Dřevěné konstrukce

Oblast zaměření: Dřevěné konstrukce
Komise : CEN/TC 124 (Timber structures)
Původce: CEN
K připomínkám do: 24.12.2018
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This document sets out requirements regarding the performance of characteristics of the following types of cross laminated timber to be used in buildings and bridges:

—    type 1: Straight or curved cross laminated timber comprising only timber layers but no large finger joints;

—    type 2: Straight cross laminated timber comprising only timber layers and large finger joints;

—    type 3: Straight cross laminated timber comprising timber and wood-based panel layers but no large finger joints.

It also lays down procedures for assessment and verification of constancy of performance (AVPC) of characteristics and specifies marking and labelling of cross laminated timber.

This document covers cross laminated timber of all three types of cross laminated timber:

—    manufactured according to this standard, which sets up provisions for:

—    boundary conditions during manufacture of cross laminated timber;

—    moisture content and temperature of timber to be bonded;

—    production of finger joints and bonds between layers;

—    to be used in service class 1 or 2 according to EN 1995‑1‑1;

—    made of coniferous species and poplar listed in this standard;

—    which may be made of layers made of different species having similar properties;

—    bonded with phenolic or aminoplastic or moisture curing one-component polyurethane or emulsion polymer isocyanate adhesives of adhesive type I according to the respective standard;

—    built up of at least three orthogonally bonded layers (at least two of them timber layers);

—    which may have, depending on the number of layers, adjacent layers bonded parallel to the grain;

—    made of timber layers which are made of strength graded timber according to EN 14081‑1;

—    made of timber layers having nominal thicknesses between 6 mm (including) and 60 mm (including) depending on the layup;

—    made of timber layers

—    which may comprise non-structural edge bonds; and

—    have a mean gap width of less than or equal to 0,6 mm and a 90th percentile of the gap width of 2 mm;

—    having nominal overall thicknesses up to 500 mm.

Additional provisions of this document apply for straight cross laminated timber comprising only timber layers and comprising large finger joints (type 2):

—    made from cross laminated timber pieces having the same cross-section and layup;

—    made from cross laminated timber pieces having nominal cross-sectional thicknesses from 51 mm (including) up to 345 mm (including) and nominal minimum thicknesses of the outer layers not less than 17 mm (including).

—    made from cross laminated timber pieces solely comprising timber layers;

—    made from plane cross laminated timber pieces;

—    with parallel x-axes of the jointed components;

—    with finger joints having a finger length of at least 45 mm and fingers which are visible at the two narrow sides of the components;

—    bonded with phenolic or aminoplastic or moisture curing one-component polyurethane adhesives of adhesive type I according to the respective standard.

Additional provisions of this document apply for straight cross laminated timber comprising timber and wood-based panel layers but no large finger joints (type 3):

—    made of structural wood-based panels specified in this European standard;

—    made of one panel per layer and;

—    having thicknesses between 6 mm (including) and 45 mm (including);

This document applies to cross laminated timber untreated or treated against biological attack.

This document  does not cover:

—    cross laminated timber treated with fire retardants;

—    cross laminated timber which is produced from re-used timber or wood-based panels comprising re-used timber.