1、Adhesives for load-bearing timber structures - Test methodsPart 3: Determination of the effect of acid damage to wood fibres by temperature and humidity cycling on the transverse tensile strengthBS EN 3023:2017BSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06EUROPEAN
2、STANDARD NORME EUROPENNE EUROPISCHE NORM EN 302-3 September 2017 ICS 83.180 Supersedes EN 302-3:2013English Version 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 te
3、nsile strength Adhsifs pour structures portantes en bois - Mthodes dessai - Partie 3: Dtermination de linfluence de lattaque dacide des fibres de bois, rsultant de traitements cycliques en temprature et humidit sur la rsistance la traction transversale Klebstoffe fr tragende Holzbauteile - Prfverfah
4、ren - Teil 3: Bestimmung des Einflusses von Sureschdigung der Holzfasern durch Temperatur- und Feuchtezyklen auf die Querzugfestigkeit This European Standard was approved by CEN on 9 July 2017. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions f
5、or 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 thr
6、ee 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 bo
7、dies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Sl
8、ovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2017 CEN All rights of exploitation in any form and by any means reserv
9、ed worldwide for CEN national Members. Ref. No. EN 302-3:2017 ENational forewordThis British Standard is the UK implementation of EN 3023:2017. It supersedes BS EN 3023:2013, which is withdrawn.The UK participation in its preparation was entrusted to Technical Committee PRI/52, Adhesives.A list of o
10、rganizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. The British Standards Institution 2017 Published by BSI Standards Limited
11、 2017ISBN 978 0 580 91267 2ICS 83.180Compliance with a British Standard cannot confer immunity from legal obligations.This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 September 2017.Amendments/corrigenda issued since publicationDate Text af
12、fectedBRITISH STANDARDBS EN 3023:2017EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 302-3 September 2017 ICS 83.180 Supersedes EN 302-3:2013English Version Adhesives for load-bearing timber structures - Test methods - Part 3: Determination of the effect of acid damage to wood fibres by tempera
13、ture and humidity cycling on the transverse tensile strength Adhsifs pour structures portantes en bois - Mthodes dessai - Partie 3: Dtermination de linfluence de lattaque dacide des fibres de bois, rsultant de traitements cycliques en temprature et humidit sur la rsistance la traction transversale K
14、lebstoffe fr tragende Holzbauteile - Prfverfahren - Teil 3: Bestimmung des Einflusses von Sureschdigung der Holzfasern durch Temperatur- und Feuchtezyklen auf die Querzugfestigkeit This European Standard was approved by CEN on 9 July 2017. CEN members are bound to comply with the CEN/CENELEC Interna
15、l 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 CE
16、N 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 versi
17、ons. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, P
18、oland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2017 CEN All rights of ex
19、ploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 302-3:2017 EBS EN 3023:2017EN 302-3:2017 (E) 2 Contents Page European foreword . 3 Introduction 4 1 Scope 6 2 Normative references 6 3 Principle . 6 4 Apparatus . 6 5 Method 7 5.1 Selection of timber 7 5
20、.2 Preparation of the bonded assemblies 7 5.3 Preparation of the test pieces . 9 5.4 Number of test pieces 9 5.5 Climatic and cyclic storage conditions 9 5.6 Test procedure 10 6 Expression of results . 10 7 Test report 11 Bibliography . 12 BS EN 3023:2017EN 302-3:2017 (E) 3 European foreword This do
21、cument (EN 302-3:2017) 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 March 2018, and con
22、flicting national standards shall be withdrawn at the latest by March 2018. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. This docum
23、ent supersedes EN 302-3:2013. Compared to EN 302-3:2013 the following modification has been made: a) EN 15416-2 is replaced by EN 302-8, Adhesives for load-bearing timber structures Test methods Part 8: Static load test of multiple bond line specimens in compression shear; b) specification of beech
24、for test pieces for gap filling adhesives in 5.1; c) reparation of test pieces for gap filling adhesives added in 5.2; d) description of climate cycling test in 5.5 completed. According to the CEN-CENELEC Internal Regulations, the national standards organisations of the following countries are bound
25、 to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
26、 Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. BS EN 3023:2017EN 302-3:2017 (E) 4 Introduction This document is one of a series dealing with adhesives for use with timber structures, and is published in support of EN 1995, Eurocode 5: Design of timbe
27、r structures. The series 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 all tog
28、ether twelve test methods (EN 302-1, EN 302-2, EN 302-3, EN 302-4, EN 302-5, EN 302-6, EN 302-7 and EN 302-8, and EN 15416-1, EN 15416-3, EN 15416-4 and EN 15416-5). These European Standards have the following titles. EN 301, Adhesives, phenolic and aminoplastic, for load-bearing timber structures C
29、lassification 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 r
30、equirements 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
31、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
32、 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 co
33、nditions with specimens loaded perpendicular to the glue line (Glasshouse test) Part 3: Creep deformation test at cyclic climate conditions with specimens loaded in bending shear Part 4: Determination of open assembly time under referenced conditions Part 5: Determination of minimum pressing time un
34、der referenced conditions BS EN 3023:2017EN 302-3:2017 (E) 5 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 u
35、ser to establish appropriate safety and health practices and to ensure compliance with any regulatory conditions. Environmental statement It is understood that some of the material permitted in this standard can have a negative environmental impact. As technological advantages lead to better alterna
36、tives for these materials, they will be eliminated from this standard to the greatest extent possible. At the end of the test, it is recommended that the user of the standard take care to carry out an appropriate disposal of the wastes, according to local regulations. BS EN 3023:2017EN 302-3:2017 (E
37、) 6 1 Scope This European Standard specifies a method for determining the effect on bond strength of damage to wood fibres caused by the action of acids from the adhesive or primer used in the gluing process during climatic cycling. It is suitable for the following applications: a) for assessing the
38、 compliance of adhesives with EN 301, EN 15425 and EN 16254; b) for assessing the suitability and quality of adhesives for load-bearing timber structures; c) for determining if the adhesive after bonding has a damaging influence on the strength of the wood due to chemical action. This test is intend
39、ed 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 test is carried out on Norway spruce (Picea abies L.) or Beech (Fagus sylvatica L.). This method is not intende
40、d for use to provide numerical design data and does not necessarily represent the performance of the bonded member in service. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated referen
41、ces, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 1245, Adhesives - Determination of pH ISO 5893, Rubber and plastics test equipment Tensile, flexural and compression types (constant rate of traverse) Spe
42、cification 3 Principle A joint between wooden adherends is submitted to defined temperature and humidity cycles and then strained to failure by a transverse tensile load. 4 Apparatus 4.1 Testing machine, which shall be either: a) a constant rate of loading machine, capable of maintaining a rate of l
43、oading of (5 1) kN/min; or b) a constant rate of traverse machine as described in ISO 5893. Special mounts are required (see Figure 1). One or both mounts shall be attached to the straining heads by a coupling, which permits self-alignment of the mounts whilst the test pieces are being pulled. 4.2 C
44、limatic cabinets, which are enclosures with air circulation capable of maintaining the test pieces under the following conditions: a) (10 2) C at approximately (87,5 2,5) % relative humidity; b) (50 2) C at approximately (87,5 2,5) % relative humidity; BS EN 3023:2017EN 302-3:2017 (E) 7 c) (50 2) C
45、with relative humidity lower than 20 %. NOTE The velocity of the air circulation at a level of 0,5 m/s to 1,0 m/s has shown to be suitable. 4.3 Airtight glass enclosure, such as a desiccator with a lid is required, with the following dimensions: a) Volume 2 l to 10 l; b) Ratio of height to width bet
46、ween 1/1 and 2/1. 5 Method 5.1 Selection of timber Carry out this test using Norway spruce (Picea abies L.) having a density of (450 25) kg/3mmeasured at 12 % moisture content. Carry out the test using beech (Fagus sylvatica L.) having a density of (700 50) kg/3mmeasured at 12 % moisture content, fo
47、r gap filling adhesives (GF). Prepare one piece of wood, at least 60 mm 60 mm in cross section and at least 1 600 mm in length or two pieces with a length of 800 mm that are free from knots, straight-grained and with growth rings not wider than 2 mm and at 30 to 60 to the surfaces of the specimen. 5
48、.2 Preparation of the bonded assemblies Cut the piece of wood lengthwise into two equal pieces of rectangular cross section and store them in standard climate 20/65 to constant mass. Constant mass is defined as the mass attained when the results of two successive weighings over an interval of 24 h d
49、iffer by not more than 0,1 % of the mass of the specimen. Condition the timber in standard atmosphere 20/65 (20 2) C and (65 5) % relative humidity) for at least 7 days prior to bonding, to achieve a moisture content of (12 1) %. Not more than 8 h before bonding, plane each surface to be bonded to the final thickness of 25 mm. Remove any dust carefully. Do not touch or soil the prepared surface. For glue mixes, adhesive and hardener blended before ap
