Two-component epoxy and polyurethane adhesives for on-site repair of cracked timber structures - Testing, requirements and repair strength verification

This European standard specifies test methods for determination of the suitability of two component epoxy and polyurethane adhesives for on-site repair of cracked timber structures. The standard specifies minimum requirements on bond strength and integrity. The standard provides minimum on-site repair provisions and specifies test and minimum strength requirements with drill cores from on-site repaired timber structures for verification of bond strength and integrity.

Zwei-Komponenten-Epoxid und Zwei-Komponenten-Polyurethan-Klebstoffe zur Reparatur von beschädigten Holzbauteilen auf der Baustelle - Prüfung, Anforderungen und Nachweis der Reparatur-Festigkeit

Dieses Dokument legt Prüfverfahren zur Bestimmung der Eignung von Zweikomponenten-Epoxid- und Zweikomponenten-Polyurethanklebstoffen für die Reparatur von Rissen in Holzkonstruktionen aus Vollholz, keilgezinkten Vollhölzern, verklebtem Vollholz und Brettschichtholz aus Nadelholz auf der Baustelle durch Injektion des Reparaturklebstoffs fest. Der Klebstoff kann auch zum Reparieren von Rissen im Bereich von Verbindungen, die durch Nägel, Schrauben, stiftförmige Verbindungen und Gewindestifte entstanden sind, verwendet werden. Der Klebstoff kann auch verwendet werden, um Fugen zwischen den Flächen von tragenden Bauteilen zu füllen. Dieses Dokument legt Mindestanforderungen an die Festigkeit der Verklebung und Unversehrtheit sowie die Maße von Rissen und Öffnungen fest. Dieses Dokument enthält auch Mindestanforderungen für die Reparatur auf der Baustelle und legt Qualitätskontrollen für die durch Verkleben reparierten Konstruktionen fest.
Dieses Dokument gilt außerdem für die Reparatur von oberflächenbehandeltem Holz. Es gilt nicht für die Reparatur von modifiziertem und vergütetem Holz mit deutlich verringerten Quellungs- und Schwindungseigenschaften, wie z. B. acetyliertes Holz, wärmebehandeltes Holz, polymerimprägniertes Holz und mit Holzschutzmitteln behandeltes Holz.
Der Klebstoff ist zur Reparatur von tragenden Holzbauwerken vorgesehen, die in den Nutzungsklassen 1 und 2 (siehe EN 1995 1 1) nicht über eine längere Zeitspanne Temperaturen von mehr als 60 °C ausgesetzt sind und die überwiegend statisch oder quasistatisch (siehe EN 1990 und EN 1991 1 1) belastet werden. Eine Überprüfung der Qualität und der Unversehrtheit der Klebstofffuge der Reparaturverklebung auf der Baustelle ist im informativen Anhang A enthalten.

Adhésifs bicomposants polyuréthanes et époxydiques pour la réparation sur site de structures en bois fissurées - Essais, exigences et vérification de la résistance des réparations

Le présent document spécifie des méthodes d’essai permettant de déterminer la pertinence d’adhésifs époxydiques et polyuréthanes bicomposants pour la réparation sur site de fissures dans des structures en bois massif, en bois massif abouté à entures multiples, en bois massif reconstitué et en bois lamellé collé à base de résineux par injection de l’adhésif de réparation. L’adhésif peut également être utilisé pour réhabiliter des fissures situées au niveau d’assemblages réalisés à l’aide de pointes, de tire-fonds, d’organes d’assemblage de type tige et de broches à filetage. L’adhésif peut aussi servir de joint épais entre les faces des composants structuraux. Le présent document spécifie les exigences minimales concernant la résistance et l’intégrité du joint, ainsi que les dimensions des fissures, fentes et ouvertures. Le présent document contient également les dispositions minimales en matière de réparation sur site et spécifie les essais de contrôle de la qualité à effectuer sur les structures réparées par collage.
Le présent document traite également de la réparation des bois ayant reçu un traitement de surface. Il ne couvre pas la réparation des bois modifiés et stabilisés ayant des propriétés de retrait et de gonflement fortement réduites, par exemple les bois acétylés, les bois traités thermiquement, les bois imprégnés de polymère et les bois traités avec un produit de préservation.
L’adhésif est destiné à la réparation des structures portantes en bois non soumises à des températures supérieures 60 °C sur une durée prolongée dans les classes de service 1 et 2, voir l’EN 1995-1-1, qui sont soumises à des charges essentiellement statiques ou quasi statiques selon l’EN 1990 et l’EN 1991 1-1. L’Annexe A, informative, présente une vérification de la qualité et de l’intégrité d’un joint de colle d’un collage réalisé lors d’une réparation sur site.

Dvokomponentna epoksi in poliuretanska lepila za popravilo nalomljenih lesenih konstrukcij na kraju samem - Preskušanje, zahteve in preverjanje trdnosti popravljenih delov

General Information

Status
Published
Public Enquiry End Date
31-Oct-2019
Publication Date
12-Apr-2021
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
01-Apr-2021
Due Date
06-Jun-2021
Completion Date
13-Apr-2021

Buy Standard

Standard
SIST EN 17418:2021 - BARVE na PDF-str 14,24,29
English language
33 pages
sale 10% off
Preview
sale 10% off
Preview

e-Library read for
1 day

Standards Content (sample)

SLOVENSKI STANDARD
SIST EN 17418:2021
01-maj-2021
Dvokomponentna epoksi in poliuretanska lepila za popravilo nalomljenih lesenih
konstrukcij na kraju samem - Preskušanje, zahteve in preverjanje trdnosti
popravljenih delov

Two-component epoxy and polyurethane adhesives for on-site repair of cracked timber

structures - Testing, requirements and repair strength verification
Zwei-Komponenten-Epoxid und Zwei-Komponenten-Polyurethan-Klebstoffe zur

Reparatur von beschädigten Holzbauteilen auf der Baustelle - Prüfung, Anforderungen

und Nachweis der Reparatur-Festigkeit

Adhésifs bicomposants polyuréthanes et époxydiques pour la réparation sur site de

structures en bois fissurées - Essais, exigences et vérification de la résistance des

réparations
Ta slovenski standard je istoveten z: EN 17418:2021
ICS:
83.180 Lepila Adhesives
91.080.20 Lesene konstrukcije Timber structures
SIST EN 17418:2021 en,fr,de

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

---------------------- Page: 1 ----------------------
SIST EN 17418:2021
---------------------- Page: 2 ----------------------
SIST EN 17418:2021
EN 17418
EUROPEAN STANDARD
NORME EUROPÉENNE
March 2021
EUROPÄISCHE NORM
ICS 83.180
English Version
Two-component epoxy and polyurethane adhesives for
on-site repair of cracked timber structures - Testing,
requirements and repair strength verification

Adhésifs bicomposants polyuréthanes et époxydiques Zwei-Komponenten-Epoxid- und Zwei-Komponenten-

pour la réparation sur site de structures en bois Polyurethan-Klebstoffe zur Reparatur von

fissurées - Essais, exigences et vérification de la beschädigten Holzbauteilen auf der Baustelle -

résistance des réparations Prüfung, Anforderungen und Nachweis der Reparatur-
Festigkeit
This European Standard was approved by CEN on 8 February 2021.

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, 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

© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 17418:2021 E

worldwide for CEN national Members.
---------------------- Page: 3 ----------------------
SIST EN 17418:2021
EN 17418:2021 (E)
Contents Page

European foreword ....................................................................................................................................................... 4

1 Scope .................................................................................................................................................................... 5

2 Normative references .................................................................................................................................... 5

3 Terms and definitions ................................................................................................................................... 6

4 Symbols ............................................................................................................................................................... 8

5 General requirements ................................................................................................................................... 8

6 Classification ..................................................................................................................................................... 8

7 Bond strength of adhesive-wood interface ............................................................................................ 9

7.1 General ................................................................................................................................................................ 9

7.2 Requirements ................................................................................................................................................... 9

7.2.1 Bond strength in longitudinal tensile shear tests ............................................................................... 9

7.2.2 Resistance to delamination ......................................................................................................................... 9

7.2.3 Effect of wood shrinkage on the shear strength................................................................................... 9

7.2.4 Effect of compression shear stress and climatic changes .............................................................. 10

7.3 Test methods ................................................................................................................................................. 10

7.3.1 Determination of bond strength in longitudinal tensile shear test ........................................... 10

7.3.2 Determination of resistance to delamination .................................................................................... 10

7.3.3 Determination of the effect of wood shrinkage on the shear strength ..................................... 10

7.3.4 Determination of the effect of compression shear stress and climatic changes ................... 10

8 Tests on cohesive strength of monolithic adhesive specimens ................................................... 11

8.1 General ............................................................................................................................................................. 11

8.2 Tensile tests ................................................................................................................................................... 11

8.2.1 Specimen ......................................................................................................................................................... 11

8.2.2 Procedure........................................................................................................................................................ 12

8.2.3 Expression of results ................................................................................................................................... 13

8.2.4 Requirements ................................................................................................................................................ 13

8.3 Compression tests ........................................................................................................................................ 13

8.3.1 Specimen ......................................................................................................................................................... 13

8.3.2 Procedure........................................................................................................................................................ 13

8.3.3 Expression of results ................................................................................................................................... 14

8.3.4 Requirements ................................................................................................................................................ 14

8.4 Block shear tests ........................................................................................................................................... 14

8.4.1 Specimen ......................................................................................................................................................... 14

8.4.2 Procedure........................................................................................................................................................ 14

8.4.3 Expression of results ................................................................................................................................... 14

8.4.4 Requirements ................................................................................................................................................ 15

9 Large scale component tests including drill core tests .................................................................. 16

9.1 Straight beams with predefined glue lines ......................................................................................... 16

9.1.1 Specimen ......................................................................................................................................................... 16

9.1.2 Conditioning of the specimens ................................................................................................................ 17

9.1.3 Test procedure .............................................................................................................................................. 18

9.1.4 Expression of results ................................................................................................................................... 18

9.1.5 Evaluation and requirements .................................................................................................................. 18

9.2 Large scale specimens with repaired glue lines ............................................................................... 19

---------------------- Page: 4 ----------------------
SIST EN 17418:2021
EN 17418:2021 (E)

9.2.1 General ............................................................................................................................................................. 19

9.2.2 Straight beams with repaired glue lines .............................................................................................. 19

9.2.3 Curved beams with repaired glue lines ................................................................................................ 19

9.3 Block shear tests with water treated drill cores ............................................................................... 22

9.3.1 General ............................................................................................................................................................. 22

9.3.2 Sampling .......................................................................................................................................................... 22

9.3.3 Specimens ........................................................................................................................................................ 22

9.3.4 Conditioning of specimens ........................................................................................................................ 22

9.3.5 Test procedure .............................................................................................................................................. 23

9.3.6 Requirements ................................................................................................................................................. 23

9.4 Long term loading and residual strength tests .................................................................................. 23

9.4.1 General ............................................................................................................................................................. 23

9.4.2 Specimens ........................................................................................................................................................ 23

9.4.3 Test procedure .............................................................................................................................................. 24

9.4.4 Requirements ................................................................................................................................................. 24

10 Repair of cracks in dowel type fasteners connections .................................................................... 25

10.1 General ............................................................................................................................................................. 25

10.2 Specimen .......................................................................................................................................................... 26

10.3 Procedure ........................................................................................................................................................ 27

10.4 Expression of the test results ................................................................................................................... 28

10.5 Requirements ................................................................................................................................................. 28

11 Working properties of the adhesive ...................................................................................................... 29

11.1 General ............................................................................................................................................................. 29

11.2 Determination of working life under reference conditions .......................................................... 29

11.3 Determination of curing time under reference conditions ........................................................... 29

11.4 Determination of time to fully cured state .......................................................................................... 29

11.4.1 General ............................................................................................................................................................. 29

11.4.2 Tensile tests .................................................................................................................................................... 29

11.4.3 Block shear tests ........................................................................................................................................... 29

11.4.4 Declared time to fully cured state ........................................................................................................... 30

12 Test report ...................................................................................................................................................... 31

12.1 General ............................................................................................................................................................. 31

12.2 Adhesive ........................................................................................................................................................... 31

12.3 Preparation of specimens and testing procedure ............................................................................ 31

12.4 Test results ...................................................................................................................................................... 31

Annex A (informative) On-site repair control test ......................................................................................... 32

Bibliography ................................................................................................................................................................. 33

---------------------- Page: 5 ----------------------
SIST EN 17418:2021
EN 17418:2021 (E)
European foreword

This document (EN 17418:2021) 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 September 2021, and conflicting national standards shall

be withdrawn at the latest by September 2021.

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, 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 the United

Kingdom.
---------------------- Page: 6 ----------------------
SIST EN 17418:2021
EN 17418:2021 (E)
1 Scope

This document specifies test methods and requirements for two-component epoxy and polyurethane

adhesives for on-site repair of cracks in timber structures made of strength graded structural timber with

rectangular cross-section, structural finger-jointed timber, glued solid timber and glued laminated timber

made of softwood species by injection of the repair adhesive with glue line thicknesses up to 8 mm. The

adhesive can also be used to rehabilitate cracks in the area of joints made by nails, screws, dowel-type

fasteners and dowels with threads. The adhesive can also be used to fill gaps between the faces of

structural components. This document addresses exclusively adhesives which fulfil the requirements

according to Clause 8.

NOTE There is no sufficient experience with adhesives which do not fulfil the requirements in 8.4.4.

This document also covers the repair of surface treated wood. It does not cover the repair of preservative

treated wood, modified and stabilized wood with considerably reduced swelling and shrinkage

properties, e.g. acetylated wood, heat treated wood and polymer impregnated wood.

The adhesive is intended for the repair of load bearing timber structures not subjected to temperatures

more than 60 °C over a longer time in service classes 1 and 2 according to EN 1995-1-1 which are loaded

predominantly static or non-fatigue quasi static, see EN 1990 and EN 1991-1-1. A verification of quality

and bond line integrity of the on-site repair bonding is given in an informative Annex A.

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 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 302-4, Adhesives for load-bearing timber structures — Test methods — Part 4: Determination of the

effects of wood shrinkage on the shear strength

EN 302-6, Adhesives for load-bearing timber structures — Test methods — Part 6: Determination of the

minimum pressing time under referenced conditions

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 383, Timber Structures — Test methods — Determination of embedment strength and foundation

values for dowel type fasteners

EN 408, Timber structures — Structural timber and glued laminated timber — Determination of some

physical and mechanical properties
EN 923, Adhesives — Terms and definitions
---------------------- Page: 7 ----------------------
SIST EN 17418:2021
EN 17418:2021 (E)

EN 13183-2, Moisture content of a piece of sawn timber — Part 2: Estimation by electrical resistance

method

EN 14080:2013, Timber structures — Glued laminated timber and glued solid timber — Requirements

EN 14358, Timber structures — Calculation and verification of characteristic values

EN 17334:2021, Glued-in rods in glued structural timber products — Testing, requirements and bond shear

strength classification
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 http://www.electropedia.org/
3.1
two component epoxy adhesive

thermosetting synthetic resin derived from an exothermic polymerization reaction of an epoxide group

with amines, acid anhydrides, phenols, alcohols or thiols
3.2
two component polyurethane adhesive
2C-PUR

urethane polymers which are cross-linked by the reaction between polyol or polyamine with isocyanate

3.3
service class 1

climatic conditions characterized by a moisture content in the materials corresponding to a temperature

of 20 °C and the relative humidity of the surrounding air only exceeding 65 % for a few weeks per year

Note 1 to entry: In service class 1, which comprises typical indoor conditions, the average moisture content in

most soft-woods will not exceed 12 %.

[SOURCE: EN 1995-1-1:2004, 2.3.1.3, modified – Indoor conditions added in Note 1 to entry]

3.4
service class 2

climatic conditions characterized by a moisture content in the materials corresponding to a temperature

of 20 °C and the relative humidity of the surrounding air only exceeding 85 % for a few weeks per year

Note 1 to entry: In service class 2, to which most covered exterior conditions belong, the average moisture

content in most softwoods will not exceed 20 %.

[SOURCE: EN 1995-1-1:2004, 2.3.1.3, modified – Covered exterior conditions added in Note 1 to entry]

3.5
service class 3

climatic conditions leading to a higher moisture contents than in service class 2

[SOURCE: EN 1995-1-1:2004, 2.3.1.3]
---------------------- Page: 8 ----------------------
SIST EN 17418:2021
EN 17418:2021 (E)
3.6
glue line
adhesive layer between the wood members
[SOURCE: EN 301:2017, 3.7]
3.7
thick glue line

glue line of nominal thickness in the range of 0,3 mm up to the maximum tested thickness but not more

than 8,0 mm at the time of bonding

Note 1 to entry: This definition of a thick glue line is different from that in EN 301. Thick glue lines are achieved

by using spacers, grooves or similar devices with a thickness of 0,3 mm to 8,0 mm when two plain members are

glued together.
3.8
close contact glue line
glue line thickness of maximum 0,1 mm

Note 1 to entry: Close contact glue line is achieved by pressing together two plane wood members with a

clamping pressure of (0,8 ± 0,1) N/mm without grooves, spacers or similar device.

[SOURCE: EN 301:2017, 3.9]
3.9
bond line
glue line including the two intermediate zones between adhesive and wood
[SOURCE: EN 15425:2017, 3.6]
---------------------- Page: 9 ----------------------
SIST EN 17418:2021
EN 17418:2021 (E)
4 Symbols
a distance between loading and support, in millimetres (mm)
b specimen width of the net cross-section, in millimetres (mm)
f apparent compression strength, in newtons per square millimetre (N/mm )
c,app
f apparent embedment strength, in newtons per square millimetre (N/mm )
h,app
f embedment strength, in newtons per square millimetre (N/mm )
h,k
f apparent tensile strength, in newtons per square millimetre (N/mm )
t,app
f apparent shear strength, in newtons per square millimetre (N/mm )
v,app
F compression test failure load, in newtons (N)
c,max
F load in long term tests, in newtons (N)
perm
F tensile test failure load, in newtons (N)
t,max
Fu ultimate load, in newtons (N)
F shear test failure load, in newtons (N)
v,max
h specimen height, in millimetres (mm)
h component height, in millimetres (mm)
t specimen thickness of the net cross-section, in millimetres (mm)
t glue line thickness, in millimetres (mm)
σ ultimate bending stress, in newtons per square millimetre (N/mm )
m,u

σ ultimate tensile stress perpendicular to grain, in newtons per square millimetre (N/mm )

t,90,u
τ ultimate shear stress, in newtons per square millimetre (N/mm )
5 General requirements

Adhesives for structural purpose shall produce joints of such strength and durability that the integrity of

the bond in the rehabilitated element is maintained throughout the intended service life of the structure.

6 Classification

If the adhesive meets the requirements of Clauses 7 to 9, the adhesive shall be classified as type I. The

classification of adhesive consists of:
— number of this document;
— type of adhesive (I);
— temperature in bond creep rupture test in °C;

— working properties (Adhesives tested for all working properties according to Clause 11 are specified

by the letter “w” at the end of the designation code.).
EXAMPLE EN 17418-I-60-w.

NOTE Presently, exclusively a temperature testing/classification for 60 °C is covered by the standard.

The wood species for which the tested adhesive can be used shall be given in the adhesive manufacturer’s

declaration.
---------------------- Page: 10 ----------------------
SIST EN 17418:2021
EN 17418:2021 (E)
7 Bond strength of adhesive-wood interface
7.1 General

Adhesives complying with this document shall meet the performance requirements specified in 7.2.1 to

7.2.4 when tested in accordance with the following test methods:

a) longitudinal tensile shear test (see 7.3.1) using bonded specimens made from beech (Fagus sylvatica

L.);

b) delamination test (see 7.3.2) on bonded specimens made from Norway spruce (Picea abies L.

H.KARST). The test with Norway spruce also covers silver fir (Abies alba MILL.) and Scots pine (Pinus

sylvestris L.). If the adhesive is to be used on wood from other conifers species or treated wood, also

prepare four laminated members using representative samples from those species or wood treated

that way and perform the delamination test according to 7.3.2;

c) shrinkage stress test (see 7.3.3) on bonded specimens made from Norway spruce (Picea abies

L. H.KARST);

d) multiple compression shear test (see 7.3.4) on bonded specimens made from beech (Fagus sylvatica

L.).
The adhesives shall be applied according to the manufacturer`s instructions.
7.2 Requirements
7.2.1 Bond strength in longitudinal tensile shear tests

The tensile shear strength values of close contact glue lines, 1,0 mm and 4,0 mm thick glue lines

determined according to 7.3.1 shall meet the requirements given in Table 1.

Table 1 — Minimum mean tensile shear strengths for close contact and gap joints on beech

specimens (in N/mm
Close contact Thick glue line Thick glue line
Treatment
glue line 1,0 mm 4,0 mm
Serial No
EN 302-1
Type Ι Type Ι Type Ι
A1 10,0 8,0 6,0
A2 6,0 4,0 3,0
A3 8,0 6,4 4,8
A4 6,0 4,0 3,0
A5 8,0 6,4 4,8
A7 8,0 5,5 4,5
7.2.2 Resistance to delamination

The limits on delamination for specimens of any glue line thickness determined according to 7.3.2 shall

be less or equal than 5 % in any specimen.
7.2.3 Effect of wood shrinkage on the shear strength

The mean shear strength after climatic treatment determined according to 7.3.3 shall not be lower than

1,5 N/mm .
---------------------- Page: 11 ----------------------
SIST EN 17418:2021
EN 17418:2021 (E)
7.2.4 Effect of compression shear stress and climatic changes

When tested in accordance with 7.3.4, not more than one of the six specimens may fail during the test

period. The mean creep deformation of all the bond lines in each of the remaining test specimens shall

not exceed 0,05 mm after the test.

If a failure within a specimen occurs as a solid wood failure without any interference with the bond line,

the specimen shall not be counted and four of the five remaining specimens shall fulfil the requirements.

In the case that more than two specimens in a test series collapse due to solid wood failure (low wood

quality), the whole test shall be repeated.
7.3 Test methods
7.3.1 Determination of bond strength in longitudinal tensile shear test

The tests shall be made in accordance with EN 302-1, but with glue line thicknesses close contact, 1,0 mm

and 4,0 mm. The specimens with glue line thickness 4 mm shall be prepared with a pressureless

preparation.

NOTE Applying a narrow slot (width about 2 mm, depth about 2 mm) between the end of the groove and the

wide side of the adherent has shown to be a suitable method for ensuring pressureless bonding of the specimens.

The method of preparation of the specimens is described in EN 302-1. Following this method, the

specimens are built-up with the adhesive layer covered by two adherents of the same thickness (on top

and below the adhesive layer).
7.3.2 Determination of resistanc
...

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.