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1、DRAFT FOR DEVELOPMENT DD ENV 302-5:2002 Adhesives for load-bearing timber structures Test methods Part 5: Determination of the conventional assembly time ICS 83.180; 91.080.20 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Licensed Copy: London South Bank University, London S
2、outh Bank University, Tue Dec 12 06:04:52 GMT+00:00 2006, Uncontrolled Copy, (c) BSI DD ENV 302-5:2002 This Draft for Development, having been prepared under the direction of the Materials and Chemicals Sector Policy and Strategy Committee, was published under the authority of the Standards Policy a
3、nd Strategy Committee on 21 January 2002 BSI 21 January 2002 ISBN 0 580 38815 8 National foreword This Draft for Development is the English language version of ENV 302-5:2002. This publication is not to be regarded as a British Standard. It is being issued in the Draft for Development series of publ
4、ications and is of a provisional nature because it is considered that further experience is required in its application before it is converted into a British Standard. It should be applied on this provisional basis, so that information and experience of its practical application may be obtained. Com
5、ments arising from the use if this Draft for Development are requested so that UK experience can be reported to the European organization responsible for its conversion into a European Standard. A review of this publication will be initiated 2 years after its publication by the European organization
6、 so that a decision can be taken on its status at the end of its three-year life. The commencement of the review period will be notified by an announcement in Update Standards. According to the replies received by the end of the review period, the responsible BSI Committee will decide whether to sup
7、port the conversion into a European Standard, to extend the life of the prestandard or to withdraw it. Comments should be sent in writing to the Secretary of BSI Technical Committee PRI/52, Adhesives, at 389 Chiswick High Road, London W4 4AL, giving the document reference and clause number and propo
8、sing, where possible, an appropriate revision of the text. A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the
9、 BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. Summary of pages This document comprises a front cover, an inside front cover, the ENV title page, pages 2 to 10, an inside b
10、ack cover and a back cover. The BSI copyright date displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. DateComments Licensed Copy: London South Bank University, London South Bank University, Tue Dec 12 06:04:52 GMT+00:00 2006, Uncontro
11、lled Copy, (c) BSI EUROPEAN PRESTANDARD PRNORME EUROPENNE EUROPISCHE VORNORM ENV 302-5 December 2001 ICS 83.180 English version Adhesives for load-bearing timber structures - Test methods - Part 5: Determination of the conventional assembly time Adhsifs pour structures portantes en bois - Mthodes de
12、ssais - Partie 5: Dtermination de la dure conventionnelle dassemblage Klebstoffe fr tragende Holzbauteile - Prfverfahren - Teil 5: Bestimmung der durchschnittlichen Antrockenzeit This European Prestandard (ENV) was approved by CEN on 4 October 2001 as a prospective standard for provisional applicati
13、on. The period of validity of this ENV is limited initially to three years. After two years the members of CEN will be requested to submit their comments, particularly on the question whether the ENV can be converted into a European Standard. CEN members are required to announce the existence of thi
14、s ENV in the same way as for an EN and to make the ENV available promptly at national level in an appropriate form. It is permissible to keep conflicting national standards in force (in parallel to the ENV) until the final decision about the possible conversion of the ENV into an EN is reached. CEN
15、members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALI
16、SATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: rue de Stassart, 36 B-1050 Brussels 2001 CENAll rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. ENV 302-5:2001 E Licensed Copy: London South Bank University, London South Bank Universit
17、y, Tue Dec 12 06:04:52 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ENV 302-5:2001 (E) 2 Contents page Foreword3 1Scope4 2Normative references4 3Terms and definitions .4 4Safety4 5Principle4 6Apparatus.5 7Procedure.5 8Expression of results6 9Test report6 Licensed Copy: London South Bank University, Lo
18、ndon South Bank University, Tue Dec 12 06:04:52 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ENV 302-5:2001 (E) 3 Foreword This European Prestandard has been prepared by Technical Committee CEN/TC 193 “Adhesives“, the secretariat of which is held by AENOR. This prestandard is one of a series dealing w
19、ith adhesives for use with timber structures. The series consists of seven test methods used to assess the performance of adhesives after specified heat and humidity treatments. The other parts of the prestandard are : ? prEN 302 - 1 Rev: Determination of longitudinal tensile shear strength; ? prEN
20、302 2 Rev: Determination of resistance to delamination; ? prEN 302 3 Rev: Determination of the effect of acid damage to wood fibres by temperature and humidity cycling on the transverse tensile strength; ? prEN 302 - 4 Rev: Determination of the effects of wood shrinkage on the shear strength; ? prEN
21、 302 - 6: Determination of the conventional pressing time; ? prEN 302 - 7: Determination of the conventional working life. No existing European Standard is superseded. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to anno
22、unce this European Prestandard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. Licensed Copy: London South Bank University, London South Bank Universit
23、y, Tue Dec 12 06:04:52 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ENV 302-5:2001 (E) 4 1 Scope This European Prestandard specifies a laboratory method of determining the conventional assembly time for adhesives for load bearing timber structures under specified conditions. This test method is not in
24、tended for use with adhesive systems in which the components are separately and sequentially applied to the substrate. This prestandard is only intended for obtaining a reliable base of comparison between similar adhesives. The method gives result which cannot be applied to the safe manufacture of t
25、imber structures without modifications for the influences of timber density/absorbency, moisture content, factory temperature and relative air humidity. 2 Normative references This European Prestandard incorporates by dated or undated reference, provisions from other publications. These normative re
26、ferences are cited at the appropriate places in the text, and the publications are listed hereafter. For dated references, subsequent amendments to or revisions of any of these publications apply to this European Prestandard only when incorporated in it by amendment or revision. For undated referenc
27、es the latest edition of the publication referred to applies (including amendments). EN 923, Adhesives ? Terms and definitions. 3 Terms and definitions For the purposes of this European Prestandard, the terms and definitions given in EN 923 and the following term and definition apply. 3.1 convention
28、al assembly time interval between adhesive application and the stage in the curing of the adhesive when a rolling ball will travel a distance of 290 mm over the surface of a glass plate coated with the test adhesive; the test arrangement being that described in this prestandard 4 Safety Persons usin
29、g this prestandard shall be familiar with normal laboratory practice. This prestandard does not purport to address all the safety problems, if any, associated with its use. It is the responsibility of the user to establish safety and health practices and to ensure compliance with any European or nat
30、ional regulatory conditions. 5 Principle A steel ball is allowed to roll down an inclined plane and across the surface of a glass plate that has been coated with the test adhesive. The procedure is repeated at various time intervals until the ball is observed to travel 290 mm across the plate. Licen
31、sed Copy: London South Bank University, London South Bank University, Tue Dec 12 06:04:52 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ENV 302-5:2001 (E) 5 6 Apparatus 6.1 Climatic room, capable of maintaining the air at a temperature of (20 ? 2) C and a relative humidity of (65 ? 5) %. 6.2 A test tab
32、le with a hard horizontal surface. 6.3 An inclined trough, equipped with a release lever at the top, through which the ball gains downhill momentum. The equipment is shown in Figure 1. 6.4 At least one solid ball with 20 mm diameter made of stainless steel and weighting (32,60 ? 0,03) g. 6.5 At leas
33、t three clean glass plates with a length of 290 mm and a width of at least 80 mm. 6.6 Suitable equipment for the preparation of an adhesive coating with a spread of (400 ? 10) g/m. An adequate equipment is shown in Figure 2. NOTE Experience shows that for most of the structural adhesives a coating t
34、hickness of 0,5 mm gives an adequate glue spread. 6.7 Balance, with an accuracy of 0,01 g. 7 Procedure 7.1 Ensure that at the start of the test the temperature of the adhesive and that of all the equipment is (20 ? 1) C. NOTE It is a common practice to store the adhesive components and all the equip
35、ment at (20 ? 1) C and relative humidity of (65 ? 5) % for one night before testing. 7.2 The test is carried out in the climatic room (6.1) in order to ensure that during the test, the air temperature and relative humidity remain (20 ? 2) C and relative humidity of (65 ? 5) % respectively. 7.3 Handl
36、e the adhesive components in accordance with the instructions of the manufacturer of the adhesive. 7.4 Thoroughly clean the balls (6.4) so that no trace of adhesive, grease or moisture is left on the surface. 7.5 Thoroughly clean the surface of the glass plates (6.5) in order to obtain a uniform glu
37、e spread. Weigh each glass plate to the nearest 0,01 g (M0i). 7.6 Prepare a sufficient amount of the glue mix in order to prepare at least three test plates (6.5). The preparation occurs in accordance with the specifications of the manufacturer. 7.7 Apply the glue mix on the cleaned conditioned glas
38、s plates (7.5) to produce a uniform coating with a glue spread of (400 ? 10) g/m. All the test plates shall be prepared within two minutes time. Start to record the time at the moment the adhesive is spread over the surface of the last test plate. Immediately weigh the coated glass plates to the nea
39、rest 0,01 g (M1i). Ensure that the adhesive surfaces are not subjected to any forced ventilation that could significantly affect its drying kinetics. Licensed Copy: London South Bank University, London South Bank University, Tue Dec 12 06:04:52 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ENV 302-5:20
40、01 (E) 6 7.8 Arrange the first test plate in line with the incline trough (6.3) in such a way that a clear untested adhesive surface is to be tested. 7.9 For each run a cleaned and conditioned ball (7.4) is placed on the upper side of the release of the inclined trough. 7.10 Release the ball and all
41、ow it to roll to a stop on the adhesive. Measure the distance in millimeters from the point where the ball initially contacts the adhesive to where the ball is in contact when it stops. 7.11 Execute steps (7.8) to (7.10) with the two other test plates respectively. 7.12 Repeat steps (7.8) to (7.11)
42、at appropriate time intervals until the ball travels over the conventional distance of 290 mm. NOTE In most of the cases 10 minutes intervals have been proven to be appropriate. In order to increase the accuracy of the determination of the conventional assembly time, it is advisable to reduce the ti
43、me interval between two runs in the final stage of the reaction. 8 Expression of results For each test plate calculate the actual glue spread expressed in g/m, using the expression: (M1i - M0i) / Si whereM1i and M0i are the mass of the coated and uncoated glass plate i respectively Si is the surface
44、 of the adhesive coating, in m, applied on plate i. For each test plate, plot the stopping distance in function of time. The individual result is the total time in minutes elapsed between the time recorded when the adhesive was spread on the glass plates and the time at which the ball travels over t
45、he conventional distance of 290 mm. The conventional assembly time of the adhesive is expressed as the average value of the three replicates rounded up to the nearest min. 9 Test report The test report shall contain the following information: a) a reference to this European Prestandard; b) the ident
46、ification of the adhesive system tested; c) the proportions taken when mixing the adhesive for use; d) the actual glue spread; e) the individual plots; f) the value of the conventional assembly time in minutes; g) the date of testing; h) a note stressing the attention on the fact that the convention
47、al assembly time obtained by this standardised method is only relevant for comparison with other adhesive systems; therefore it cannot be used as such for production purposes in the plant. Licensed Copy: London South Bank University, London South Bank University, Tue Dec 12 06:04:52 GMT+00:00 2006,
48、Uncontrolled Copy, (c) BSI ENV 302-5:2001 (E) 7 Key 1 Overall view Figure 1 Testing equipment suitable for the determination of the conventional assembly time Licensed Copy: London South Bank University, London South Bank University, Tue Dec 12 06:04:52 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ENV
49、 302-5:2001 (E) 8 Dimensions in millimetres Key 1 Steel ball 2 Graduated marks 3 Based support Figure 2 Trapping support Licensed Copy: London South Bank University, London South Bank University, Tue Dec 12 06:04:52 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ENV 302-5:2001 (E) 9 Dimensions in millimetres Key 1 Steel ball ? 20 mm Figure 3 Launching pad (section) Licensed Copy: London South Bank University, London South Bank University, Tue Dec 12 06:04:52 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ENV 302-5:2001 (E) 10 Dimensions in millimetres Figur
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