prEN 18070
(Main)Performance of wood adhesives at high temperatures and fire. Test methods, evaluation and classification.
Performance of wood adhesives at high temperatures and fire. Test methods, evaluation and classification.
This document specifies a test method for comparing the compression shear strength of adhesive bonds and solid wood at 180 °C and a second elevated temperature. The maximum load of the test pieces after exposure to 180 °C and a specific elevated temperature for a specified duration of time is evaluated. It is applicable to adhesives used in load bearing timber structures and to other wood adhesives.
This method is intended primarily to obtain data for the performance of wood adhesives at high temperatures. The result of this method (temperature class) can be used to classify the adhesive with respect to its performance in fire.
Leistungseigenschaften von Holzklebstoffen bei hohen Temperaturen und im Brandfall - Prüfverfahren, Bewertung und Klassifizierung
Dieses Dokument legt ein Prüfverfahren zum Vergleich der Druck-Scherfestigkeit von Klebstoffverbindungen und Vollholz bei 180 °C und einer zweiten erhöhten Temperatur fest. Die Bruchkraft der Prüfkörper nach der Einwirkung von 180 °C und einer weiteren erhöhten Temperatur für eine festgelegte Zeitspanne wird beurteilt. Es ist anwendbar für Klebstoffe für tragende Holzbauteile und andere Holzklebstoffe.
Dieses Verfahren ist hauptsächlich dafür vorgesehen, Leistungsdaten von Holzklebstoffen bei erhöhten Temperaturen zu erhalten. Das Ergebnis dieses Verfahrens (Temperaturklasse) kann dafür verwendet werden, Klebstoffe anhand ihres Verhaltens im Brandfall zu klassifizieren.
Performances des adhésifs pour bois à hautes températures et au feu - Méthodes d’essai, évaluation et classification
Le présent document spécifie une méthode d’essai visant à comparer la résistance au cisaillement par compression de joints de colle et celle du bois massif, à 180 °C et à une seconde température élevée. Après exposition des éprouvettes, pendant une durée déterminée, à une température de 180 °C d’une part, et à une température élevée définie d’autre part, la charge maximale des éprouvettes est évaluée. Ce document s’applique aux adhésifs utilisés sur des structures portantes en bois et aux autres adhésifs pour bois.
Cette méthode vise principalement à obtenir des données relatives aux performances des adhésifs pour bois à des températures élevées. Les résultats obtenus avec cette méthode peuvent être utilisés pour attribuer une classe de température à l’adhésif en fonction de ses performances au feu.
Delovanje lepil za les pri visokih temperaturah in požaru. Preskusne metode, vrednotenje in razvrščanje.
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
01-junij-2024
Delovanje lepil za les pri visokih temperaturah in požaru. Preskusne metode,
vrednotenje in razvrščanje.
Performance of wood adhesives at high temperatures and fire. Test methods, evaluation
and classification.
Leistungseigenschaften von Holzklebstoffen bei hohen Temperaturen und im Brandfall -
Prüfverfahren, Bewertung und Klassifizierung
Performances des adhésifs pour bois à hautes températures et au feu - Méthodes
d’essai, évaluation et classification
Ta slovenski standard je istoveten z: prEN 18070
ICS:
79.040 Les, hlodovina in žagan les Wood, sawlogs and sawn
timber
83.180 Lepila Adhesives
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
DRAFT
EUROPEAN STANDARD
NORME EUROPÉENNE
EUROPÄISCHE NORM
March 2024
ICS 83.180; 79.060.99
English Version
Performance of wood adhesives at high temperatures and
fire. Test methods, evaluation and classification.
Leistungseigenschaften von Holzklebstoffen bei hohen
Temperaturen und im Brandfall - Prüfverfahren,
Bewertung und Klassifizierung
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, Türkiye 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
© 2024 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 18070:2024 E
worldwide for CEN national Members.
Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Principle . 5
5 Apparatus . 5
5.1 Test jig . 5
5.2 Climate chamber or oven . 5
5.3 Thermocouples . 5
5.4 Testing machine . 6
6 Test specimens . 6
6.1 Selection of wood . 6
6.2 Preparation of test pieces . 6
7 Test procedure . 8
7.1 Number of test pieces . 8
7.2 Test temperature . 9
7.3 Temperature treatment before the shear test . 9
7.4 Performance of the shear tests . 10
7.5 Evaluation of result . 10
8 Requirements . 11
9 Expression of results and test report . 12
Bibliography . 13
European foreword
This document (prEN 18070:2024) 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.
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 can 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, the user of the document should take care to carry out an appropriate disposal of
the wastes, see local regulation for additional guidance.
1 Scope
This document specifies a test method for comparing the compression shear strength of adhesive bonds
and solid wood at 180 °C and a second elevated temperature. The maximum load of the test pieces after
exposure to 180 °C and a specific elevated temperature for a specified duration of time is evaluated. It is
applicable to adhesives used in load bearing timber structures and to other wood adhesives.
This method is intended primarily to obtain data for the performance of wood adhesives at high
temperatures. The result of this method (temperature class) can be used to classify the adhesive with
respect to its performance in fire.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
EN 923, Adhesives - Terms and definitions
EN 14080:2013, Timber structures - Glued laminated timber and glued solid timber - Requirements
3 Terms and definitions
For the purposes of this document the terms and definitions given in EN 923 apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at https://www.electropedia.org/
4 Principle
Solid wood test pieces and adhesively bonded test pieces are prepared. Both types of test pieces are tested
in a compression shear test according to EN 14080:2013, Annex D, after exposure to 180 °C and after
exposure to another elevated temperature. The compression shear strength of the solid wood test pieces
and the adhesively bonded test pieces at 180 °C and the elevated temperature is compared in order to
evaluate the shear strength of the adhesive at elevated temperature.
5 Apparatus
5.1 Test jig
The test equipment described in EN 14080:2013, Annex D is suitable for the performance of the shear
test.
5.2 Climate chamber or oven
A climate chamber or oven capable of maintaining the targeted temperature to within ± 2 °C and with
sufficient air circulation to provide constant temperature conditions within the oven interior for the
heating of the test pieces.
5.3 Thermocouples
Thermocouples capable of measuring the temperature in the test pieces to within ± 2 °C. The recording
equipment shall have the same or smaller tolerances.
5.4 Testing machine
A testing machine capable of performing the block shear test specified in EN 14080:2013, Annex D, with
an accuracy of ± 1 % of the maximum load is required for the performance of the shear tests.
6 Test specimens
6.1 Selection of wood
Norway spruce (Picea abies L.) with a density of (450 ± 15) kg/m at 12 % moisture content is used.
The material shall be straight-grained and free from knots, reaction wood, machining defects (such as
chipped grain, dubbed ends, feed roll polish, coarse knife marks and feed roll compression) and any
drying defects such as case hardening, collapse, splits or checks. The raw material for the preparation of
the test pieces shall have dimensions of at least 60 mm (width) × 50 mm (height) and a length of at least
800 mm.
The angle of the annual rings to the surface, as measured from the wide face, shall be between 45° and
90°.
The wood shall be conditioned at (20 ± 2) °C and a relative humidity of (65 ± 5) % until a moisture
content of (12 ± 1) % has been obtained.
Plane each lamination not more than 8 h before the bonding of the test pieces.
6.2 Preparation of test pieces
Solid wood block shear test pieces and adhesively bonded block shear test pieces shall be produced. To
ensure that all test pieces have a comparable wood quality, the solid wood test pieces and the adhesively
bonded test pieces shall be produced using the same raw material following the principle as shown in
Figure 1.
Dimensions in millimetres
Key
1 solid wood 180 180 °C
2 bonded T2 second elevated temperature
Figure 1 — Principle for production of side-matched test pieces
Use wood with a cross-section of 60 mm × 50 mm and a length of at least 800 mm. Four solid wood test
pieces, two for testing at 180 °C and two for testing at the elevated test temperature, and four adhesively
bonded test pieces, two for testing at 180 °C and two for testing at the elevated test temperature, shall be
produced from each piece of wood (see Figure 1).
If a knot is present within the wood, this section of the wood shall be disregarded and the knot shall be
cut out. In such a case, the two test pieces which are to be compared (180 °C and the second elevated
temperature T2), shall be adjacent and taken from the same side next to the knot. The adjacent test pieces
shall be cut with a distance from the knot of at least the diameter of the knot.
A sufficient number of wood pieces with a length of 800 mm shall be prepared, to enable the preparation
and testing of at least 20 bonded test pieces and at least 20 solid wood test pieces in accordance with
Figure 2 and the performance of pre-tests (see 7.3). The solid wood control test pieces shall be produced
with the same dimensions as the bonded test pieces. The bonded test pieces and the matched solid wood
test pieces shall be produced as pairs. Care shall be taken to ensure the same annual ring orientation
when bonding the laminations together into a bonded assembly.
NOTE Experience has shown that usually some test pieces are needed for pre-tests, to adjust the correct
temperature of the heating chamber, and to check the temperature evolution within the test piece and whether the
target temperature is reached within the correct time span (see 7.3). Therefore, it is very useful to prepare a
sufficient number of spare test pieces.
The bonded test pieces shall be prepared from laminations (16,0 ± 0,1) mm thick (after planing) by
(60,0 ± 0,1) mm wide. The adhesive preparation and the bonding procedure shall follow the adhesive
manufacturer’s recommendation.
After the bonding process, the bonded laminations shall be conditioned for a minimum of 14 d in standard
climate 20 °C and 65 % relative humidity. After the conditioning period, the bonded laminations shall be
planed or cut to the final width and the
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.