DIN EN ISO 8970:2010-11

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, evidence 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. This International Standard specifies a method, based on density, 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 of wood. This document (EN ISO 8970:2010) has been prepared by Technical Committee ISO/TC 165 "Timber structures", the secretariat of which is held by SCC (Canada), in collaboration with Technical Committee CEN/TC 124 "Timber structures", the secretariat of which is held by AFNOR (France). At DIN, the German Institute for Standardization e. V., the responsible Working Committee is NA 005-04-01 AA "Holzbau" (Spiegelausschuss CEN/TC 124, CEN/TC 250/SC 5) ("Timber structures" (Mirror Committee of CEN/TC 124, CEN/TC 250/SC 5) of the Building and Civil Engineering Standards Committee (NABau). The following changes have been made with respect to DIN EN 28970:1991-07: a) only one method for the selection of pieces of wood is specified; b) the scope has been specified more precisely so that this standard only relates to specimens of wood. c) the sampling method has been revised; d) factor k has been redefined; e) the standard has been completely editorially revised.