SIST EN 302-8:2023
(Main)Adhesives for load-bearing timber structures - Test methods - Part 8: Static load test of multiple bond line specimens in compression shear
Adhesives for load-bearing timber structures - Test methods - Part 8: Static load test of multiple bond line specimens in compression shear
This document specifies a method of determining the ability of adhesive bonds to resist static load. It is applicable to adhesives used in load bearing timber structures.
It is suitable for the following applications:
a) for assessing the compliance of adhesives according to EN 301, EN 15425 and EN 16254;
b) for assessing the suitability and quality of adhesives for load-bearing timber structures;
c) for assessing the effect on the bond strength resulting from constant load at different climate conditions.
This method 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 8: Statische Belastungsprüfung an Prüfkörpern mit mehreren Klebfugen bei Druck-Scherbeanspruchung
Dieses Dokument legt ein Verfahren zur Bestimmung der Beständigkeit von Klebstoffverbindungen gegen statische Belastung fest. Es gilt für Klebstoffe, die für tragende Holzbauteile verwendet werden.
Das Verfahren ist für folgende Anwendungsfälle geeignet:
a) zur Beurteilung der Übereinstimmung von Klebstoffen mit EN 301, EN 15425 und EN 16254;
b) zur Beurteilung der Eignung und Qualität von Klebstoffen für tragende Holzbauteile;
c) zur Beurteilung der Auswirkung von konstanter Belastung bei verschiedenen Klimabedingungen auf die Klebfestigkeit.
Dieses Verfahren dient hauptsächlich zur Bestimmung von Leistungswerten zur Klassifizierung von Klebstoffen für tragende Holzbauteile entsprechend ihrer Eignung zum Einsatz unter bestimmten Klimabedingungen.
Dieses Verfahren ist nicht dafür vorgesehen, Bemessungswerte bereitzustellen und gibt nicht zwangsläufig das Verhalten des verklebten Bauteiles im Gebrauch wieder.
Adhésifs pour structures portantes en bois - Méthodes d'essai - Partie 8 : Essai de charge statique d'éprouvettes à joints de colle multiples en cisaillement par compression
Le présent document spécifie une méthode de détermination de la résistance à la charge statique des joints de colle. Cette méthode est applicable aux adhésifs utilisés sur des structures portantes en bois.
Elle convient aux applications suivantes :
a) l’évaluation de la conformité des adhésifs aux normes EN 301, EN 15425 et EN 16254 ;
b) l’évaluation de l’aptitude à l’emploi et de la qualité des adhésifs destinés aux structures portantes en bois ;
c) l’évaluation de l’incidence d’une charge constante appliquée dans différentes conditions climatiques sur la résistance à la rupture d’un joint.
Cette méthode a pour objectif principal de permettre l’obtention de données relatives aux performances en vue de classer les adhésifs destinés aux structures portantes en bois suivant leur aptitude à l’emploi dans des conditions climatiques définies.
Elle n’est pas destinée à permettre l’obtention de données utilisables pour le calcul des structures, et ne représente pas nécessairement les performances en service du produit collé.
Lepila za nosilne lesene konstrukcije - Preskusne metode - 8. del: Preskus statične obremenitve preskušancev z več lepljenimi spoji pri tlačni strižni obremenitvi
Ta dokument določa metodo za ugotavljanje odpornosti lepil proti statični obremenitvi. Uporablja se za lepila za nosilne lesene konstrukcije.
Uporablja se:
a) za oceno skladnosti lepil s standardi EN 301, EN 15425 in EN 16254;
b) za oceno ustreznosti in kakovosti lepil za nosilne lesene konstrukcije;
c) za oceno vpliva na sprijemno trdnost, ki je posledica neprekinjene obremenitve pri različnih podnebnih razmerah.
Ta metoda je namenjena zlasti za pridobivanje 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 302-8:2023
01-julij-2023
Lepila za nosilne lesene konstrukcije - Preskusne metode - 8. del: Preskus statične
obremenitve preskušancev z več lepljenimi spoji pri tlačni strižni obremenitvi
Adhesives for load-bearing timber structures - Test methods - Part 8: Static load test of
multiple bond line specimens in compression shear
Klebstoffe für tragende Holzbauteile - Prüfverfahren - Teil 8: Statische
Belastungsprüfung an Prüfkörpern mit mehreren Klebfugen bei Druck-
Scherbeanspruchung
Adhésifs pour structures portantes en bois - Méthodes d'essai - Partie 8 : Essai de
charge statique d'éprouvettes à joints de colle multiples en cisaillement par compression
Ta slovenski standard je istoveten z: EN 302-8:2023
ICS:
83.180 Lepila Adhesives
91.080.20 Lesene konstrukcije Timber structures
SIST EN 302-8:2023 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST EN 302-8:2023
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SIST EN 302-8:2023
EN 302-8
EUROPEAN STANDARD
NORME EUROPÉENNE
April 2023
EUROPÄISCHE NORM
ICS 83.180 Supersedes EN 302-8:2017
English Version
Adhesives for load-bearing timber structures - Test
methods - Part 8: Static load test of multiple bond line
specimens in compression shear
Adhésifs pour structures portantes en bois - Méthodes Klebstoffe für tragende Holzbauteile - Prüfverfahren -
d'essai - Partie 8 : Essai de charge statique Teil 8: Statische Belastungsprüfung an Prüfkörpern mit
d'éprouvettes à joints de colle multiples en cisaillement mehreren Klebfugen bei Druck-Scherbeanspruchung
par compression
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 302-8:2023 E
worldwide for CEN national Members.
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SIST EN 302-8:2023
EN 302-8:2023 (E)
Contents Page
European foreword . 3
Introduction . 4
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 7
4 Principle . 7
5 Apparatus . 7
5.1 Test jig . 7
5.2 Equipment for climate control . 10
5.3 Testing machine . 10
6 Test specimens . 10
6.1 Selection of wood . 10
6.2 Preparation of the laminated members . 10
6.2.1 Test pieces with close contact glue line . 10
6.3 Preparation of test specimens . 17
7 Test procedure . 18
7.1 Application of load . 18
7.2 Test climates . 19
7.3 Measurements and evaluation of result . 19
8 Test report . 19
8.1 The adhesives . 19
8.2 Preparation of test pieces and testing procedure . 20
8.3 Test results . 20
2
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SIST EN 302-8:2023
EN 302-8:2023 (E)
European foreword
This document (EN 302-8:2023) 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 October 2023, and conflicting national standards shall
be withdrawn at the latest by October 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 302-8:2017.
The main changes compared to the previous edition are listed below:
a) test of test pieces with bond line thickness 0,5 mm, 1 mm and 2 mm has been included in the
document;
b) Clause 8 Test report has been deleted;
c) 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 302-8:2023
EN 302-8:2023 (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,
EN 302-8, 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 302-8:2023
EN 302-8:2023 (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 document may have negative environmental
impact. As technological advantages lead to better alternatives for these materials, they will be
eliminated from this document to the extent possible.
At the end of the test, it is recommended that the users of this document take care to carry out an
appropriate disposal of the wastes, according to local regulation.
5
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SIST EN 302-8:2023
EN 302-8:2023 (E)
1 Scope
This document specifies a method of determining the ability of adhesive bonds to resist static load. It is
applicable to adhesives used in load bearing timber structures.
It is applicable for the following applications:
a) for assessing the compliance of adhesives according to 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 assessing the effect on the bond strength resulting from constant load at different climate
conditions.
This method 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 301, Adhesives, phenolic and aminoplastic, for load-bearing timber structures - Classification and
performance requirements
EN 384:2016+A2:2022, Structural timber - Determination of characteristic values of mechanical
properties and density
EN 923, Adhesives - Terms and definitions
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
6
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SIST EN 302-8:2023
EN 302-8:2023 (E)
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 in the range of 0,5 mm to 2,0 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.
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.
4 Principle
Bonded test pieces are subjected to a constant compression shear load under a series of three different
climates. Number of failures and the amount of deformation is measured after the end of the last
climate cycle.
5 Apparatus
5.1 Test jig
The test equipment is shown in Figure 1 and Figure 2.
7
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SIST EN 302-8:2023
EN 302-8:2023 (E)
Dimensions in millimetres
Key
1 top plate
2 spacer plate
3 base plate
4 tension rod
5 centre rod
Figure 1 — Test jig
8
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SIST EN 302-8:2023
EN 302-8:2023 (E)
Dimensions in millimetres
Key
1 top plate 4 tension rod (the given lengths are minimum values)
2 spacer plate 5 centre rod (the given length is a minimum value)
3 base plate
Figure 2 — Nominal dimensions of plates and rods
If longer rods are used, distance blocks need to be placed on top and/or under the specimen. The
distance blocks shall be prepared in such a way that the two contact surfaces, between the distance
9
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SIST EN 302-8:2023
EN 302-8:2023 (E)
block and the jig and between the distance block and the specimen, are parallel. Dimension of distance
blocks: at least 48 mm × 51 mm × 10 mm.
NOTE 1 Blocks produced from several pieces of plywood bonded together have been found suitable.
The spring shall have the following characteristics:
— outside diameter (unloaded): 105 mm;
— end fix: both ends fixed and grounded;
— free length: 320 mm;
— compression at maximum load: 45 mm to 50 mm.
NOTE 2 A spring rate of 81 N/mm has been shown to be suitable.
5.2 Equipment for climate control
The equipment used shall be c
...
SLOVENSKI STANDARD
oSIST prEN 302-8:2022
01-april-2022
Lepila za nosilne lesene konstrukcije - Preskusne metode - 8. del: Preskus statične
obremenitve preskušancev z več lepljenimi spoji pri tlačni strižni obremenitvi
Adhesives for load-bearing timber structures - Test methods - Part 8: Static load test of
multiple bond line specimens in compression shear
Klebstoffe für tragende Holzbauteile - Prüfverfahren - Teil 8: Statische
Belastungsprüfung an Prüfkörpern mit mehreren Klebfugen bei Druck-
Scherbeanspruchung
Adhésifs pour structures portantes en bois - Méthodes d'essai - Partie 8 : Essai de
charge statique d'éprouvettes à joints de colle multiples en cisaillement par compression
Ta slovenski standard je istoveten z: prEN 302-8
ICS:
83.180 Lepila Adhesives
91.080.20 Lesene konstrukcije Timber structures
oSIST prEN 302-8:2022 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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oSIST prEN 302-8:2022
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oSIST prEN 302-8:2022
DRAFT
EUROPEAN STANDARD
prEN 302-8
NORME EUROPÉENNE
EUROPÄISCHE NORM
February 2022
ICS 83.180 Will supersede EN 302-8:2017
English Version
Adhesives for load-bearing timber structures - Test
methods - Part 8: Static load test of multiple bond line
specimens in compression shear
Adhésifs pour structures portantes en bois - Méthodes Klebstoffe für tragende Holzbauteile - Prüfverfahren -
d'essai - Partie 8 : Essai de charge statique Teil 8: Statische Belastungsprüfung an Prüfkörpern mit
d'éprouvettes à joints de colle multiples en cisaillement mehreren Klebfugen bei Druck-Scherbeanspruchung
par compression
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
© 2022 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 302-8:2022 E
worldwide for CEN national Members.
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oSIST prEN 302-8:2022
prEN 302-8:2022 (E)
Contents Page
European foreword . 3
Introduction . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Principle . 6
5 Apparatus . 7
5.1 Test jig . 7
5.2 Equipment for climate control . 9
5.3 Testing machine . 9
6 Test specimens . 9
6.1 Selection of wood . 9
6.2 Preparation of the laminated members. 9
6.2.1 Test pieces with thin bond line . 9
6.2.2 Test pieces with thick bond line . 12
6.3 Preparation of test specimens . 16
7 Test procedure . 17
7.1 Application of load . 17
7.2 Test climates . 17
7.3 Measurements and evaluation of result . 18
8 Test report . 18
Bibliography . 20
2
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oSIST prEN 302-8:2022
prEN 302-8:2022 (E)
European foreword
This document (prEN 302-8:2022) 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 302-8:2017.
Compared to EN 302-8:2017, the following modifications have been made:
a) test of test pieces with bond line thickness 0,5 mm and 1 mm included in the standard.
This document is one of a package dealing with adhesives for use with timber structures, and is published
in support to EN 1995, Eurocode 5: Design of timber structures (all parts).
The package consists of
— three classification and performance requirements for adhesives for load-bearing timber structures;
phenolic and aminoplastic adhesives (EN 301), one component polyurethane adhesives (EN 15425)
and emulsion polymerized isocyanate adhesives (EN 16254), and
— twelve test methods (EN 302 parts 1 to 8, EN 15416 parts 1, 3, 4 and 5).
These European Standards have the following titles:
— EN 301, Adhesives, phenolic and aminoplastic, for load-bearing timber structures — Classification and
performance requirements
— 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 302-1, Adhesives for load-bearing timber structures — Test methods — Part 1: Determination of
longitudinal tensile shear strength
— EN 302-2, Adhesives for load-bearing timber structures — Test methods — Part 2: Determination of
resistance to delamination
— EN 302-3, Adhesives for load-bearing timber structures — Test methods — Part 3: Determination of
the effect of acid damage to wood fibres by temperature and humidity cycling on the transverse tensile
strength
— EN 302-4, Adhesives for load-bearing timber structures — Test methods — Part 4: Determination of
the effects of wood shrinkage on the shear strength
— EN 302-5, Adhesives for load-bearing timber structures — Test methods — Part 5: Determination of
maximum assembly time under referenced conditions
— EN 302-6, Adhesives for load-bearing timber structures — Test methods — Part 6: Determination of
the minimum pressing time under referenced conditions
3
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oSIST prEN 302-8:2022
prEN 302-8:2022 (E)
— EN 302-7, Adhesives for load-bearing timber structures — Test methods — Part 7: Determination of
the working life under referenced conditions
— EN 302-8, Adhesives for load-bearing timber structures — Test methods — Part 8: Static load test of
multiple bond line specimens in compression shear
— EN 15416-1, 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)
— EN 15416-3, Adhesives for load bearing timber structures other than phenolic and aminoplastic — Test
methods — Part 3: Creep deformation test at cyclic climate conditions with specimens loaded in
bending shear
— EN 15416-4, Adhesives for load bearing timber structures other than phenolic and aminoplastic — Test
methods — Part 4: Determination of open assembly time under referenced conditions
— EN 15416-5, Adhesives for load bearing timber structures other than phenolic and aminoplastic — Test
methods — Part 5: Determination of minimum pressing time under referenced conditions
4
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oSIST prEN 302-8:2022
prEN 302-8:2022 (E)
Introduction
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 document may have negative environmental
impact. As technological advantages lead to better alternatives for these materials, they will be eliminated
from this document to the extent possible.
At the end of the test, it is recommended that the user of this document take care to carry out an
appropriate disposal of the wastes, according to local regulation.
5
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oSIST prEN 302-8:2022
prEN 302-8:2022 (E)
1 Scope
This document specifies a method of determining the ability of adhesive bonds to resist static load. It is
applicable to adhesives used in load bearing timber structures.
It is suitable for the following applications:
a) for assessing the compliance of adhesives according to EN 301, EN 15425 and EN 16254;
b) for assessing the suitability and quality of adhesives for load-bearing timber structures;
c) for assessing the effect on the bond strength resulting from constant load at different climate
conditions.
This method 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 301:2017, Adhesives, phenolic and aminoplastic, for load-bearing timber structures - Classification and
performance requirements
EN 15425:2017, Adhesives - One component polyurethane (PUR) for load-bearing timber structures -
Classification and performance requirements
EN 16254:2013+A1:2016, Adhesives - Emulsion polymerized isocyanate (EPI) for load-bearing timber
structures - Classification and performance requirements
3 Terms and definitions
No terms and definitions are listed in this document.
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
4 Principle
Bonded test pieces are subjected to a constant compression shear load under a series of three different
climates. Number of failures and the amount of deformation is measured after the end of the last climate
cycle.
6
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oSIST prEN 302-8:2022
prEN 302-8:2022 (E)
5 Apparatus
5.1 Test jig
The test equipment is shown in Figure 1 and Figure 2.
Dimensions in millimetres
Key
1 top plate
2 spacer plate
3 base plate
4 tension rod
5 centre rod
Figure 1 — Test jig
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oSIST prEN 302-8:2022
prEN 302-8:2022 (E)
Dimensions in millimetres
Key
1 top plate 3 base plate
2 spacer plate 4 tension rod (the given lengths are minimum values)
5 centre rod. (the given length is a minimum value)
Figure 2 — Dimensions of plates and rods
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oSIST prEN 302-8:2022
prEN 302-8:2022 (E)
If longer rods are used, distance blocks need to be placed on top and/or under the specimen. The distance
blocks shall be prepared in such a way that the two contact surfaces, between the distance block and the
jig and between the distance block and the specimen, are parallel. Dimension of distance blocks: at least
48 mm × 51 mm × 10 mm.
NOTE 1 Blocks produced from several pieces of plywood bonded together have been found suitable.
The spring shall have the following characteristics:
— outside diameter (unloaded): 105 mm;
— end fix: both ends fixed and grounded;
— free length: 320 mm;
— compression at maximum load: 45 mm to 50 mm.
NOTE 2 A spring rate of 81 N/mm has shown to be suitable.
5.2 Equipment for climate control
The used equipment shall be capable of maintaining (50 ± 2) °C, (70 ± 2) °C or (90 ± 2) °C with a relative
humidity of (10 ± 5) % in order to reach one of the climate conditions 1a, 1b or 1c in Table 1, and the two
climates (20 ± 2) °C and (85 ± 5) % relative humidity and (50 ± 2) °C and (75 ± 5) % relative humidity.
5.3 Testing machine
A testing machine capable of applying a compression load is required.
6 Test specimens
6.1 Selection of wood
3
Untreated beech wood (Fagus sylvatica L.) with a density of (700 ± 50) kg/m at 12 % moisture content
shall be used. The material shall be straight-grained and free from knots, machini
...
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