SIST EN 302-2:2023
(Main)Adhesives for load-bearing timber structures - Test methods - Part 2: Determination of resistance to delamination
Adhesives for load-bearing timber structures - Test methods - Part 2: Determination of resistance to delamination
This document specifies a method for determining the resistance to delamination in glue lines.
It is suitable for the following applications:
a) for assessing the compliance of adhesives with EN 301, EN 15425, EN 16254, EN 17334 and EN 17418;
b) for assessing the suitability and quality of adhesives for load-bearing timber structures;
c) for comparing the effects on the bond strength resulting from the choice of bonding conditions, from different climatic conditioning and from the treatment of the test pieces before and after bonding.
This test is not applicable for modified and stabilized wood with strongly reduced swelling and shrinkage properties, such as acetylated wood, heat-treated wood and polymer impregnated wood.
This test is intended primarily to obtain performance data for the classification of adhesives for load-bearing timber structures according to their suitability for use in defined climatic environments.
This method is not intended to provide data for structural design and does not necessarily represent the performance of the bonded member in service.
Klebstoffe für tragende Holzbauteile - Prüfverfahren - Teil 2: Bestimmung der Delaminierungsbeständigkeit
Diesem Dokument legt ein Verfahren zur Bestimmung der Beständigkeit von Klebstoffverbindungen gegen Delaminierung fest.
Es ist für folgende Anwendungsfälle geeignet:
a) zur Beurteilung der Übereinstimmung von Klebstoffen mit EN 301, EN 15425, EN 16254, EN 17334 und EN 17418;
b) zur Beurteilung der Eignung und Qualität von Klebstoffen für tragende Holzbauteile;
c) zum Vergleich der Auswirkungen der gewählten Verklebungsbedingungen von verschiedenen klimatischen Beanspruchungen und von der Behandlung der Prüfkörper vor und nach der Verklebung auf die Klebfestigkeit.
Diese Prüfung gilt nicht für modifiziertes und vergütetes Holz mit stark verringerten Quellungs- und Schwindungseigenschaften, wie beispielsweise acetyliertes Holz, wärmebehandeltes Holz und polymerimprägniertes Holz.
Diese Prüfung ist hauptsächlich dafür vorgesehen, Leistungsdaten für die Klassifizierung von Klebstoffen für tragende Holzbauteile entsprechend ihrer Eignung zur Verwendung in festgelegten klimatischen Umgebungen zu erhalten.
Dieses Verfahren ist nicht dafür vorgesehen, Bemessungswerte bereitzustellen, und gibt nicht zwangsläufig die Leistungsfähigkeit des verklebten Bauteiles im Gebrauch wieder.
Adhésifs pour structures portantes en bois - Méthodes d’essai - Partie 2 : Détermination de la résistance à la délamination
Le présent document spécifie une méthode qui permet de déterminer la résistance à la délamination des joints de colle.
Cette méthode s’applique dans les cas suivants :
a) évaluation de la conformité des adhésifs aux EN 301, EN 15425, EN 16254, EN 17334 et EN 17418 ;
b) évaluation de l’aptitude à l’emploi et de la qualité des adhésifs pour les structures portantes en bois ;
c) comparaison des effets sur la résistance à la rupture d’un joint en fonction du choix des conditions de collage, des divers conditionnements climatiques et du traitement des éprouvettes avant et après le collage.
Cet essai ne s’applique pas aux bois modifiés et stabilisés ayant des propriétés de retrait et de gonflement fortement réduites, par exemple les bois acétylés, les bois traités thermiquement et les bois imprégnés de polymère.
Cet essai vise principalement à obtenir des données de performance en vue de la classification des adhésifs pour structures portantes en bois en fonction de leur aptitude à l’utilisation dans des environnements climatiques définis.
Cette méthode n’est pas destinée à fournir des données pour le calcul des structures et ne représente pas nécessairement les performances en service de l’élément collé.
Lepila za nosilne lesene konstrukcije - Preskusne metode - 2. del: Ugotavljanje odpornosti lepljenega stika proti razslojevanju (delaminaciji)
Ta dokument določa metodo za ugotavljanje odpornosti lepljenega stika proti razslojevanju (delaminaciji).
Metoda se uporablja:
a) za oceno skladnosti lepil s standardi EN 301, EN 15425, EN 16254, EN 17334 in EN 17418;
b) za oceno ustreznosti in kakovosti lepil za nosilne lesene konstrukcije;
c) za primerjavo vpliva na sprijemno trdnost, ki izhaja iz izbire pogojev lepljenja, različnih podnebnih danosti in obdelave preskusnih kosov pred lepljenjem in po njem.
Ta preskus se ne uporablja za obdelan in stabiliziran les, ki se bistveno manj nabreka in krči, kot so acetiliran les, toplotno obdelan les in polimerno impregniran les.
Ta preskus je namenjen zlasti pridobivanju podatkov o lastnostih za razvrstitev lepil za nosilne lesene konstrukcije glede na njihovo ustreznost za uporabo v opredeljenih podnebnih okoljih.
Ta metoda ni namenjena zagotavljanju podatkov za konstrukcijsko zasnovo, pri čemer ne predstavlja nujno lastnosti zlepljenega elementa v uporabi.
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN 302-2:2023
01-april-2023
Lepila za nosilne lesene konstrukcije - Preskusne metode - 2. del: Ugotavljanje
odpornosti lepljenega stika proti razslojevanju (delaminaciji)
Adhesives for load-bearing timber structures - Test methods - Part 2: Determination of
resistance to delamination
Klebstoffe für tragende Holzbauteile - Prüfverfahren - Teil 2: Bestimmung der
Delaminierungsbeständigkeit
Adhésifs pour structures portantes en bois - Méthodes d’essai - Partie 2 : Détermination
de la résistance à la délamination
Ta slovenski standard je istoveten z: EN 302-2:2023
ICS:
83.180 Lepila Adhesives
91.080.20 Lesene konstrukcije Timber structures
SIST EN 302-2:2023 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST EN 302-2:2023
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SIST EN 302-2:2023
EN 302-2
EUROPEAN STANDARD
NORME EUROPÉENNE
February 2023
EUROPÄISCHE NORM
ICS 83.180 Supersedes EN 302-2:2017
English Version
Adhesives for load-bearing timber structures - Test
methods - Part 2: Determination of resistance to
delamination
Adhésifs pour structures portantes en bois - Méthodes Klebstoffe für tragende Holzbauteile - Prüfverfahren -
d'essai - Partie 2 : Détermination de la résistance à la Teil 2: Bestimmung der Delaminierungsbeständigkeit
délamination
This European Standard was approved by CEN on 18 December 2022.
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, 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, Türkiye 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
© 2023 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 302-2:2023 E
worldwide for CEN national Members.
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SIST EN 302-2:2023
EN 302-2:2023 (E)
Contents Page
European foreword . 3
Introduction . 4
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Symbols . 7
5 Principle . 7
6 Apparatus . 7
7 Method . 8
7.1 Selection of timber . 8
7.2 Preparation of the bonded members . 8
7.2.1 Bonded members with thin glue lines. 8
7.2.2 Bonded members with thick glue lines. 9
7.3 Preparation of test pieces . 10
7.3.1 Bonded members with thin glue lines. 10
7.3.2 Bonded members with thick glue lines. 10
7.4 Test procedures . 10
7.4.1 General. 10
7.4.2 High temperature procedure (for type I adhesives) . 10
7.4.3 Low temperature procedure (for type II adhesives) . 11
7.5 Measurement and evaluation of delamination . 12
8 Expression of results . 13
9 Test report . 13
9.1 The adhesives . 13
9.2 Preparation of test pieces and testing procedure . 14
9.3 Test results . 14
2
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SIST EN 302-2:2023
EN 302-2:2023 (E)
European foreword
This document (EN 302-2:2023) has been prepared by Technical Committee CEN/TC 193 “Adhesives”,
the secretariat of which is held by UNE.
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 August 2023, and conflicting national standards shall
be withdrawn at the latest by August 2023.
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.
This document supersedes EN 302-2:2017.
Compared to EN 302-2:2017, the following modifications have been made:
a) the list of standards in the Introduction has been updated;
b) two new standards, EN 17334 and EN 17418, have been included in the Scope;
c) two new clauses (Terms and definitions and Symbols) have been introduced;
d) for preservative treated wood the test with pine also covers fir and spruce;
e) 2 mm glue line thickness has been replaced by thick glue lines;
f) nominal glue line thickness of test pieces has been included under 9.2;
g) the Bibliography has been deleted.
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
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, 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, Türkiye and the
United Kingdom.
3
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SIST EN 302-2:2023
EN 302-2:2023 (E)
Introduction
This document is one of a series dealing with adhesives for use with timber structures, and is published
in support of the EN 1995 series, Eurocode 5: Design of timber structures. The series consists of five
classification and performance requirements for adhesives for load-bearing timber structures, phenolic
and aminoplastic adhesives (EN 301), one component polyurethane adhesives (EN 15425), emulsion
polymer isocyanate adhesives (EN 16254), two component epoxy and polyurethane adhesives for glued
in rods (EN 17334) and for on-site repair of cracked timber structures (EN 17418) and all together
twelve test methods (EN 302-1, EN 302-2, EN 302-3, EN 302-4, EN 302-5, EN 302-6, EN 302-7 and
EN 302-8 and EN 15416-1, EN 15416-3, EN 15416-4 and EN 15416-5).
These European Standards have the following titles:
EN 301, Adhesives, phenolic and aminoplastic, for load-bearing timber structures — Classification and
performance requirements
EN 302, Adhesives for load-bearing timber structures — Test methods:
— Part 1: Determination of longitudinal tensile shear strength
— Part 2: Determination of resistance to delamination
— Part 3: Determination of the effect of acid damage to wood fibres by temperature and humidity
cycling on the transverse tensile strength
— Part 4: Determination of the effects of wood shrinkage on the shear strength
— Part 5: Determination of maximum assembly time under referenced conditions
— Part 6: Determination of the minimum pressing time under referenced conditions
— Part 7: Determination of the working life under referenced conditions
— Part 8: Static load test of multiple bond line specimens in compression shear
EN 15416, Adhesives for load bearing timber structures other than phenolic and aminoplastic — Test
methods:
— Part 1: Long-term tension load test perpendicular to the bond line at varying climate conditions with
specimens perpendicular to the glue line (Glass house test)
— Part 3: Creep deformation test at cyclic climate conditions with specimens loaded in bending shear
— Part 4: Determination of open assembly time under referenced conditions
— Part 5: Determination of minimum pressing time under referenced conditions
EN 15425, Adhesives — One component polyurethane (PUR) for load-bearing timber structures —
Classification and performance requirements
EN 16254, Adhesives — Emulsion polymer isocyanate (EPI) for load-bearing timber structures —
Classification and performance requirements
4
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SIST EN 302-2:2023
EN 302-2:2023 (E)
EN 17334, Glued-in rods in glued structural timber products — Testing, requirements and bond shear
strength classification
EN 17418, Two-component epoxy and polyurethane adhesives for on-site repair of cracked timber
structures — Testing, requirements and repair strength verification
Safety statement
Persons using this document should be familiar with the normal laboratory practice, if applicable. This
document cannot address all of the safety problems, if any, associated with its use. It is the
responsibility of the user to establish appropriate safety and health practices and to ensure compliance
with any regulatory conditions.
Environmental statement
It is understood that some of the material permitted in this standard can have a negative environmental
impact. As technological advantages lead to better alternatives for these materials, they will be
eliminated from this standard to the greatest extent possible.
At the end of the test, it is recommended that the users of the standard take care to carry out an
appropriate disposal of the wastes, according to local regulations.
5
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SIST EN 302-2:2023
EN 302-2:2023 (E)
1 Scope
This document specifies a method for determining the resistance to delamination in glue lines.
It is applicable to the following applications:
a) for assessing the compliance of adhesives with EN 301, EN 15425, EN 16254, EN 17334 and
EN 17418;
b) for assessing the suitability and quality of adhesives for load-bearing timber structures;
c) for comparing the effects on the bond strength resulting from the choice of bonding conditions,
from different climatic conditioning and from the treatment of the test pieces before and after
bonding.
This test does not apply to modified and stabilized wood with strongly reduced swelling and shrinkage
properties, such as acetylated wood, heat-treated wood and polymer impregnated wood.
This test is intended primarily to obtain performance data for the classification of adhesives for load-
bearing timber structures according to their suitability for use in defined climatic environments.
This method is not intended to provide data for structural design and does not necessarily represent
the performance of the bonded member in service.
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 384:2016+A2:2022, Structural timber - Determination of characteristic values of mechanical
properties and density
EN 923, Adhesives - Terms and definitions
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 923 and the following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at https://www.electropedia.org/
3.1
glue line
adhesive layer between the wood members
3.2
thick glue line
glue line of nominal thickness of more than 0,1 mm, at the time of bonding
Note 1 to entry: Thick glue lines are achieved by using spacers, grooves or similar devices when two plain
members are glued together.
6
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SIST EN 302-2:2023
EN 302-2:2023 (E)
3.3
close contact glue line
glue line of thickness maximum 0,1 mm
Note 1 to entry: Close contact glue line can be achieved by pressing together two plane wood members with a
2
clamping pressure of (0,8 ± 0,1) N/mm without additional grooves, spacers or similar devices.
2
Note 2 to entry: A clamping pressure of (0,6 ± 0,1) N/mm is considered a sufficient pressure to form close
contact glue line in this test.
4 Symbols
D delamination
l total delamination length on both end-grain surfaces
1
l total nominal length of the glue lines on both end-grain surfaces
2
m original mass of the test piece
o
t nominal thickness of the thick glueline
5 Principle
Bonded, laminated specimens are subjected to an impregnation-drying procedure. The specimens are
impregnated with water by immersing them and applying alternating high and low (vacuum) pressure.
They are then dried rapidly in a specified air stream at low humidity (see 6.4). The extent of open glue
lines, delamination, as a result of these treatments is measured and compared with the total length of
glue lines on both end-grain faces of the specimen.
6 Apparatus
6.1 Autoclave or similar pressure vessel designed to safely withstand a pressure of at least
625 kPa absolute (525 kPa above nominal atmospheric pressure).
6.2 Vacuum pump or similar device, capable of reducing the pressure in the vessel (6.1) to below
20 kPa absolute (80 kPa below nominal atmospheric pressure).
6.3 Pump or similar device, for obtaining a pressure of at least 600 kPa absolute (500 kPa above
nominal atmospheric pressure).
6.4 Air-circulating oven(s) or chamber(s), capable of drying the test pieces (see 7.4) in the
following climate condition:
a) for low temperature procedure (type II adhesive) a temperature of (27,5 ± 2,5) °C, circulating the
air within the chamber, maintaining a constant relative humidity of (30 ± 5) %; and
b) for high temperature procedure (type I adhesive) a temperature of (65 ± 3) °C, circulating the air
within the chamber, maintaining a relative humidity of (12,5 ± 2,5) %.
NOTE Air speed velocity of 2 m/s to 3 m/s in empty chamber has shown to be suitable to achieve drying
times according to 7.4.2 and 7.4.3.
6.5 Balance, allowing measurements with an uncer
...
SLOVENSKI STANDARD
oSIST prEN 302-2:2021
01-november-2021
Nadomešča:
SIST EN 302-2:2017
Lepila za nosilne lesene konstrukcije - Preskusne metode - 2. del: Ugotavljanje
odpornosti lepljenega stika proti razslojevanju (delaminaciji)
Adhesives for load-bearing timber structures - Test methods - Part 2: Determination of
resistance to delamination
Klebstoffe für tragende Holzbauteile - Prüfverfahren - Teil 2: Bestimmung der
Delaminierungsbeständigkeit
Adhésifs pour structures portantes en bois - Méthodes d'essais - Partie 2 : Détermination
de la résistance à la délamination
Ta slovenski standard je istoveten z: prEN 302-2
ICS:
83.180 Lepila Adhesives
91.080.20 Lesene konstrukcije Timber structures
oSIST prEN 302-2:2021 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
---------------------- Page: 1 ----------------------
oSIST prEN 302-2:2021
---------------------- Page: 2 ----------------------
oSIST prEN 302-2:2021
DRAFT
EUROPEAN STANDARD
prEN 302-2
NORME EUROPÉENNE
EUROPÄISCHE NORM
September 2021
ICS 83.180 Will supersede EN 302-2:2017
English Version
Adhesives for load-bearing timber structures - Test
methods - Part 2: Determination of resistance to
delamination
Adhésifs pour structures portantes en bois - Méthodes Klebstoffe für tragende Holzbauteile - Prüfverfahren -
d'essais - Partie 2 : Détermination de la résistance à la Teil 2: Bestimmung der Delaminierungsbeständigkeit
délamination
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 193.
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 302-2:2021 E
worldwide for CEN national Members.
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oSIST prEN 302-2:2021
prEN 302-2:2021 (E)
Contents Page
European foreword . 3
Introduction . 4
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Symbols . 7
5 Principle . 7
6 Apparatus . 7
7 Method . 7
7.1 Selection of timber . 7
7.2 Preparation of the bonded members . 8
7.3 Preparation of test pieces . 9
7.4 Test procedures . 9
7.5 Measurement and evaluation of delamination . 11
8 Expression of results . 12
9 Test report . 12
9.1 The adhesives . 12
9.2 Preparation of test pieces and testing procedure . 13
9.3 Test results . 13
Bibliography . 14
2
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oSIST prEN 302-2:2021
prEN 302-2:2021 (E)
European foreword
This document (prEN 302-2:2021) has been prepared by Technical Committee CEN/TC 193 “Adhesives”,
the secretariat of which is held by UNE.
This document is currently submitted to the CEN Enquiry.
This document will supersede EN 302-2:2017.
In comparison with the previous edition, the following technical modifications have been made:
— list of standards in Introduction updated;
— two new standards, EN 17334 and EN 17418, have been included in the scope;
— two new clauses (Terms and definitions and Symbols) are introduced;
— the Bibliography has been deleted.
3
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oSIST prEN 302-2:2021
prEN 302-2:2021 (E)
Introduction
This document is one of a series dealing with adhesives for use with timber structures, and is published
in support of EN 1995, Eurocode 5: Design of timber structures. The series consists of five classification
and performance requirements for adhesives for load-bearing timber structures, phenolic and
aminoplastic adhesives (EN 301), one component polyurethane adhesives (EN 15425), emulsion
polymerised isocyanate adhesives (EN 16254), two component epoxy and polyurethane adhesives for
glued in rods (EN 17334) and for on-site repair of cracked timber structures (EN 17418) and all together
twelve test methods (EN 302-1, EN 302-2, EN 302-3, EN 302-4, EN 302-5, EN 302-6, EN 302-7 and
EN 302-8 and EN 15416-1, EN 15416-3, EN 15416-4 and EN 15416-5).
These European Standards have the following titles:
EN 301, Adhesives, phenolic and aminoplastic, for load-bearing timber structures — Classification and
performance requirements
EN 302, Adhesives for load-bearing timber structures — Test methods
— Part 1: Determination of longitudinal tensile shear strength
— Part 2: Determination of resistance to delamination
— Part 3: Determination of the effect of acid damage to wood fibres by temperature and humidity
cycling on the transverse tensile strength
— Part 4: Determination of the effects of wood shrinkage on the shear strength
— Part 5: Determination of maximum assembly time under referenced conditions
— Part 6: Determination of the minimum pressing time under referenced conditions
— Part 7: Determination of the working life under referenced conditions
— Part 8: Static load test of multiple bond line specimens in compression shear
EN 15416, Adhesives for load bearing timber structures other than phenolic and aminoplastic — Test
methods
— Part 1: Long-term tension load test perpendicular to the bond line at varying climate conditions
with specimens loaded perpendicular to the glue line (Glasshouse test)
— Part 3: Creep deformation test at cyclic climate conditions with specimens loaded in bending shear
— Part 4: Determination of open assembly time under referenced conditions
— Part 5: Determination of minimum pressing time under referenced conditions
EN 15425, Adhesives — One component polyurethane (PUR) for load bearing timber structures —
Classification and performance requirements
EN 16254, Adhesives — Emulsion polymerized isocyanate (EPI), for load-bearing timber structures —
Classification and performance requirements
EN 17334, Glued-in rods in glued structural timber products — Testing, requirements and bond shear
strength classification
EN 17418, Two-component epoxy and polyurethane adhesives for on-site repair of cracked timber
structures — Testing, requirements, and repair strength verification
4
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oSIST prEN 302-2:2021
prEN 302-2:2021 (E)
Safety statement
Persons using this document should be familiar with the normal laboratory practice, if applicable. This
document cannot address all of the safety problems, if any, associated with its use. It is the responsibility
of the user to establish appropriate safety and health practices and to ensure compliance with any
regulatory conditions.
Environmental statement
It is understood that some of the material permitted in this standard can have a negative environmental
impact. As technological advantages lead to better alternatives for these materials, they will be eliminated
from this standard to the greatest extent possible.
At the end of the test, it is recommended that the user of the standard take care to carry out an appropriate
disposal of the wastes, according to local regulations.
5
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oSIST prEN 302-2:2021
prEN 302-2:2021 (E)
1 Scope
This document specifies a method for determining the resistance to delamination in glue lines.
It is suitable for the following applications:
a) for assessing the compliance of adhesives with EN 301, EN 15425, EN 16254, EN 17334 and
EN 17418;
b) for assessing the suitability and quality of adhesives for load-bearing timber structures;
c) for comparing the effects on the bond strength resulting from the choice of bonding conditions, from
different climatic conditioning and from the treatment of the test pieces before and after bonding.
This test is not applicable for modified and stabilized wood with strongly reduced swelling and shrinkage
properties, such as acetylated wood, heat-treated wood and polymer impregnated wood.
This test is intended primarily to obtain performance data for the classification of adhesives for load-
bearing timber structures according to their suitability for use in defined climatic environments.
This method is not intended to provide data for structural design and does not necessarily represent the
performance of the bonded member in service.
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 923, Adhesives - Terms and definitions
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 923 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at https://www.electropedia.org/
3.1
glue line
adhesive layer between the wood members
3.2
thick glue line
glue line of nominal thickness of more than 0,1 mm, at the time of bonding, achieved by using spacers
3.3
close contact glue line
glue line of thickness maximum 0,1 mm
Note 1 to entry: Close contact glue line can be achieved by pressing together two plane wood members with a
2
clamping pressure of (0,8 ± 0,1) N/mm without additional grooves, spacers or similar devices.
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oSIST prEN 302-2:2021
prEN 302-2:2021 (E)
4 Symbols
D delamination
l total delamination length
1
l total nominal length of the glue lines
2
5 Principle
Bonded, laminated specimens are subjected to an impregnation-drying procedure. The specimens are
impregnated with water by immersing them and applying alternating high and low (vacuum) pressure.
They are then dried rapidly in a specified air stream at low humidity (see 6.4). The extent of open glue
lines, delamination, as a result of these treatments is measured and compared with the total length of
glue lines on both end-grain faces of the specimen.
6 Apparatus
6.1 Autoclave or similar pressure vessel designed to safely withstand a pressure of at least 625 kPa
absolute (525 kPa above nominal atmospheric pressure).
6.2 Vacuum pump or similar device, capable of reducing the pressure in the vessel (6.1) to below
20 kPa absolute (80 kPa below nominal atmospheric pressure).
6.3 Pump or similar device, for obtaining a pressure of at least 600 kPa absolute (500 kPa above
nominal atmospheric pressure).
6.4 Air-circulating oven(s) or chamber(s), capable of drying the test pieces (see 7.4.2) in the
following climate condition:
a) for low temperature procedure (type II adhesive) a temperature of (27,5 ± 2,5) °C, circulating the air
within the chamber, maintaining a constant relative humidity of (30 ± 5) %; and
b) for high temperature procedure (type I adhesive) a temperature of (65 ± 3) °C, circulating the air
within the chamber, maintaining a relative humidity of (12,5 ± 2,5) %.
NOTE Air speed velocity of 2 m/s to 3 m/s in empty chamber has shown to be suitable to achieve drying times
according to 7.4.2 and 7.4.3.
6.5 Balance, allowing measurements with an accuracy of ±1 g.
6.6 Wood chisel and hammer, or similar devices capable of opening the glue lines.
7 Method
7.1 Selection of timber
Use flat-sawn, straight-grained Norway spruce (Picea abies L.), free of reaction wood, with a density of
3
(450 ± 25) kg/m at (12 ± 1) % moisture content. Preferably, knot-free wood should be used, but
allowances are made for boards with knots up to a maximum of 20 mm in diameter, but splay (spike)
knot is not allowed. The test with Norway spruce also covers approval of silver fir (Abies alba) and Scots
pine (Pinus sylvestris).
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oSIST prEN 302-2:2021
prEN 302-2:2021 (E)
If the adhesive is to be used on wood from other conifer species like larch (Larix decidua), Douglas fir
(Pseudotsuga menziesii) and pines with coloured heartwood [other than Scots pine (Pinus sylvestris)],
from hardwood species and/or on preservative treated wood, also prepare four laminated members
using representative samples of this wood species, using wood with mean density.
For preservative treated wood the test with Scots pine (Pinus sylvestris) also covers approval for the
bonding of silver fir (Abies alba) and Norway spruce (Picea abies L.).
NOTE The effectiveness of the preservative treatment is not dealt with in this document.
Condition the timber in the standard climate [20/65] (20 ± 2) °C and a relative humidity of (65 ± 5) % for
at least 7 days prior to
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