1、November 2010 Translation by DIN-Sprachendienst.English price group 7No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).IC
2、S 79.040; 91.080.20!$l1“1731488www.din.deDDIN EN ISO 8970Timber structures Testing of joints made with mechanical fasteners Requirements for wood density (ISO 8970:2010)English translation of DIN EN ISO 8970:2010-11Holzbauwerke Prfung von mechanischen Verbindungen Anforderungen an die Rohdichte des
3、Holzes (ISO 8970:2010)Englische bersetzung von DIN EN ISO 8970:2010-11Structures en bois Essai des assemblages raliss par organes mcaniques Exigences concernant la masse volumique du bois (ISO 8970:2010)Traduction anglaise de DIN EN ISO 8970:2010-11SupersedesDIN EN 28970:1991-07www.beuth.deDocument
4、comprises pagesIn case of doubt, the German-language original shall be considered authoritative.911.10 DIN EN ISO 8970:2010-11 2 A comma is used as the decimal marker. National foreword This standard has been prepared by Technical Committee ISO/TC 165 “Timber structures” in collaboration with Techni
5、cal Committee CEN/TC 124 “Timber structures (Secretariat: AFNOR, France). The responsible German body involved in its preparation was the Normenausschuss Bauwesen (Building and Civil Engineering Standards Committee), Working Committee NA 005-04-01 AA Holzbau (Sp CEN/TC 124, CEN/TC 250/SC 5). Amendme
6、nts This standard differs from DIN EN 28970:1991-07 as follows: a) only one method for the selection of pieces of wood has been specified; b) the scope now expressly states that the standard is applicable only to specimens of wood; c) Subclause 4.2 “Sampling method and requirements” has been revised
7、; k has been revised; ) the standard has been editorially revised. Previous editions DIN EN 28970: 1991-07 ”d) factor eEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 8970 June 2010 ICS 91.080.20 Supersedes EN 28970:1991English Version Timber structures - Testing of joints made with mechani
8、cal fasteners - Requirements for wood density (ISO 8970:2010) Structures en bois - Essai des assemblages raliss par organes mcaniques - Exigences concernant la masse volumique du bois (ISO 8970:2010) Holzbauwerke - Prfung von mechanischen Verbindungen -Anforderungen an die Rohdichte des Holzes (ISO
9、8970:2010) This European Standard was approved by CEN on 12 June 2010. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliograph
10、ical references concerning such national standards may be obtained on application to the CEN Management Centre or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a C
11、EN member into its own language and notified to the CEN Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
12、Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marn
13、ix 17, B-1000 Brussels 2010 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 8970:2010: EContents DIN EN ISO 8970:2010-11 EN ISO 8970:2010 (E) 2 Page Foreword3 Introduction .4 1 Scope 5 2 Normative references 5 3 Symbols and uni
14、ts.5 4 Timber sampling method and requirements.5 4.1 General5 4.2 Sampling method and requirements .6 5 Test report 6 Bibliography 7 Foreword This document (EN ISO 8970:2010) has been prepared by Technical Committee ISO/TC 165 “Timber structures” in collaboration with Technical Committee CEN/TC 124
15、“Timber structures” the secretariat of which is held by AFNOR. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by December 2010, and conflicting national standards shall be withdrawn at the latest by
16、 December 2010. Attention is drawn to the possibility that some of the elements of this document 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 28970:1991. According to the CEN/CENELEC I
17、nternal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Lu
18、xembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Endorsement notice The text of ISO 8970:2010 has been approved by CEN as a EN ISO 8970:2010 without any modification. DIN EN ISO 8970:2010-11 EN ISO 8970:2010 (E) 3
19、 Introduction The need to prescribe restriction of density for timber connection tests dates back many decades. In using the standard density, the boundaries set are considered too restrictive. This leads to difficulties in sampling timber elements and increased laboratory testing costs. Moreover, e
20、vidence has surfaced that the effect of density on the load-bearing capacity of connections is in many cases less significant than expected, and that many other parameters influence it. DIN EN ISO 8970:2010-11 EN ISO 8970:2010 (E) 4 1 Scope This International Standard specifies a method, based on de
21、nsity, for the selection of pieces of wood used in determining the strength and stiffness properties of connections made with mechanical fasteners. It is assumed the wood density is normally distributed and that any deviations are reported. This International Standard is applicable only to specimens
22、 of wood. NOTE It is emphasized that the wood density is only one of the properties that can influence the strength of a joint. Other relevant properties are, for example, growth-ring size, slope of grain, toughness and hardness. 2 Normative references The following referenced documents are indispen
23、sable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 3131, Wood Determination of density for physical and mechanical tests 3 Symbols and units k
24、factor is the standard deviation, expressed in kilograms per cubic metre is the density of the wood to which the test results should be applied, expressed in kilograms per cubic metre mis the mean wood density to which the test results should be applied, expressed in kilograms per cubic metre m,seli
25、s the mean wood density of all selected pieces to which the test results should be applied, expressed in kilograms per cubic metre 4 Timber sampling method and requirements 4.1 General This International Standard specifies a method for the selection of wood of the required density. The density shall
26、 be determined in accordance with ISO 3131, with mass and volume corresponding to equilibrium at a temperature of (20 2) C and relative humidity of (65 5) %. DIN EN ISO 8970:2010-11 EN ISO 8970:2010 (E) 5 If other conditions, such as tropical conditions, are used, they shall be permitted and reporte
27、d. The data should be adjusted at the specific moisture content relative to those conditions. 4.2 Sampling method and requirements The sampling method is based on the principle that all selected pieces have a density comparable with that of the wood to which the connection test results shall be appl
28、ied. The test data may be used directly for calculating characteristic values, etc. of the joints. NOTE The wood density relates to one wood species or a group of wood species. The wood shall be of uniform quality and without localized defects that can influence the test results. The wood density, ,
29、 of all selected pieces shall satisfy the condition given by Equation (1): (1 k)mu u (1 + k)m(1) where mis the mean density of the wood to which the test results are applied; k is equal to 1,6 /mor 0,25 for cases where is unknown; is the standard deviation of the wood to which the test results are a
30、pplied. The mean wood density, m,sel, of all selected pieces shall satisfy the condition given by Equation (2): 0,95mu m,selu 1,05m(2) where mis the mean density of the wood to which the test results are applied; m,selis the mean density of all selected pieces. 5 Test report The following informatio
31、n shall be included in the test report: a) reference to this International Standard, i.e. ISO 8970:2010; b) the wood species or wood species group; c) the moisture content at the time of selection; d) the mean density including the (assumed) standard deviation of the wood to which the test result sh
32、ould be applied; e) the density distribution of the selected pieces; f) the mean density of all selected pieces; g) confirmation that the selected pieces satisfy the conditions mentioned in this International Standard; h) any other information which can influence the use of the test results. DIN EN ISO 8970:2010-11 EN ISO 8970:2010 (E) 6 Bibliography 1 LEIJTEN, A.J.M., KHLER, J., JORISSEN, A.J.M., Timber density restrictions for timber connection tests according to ISO 8970/EN 28970, In: Proceedings of CIB-W18, paper 39-21-1, 2006 DIN EN ISO 8970:2010-11 EN ISO 8970:2010 (E) 7
