ISO 22390-2010 Timber structures - Laminated veneer lumber - Structural properties《木材结构 层压胶合板 结构特性》.pdf

1、 Reference number ISO 22390:2010(E) ISO 2010INTERNATIONAL STANDARD ISO 22390 First edition 2010-08-01 Timber structures Laminated veneer lumber Structural properties Structures en bois Lamibois Proprits structurelles ISO 22390:2010(E) PDF disclaimer This PDF file may contain embedded typefaces. In a

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4、rinting. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below. COPYRIGHT PROTECTED DOCUMENT ISO 2010 All rights reserved. Unless other

5、wise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISOs member body in the country of the requester. ISO copyright

6、 office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO 2010 All rights reservedISO 22390:2010(E) ISO 2010 All rights reserved iiiContents Page Foreword iv Introduction.v 1 Scope1 2 Normative refer

7、ences1 3 Terms and definitions .2 4 Requirements.3 4.1 Veneers.3 4.2 Bonding quality .3 4.3 Dimensions and tolerances3 5 Test methods .4 5.1 General.4 5.2 Edgewise bending strength .4 5.3 Flatwise bending strength4 5.4 Tension strength parallel to the grain .5 5.5 Compression strength parallel to th

8、e grain5 5.6 Shear strength (edge) related to edgewise bending6 5.7 Shear strength (flat) related to flatwise bending6 5.8 Compression strength perpendicular to the grain 6 6 Stiffness6 6.1 General.6 6.2 Modulus of elasticity in edgewise bending 6 6.3 Modulus of elasticity in flatwise bending .7 6.4

9、 Modulus of elasticity in tension parallel to the grain 7 6.5 Modulus of elasticity in compression parallel to the grain.7 7 Other physical characteristics .7 7.1 Density7 7.2 Moisture content7 7.3 Species equivalency for connection properties 8 7.4 Creep and duration of load effects 8 Bibliography9

10、 ISO 22390:2010(E) iv ISO 2010 All rights reservedForeword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each

11、 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 take part in the work. ISO collaborates closely with the Internationa

12、l Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards

13、 adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of

14、 patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 22390 was prepared by Technical Committee ISO/TC 165, Timber structures. ISO 22390:2010(E) ISO 2010 All rights reserved vIntroduction Laminated veneer lumber (LVL) is being produced in many countries

15、 under different national standards and these products are being exported from one country to another. While the national standards have many similarities, there are also many areas of dissimilarity. Thus, there is a need for the development of this International Standard to establish consistency be

16、tween these standards in order to ensure the suitability of LVL for structural end-use applications, regardless of country of manufacture or country of end use. It is intended for this to have value to industry, consumers, governments and distributors. INTERNATIONAL STANDARD ISO 22390:2010(E) ISO 20

17、10 All rights reserved 1Timber structures Laminated veneer lumber Structural properties 1 Scope This International Standard specifies requirements for establishing the characteristic properties of structural laminated veneer lumber (LVL), including 5th percentile strength values, stiffness character

18、istics and other performance characteristics, related to its end use as a structural product for dry use (bonding class 1). It is applicable to members used in flatwise or edgewise bending orientations. It does not cover the assessment of formaldehyde requirements, biological durability, fire perfor

19、mance or manufacturing, such as quality control and marking. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (

20、including any amendments) applies. ISO 10033-1, Laminated veneer lumber Bonding quality Part 1: Test methods ISO 10033-2, Laminated veneer lumber Bonding quality Part 2: Requirements ISO 13910, Structural timber Characteristic values of strength-graded timber Sampling, full-size testing and evaluati

21、on ISO 16572, Timber structures Wood-based panels Test methods for structural properties ISO 16979, Wood-based panels Determination of moisture content EN 408-03, Timber structures Structural timber and glued laminated timber Determination of some physical and mechanical properties ASTM D143-09, Sta

22、ndard Test Methods for Small Clear Specimens of Timber ASTM D198-09, Standard Test Methods of Static Tests of Lumber in Structural Sizes ASTM D4761-05, Standard Test Methods for Mechanical Properties of Lumber and Wood-Base Structural Material ASTM D5456-06, Standard Specification for Evaluation of

23、Structural Composite Lumber Products ASTM D6815-09, Standard Specification for Evaluation of Duration of Load and Creep Effects of Wood and Wood-Based Products MAFF Notification No. 701, Japanese Agricultural Standard for Laminated Veneer Lumber ISO 22390:2010(E) 2 ISO 2010 All rights reserved3 Term

24、s and definitions For the purposes of this document, the following terms and definitions apply. 3.1 laminated veneer lumber LVL composite of wood veneer sheet elements manufactured from one or more species, either separately or mixed, with wood fibres primarily oriented along the length of the membe

25、r NOTE This does not exclude laminated veneer lumber with cross-laminated veneers. 3.2 characteristic value for strength estimate of the 5th percentile values based on a statistical distribution obtained from results of tests on the defined properties in accordance with Clauses 5 and 6 with the test

26、 duration between 60 s and 300 s 3.3 characteristic value for stiffness estimate of the mean property from results of tests on the defined properties in accordance with Clauses 5 and 6 with the test duration between 60 s and 300 s NOTE The characteristic values used for 3.2 and 3.3 are either an est

27、imate of the 5th percentile value or an estimate of the mean value of the sample as determined from ISO/TC 165 draft document on the evaluation of characteristic values for structural timber products. 3.4 population assembly of samples that are clearly defined since the characteristic properties app

28、ly only to that population NOTE The sample size is chosen to be representative of the reference population, taking into consideration the occurrence of strength-reducing characteristics which affect the structural property being evaluated. 3.5 test specimen specimen cut from random locations within

29、the pieces of the LVL samples 3.6 thickness d least dimension of a cross-section, which is perpendicular to the plane of the veneers See Figure 1. 3.7 width b largest dimension of a cross-section, which is perpendicular to the thickness (or parallel to the plane of the veneers) See Figure 1. 3.8 dep

30、th dimension of the specimen related to the direction of the applied load, b for edgewise (joist) and d for flatwise (plank) ISO 22390:2010(E) ISO 2010 All rights reserved 3a) Cross-section related to edgewise bending b) Cross-section related to flatwise bending Figure 1 Thickness, d, and width, b,

31、of cross-section of laminated veneer lumber 4 Requirements 4.1 Veneers The minimum number of veneers in the cross-section shall be five. The maximum thickness of each veneer shall be 6 mm. 4.2 Bonding quality The LVL shall utilize a structural adhesive suitable for dry service (bonding class 1) and

32、the bonding quality and adhesive qualification shall be determined in accordance with ISO 10033-1 and ISO 10033-2. NOTE 1 Attention is drawn to national standards which can be applicable. NOTE 2 Examples of applicable national standards include EN 314-1, ASTM D5456 and JAS Notification No. 701. NOTE

33、 3 Additional testing to cover more severe bonding service conditions (bonding classes 2 and 3) can be considered as a manufacturers option and can be required by some national standards. 4.3 Dimensions and tolerances The dimensions of the test specimens shall be measured to the following accuracy:

34、a) for dimensions u 150 mm: 0,1 mm; b) for dimensions 150 mm and u 400 mm: 0,5 mm; c) for dimensions 400 mm: 1 mm. All measurements shall be made after the test pieces have been conditioned in accordance with Clause 5. Width and thickness measurements (see Figure 1) shall be the average of three mea

35、surements taken at three different positions within the middle third of the specimen. Where possible, the measurements should not be taken within 150 mm of the ends of the test piece. Local thickness deviations related to discontinuities of the veneers, e.g. knotholes and veneer joints, are allowed,

36、 but should be avoided in the measurement of section properties. ISO 22390:2010(E) 4 ISO 2010 All rights reservedThe angle of the cross-section, , shall not deviate by more than 1:50 (about 1,1) from a right angle. See Figure 2, where is the angle between the vertical axis and the sloped end. Figure

37、 2 Example of an angle, , of a cross-section of laminated veneer lumber 5 Test methods 5.1 General Characteristic strength values for edgewise and flatwise bending, tension parallel to the grain, compression parallel to the grain, edgewise and flatwise longitudinal shear and the mean compression per

38、pendicular to grain strength shall be determined for laminated veneer lumber, as required by the product end-use application in accordance with 3.2 and the following requirements using the test methods in this clause. All test specimens shall be conditioned to an equilibrium moisture content resulti

39、ng from a temperature of (20 2) C and a relative humidity of (65 5) %. A test piece is considered to be conditioned when it attains constant mass. Constant mass is deemed to have been attained when the results of two successive weighings, carried out at intervals of not less than 6 hours, do not dif

40、fer by more than 1 %. If test pieces cannot be conditioned due to their size, the moisture content at time of test shall be reported and shall be within 2% of the moisture content of a subsample of the same product and grade conditioned in accordance with 7.2, or the provisions of ASTM D5456 may be

41、used for developing a moisture content correlation for applications to large specimens. If other conditions, such as tropical conditions, are used, they shall be permitted and reported. The data should be developed at the specific moisture content relative to those conditions. 5.2 Edgewise bending s

42、trength The edgewise bending strength test shall be carried out using a symmetric third-point load set-up as given in ISO 13910 (see Figure 3). In edgewise bending, the specimen dimension d in Figure 1 a) and b in Figure 3 shall be at least 38 mm and the test span shall be at least 18 times dimensio

43、n b in Figure 1 a). In addition, the minimum size of the specimen shall not be less than the minimum structural size manufactured. NOTE 1 If b see Figure 1 a) is different than the reference width of 38 mm, the test results can be adjusted to a common size or value based on national codes. NOTE 2 Th

44、e provisions of ASTM D5456 provide an example of a methodology to adjust for size effects. 5.3 Flatwise bending strength The flatwise bending strength tests shall be carried out using a symmetric third-point load set-up as given in ISO 13910 (see Figure 3). The test span of the specimen shall be at

45、least 18 times the depth of the cross- section dimension d in Figure 1 b). The minimum size of the specimen shall not be less than the minimum structural size manufactured. ISO 22390:2010(E) ISO 2010 All rights reserved 5Key A and C centreline of bearing B mid-span b width of the test specimen d thi

46、ckness or depth of the specimen e centrepoint deflection of the centreline of the specimen relative to the position of the centreline at the ends of the specimen F load NOTE For illustrative purposes, Figure 3 is shown for edgewise bending only. Figure 3 Configuration for one-third-point loading for

47、 determination of bending strength and stiffness 5.4 Tension strength parallel to the grain The tension strength tests parallel to the grain shall be carried out using gripping devices which permit as far as possible the application of a tensile load without inducing bending. The gripping devices an

48、d loading conditions actually used shall be reported. The length of the specimen between the testing machine grips shall be at least 900 mm or at least 8 times the larger cross-sectional dimension and the minimum size of the specimen shall not be less than the minimum structural size manufactured. I

49、f the length of the specimen between the testing machine grips is different than the reference length of 900 mm, the test results may need to be adjusted to a common size or value based on national codes. A failure in the grips of the test machine invalidates the results and a new test shall be required. NOTE The provisions of ASTM D5456 provide an example of a methodology that can be used to adjust for length effects. 5.5 Compression strength parallel to the grain The compression str