1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS EN 302-2:2013Adhesives for load-bearing timber structures T e s t m e t h o d sPart 2: Determination of r e s i s t a n c e to delaminationBS EN 302-2:2013 BRITISH STANDARDNat
2、ional forewordThis British Standard is the UK implementation of EN 302-2:2013. It supersedes BS EN 302-2:2004, which is withdrawn.The UK participation in its preparation was entrusted to T e c h n i c a l C o m m i t t e e P R I / 5 2 , A d h e s i v e s .A list of organizations represented on this
3、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 2013. Published by BSI Standards Limited 2013.ISBN 978 0 580 75256 8 ICS
4、 83.180 Compliance with a British Standard cannot confer immunityfrom legal obligations.This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 April 2013.Amendments issued since publicationDate T e x t a f f e c t e dBS EN 302-2:2013EUROPEAN STAN
5、DARD NORME EUROPENNE EUROPISCHE NORM EN 302-2 March 2013 ICS 83.180 Supersedes EN 302-2:2004English Version Adhesives for load-bearing timber structures - Test methods - Part 2: Determination of resistance to delamination Adhsifs pour structures portantes en bois - Mthodes dessai - Partie 2: Dtermin
6、ation de la rsistance la dlamination Klebstoffe fr tragende Holzbauteile - Prfverfahren - Teil 2: Bestimmung der Delaminierungsbestndigkeit This European Standard was approved by CEN on 5 February 2013. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the con
7、ditions 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 exis
8、ts 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 sta
9、ndards 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, Poland, Portugal, Romania, Slovakia, S
10、lovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2013 CEN All rights of exploitation in any form and by any means reserved worldwid
11、e for CEN national Members. Ref. No. EN 302-2:2013: EBS EN 302-2:2013EN 302-2:2013 (E) 2 Contents Page 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 5.2 Preparation of the bonded members .7 5.3 Preparation of test piec
12、es .8 5.4 Test procedures .8 5.4.1 General 8 5.4.2 High temperature procedure (for type I adhesives) .9 5.4.3 Low temperature procedure (for type II adhesives) .9 5.5 Measurement and evaluation of delamination . 10 6 Expression of results . 11 7 Test report . 11 7.1 The adhesives . 11 7.2 Preparatio
13、n of test pieces and testing procedure . 11 7.3 Test results 12 Bibliography . 13 BS EN 302-2:2013EN 302-2:2013 (E) 3 Foreword This document (EN 302-2:2013) has been prepared by Technical Committee CEN/TC 193 “Adhesives”, the secretariat of which is held by AENOR. This European Standard shall be giv
14、en the status of a national standard, either by publication of an identical text or by endorsement, at the latest by September 2013 and conflicting national standards shall be withdrawn at the latest by September 2013. Attention is drawn to the possibility that some of the elements of this document
15、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 document supersedes EN 302-2:2004. The following modifications have been made: The glue spread for minimum and maximum assembly time is now given for aminoplastic
16、 and phenolic adhesives; The standard is now used for assessing the compliance for adhesives with EN 301, EN 15425 and prEN 16254. According to the CEN-CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria
17、, 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, Slovakia, Slovenia, Spain, Sweden,
18、Switzerland, Turkey and the United Kingdom. .BS EN 302-2:2013EN 302-2:2013 (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 timber structures. The series consists of three classifi
19、cation and performance requirements for adhesives for load-bearing timber structures, phenolic and aminoplastic adhesives (EN 301), one component polyurethane adhesives (EN 15425) and emulsion polymerised isocyanate adhesives (prEN 16254), and all together eleven test methods (EN 302 Parts 1 to 7 an
20、d EN 15416 Parts 2 to 5). These European Standards have the following titles: EN 301, Adhesives, phenolic and aminoplastic, for load-bearing timber structures Classification and performance requirements EN 15425, Adhesives One component polyurethane for load bearing timber structures Classification
21、and performance requirements prEN 16254, Adhesives Emulsion polymerized isocyanate (EPI), for load-bearing timber structures Classification and performance requirements EN 302, Adhesives for load-bearing timber structures Test methods Part 1: Determination of longitudinal tensile shear strength Part
22、 2: Determination of resistance to delamination Part 3: Determination of the effect of acid damage to wood fibres by temperature and humidity cycling on the transverse tensile strength Part 4: Determination of the effects of wood shrinkage on the shear strength Part 5: Determination of maximum assem
23、bly time under referenced conditions Part 6: Determination of the minimum pressing time under referenced conditions Part 7: Determination of the working life under referenced conditions EN 15416, Adhesives for load bearing timber structures other than phenolic and aminoplastic Test methods Part 2: S
24、tatic load test of multiple bondline specimens in compression shear Part 3: Creep deformation test at cyclic climate conditions with specimens loaded in bending shear Part 4: Determination of open assembly time for one component polyurethane adhesives Part 5: Determination of conventional pressing t
25、ime 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
26、and to ensure compliance with any regulatory conditions. BS EN 302-2:2013EN 302-2:2013 (E) 5 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 alternatives for these mater
27、ials, 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 302-2:2013EN 302-2:2013 (E) 6 1 Scope This Eur
28、opean Standard specifies a method for determining the resistance to delamination in glue lines. It is suitable for the following applications: a) for assessing the compliance of adhesives with EN 301, EN 15425 and prEN 16254; b) for assessing the suitability and quality of adhesives for load-bearing
29、 timber structures; c) for comparing the effects on the bond strength resulting from the choice of bonding conditions, from different climatic conditioning and from the treatment of the test pieces before and after bonding. This test is not applicable for modified and stabilised wood with strongly r
30、educed swelling and shrinkage properties, such as acetylated wood, heat-treated wood and polymer impregnated wood. This test is intended primarily to obtain performance data for the classification of adhesives for load-bearing timber structures according to their suitability for use in defined clima
31、tic environments. This method is not intended to provide data for structural design, and does not necessarily represent the performance of the bonded member in service. 2 Normative references Not applicable. 3 Principle Bonded, laminated specimens are subjected to an impregnation-drying procedure. T
32、he specimens are impregnated with water by immersing them and applying alternating high and low (vacuum) pressure. They are then dried rapidly in a specified air stream at low humidity (see 4.4). The extent of open glue lines, delamination, as a result of these treatments is measured and compared wi
33、th the total length of glue lines on both end-grain faces of the specimen. 4 Apparatus 4.1 Autoclave or similar pressure vessel, designed to safely withstand a pressure of at least 625 kPa absolute (525 kPa above nominal atmospheric pressure). 4.2 Vacuum pump or similar device, capable of reducing t
34、he pressure in the vessel (4.1) to below 20 kPa absolute (80 kPa below nominal atmospheric pressure). 4.3 Pump or similar device, for obtaining a pressure of at least 600 kPa absolute (500 kPa above nominal atmospheric pressure). 4.4 Air-circulating oven(s) or chamber(s), capable of drying the test
35、pieces (see 5.4) in the following climate condition: a) for low temperature procedure (type II adhesive) a temperature of (27,5 2,5) C, circulating the air within the chamber, maintaining a constant relative humidity of (30 5) %; and b) for high temperature procedure (type I adhesive) a temperature
36、of (65 3) C, circulating the air within the chamber, maintaining a relative humidity of (12,5 2,5) %. BS EN 302-2:2013EN 302-2:2013 (E) 7 NOTE Air speed velocity of 2 m/s to 3 m/s in empty chamber has shown to be suitable to achieve drying times according to 5.4.2 and 5.4.3. 4.5 Balance, allowing me
37、asurements with an accuracy of 1 g. 4.6 Wood chisel and hammer, or similar devices capable of opening the glue lines. 5 Method 5.1 Selection of timber Use flat-sawn, straight-grained Norway spruce (Picea abies L.), free of reaction wood, with a density of (450 25) kg/m at (12 1) % moisture content.
38、Preferably, knot-free wood should be used, but allowances are made for boards with knots up to a maximum of 20 mm in diameter, but splay (spike) knot is not allowed. The test with Norway spruce also covers approval of silver fir (Abies alba) and Scots pine (Pinus sylvestris). If the adhesive is to b
39、e used on wood from other conifer species like larch (Larix decidua), Douglas fir (Pseudotsuga menziesii) and pines with coloured heartwood (other than Scots pine (Pinus sylvestris), from hardwood species and/or on preservative treated wood, also prepare four laminated members using representative s
40、amples using wood with mean density. Condition the timber in the standard climate 20/65 (20 2) C and a relative humidity of (65 5) %) for at least 7 days prior to bonding, ensuring that the timber has a moisture content of (12 1) %. 5.2 Preparation of the bonded members Make four laminated members,
41、two with short assembly time and two with long assembly time. For each laminated member, prepare six lamellae at least (150 5) mm wide, (30 1) mm thick and approximately 500 mm long from six different boards. The desired thickness is achieved by planing 38 mm thick lamellae. Store the lamellae in st
42、andard climate 20/65 before planing and gluing. Bond the lamellae in accordance with Table 1, within 8 h of planing. Within each assembly, ensure that the six lamellae present the same growth ring symmetry. BS EN 302-2:2013EN 302-2:2013 (E) 8 Table 1 Preparation of the bonded members Parameters Memb
43、ers 1 and 2 Members 3 and 4 Adhesive spread, single sided (can be 2 faces for hardwood) Mixed and/or separate For aminoplastic and phenolic adhesives: 250 g/m For other adhesives as recommended by the adhesive manufacturer For aminoplastic and phenolic adhesives: 400 g/m For other adhesives as recom
44、mended by the adhesive manufacturer Air temperature (20 2) C (20 2) C Open assembly time Maximum 5 min cMaximum 5 mincClosed assembly time Minimum dMaximum dPressure (conifers) a(0,6 0,1) N/mm (0,6 0,1) N/mm Pressure time bAs recommended bAs recommended baFor hardwood species, larch, Douglas fir and
45、 pines with coloured heartwood, the pressure shall be that recommended by the adhesive manufacturer. bAs recommended by the adhesive manufacturer for a curing temperature of (20 2) C. c Or as recommended by the adhesive manufacturer. d As recommended by the adhesive manufacturer at standard climate.
46、 If the adhesive system is intended for only separate application, then premixed adhesive and hardener shall not be tested by this standard. After bonding and pressing and before cutting and testing, condition the assembly for 7 days to 14 days in the standard climate 20/65. 5.3 Preparation of test
47、pieces Trim the bonded member to a width of at least 145 mm. From a full cross-section of each of the four laminated members to be tested, cut two test pieces using a sharp saw or other tool that produces a smooth surface. Remove sections 75 mm long by cutting perpendicularly to the surface of the a
48、ssembly and not less than 50 mm from either end of the member. Record the time elapsed between the preparation of the test pieces and testing. 5.4 Test procedures 5.4.1 General Weigh and record the original mass (m0) of the test pieces to the nearest gram. Place the test pieces in the pressure vesse
49、l and secure them to prevent them from floating. Add water at a temperature of 10 C to 25 C to completely submerge the test pieces. Separate the test pieces by using at least 5 mm thick stickers, wire screens or other means in such a way that all end-grain surfaces are freely exposed to the water. Carry out either the high temperature procedure according to 5.4.2 for testing compliance with the requirements for type I adhesives for use in severe climatic conditions, or the
