Glued-in rods in glued structural timber products - Testing, requirements and bond shear strength classification

This document specifies test methods for the determination of the suitability of two component epoxy and two component polyurethane adhesives for glued-in steel rods in glued laminated timber (GLT) and glued solid timber (GST) according to EN 14080, cross laminated timber (CLT) according to EN 16351 and laminated veneer lumber (LVL) according to EN 14374.
It specifies performance requirements and the determination of characteristic bond strength values for such adhesives for the prefabrication under factory or factory-like conditions of load-bearing timber-steel rod joints only. This document does not cover the performance of adhesives for on-site gluing (except for factory-like conditions).
Several provisions of this document can apply to repair and upgrading of existing timber structures including (cracked/fissured) solid wood beams. For adhesives for on-site repair or applications with solid timber additional provisions need to be taken into account. Such provisions are not part of this document.
This document also covers glued–in rods in surface treated wood. It does not cover glued-in rods in modified and stabilized wood with considerably reduced swelling and shrinkage properties, e.g. such as acetylated wood, heat treated wood, polymer impregnated wood and preservative treated wood.
The joints are intended for load-bearing timber structures subjected to temperatures up to 60 °C over a longer time in service classes 1 and 2 which are loaded predominantly static or quasi static according to EN 1990 and EN 1991-1-1.
A design procedure for glued-in rods for timber structures is given in an informative Annex A.

Eingeklebte Stangen in tragenden geklebten Holzprodukten - Prüfung, Anforderungen und Scherfestigkeitsklassifizierung

Dieses Dokument legt Prüfverfahren für die Bestimmung der Eignung von Zweikomponenten-Epoxid- und Zweikomponenten-Polyurethanklebstoffen für eingeklebte Stahlstangen in Brettschichtholz (GLT, en: glued laminated timber) und in verklebtem Vollholz (GST, en: glued solid timber) nach EN 14080, in Kreuzlagenholz (CLT, en: cross laminated timber) nach EN 16351 und in Furnierschichtholz (LVL, en: laminated veneer lumber) nach EN 14374 fest.
Es legt Leistungsanforderungen und die Bestimmung der charakteristischen Festigkeitswerte der Verklebung für solche Klebstoffe für die Vorfertigung von ausschließlich tragenden Verbindungen von Holz mit Stahlstangen unter Werksbedingungen oder werksähnlichen Bedingungen fest. Dieses Dokument deckt die Leistungsfähigkeit von Klebstoffen für das Kleben vor Ort (außer für werksähnliche Bedingungen) nicht ab.
Mehrere Bestimmungen dieses Dokuments können für die Reparatur und Nachrüstung bestehender Holzkonstruktionen gelten, einschließlich (gerissener/gespaltener) Vollholzbalken. Bei Klebstoffen für die Reparatur vor Ort oder Anwendungen mit Vollholz sind zusätzliche Bestimmungen zu beachten. Derartige Bestimmungen sind nicht Teil dieses Dokuments.
Dieses Dokument deckt außerdem in oberflächenbehandeltes Holz eingeklebte Stangen ab. Nicht abgedeckt sind eingeklebte Stangen in modifiziertem und stabilisiertem Holz mit deutlich verringerten Quellungs- und Schwindungseigenschaften, wie z. B. acetyliertes Holz, wärmebehandeltes Holz, polymerimprägniertes Holz und mit Konservierungsmitteln behandeltes Holz.
Die Verbindungen sind für tragende Holzkonstruktionen vorgesehen, die in den Nutzungsklassen 1 und 2 über einen längeren Zeitraum Temperaturen bis zu 60 °C ausgesetzt sind und die überwiegend statisch oder quasistatisch nach EN 1990 und EN 1991 1 1 belastet werden.
Ein Auslegungsverfahren für eingeklebte Stangen für Holzkonstruktionen ist in einem informativen Anhang A aufgeführt.

Goujons collés dans les produits en bois de structure collé - Essais, exigences et classification de la résistance au cisaillement du joint

Le présent document spécifie des méthodes d’essai visant à déterminer l’aptitude à l’emploi des adhésifs bicomposants époxydiques et polyuréthanes pour les goujons en acier collés dans du bois lamellé collé (GLT) et du bois massif reconstitué (GST) selon l’EN 14080, dans du bois lamellé croisé (CLT) selon l’EN 16351 et dans du lamibois (LVL) selon l’EN 14374.
Il spécifie les exigences de performance et la détermination des valeurs caractéristiques de résistance du joint pour ces adhésifs, uniquement pour ce qui concerne la préfabrication en conditions d’usine ou dans des conditions similaires aux conditions d’usine des assemblages entre éléments porteurs en bois et goujons en acier. Le présent document ne couvre pas les performances des adhésifs pour le collage sur site (à l’exception des conditions similaires aux conditions d’usine).
Plusieurs dispositions du présent document peuvent s’appliquer à la réparation et à la remise en état de structures en bois existantes, y compris de poutres en bois massif (fissurées). S’agissant des adhésifs destinés aux réparations sur site ou à des applications avec bois massif, des dispositions supplémentaires doivent être prises en compte. Ces dispositions ne figurent pas dans le présent document.
Le présent document traite également des goujons collés dans du bois ayant reçu un traitement de surface. Il ne couvre pas les goujons collés dans les 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.
Les assemblages sont destinés à des structures portantes en bois soumises à des températures pouvant atteindre 60 °C sur une durée prolongée dans les classes de service 1 et 2, qui sont soumises à des charges essentiellement statiques ou quasi-statiques selon l’EN 1990 et l’EN 1991-1-1.
Une méthode de calcul pour les goujons collés destinés aux structures en bois est décrite dans l’Annexe A, informative.

Vlepljene palice v lepljenih lesenih gradbenih proizvodih - Preskušanje, zahteve in klasifikacija strižne trdnosti spojev

General Information

Status
Published
Public Enquiry End Date
30-Jan-2019
Publication Date
15-Apr-2021
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
01-Apr-2021
Due Date
06-Jun-2021
Completion Date
16-Apr-2021

Buy Standard

Standard
SIST EN 17334:2021
English language
42 pages
sale 10% off
Preview
sale 10% off
Preview

e-Library read for
1 day

Standards Content (sample)

SLOVENSKI STANDARD
SIST EN 17334:2021
01-maj-2021

Vlepljene palice v lepljenih lesenih gradbenih proizvodih - Preskušanje, zahteve in

klasifikacija strižne trdnosti spojev

Glued-in rods in glued structural timber products - Testing, requirements and bond shear

strength classification

Eingeklebte Stangen in tragenden geklebten Holzprodukten - Prüfung, Anforderungen

und Scherfestigkeitsklassifizierung

Goujons collés dans les produits en bois de structure collé - Essais, exigences et

classification de la résistance au cisaillement du joint
Ta slovenski standard je istoveten z: EN 17334:2021
ICS:
83.180 Lepila Adhesives
91.080.20 Lesene konstrukcije Timber structures
SIST EN 17334:2021 en,fr,de

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

---------------------- Page: 1 ----------------------
SIST EN 17334:2021
---------------------- Page: 2 ----------------------
SIST EN 17334:2021
EN 17334
EUROPEAN STANDARD
NORME EUROPÉENNE
March 2021
EUROPÄISCHE NORM
ICS 83.180
English Version
Glued-in rods in glued structural timber products -
Testing, requirements and bond shear strength
classification

Goujons collés dans les produits en bois de structure Eingeklebte Stangen in tragenden geklebten

collé - Essais, exigences et classification de la résistance Holzprodukten - Prüfung, Anforderungen und

au cisaillement du joint Scherfestigkeitsklassifizierung
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 17334:2021 E

worldwide for CEN national Members.
---------------------- Page: 3 ----------------------
SIST EN 17334:2021
EN 17334:2021 (E)
Contents Page

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

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

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

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

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

5 General requirements ................................................................................................................................ 11

6 Classification .................................................................................................................................................. 11

6.1 Adhesive .......................................................................................................................................................... 11

6.2 Rods, wood products and species........................................................................................................... 11

7 Bond strength of the adhesive-wood interface ................................................................................. 11

7.1 General ............................................................................................................................................................. 11

7.2 Requirements ................................................................................................................................................ 12

7.2.1 Bond strength in longitudinal tensile shear test .............................................................................. 12

7.2.2 Resistance to delamination ...................................................................................................................... 12

7.2.3 Effect of wood shrinkage on the shear strength................................................................................ 12

7.2.4 Effect of compression shear and climatic changes ........................................................................... 12

7.3 Test methods ................................................................................................................................................. 12

7.3.1 Determination of bond strength in longitudinal tensile shear test ........................................... 12

7.3.2 Determination of resistance to delamination .................................................................................... 13

7.3.3 Determination of the effect of wood shrinkage on the shear strength ..................................... 13

7.3.4 Determination of compression shear and climatic changes ........................................................ 13

8 Bond shear strength of glued-in steel rods ......................................................................................... 13

8.1 General ............................................................................................................................................................. 13

8.2 Specimen ......................................................................................................................................................... 13

8.2.1 Build-up, dimensions .................................................................................................................................. 13

8.2.2 Timber material ........................................................................................................................................... 14

8.2.3 Steel rod ........................................................................................................................................................... 15

8.3 Procedure........................................................................................................................................................ 16

8.3.1 Manufacture of bond ................................................................................................................................... 16

8.3.2 Test schemes .................................................................................................................................................. 17

8.3.3 Test procedure .............................................................................................................................................. 18

8.4 Expression of test results .......................................................................................................................... 20

8.5 Determination of declared characteristic bond shear strength values.................................... 21

9 Determination of bond temperature resistance ............................................................................... 22

9.1 General ............................................................................................................................................................. 22

9.2 Specimen ......................................................................................................................................................... 23

9.3 Procedure........................................................................................................................................................ 23

10 Bond creep rupture test at very high and low moisture content ................................................ 26

10.1 General ............................................................................................................................................................. 26

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

10.3 Procedure........................................................................................................................................................ 26

10.4 Requirement .................................................................................................................................................. 26

11 Working properties of the adhesive ...................................................................................................... 27

---------------------- Page: 4 ----------------------
SIST EN 17334:2021
EN 17334:2021 (E)

11.1 General ............................................................................................................................................................. 27

11.2 Determination of working life under reference conditions .......................................................... 27

11.3 Determination of open assembly time .................................................................................................. 27

11.4 Determination of curing time under reference conditions ........................................................... 27

11.5 Determination of time to fully cured state .......................................................................................... 28

11.5.1 General ............................................................................................................................................................. 28

11.5.2 Specimens and manufacture .................................................................................................................... 28

11.5.3 Number and treatment of the specimens ............................................................................................ 30

11.5.4 Test procedures ............................................................................................................................................ 30

11.5.5 Expression of results ................................................................................................................................... 31

11.5.6 Determination of time to fully cured state .......................................................................................... 31

11.5.7 Declared time to fully cured state ........................................................................................................... 32

12 Test report ...................................................................................................................................................... 32

12.1 The adhesive ................................................................................................................................................... 32

12.2 Preparation of specimens and testing procedure ............................................................................ 33

12.3 Test results ...................................................................................................................................................... 33

Annex A (informative) Design procedure for glued in rods in GLT, GST, LVL and CLT..................... 34

Annex B (informative) Common alternatives for adhesive infill in drilled holes .............................. 41

Bibliography ................................................................................................................................................................. 42

---------------------- Page: 5 ----------------------
SIST EN 17334:2021
EN 17334:2021 (E)
European foreword

This document (EN 17334:2021) 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 17334:2021
EN 17334:2021 (E)
1 Scope

This document specifies test methods for the determination of the suitability of two component epoxy

and two component polyurethane adhesives for glued-in steel rods in glued laminated timber (GLT) and

glued solid timber (GST) according to EN 14080, cross laminated timber (CLT) according to EN 16351

and laminated veneer lumber (LVL) according to EN 14374.

NOTE 1 The English term “glued-in rods” has been chosen as the established term instead of “bonded-in rods”.

It specifies performance requirements and the determination of characteristic bond strength values for

such adhesives for the prefabrication under factory or factory-like conditions of joints between load-

bearing timber products and steel rods only. This document does not cover the performance of adhesives

for on-site gluing (except for factory-like conditions).

NOTE 2 Factory like conditions provide shelter from direct weathering and dirt, prevent undue movement of the

joints during curing of the adhesive and provide temperature and relative humidity conditions and control as in

factory production environment.

This document also covers glued–in rods in surface treated wood. It does not cover glued-in rods in

modified and stabilized wood with considerably reduced swelling and shrinkage properties, e.g.

acetylated wood, heat treated wood, polymer impregnated wood and preservative treated wood.

The joints are intended for load-bearing timber structures in service classes 1 and 2 according to

EN 1995-1-1 which are loaded predominantly static or quasi static according to EN 1990 and

EN 1991-1-1. The joints are intended for load-bearing timber structures which are not subjected to a

prolonged exposure to temperatures over 60 °C.

A design procedure for glued-in rods in glued structural timber products is given in the informative

Annex A.

NOTE 3 Several provisions of this document can apply to in situ repair and upgrading of existing timber

structures including (cracked/fissured) solid wood beams. For adhesives for glued-in rods used in on-site repair or

applications with solid timber additional provisions apply, e.g. related to rheology and site temperature conditions.

Such provisions are not part of this document.
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 302-5, Adhesives for load-bearing timber structures — Test methods — Part 5: Determination of

maximum assembly time under referenced conditions
---------------------- Page: 7 ----------------------
SIST EN 17334:2021
EN 17334:2021 (E)

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 923, Adhesives — Terms and definitions

EN 10080, Steel for the reinforcement of concrete — Weldable reinforcing steel — General

EN 13183-1, Moisture content of a piece of sawn timber — Part 1: Determination by oven dry 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 14374, Timber structures — Structural laminated veneer lumber — Requirements
EN 16351, Timber structures — Cross laminated timber — Requirements

EN ISO 898-1, Mechanical properties of fasteners made of carbon steel and alloy steel — Part 1: Bolts,

screws and studs with specified property classes — Coarse thread and fine pitch thread (ISO 898-1)

EN ISO 3506-1, Fasteners — Mechanical properties of corrosion-resistant stainless steel fasteners — Part 1:

Bolts, screws and studs with specified grades and property classes (ISO 3506-1)
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:

— IEC Electropedia: available at http://www.electropedia.org/
— ISO Online browsing platform: available at https://www.iso.org/obp
3.1
two component epoxy adhesive

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

with amines, acid anhydrides, phenols, alcohols or thiols
3.2
two component polyurethane adhesive

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

---------------------- Page: 8 ----------------------
SIST EN 17334:2021
EN 17334:2021 (E)
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 softwoods 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
glue line
adhesive layer between the wood members
[SOURCE: EN 301:2017, 3.7]
3.6
thick glue line

glue line of nominal thickness in the range of 0,3 mm to 4,0 mm at the time of bonding

Note 1 to entry: Thick glue lines are achieved by using spacers, grooves or similar devices with a thickness of

0,3 mm to 4,0 mm when two plain members are glued together.

[SOURCE: EN 301:2017, 3.8, modified — Maximum thickness has been increased to 4 mm.]

3.7
close contact glue line
glue line thickness of maximum 0,1 mm

Note 1 to entry: Close contact glue line is considered to be 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, modified — “considered to be” has been added.]
3.8
bond line
glue line including the two intermediate zones between adhesive and wood
[SOURCE: EN 15425:2017, 3.6]
---------------------- Page: 9 ----------------------
SIST EN 17334:2021
EN 17334:2021 (E)
4 Symbols
a cross-section length of specimen, in millimetres (mm)
a equation parameter, in newtons per square millimetre (N/mm )
0,250
a equation parameter, in newtons per square millimetre (N/mm )
0,500
a equation parameter, in newtons per square millimetre (N/mm )
200
a equation parameter, in newtons per square millimetre (N/mm )
400
a equation parameter, in newtons per square millimetre (N/mm )
500
a equation parameter, in newtons per square millimetre (N/mm )
600
b edge lengths of the net cross-section, in millimetres (mm)
c equation parameter, in newtons per cubic millimetre (N/mm )
200
c equation parameter, in newtons per cubic millimetre (N/mm )
500
d nominal rod diameter, in millimetres (mm)
d distance of displacement sensor to rod axis, in millimetre (mm)

d distance of displacement sensor fixation vs. specimen and grain face, in millimetre

(mm)
d diameter of drilled hole, in millimetres (mm)
drill
f apparent tensile strength, in newtons per square millimetre (N/mm )
t,app
F tension load in newtons (N)
F maximum load in tensile test, in newtons (N)
t,max
F maximum load in block shear test, in newtons (N)
v,max
F target load (temperature resistance test), in newtons (N)
target

F target load (creep rupture test at very high and low moisture content), in newtons

t,DOL
(N)
f block shear strength (monolithic adhesive specimen), in newtons per square
millimetre (N/mm )
f bond strength, in newtons per square millimetre (N/mm )
f characteristic bond strength value of bond length of 200 mm
vr,200,k

f declared characteristic bond strength value (5 % quantile) of bond length range

vr,250,k,dc
l ≤ 250 mm, in newtons per square millimetre (N/mm )
f characteristic bond strength value of bond length of 400 mm
vr,400,k
declared characteristic bond strength value (5 % quantile) of bond length range
vr,la 500,≤ k,dc
250 mm < la ≤ 500 mm, in newtons per square millimetre (N/mm )
f characteristic bond strength value of bond length of 600 mm
vr,600,k
declared characteristic bond strength value (5 % quantile) of bond length range
vr,la 1000,≤ k,dc
500 mm < l ≤ 1 000 mm
f characteristic bond strength value of bond length range l
vr,la,k a
f mean bond strength for a bond line thickness of 2 mm, in newtons per square
vr,la,2mm,mean
millimetre (N/mm )
---------------------- Page: 10 ----------------------
SIST EN 17334:2021
EN 17334:2021 (E)
f mean bond strength for a bond line thickness of 4 mm, in newtons per square
vr,la,4mm,mean
millimetre (N/mm )
f mean bond strength for a bond line thickness of 6 mm, in newtons per square
vr,la,6mm,mean
millimetre (N/mm )

f characteristic bond strength value (5 % quantile), in newtons per square millimetre

vr,la,tB,k
(N/mm )
f arithmetic mean bond strength value in newtons per square millimetre (N/mm )
vr,la,tB,mean

f declared characteristic bond shear strength (5 % quantile), in newtons per square

vr,k,dc
millimetre (N/mm )

f density influenced bond shear strength, in newtons per square millimetre (N/mm )

vr,ρ

f density corrected bond shear strength, in newtons per square millimetre (N/mm )

vr,ρref
k bond strength ratio between two bond line thicknesses
d,la
l total length of timber specimen, in millimetres (mm)
l nominal bonded length of steel rod, in millimetres (mm)
l maximum declared rod length, in millimetres (mm)
a,dc,max
l minimum declared rod length, in millimetres (mm)
a,dc,min
l length to fix the rod in the grips of the test machine, in millimetres (mm)
clamping
l length of drill hole, in millimetres (mm)
drill

l length of the rod inside the drill hole that is not able to take load (e.g. spacers), in

not bonded
millimetres (mm)

l distance between the grounds of the drilled holes in the specimen, in millimetres

(mm)
l edge lengths of the net cross-section, in millimetres (mm)
l total rod length, in millimetres (mm)
rod,tot

𝜌𝜌 density of the timber specimen at 12 % moisture content, in kilograms per cubic

metre (kg/m )
𝜌𝜌 reference density, in kilograms per cubic metre (kg/m )
ref
s slip displacement
t bond line thickness, in millimetres (mm) (t = (d − d)/2)
b b drill
t total bond line thickness, in millimetres (mm) (t = 2 t )
B B b
T Temperature, in degrees Celsius (°C)
T applied temperature, in degrees Celsius (°C)
app
T target temperature at bond line, in degrees Celsius (°C)
bond,target
t loading time
t cooling down period, in hours (h)
cool
tcycle,1 time of first heating-cooling-load-cycle, in hours (h)
t time of second heating-cooling-load-cycle, in hours (h)
cycle,2
t heating period, in hours (h)
heat
---------------------- Page: 11 ----------------------
SIST EN 17334:2021
EN 17334:2021 (E)
t total time of both temperature-load cycles, in hours (h)
total
t time of the attainment of the target load, in minutes
ramp
t constant temperature period, in hours (h)
rod60
u percentage target wood moisture content (%)
target
V density correction exponent

Δu difference in average moisture contents between the moist and dry state, in percent

(%)
Additional symbols of Annex A:
A stress design relevant cross-section of steel rod, in square millimetres (mm )

a minimum distance of axially loaded glued-in rods (in grain direction), in millimetres

(mm)

a minimum distance of axially loaded glued-in rods (perpendicular grain direction), in

millimetres (mm)
a , a minimum edge distance of axially loaded glued-in rods, in millimetres (mm)
1,c 2,c
a minimum distance of axially loaded glued-in rods (loaded end grain face), in
3,t
millimetres (mm)
a minimum distance of axially loaded glued-in rods (unloaded end grain face), in
3,c
millimetres (mm)
a minimum distance of axially loaded glued-in rods (loaded edge), in millimetres
4,t
(mm)

a minimum distance of axially loaded glued-in rods (unloaded edge), in millimetres

4,c
(mm)

γ partial factor for material properties, also accounting for model uncertainties and

dimensional variations
F design value for the withdrawal (pull-out) capacity, in newtons (N)
ax,Rd

F , F design values of shear force at both sides of the connection, in newtons (N)

v,Ed,1 v,Ed,2
f design value of bond shear strength, in newtons per square millimetre (N/mm )
vr,d

f declared characteristic bond strength value (5 % quantile) of bond length range l ,

vr,la,dc,k a
in newtons per square millimetre (N/mm )
f design value of yield strength of steel rod, in newtons per square millimetre
y,d
(N/mm )

F , F design value and characteristic value of resistance to tension perpendicular to grain

90,Rd 90,Rk
of the loaded member, in newtons (N)
h, b depth and width of timber member, in millimetres (mm)
h projected rod embedment length perpendicular to grain, in millimetres (mm)
kmod modification factor for duration of load and moisture content
l minimum bond length, in millimetres (mm)
a,min
---------------------- Page: 12 ----------------------
SIST EN 17334:2021
EN 17334:2021 (E)
5 General requirements

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

the bond in the glued-in rod joint is maintained throughout the expected lifetime of the structure.

6 Classification
6.1 Adhesive

If the adhesive meets the requirements of Clause 7 to Clause 10 it shall be classified as type I. The

classification of the adhesive consists of:
— number of this document and year of publication;
— type of adhesive (I);
— bond temperature resistance, in degrees Celsius °C;
— maximum bond length, in millimetres;
— maximum bond line thickness, in millimetres;

— working properties (adhesives tested for working properties according to Clause 11 are specified by

the letter “w” at the end of the designation code).
EXAMPLE EN 17334:2021-I-60-500-4 w.
6.2 Rods, wood products and species

The type of rod (rebars, rods with metric thread), the tested rod dimensions d and l , the applicable wood

product (GLT, GST, CLT including lay-up and LVL including lay-up) and wood species shall be declared.

7 Bond strength of the 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) 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 mad
...

Questions, Comments and Discussion

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