1、 ISO 2016 Timber structures Determination of characteristic values Part 3: Glued laminated timber Structures en bois Dtermination des valeurs caractristiques Partie 3: Exigences pour les bois lamell-coll INTERNATIONAL STANDARD ISO 12122-3 First edition 2016-07-01 Reference number ISO 12122-3:2016(E)
2、 ISO 12122-3:2016(E)ii ISO 2016 All rights reserved COPYRIGHT PROTECTED DOCUMENT ISO 2016, Published in Switzerland All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including ph
3、otocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISOs member body in the country of the requester. ISO copyright office Ch. de Blandonnet 8 CP 401 CH-1214 Vernier, Geneva, Switzerland Tel. +41
4、 22 749 01 11 Fax +41 22 749 09 47 copyrightiso.org www.iso.org ISO 12122-3:2016(E)Foreword iv Introduction v 1 Scope . 1 2 Normative references 1 3 T erms and definitions . 1 4 Symbols and abbreviated terms . 1 5 Reference population 1 6 Sampling 2 6.1 Sampling method 2 6.2 Sample size . 2 7 Sample
5、 conditioning . 2 8 Test data 2 8.1 Test method . 2 8.2 Test data compatible with product description . 3 8.3 Failure modes . 3 9 Evaluation of characteristic values for structural properties . 3 9.1 Structural properties . 3 9.2 Characteristic modulus of elasticity or stiffness 3 9.3 Characteristic
6、 values of strength or capacity 3 9.3.1 Characteristic bearing strength 3 9.3.2 Other characteristic values for strength or capacity based on the 5th percentile test value 3 10 Report 3 Annex A (informative) Commentary . 4 Annex B (informative) Analytical models for determining characteristic proper
7、ties of glued laminated timber . 8 Bibliography 9 ISO 2016 All rights reserved iii Contents Page ISO 12122-3:2016(E) Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Stand
8、ards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also ta
9、ke part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In p
10、articular the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives). Attention is drawn to the possibility that some of the elements
11、of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (se
12、e www.iso.org/patents). Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement. For an explanation on the meaning of ISO specific terms and expressions related to conformit y assessment, as well as information about ISOs adherenc
13、e to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following URL: www.iso.org/iso/foreword.html. The committee responsible for this document is ISO/TC 165, Timber structures. ISO 12122 consists of the following parts, under the general title Timber st
14、ructures Determination of characteristic values: Part 1: Basic requirements Part 2: Sawn timber Part 3: Glued laminated timber Part 4: Engineered wood products 1) Part 6: Large components and assemblies 1) The following parts are under preparation: Part 5: Mechanical connections 1) To be published.i
15、v ISO 2016 All rights reserved ISO 12122-3:2016(E) Introduction This part of ISO 12122 sets out a framework for establishing characteristic values from test results on a sample drawn from a clearly defined reference population of glued laminated timber. The characteristic value is an estimate of the
16、 property of the reference population with a consistent level of confidence prescribed in this part of ISO 12122. This part of ISO 12122 is to be used in conjunction with ISO 12122-1. This part of ISO 12122 permits the evaluation of characteristic values on testing on commercial sized specimens of g
17、lued laminated timber. Where the characteristic values are derived using calculations based on laminate structural properties, this part of ISO 12122 does not apply, but Annex B references other methods for estimating characteristic values. In some cases, characteristic values determined in accordan
18、ce with this part of ISO 12122 may be modified to become a design value. This part of ISO 12122 has the following annexes: Annex A presents a commentary on this part of ISO 12122; Annex B presents information on analytical models for determining characteristic values of glued laminated timber. ISO 2
19、016 All rights reserved v Timber structures Determination of characteristic values Part 3: Glued laminated timber 1 Scope This part of ISO 12122 gives methods for the determination of characteristic values for a defined population of glued laminated timber products, calculated from test values. It p
20、resents methods for the determination of a) characteristic value of mean-based properties, and b) characteristic value of 5th percentile-based properties. NOTE Annex B gives information on the methods that have been successfully used to estimate the characteristic values of glued laminated timber pr
21、oducts from properties of the laminates. 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 references, only the edition cited applies. For undated references, the latest edition of the
22、 referenced document (including any amendments) applies. ISO 8375, Timber structures Glued laminated timber Test methods for determination of physical and mechanical properties ISO 12122-1, Timber structures Determination of characteristic values Part 1: Basic requirements 3 T erms a nd definiti ons
23、 For the purposes of this document, the terms and definitions given in ISO 12122-1 and ISO 12578 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: avai
24、lable at http:/ /www.iso.org/obp 4 Symbols and abbreviated terms Symbols defined in the relevant ISO product or test standard shall be used. Other symbols are defined in ISO 12122-1. 5 Reference population In addition to the requirements for definition of the reference population in ISO 12122-1, the
25、 following attributes of glued laminated timber may be included: a) sources of raw material; INTERNATIONAL ST ANDARD ISO 12122-3:2016(E) ISO 2016 All rights reserved 1 ISO 12122-3:2016(E) b) seasoning method (if seasoned); c) grading or production method for laminates including presence and frequenc
26、y of finger joints; d) layup of the glued laminated product; e) specification of adhesives, method of application and method of curing adhesives; f) quality control measures; g) variations in the laminates (if any). 6 Sampling 6.1 Sampling method The sampling method shall comply with the performance
27、 objective of sampling defined in ISO 12122-1. Representation of each of the variants in the sample shall approximate the representation of the same variants in the reference population. The sampling method shall be documented in the report as detailed in Clause 10 and this documentation shall indic
28、ate a response to each of the identified attributes of the reference population listed in compliance with Clause 5 and in ISO 12122-1 or otherwise important to the description of the reference population. 6.2 Sample size The sample size shall comply with requirements of ISO 12122-1 and shall take in
29、to account the coefficient of variation (V) expected for the glued laminated timber in the reference population. NOTE 1 See notes under the relevant clause in ISO 12122-1. NOTE 2 ISO 12122-1 gives some guidance on selecting sample size. 7 Sample conditioning The sample storage and testing environmen
30、t shall reflect conditioning in accordance with the definition of the reference population as indicated in ISO 12122-1. Due to the large size of glued laminated timber, it is acceptable to test the sample at as-tested conditions provided that the results are adjusted in accordance with 8.2. 8 Test d
31、ata 8.1 Test method The test data shall be obtained from a) ISO 8375, or b) a standard test method appropriate for the glued laminated timber reference population provided equivalency factors with ISO 8375 can be established. NOTE See notes under the relevant clause in ISO 12122-1. Test methods invo
32、lve many variables that will affect results including loading configuration and rates, specimen positioning and measurement methods. The level of precision of these variables should be appropriate to the objectives of the testing and the adjustments required in 8.2.2 ISO 2016 All rights reserved ISO
33、 12122-3:2016(E) 8.2 Test data compatible with product description Where the characteristic value is applicable to a standard size or moisture content, adjustments to the raw test data may be required. Any adjustment shall be in accordance with ISO 12122-1 and shall be detailed in the report. NOTE T
34、hese adjustments include those required to pool data from different test programs as outlined in ISO 12122-1. 8.3 Failure modes The failure modes obtained in the tests shall be recorded. The data shall only be included in the analysis if it comes from a test in which the failure mode appropriate to
35、the property was obtained. NOTE The same test method may produce different failure modes on different products. The characteristic value may be underestimated by tests that produce failure modes that are different to ones that the test method was intended to produce. 9 Evaluation of characteristic v
36、alues for structural properties 9.1 Structural properties For glued laminated timber, determination of the characteristic values for structural properties shall be in accordance with ISO 12122-1 using data of material properties from glued laminated timber tests (see Annex A for more information). N
37、OTE Annex A gives guidance on the type of property that is appropriate for glued laminated timber. 9.2 Characteristic modulus of elasticity or stiffness The characteristic modulus of elasticity or stiffness used for serviceability shall be the mean value taken as the average of the test values evalu
38、ated in accordance with ISO 12122-1, and in the case of its use in the ultimate limit state it shall be either the average or the 5th percentile value. NOTE In some cases, where a reduction of modulus of elasticity or stiffness is not already factored into the behaviour equation used for design, a 5
39、th percentile value of modulus of elasticity can be required to design for beam or column stability. 9.3 Characteristic values of strength or capacity 9.3.1 Characteristic bearing strength The characteristic values for bearing strength, both parallel and perpendicular to grain, shall be the mean pro
40、perty obtained from results of tests. 9.3.2 Other characteristic values for strength or capacity based on the 5th percentile test value The 75 % lower single-sided confidence limit of the test 5th percentile value shall be evaluated. Suitable methods for evaluating the 5th percentile value of the te
41、st data and estimating the 75 % lower single- sided confidence limit are presented in ISO 12122-1. 10 Report The report shall comply with the requirements of ISO 12122-1. ISO 2016 All rights reserved 3 ISO 12122-3:2016(E) Annex A (informative) Commentary A.1 Commentary on scope This part of ISO 1212
42、2 presents methods for determining characteristic values for glued laminated structural timber. It is to be used in conjunction with ISO 12122-1. The part of ISO 12122 presents a uniform methodology for the evaluation of characteristic values that are consistent with the characteristic values found
43、for other structural timber products. The part of ISO 12122 does not establish methods for the determination of design values. These may be determined based on characteristic values from test data, but for glued laminated timber will also incorporate appropriate safety factors to account for any or
44、all of the following factors. Expected changes in product or product properties over a long period. These changes could be due to variations in timber resource quality, production methods or adhesives. The complexity of the reference population. For example, where the reference population has a larg
45、e number of producers who draw their resource over a large area, then the sampling may not effectively reflect all possible combinations of resource quality and production methods. In this way, the sample may not be truly representative and a safety factor may be applied to allow for that. Variation
46、s over time of the layup used for the glued laminated timber. These variations may include presence or frequency of finger joints. Anticipated variations in quality control across the reference population in the future. Characteristic values presented in this part of ISO 12122 relate only to the det
47、ermination of characteristic values from the results of tests on full-scale glued laminated timber products. The whole suite of ISO 12122 standards has this common basis. However, in many cases, the characteristic properties for glued laminated timber are estimated from calculation using models that
48、 relate the laminate properties to the properties of the composite beams. The scope of this part of ISO 12122 does not cover these methods, but Annex B contains information linking to some commonly accepted models for these calculations. This part of ISO 12122 can be used to verify such models using
49、 tests on full-scale glued laminated timber products. A.2 Commentary on normative references No commentary. A.3 C ommentary on t erms and definitions No commentary. (See ISO 12122-1). A.4 Commentary on symbols No commentary. (See ISO 12122-1).4 ISO 2016 All rights reserved ISO 12122-3:2016(E) A.5 Commentary on reference population Characteristic values can be taken to represent the properties of the material from which the sample was taken. The reference population is the definition of the parent popula
