ISO 19624:2018

INTERNATIONAL ISO
STANDARD 19624
First edition
2018-09
Bamboo structures — Grading of
bamboo culms — Basic principles and
procedures
Structures en bambou — Classement des tiges de bambou
Reference number
©
ISO 2018
© ISO 2018
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ii © ISO 2018 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols . 4
5 General . 4
5.1 Grading. 4
5.2 Grades . 4
5.3 Graded bamboo culms . 5
5.4 Grading operations . 5
5.5 Secondary properties . 5
6 Visual grading . 5
6.1 General . 5
6.2 Visual grading requirements . 5
6.2.1 General. 5
6.2.2 Condition properties . 6
6.2.3 Geometric properties . 7
6.3 Other requirements for visual grading .10
6.3.1 Moisture content .10
6.3.2 Age at harvesting .10
6.4 Check on visual grading process .11
7 Machine grading.11
7.1 General .11
7.2 Machine grading process requirements .11
7.3 Indicating properties .11
7.4 Grade-determining properties .12
7.5 Visual override .12
7.6 Hybrid grading methods .12
8 Structural properties of graded bamboo .12
8.1 General .12
8.2 Initial evaluation .12
8.2.1 Developing visual grading rules .13
8.2.2 Developing grading settings for machine grading .13
8.2.3 Sampling.13
8.2.4 Sample size for initial evaluation .14
8.2.5 Other considerations during initial evaluation testing .14
8.3 Periodic evaluation .14
8.4 Reduced test programmes and secondary properties .15
9 Product identification .15
10 Documentation .15
Annex A (informative) Example of application of clauses in this document to a visual
grading standard for bamboo culms based on external diameter and flexural properties 16
Bibliography .22
Foreword
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This document was prepared by ISO Technical Committee 165, Timber structures.
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iv © ISO 2018 – All rights reserved

Introduction
The general principle of this document is that any type of grading procedure is acceptable, provided it is
defined, controlled, and documented to the extent required to achieve the degree of reliability intended
for the structural application of the product. This document specifies procedures that conform to
this principle. The grading procedures outlined in this document require visual, dimensional and
mechanical stages to ensure conformity.
Annex A provides an example conformance standard reflecting the requirements of this document.
INTERNATIONAL STANDARD ISO 19624:2018(E)
Bamboo structures — Grading of bamboo culms — Basic
principles and procedures
1 Scope
This document specifies grading procedures for visually and mechanically sorting round, or pole,
bamboo for structural applications using such fundamental elements. Visual sorting is based on
observable characteristics of the piece(s). Mechanical sorting is based on non-destructive measurement
of properties known to correlate to characteristic values defining a grade.
The grading procedures in this document can be used in a quality acceptance regime, although this
document does not define or address acceptance criteria.
This document is applicable only for bamboo that is graded in the seasoned state.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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 22156, Bamboo — Structural design
ISO 22157-1, Bamboo — Determination of physical and mechanical properties — Part 1: Requirements
ISO 12122-1, Timber structures — Determination of characteristic values — Part 1: Basic requirements
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https: //www .iso .org/obp
— IEC Electropedia: available at http: //www .electropedia .org/
3.1
bamboo culm
single shoot of bamboo
Note 1 to entry: A culm is comprised of the entire unaltered bamboo cross section and is usually a hollow cylinder
except at nodes.
3.2
bow
measure of variation of culm from straight condition, reported as the ratio of greatest transverse
variation to reference length of culm
3.3
dry bamboo
seasoned bamboo
bamboo that has been subjected to a drying process and with moisture content of 19 % or less
3.4
fissure
longitudinally oriented separation or split of the bamboo wall running parallel to the fibres at the end of
a culm or at any internode of the piece that may or may not penetrate through the entire wall thickness
Note 1 to entry: An example o
...