SIST EN 338:2010
(Main)Structural timber - Strength classes
Structural timber - Strength classes
This European Standard establishes a system of strength classes for general use in structural codes. It gives characteristic strength and stiffness properties and density values for each class and the rules for the allocation of timber populations (i.e. combinations of species, source and grade) to the classes. This standard is applicable to all softwood and hardwood timber for structural use.
Bauholz für tragende Zwecke - Festigkeitsklassen
Diese Norm legt ein System von Festigkeitsklassen für den allgemeinen Gebrauch in Bemessungsnormen fest.
Sie gibt charakteristische Werte der Festigkeit, Steifigkeit und Rohdichte für jede Klasse sowie Regeln für die Zuordnung von Holzgrundgesamtheiten (d. h. Kombinationen von Holzarten, Herkunft und Sortierklasse) zu den Klassen an.
Diese Norm gilt für alle Nadel- und Laubhölzer für tragende Zwecke.
Bois de structure - Classes de résistance
La présente norme établit un système de classes de résistance d’utilisation générale pour les codes de calculs de structures.
Elle donne, pour chaque classe, les valeurs caractéristiques des propriétés de résistance et de rigidité et les valeurs de masse volumique, ainsi que les règles d'affectation des populations de bois (c’est-à-dire les combinaisons d’essences, de provenance et de qualités) aux classes.
Cette norme s’applique à tous les bois résineux et feuillus à usage structurel.
Konstrukcijski les - Trdnostni razredi
Ta evropski standard vzpostavlja sistem trdnostnih razredov za splošno uporabo v konstrukcijskih kodeksih. Podaja značilne trdnostne lastnosti in lastnosti togosti ter vrednosti gostote za vsak razred, ter pravila za dodeljevanje populacij lesa (t.j. kombinacij vrst, vira in stopnje) v razrede. Ta standard se uporablja za ves mehki les in trdi les, ki se uporablja za konstrukcije.
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Standards Content (Sample)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Konstrukcijski les - Trdnostni razrediBauholz für tragende Zwecke - FestigkeitsklassenBois de structure - Classes de résistanceStructural timber - Strength classes79.040Les, hlodovina in žagan lesWood, sawlogs and sawn timberICS:Ta slovenski standard je istoveten z:EN 338:2009SIST EN 338:2010en,fr,de01-april-2010SIST EN 338:2010SLOVENSKI
STANDARDSIST EN 338:20041DGRPHãþD
SIST EN 338:2010
EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 338
October 2009 ICS 79.040 Supersedes EN 338:2003English Version
Structural timber - Strength classes
Bois de structure - Classes de résistance
Bauholz für tragende Zwecke - Festigkeitsklassen This European Standard was approved by CEN on 29 September 2009.
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 bibliographical 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 CEN 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, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre:
Avenue Marnix 17,
B-1000 Brussels © 2009 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 338:2009: ESIST EN 338:2010
EN 338:2009 (E) 2 Content page Foreword . 3Introduction . 41Scope . 52Normative references . 53Terms and definitions . 54Symbols and abbreviations . 55Classification of structural timber . 66Allocation of a timber population to a strength class. 86.1Grading . 86.1.1Visually graded timber . 86.1.2Machine graded timber . 86.2Classification . 86.2.1Characteristic values . 86.2.2Allocation to a strength class . 8Annex A (informative)
Determination of values in addition to bending strength, stiffness and density . 9Bibliography . 10 SIST EN 338:2010
EN 338:2009 (E) 3 Foreword This document (EN 338:2009) has been prepared by Technical Committee CEN/TC 124 “Timber structures”, the secretariat of which is held by SFS. 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 April 2010, and conflicting national standards shall be withdrawn at the latest by April 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 338:2003. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. SIST EN 338:2010
EN 338:2009 (E) 4 Introduction This European Standard has additional strength classes which are more suitable to the characteristic values of temperate hardwoods. It also has modified characteristic values for the softwood classes for shear strength and tension strength perpendicular to grain. The equations given for these two properties in Annex A have been modified accordingly.
Due to variations in the type and quality of timber available, the variety of end uses and the size of production output of the local timber industry, many different combinations of species and strength grade exist with different strength properties, which therefore complicate the design and specification of timber structures. A strength class system groups together grades and species with similar strength properties thus making them interchangeable. This then permits an engineer to specify a chosen strength class and use the characteristic strength values of that class in design calculations.
Advantages of the strength class system are:
a) Additional species/grades can be incorporated into the system at any time without affecting existing specifications for structural timber.
b) At the time of carrying out design calculations, an engineer need not be aware of the costs and availability of alternative species and grades. He can simply design using the strength, stiffness and density values of a particular class and then specify that class; he can then use the tenders to select the most suitable and economic species/grade on offer. Note that, where a particular species is not acceptable (e.g. for reasons of durability) for a project, the specification needs to make
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