile-testing machine . 6
5.2 Devices for measuring the thickness and width of the test specimens . 7
5.3 Punch die tool . 7
5.4 Device for application of the gauge marks . 7
6 Test specimen . 7
6.1 Dimensions and figure of the test specimen . 7
6.2 Test specimen preparation. 8
7 Test procedure . 8
8 Calculation . 9
9 Test report . 9
Annex A (informative) Neo-Hookean constitutive model . 11
Bibliography . 13

European foreword
This document (EN 17096:2018) has been prepared by Technical Committee CEN/TC 189
“Geosynthetics”, the secretariat of which is held by NBN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by May 2019, and conflicting national standards shall be
withdrawn at the latest by May 2019.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
1 Scope
This document specifies a test method for the measurement of the strain hardening modulus which is
used as a measure for the resistance to slow crack growth of polyethylene. The strain hardening
modulus is obtained from true stress versus draw ratio curves on PE-HD geosynthetic barrier samples.
This standard specifies how measurement is performed and how the strain hardening modulus is
determined. Details of the required equipment, precision and sample preparations are given.
This test method is suitable for all PE-HD types of GBR-P.
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 1849-2:2009, Flexible sheets for waterproofing - Determination of thickness and mass per unit area -
Part 2: Plastic and rubber sheets
EN ISO 9863-1:2016, Geosynthetics - Determination of thickness at specified pressures - Part 1: Single
layers (ISO 9863-1:2016)
EN ISO 527-1, Plastics - Determination of tensile properties - Part 1: General principles (ISO 527-1)
EN ISO 7500-1, Metallic materials - Calibration and verification of static uniaxial testing machines - Part
1: Tension/compression testing machines - Calibration and verification of the force-measuring system (ISO
7500-1)
EN ISO 9513, Metallic materials - Calibration of extensometer systems used in uniaxial testing (ISO 9513)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
Note 1 to entry: The symbols, their terms and definitions, as given below, are in line with EN ISO 527-1 and/or
ISO 18488.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1
gauge length
l
initial distance between the gauge marks on the central part of the test specimen
Note 1 to entry: Gauge length is expressed in mm.
3.2
thickness
d
initial dimension of the cross-section perpendicular to the plane in the central part of a test specimen
Note 1 to entry: Thickness is expressed in mm.
3.3
width
b
initial dimension of the cross-section in the central part of a test specimen
Note 1 to entry: Width is expressed in mm.
3.4
test speed
v
rate of separation of the gripping jaws
Note 1 to entry: Test speed is expressed in mm/min.
3.5
length
l
distance between the gauge marks on the central part of the test specimen at any given moment
Note 1 to entry: Length is expressed in mm.
3.6
stress
𝜎𝜎
normal force per unit area of the original cross-section within the gauge length
Note 1 to entry: Stress is expressed in MPa.
3.7
yield stress
𝜎𝜎
y
stress at the strain at yield
Note 1 to entry: Stress at yield is expressed in MPa.
3.8
true stress
𝜎𝜎
T
draw ratio multiplied with the normal force per unit area of the original cross-section within the gauge
length
Note 1 to entry: True stress is expressed in MPa.
3.9
strain
𝜀𝜀
increase in length per unit original length of the gauge
Note 1 to entry: Strain is expressed as a percentage (%).
3.10
strain at yield
𝜀𝜀
y
first occurrence in a tensile test of strain increase without a stress increase
Note 1 to entry: Strain at yield is expressed as a percentage (%).
3.11
draw ratio
λ
actual length per unit original length of the gauge
Note 1 to entry: Draw ratio at yield is expressed as a dimensionless ratio.
3.12
strain hardening modulus

p
slope of the Neo-Hookean constitutive model between a draw ratio of 8 and up to the point of maximum
stress but not above 12
Note 1 to entry: Strain hardening modulus is expressed in MPa.
3.13
variation coefficient
C
ν
standard deviation of the test results divided by the arithmetic mean of the test results multiplied by
Note 1 to entry: Variation coefficient is expressed as a percentage (%).
4 Principle
A stress-strain curve is measured at (80 ± 1) °C sufficiently beyond the natural draw ratio and the strain
hardening modulus determined from the slope after the natural draw ratio (see informative Annex A).
5 Apparatus
5.1 Tensile-testing machine
5.1.1 The machine shall comply with EN ISO 527-1. The tensile-testing machine shall be capable of
maintaining a test speed of (10 ± 2) mm/min.
5.1.2 Load cell, which shall comply with class 1 as defined in EN ISO 7500-1.
Due to measurement at elevated temperature of (80 ± 1) °C, the measured forces are low. Therefore, a
load cell with a range of 250 N is recommended.
5.1.3 Non-contact extensometer, which shall comply with the same accuracy requirements as given
for contact extensometers in EN ISO 9513. A non-contact extensometer shall be used because the test is
performed at an elevated temperature of (80 ± 1) °C. The traverse displacement shall not be used as to
measure strain.
5.1.4 Temperature chamber, to control the temperature at (80 ± 1) °C.
A switch to enable closing and opening the clamps without opening the temperature chamber is
recommended but not necessary, if the testing device is able to hold force of zero.
5.2 Devices for measuring the thickness and width of the test specimens
5.2.1 Thickness (d) shall be measured according to EN ISO 9863-1:2016, Annex A.
5.2.2 Width (b) shall be measured with an optical device with an accuracy of 0,01 mm, according to
EN 1849-2:2009, 5.4.3. Three additional specimens, which are not used for determination of strain
hardening modulus but which are punched using the identical punch die tool as for the test specimens
tested for strain hardening modulus shall be measured optically. A cutting of the cross section area
perpendicular to the axis of the specimen within the gauge length of each of the three specimens shall
be prepared. The widest width as well as the narrowest width of each specimen’s cutting shall be
determined and recorded. The mean value of all six values regarding width (two measured values per
specimen) will be applied for all test specimens tested for strain hardening modulus for calculation of
stress.
The dimensions of the cross section area have a great influence on the value of strain hardening
modulus. Due to the punching, the width of specimens might be conical shaped. The dimensions close to
the bottom surface of the geosynthetic barrier and close to the top surface of the geosynthetic barrier
might be significantly different. Mechanical measurement of width cannot take this into account.
Therefore, special attention has to be payed to determination of width by performing optical
measurements instead of mechanical measurements.
5.3 Punch die tool
A punch die tool for the specimen geometry specified in 6.1 shall be used.
5.4 Device for application of the gauge marks
A suitable device for the application of the gauge marks for the non-contact extensometer shall be used.
The gauge mark shall be suitable for the optical sensor system used.
6 Test specimen
6.1 Dimensions and figure of the test specimen
The specimen geometry as shown in Figure 1 shall be used.
A large clamping area of the specimen to avoid slippage in the clamps is required to accurately measure
the strain hardening regime.
Key
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