ISO 8375-2017 Timber structures - Glued laminated timber - Test methods for determination of physical and mechanical properties《木结构 粘合层压木材 物理和机械性能的测定用试验方法》.pdf

1、 ISO 2017 Timber structures Glued laminated timber Test methods for determination of physical and mechanical properties Structures en bois Bois lamell-coll Mthodes dessai pour la dtermination de certaines proprits physiques et mcaniques INTERNATIONAL STANDARD ISO 8375 Third edition 2017-0 6 Referenc

2、e number ISO 8375:2017(E) ISO 8375:2017(E)ii ISO 2017 All rights reserved COPYRIGHT PROTECTED DOCUMENT ISO 2017, 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 me

3、chanical, including photocopying, 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

4、 Switzerland Tel. +41 22 749 01 11 Fax +41 22 749 09 47 copyrightiso.org www.iso.org ISO 8375:2017(E)Foreword v 1 Scope . 1 2 Normative references 1 3 T erms and definitions . 1 4 S ymbols and suffix es 2 4.1 Symbols . 2 4.2 Suffixes . 3 5 Determination of dimensions of test specimens . 3 6 Determi

5、nation of moisture content of test specimens . 3 7 Determination of density of test specimens 4 8 Conditioning of test specimens . 4 9 Determination of local (shear-free) modulus of elasticity of the beam in bending .4 9.1 Test specimen . 4 9.2 Procedure 4 9.3 Expression of results 5 10 Determinatio

6、n of global modulus of elasticity of the beam in bending 6 10.1 Test specimen . 6 10.2 Procedure 6 10.3 Expression of results 7 11 Determination of shear modulus of the beam Variable span method 7 11.1 General . 7 11.2 Test piece . 8 11.3 Procedure 8 11.4 Expression of results 9 11.4.1 Determination

7、 of K 1and K 2. 9 11.4.2 Shear modulus . 9 12 Determination of bending strength of the beam10 12.1 Test specimen 10 12.2 Procedure .10 12.3 Expression of results .11 13 Determination of the modulus of elasticity in tension parallel to the grain of the glued laminated timber 11 13.1 General 11 13.2 T

8、est specimen 11 13.3 Procedure .11 13.4 Expression of results .12 14 Determination of the parallel to the grain tension strength of the glued laminated timber 12 14.1 Test specimen 12 14.2 Procedure .12 14.3 Expression of results .12 15 Determination of the modulus of elasticity in compression paral

9、lel to the grain of the glued laminated timber13 15.1 General 13 15.2 Test specimen 13 15.3 Procedure .13 15.4 Expression of results .13 ISO 2017 All rights reserved iii Contents Page ISO 8375:2017(E)16 Determination of the parallel to grain compression strength of the glued laminated timber 14 16.1

10、 Test specimen 14 16.2 Procedure .14 16.3 Expression of results .14 17 Determination of the modulus of elasticity in compression and tension perpendicular to the grain of the glued laminated timber .14 17.1 Requirements for test specimens 14 17.2 Procedure .15 17.3 Expression of results .15 17.3.1 C

11、ompression perpendicular to the grain .15 17.3.2 Tension perpendicular to the grain 16 18 Determination of tension and compression strengths perpendicular to the grain of the glued laminated timber17 18.1 Requirements for test specimens 17 18.1.1 Fabrication .17 18.1.2 Surface preparation 17 18.2 Pr

12、ocedure .17 18.3 Expression of results .19 18.3.1 Compression perpendicular to the grain .19 18.3.2 Tension perpendicular to the grain 20 19 Determination of shear strength parallel to the grain Small specimen test 20 19.1 Requirements for test specimens 20 19.1.1 Fabrication .20 19.1.2 Surface prep

13、aration 20 19.2 Procedure .21 19.3 Expression of results .22 20 Determination of shear strength parallel to the grain Full size beam test 23 20.1 Specimen .23 20.2 Procedure .23 20.3 Expression of result .24 21 Test report 25 21.1 General 25 21.2 Test specimen 25 21.3 Test method 25 21.4 Test result

14、s.25 Bibliography .26 iv ISO 2017 All rights reserved ISO 8375:2017(E) Foreword 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 techn

15、ical 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 take part in the work. ISO collaborates closely

16、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 particular the different approval criteria need

17、ed 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 of this document may be the subject of pate

18、nt 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 (see www .iso .org/ patents). Any trade name u

19、sed in this document is information given for the convenience of users and does not constitute an endorsement. For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to t

20、he World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following URL: w w w . i s o .org/ iso/ foreword .html. This document was prepared by Technical Committee ISO/TC 165, Timber structures. This third edition cancels and replaces the second edition (ISO 8375:

21、2009), which has been technically revised. ISO 2017 All rights reserved v Timber structures Glued laminated timber Test methods for determination of physical and mechanical properties 1 Scope This document specifies test methods suitable for determining the following characteristic values of glued l

22、aminated timber: modulus of elasticity in bending; shear modulus; bending strength; modulus of elasticity in tension parallel to the grain; tension strength parallel to the grain; modulus of elasticity in compression parallel to the grain; compression strength parallel to the grain; modulus of elast

23、icity in tension perpendicular to the grain; tension strength perpendicular to the grain; modulus of elasticity in compression perpendicular to the grain; compression strength perpendicular to the grain and shear strength. In addition, the determination of dimensions, moisture content and density ar

24、e specified. This document is applicable to rectangular shapes of glued laminated timber. 2 Normative references There are no normative references in this document. 3 T erms a nd definiti ons For the purposes of this document, the following terms and definitions apply. ISO and IEC maintain terminolo

25、gical databases for use in standardization at the following addresses: ISO Online browsing platform: available at h t t p :/ www .iso .org/ obp IEC Electropedia: available at h t t p :/ www .electropedia .org/ 3.1 density characteristic mean density obtained at a 75 % confidence limit with mass and

26、volume corresponding to equilibrium moisture content at a temperature of 20 C and a relative humidity of 65 % Note 1 to entry: ISO 12122-1 and ISO 12122-3 provide guidelines for statistical processing of data to determine characteristic values such as density. 3.2 strength characteristic lower 5-per

27、centile value at a 75 % confidence limit obtained from the results of tests using test specimens at an equilibrium moisture content resulting from a temperature of 20 C and a relative humidity of 65 % or the strength value at the observed moisture content when full size members are tested Note 1 to

28、entry: ISO 12122-1 and ISO 12122-3 provide guidelines for statistical processing of data to determine characteristic values such as strength. INTERNATIONAL ST ANDARD ISO 8375:2017(E) ISO 2017 All rights reserved 1 ISO 8375:2017(E) 3.3 elasticity characteristic mean stiffness at a 75 % confidence lim

29、it obtained from the results of tests using test specimens at an equilibrium moisture content resulting from a temperature of 20 C and a relative humidity of 65 % Note 1 to entry: ISO 12122-1 and ISO 12122-3 provide guidelines for statistical processing of data to determine characteristic values suc

30、h as elasticity. 3.4 specimen item to be tested for the determination of all characteristic values Note 1 to entry: The minimum number of test specimens required for the determination of all characteristic values is provided in ISO 12122-1 and ISO 12122-3, unless otherwise noted for the specific tes

31、t involved. 3.5 population specimens (3.4) used to determine characteristic values Note 1 to entry: Specimens should be reflective of the population they are intended to represent. 4 S ymbols and suffix es 4.1 Symbols A cross-sectional area, in square millimetres a distance between a loading positio

32、n and the nearest support in a bending test, in mil- limetres b width of cross section in a bending test, or the smaller dimension of the cross section, in millimetres E c,0 modulus of elasticity in compression parallel to the grain, in megapascals E c,90 modulus of elasticity in compression perpend

33、icular to the grain, in megapascals E m,g global modulus of elasticity in bending, in megapascals E m,app apparent modulus of elasticity in bending, in megapascals E t,0 modulus of elasticity in tension parallel to the grain, in megapascals E t,90 modulus of elasticity in tension perpendicular to th

34、e grain, in megapascals F load, in newtons F c,90,max maximum compressive load perpendicular to the grain, in Newtons F c,90,max,est estimated maximum compressive load perpendicular to the grain, in Newtons F max maximum load, in Newtons F max,est estimated maximum load, in Newtons F t,90,max maximu

35、m tensile load perpendicular to the grain, in Newtons f c,0 compressive strength parallel to the grain, in megapascals2 ISO 2017 All rights reserved ISO 8375:2017(E) f c,90 compressive strength perpendicular to the grain, in megapascals f m bending strength, in megapascals f t,0 tensile strength par

36、allel to the grain, in megapascals f t,90 tensile strength perpendicular to the grain, in megapascals f v shear strength parallel to the grain, in megapascals G shear modulus, in megapascals h depth of cross section in a bending test, or the larger dimension of the cross section, or the test specime

37、n height in perpendicular to grain tests, in millimetres h 0 gauge length, in millimetres I second moment of area, in millimetres to the fourth power K, k coefficients k G coefficient for shear modulus l span in bending, or length of test specimen between the testing machine grips in com- pression a

38、nd tension, in millimetres S section modulus, in millimetres to the third power w deformation, in millimetres 4.2 Suffix es 1, 2 loads or deformations at particular points of a test, referred to as necessary in the text 5 Determination of dimensions of test specimens The dimensions of the test speci

39、men shall be measured to an accuracy of 1 %. The dimension measuring devices shall be such as to permit measuring dimensions in millimetres to three significant figures. All measurements shall be made when the test specimens are conditioned as specified in Clause 8. If the width or thickness varies

40、within a test specimen, these dimensions should be recorded as the average of three separate measurements taken at different positions on the length of each specimen. Where possible, the measurements should not be taken closer than 150 mm to the ends of the specimen. 6 Determination of moisture cont

41、ent of test specimens The moisture content of the test specimen shall be determined on a section taken from the test specimen. In strength tests for bending, shear, tension parallel and perpendicular to grain and compression parallel and perpendicular to grain, the moisture content of the test speci

42、men shall be determined as soon as practical after testing or the specimen shall be sealed to prevent any further moisture change until testing can be initiated. The section shall be cut as close as possible to the fracture. As an alternative, the provisions of ISO 3130 or ASTM D4442 may be used for

43、 determining moisture content. ISO 2017 All rights reserved 3 ISO 8375:2017(E) 7 Determination of density of test specimens If a density value is needed, the density shall be determined on a portion of the cross section or the entire cross section taken from the test specimen near the fracture area.

44、 In strength tests such as bending and parallel to grain, the density of the test specimen shall be determined after the testing and the section shall be cut as close as possible to the fracture. For perpendicular to grain test specimens, the density of the test specimens shall be determined prior t

45、o test from the measurements of mass and volume of the whole test specimen. As an alternative, the provisions of ISO 3131 or ASTM D2395 are acceptable for determining density. 8 Conditioning of test specimens The tests shall be carried out on specimens that are conditioned at the standard environmen

46、t of (20 2) C and (65 5) % relative humidity. A test piece is conditioned when it attains constant mass. Constant mass is considered to be attained when the results of two successive weightings, carried out at an interval of 6 h, do not differ by more than 0,1 % of the mass of the test specimen. The

47、 provisions of ASTM D4933 are also acceptable to establish moisture conditioning. Where the timber to be tested cannot be readily conditioned to the above standard environment, that fact shall be reported and the moisture content of the test specimen shall be reported with the test results. For smal

48、l specimens, unless otherwise protected, test specimens shall not be removed from the conditioning environment more than 1 h before testing. NOTE Test specimens can be stored in the test area for up to 24 h provided they are closely stacked and wrapped in vapour-tight wrapping. 9 Determination of lo

49、cal (shear-free) modulus of elasticity of the beam in bending 9.1 Test specimen The test specimen shall have a minimum length to permit testing with a span of approximately 18 times the depth of the section. The test span shall be reported. 9.2 Procedure The test specimen shall be symmetrically loaded in bending at two points over a span of 18 ( 3) times the depth as shown in Figure 1. The span between load heads shall be six times the specimen depth. All spans and distances shall be noted and measured to the nearest mi