ISO 22157-1:2004

Bamboo — Determination of physical and mechanical properties — Part 1: Requirements

ISO 22157-1:2004 specifies test methods for evaluating the following characteristic physical and strength properties for bamboo: moisture content, mass per volume, shrinkage, compression, bending, shear and tension.

Bambou — Détermination des propriétés physiques et mécaniques — Partie 1: Exigences

General Information

• Status: Withdrawn
• Publication Date: 13-Jun-2004
• Withdrawal Date: 13-Jun-2004
• ICS: 79.040 - Wood, sawlogs and sawn timber
• Technical Committee: ISO/TC 165 - Timber structures
• Drafting Committee: ISO/TC 165 - Timber structures
• Current Stage: 9599 - Withdrawal of International Standard
• Completion Date: 18-Jan-2019

Relations

• Revised: ISO 22157:2019 - Bamboo structures — Determination of physical and mechanical properties of bamboo culms — Test methods
• Effective Date: 12-Feb-2014

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 22157-1
First edition
2004-06-01


Bamboo — Determination of physical and
mechanical properties —
Part 1:
Requirements
Bambou — Détermination des propriétés physiques et mécaniques —
Partie 1: Exigences




Reference number
ISO 22157-1:2004(E)
©
ISO 2004

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ISO 22157-1:2004(E)
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ii © ISO 2004 – All rights reserved

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ISO 22157-1:2004(E)
Contents Page
Foreword. iv
Introduction . v
1 Scope. 1
2 Terms and definitions. 1
3 Symbols and abbreviated terms. 2
4 Organization and use of this part of ISO 22157 . 2
5 Sampling and storage of specimens . 3
6 Moisture content . 5
7 Mass by volume . 7
8 Shrinkage. 8
9 Compression . 9
10 Bending. 12
11 Shear . 15
12 Tension. 17
Bibliography . 19

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ISO 22157-1:2004(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 22157-1 was prepared by Technical Committee ISO/TC 165, Timber structures, in collaboration with
INBAR, International Network for Bamboo and Rattan.
ISO 22157 consists of the following parts, under the general title Bamboo — Determination of physical and
mechanical properties:
 Part 1: Requirements
 Part 2: Laboratory manual
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ISO 22157-1:2004(E)
Introduction
This part of ISO 22157 was originally prepared and submitted by INBAR, the International Network for Bamboo
and Rattan, which is an international agency with its head office in Beijing. The aim is to bring bamboo towards
the level of an internationally recognized and accepted building and engineering material. INBAR aims to do so in
favour of the well-being of lower income groups in developing countries, and in favour of a better environment in
bamboo-growing countries.
Discussion about the need of an International Standard started already in 1988, during the International Bamboo
Workshop in Cochin, India. Due to lack of funds, the real work started as late as in 1997, when INBAR was
launched as an International Agency, and when the Dutch Government provided the required funding.
In 1998, draft texts were written and distributed to a group of specialists inside INBAR who acted as volunteers
and spent their time and expertise to propose improvements. Members of this group met for the first time in a
meeting on 30-31 October 1998 in San José, Costa Rica. Participants were N.S. Adkoli, K. Ghavami,
R. Gnanaharan, H.N.S. Jagadeesh, J.J.A. Janssen, K.S. Pruthi, I.V. Ramanuja Rao, D. Sands, J.O. Siopongco,
K. Stochlia and D. Tingley.
During 1999, the results from this meeting were incorporated in the draft texts. In September, these were
discussed in a meeting with ISO/TC 165 in Harbin, China. In October 1999, a meeting took place with
representatives of the National Standard Institutes of Bangladesh, China, Colombia, Ecuador, Ethiopia, India,
Indonesia, Nepal, Philippines, Tanzania, Thailand and Vietnam. This meeting was held at FPRDI in Los Baños,
Philippines. The outcome of this meeting was a considerable improvement of the texts, and a general agreement
to submit the draft texts to ISO for the formal procedure.
Besides INBAR, CIB (especially committee W 18 B) has also been involved in the preparation. Discussions during
meetings of W 18 B (e.g. Singapore 1987 and Kuala Lumpur 1992) have greatly contributed.
Because this part of ISO 22157 is the first Iinternational Standard on bamboo, it does not cancel or replace
other documents in whole or in part, besides the draft documents prepared and distributed for internal
discussion by INBAR during 1998 and 1999. For similar reasons, significant technical changes from previous
editions apply only to these previous draft documents.

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INTERNATIONAL STANDARD ISO 22157-1:2004(E)

Bamboo — Determination of physical and mechanical
properties —
Part 1:
Requirements
1 Scope
This part of ISO 22157 specifies test methods for evaluating the following characteristic physical and strength
properties for bamboo: moisture content, mass per volume, shrinkage, compression, bending, shear and
tension.
This part of ISO 22157 covers tests on specimens of bamboo that are conducted to obtain data, which can be
used to establish characteristic strength functions and to arrive at the allowable stresses. The data can also
be used to establish the relationship between mechanical properties and factors, such as moisture content,
mass per volume, growth site, position along the culm, presence of node and internode, etc., for quality-
control functions.
2 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
2.1
bamboo culm
single shoot of bamboo that is usually hollow, except at nodes which are often swollen
2.2
bamboo clump
cluster of bamboo culms emanating from two or more rhizomes in the same place
2.3
cross-sectional area
area of the section perpendicular to the direction of the principal fibres and vessels
2 2
NOTE This is calculated as (π/4) × [D − (D − 2t) ], in which D and t are the means of the outer diameter and the wall
thickness, resulting from measurements on the specimen.
2.4
outer diameter
diameter of a cross-section of a piece of bamboo measured from two opposite points on the outer surface
2.5
moisture content
percentage of water related to oven-dry mass
2.6
wall thickness
thickness of the wall of a piece of bamboo
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ISO 22157-1:2004(E)
3 Symbols and abbreviated terms
The following symbols and units apply.
2 2 2
A The cross-sectional area in mm , Calculated as (π/4) × [D − (D − 2t) ], in which D and t are the
means of the measurements on the specimen.
D The outer diameter in mm.
δ Deflection or deformation in mm (pronounced “delta”).
E The modulus of elasticity in MPa.
F The load in N.
G The shear modulus in MPa.
4
I The second moment of area in mm .
B
L Full span in bending; length of test piece in compression, shear and tension, in mm.
m Mass in g (kg is also allowed as a unit).
MC Moisture content in %.
π Usually taken as 3,14.
3
ρ Mass by volume (density) in kg/m (pronounced “rho”).
σ Stress in MPa (pronounce “sigma”).
t Wall thickness in mm.
τ Shear stress in MPa (pronounced “tau”).
3
V Volume of test piece in mm , calculated as A × L, or as measured.
3
W Section modulus in mm .
× Symbol for multiplication.
Subscript
ult Ultimate (used for strength at failure)
2
NOTE 1 MPa = 1 N/mm
4 Organization and use of this part of ISO 22157
4.1 Introduction
This part of ISO 22157 is organized to provide clear requirements for standard tests to be carried out to
determine the properties of bamboo as a building or engineering material. The manual for laboratory staff,
ISO/TR 22157-2, is complementary to this part.
NOTE This allows for a more formal content of this part of ISO 22157, and a practical and informal guide (a “how to
do it”) in the manual.
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ISO 22157-1:2004(E)
4.2 General procedures
4.2.1 Measurement and weight
Prior to each test, the dimensions of each specimen shall be measured correct to
 10 mm for the length of the culm,
 1 mm for the length or height of a specimen, parallel to the axis of the culm,
 1 mm for the diameter of the culm; in each cross-section, the diameter shall be taken twice, in directions
perpendicular to each other, and
 0,1 mm for the wall thickness; in each cross-section, the wall thickness shall be taken four times, in the
same places as the diameter has been taken (twice).
The specimen shall be weighed correct to
 10 g for a culm,
 1 g for a specimen of more than 100 g, and
 0,1 g for a specimen of less than 100 g.
4.2.2 Temperature and humidity
To avoid significant changes in strength properties, all test specimens shall be tested within the temperature
range of 27 °C ± 2 °C, and the relative air humidity range of 70 ± 5 %.
NOTE This allows for a comparison of test results, and reproducible tests.
However, if tests are meant for local use of the results in the region itself, or if the laboratory is unable to
follow the conditions specified above, ambient temperature and relative humidity can be used. The exact
values of the temperature and relative humidity of the air shall be recorded, and mentioned in the test report.
4.2.3 Rate of loading
The rate of loading of the testing machine shall not vary by more than ± 20 % from the specified speed for a
given test. The load shall be applied continuously without interruption at the required speed throughout the
test. The rate of traverse of the movable head of the testing machine shall mean the free running or no-load
speed of the head in the mechanical-drive type of machine, and the loaded head speed for testing machines
of the hydraulic loading type.
4.2.4 Calibration
All apparatus and testing equipment used in obtaining data shall be calibrated at sufficiently frequent intervals
to ensure accuracy.
5 Sampling and storage of specimens
5.1 Sampling
Material for any particular species shall be taken:
 in the case of tests on properties for commercial purposes: from a number of different localities,
representative of different growth conditions throughout the geographical range of the species;
 in the case of scientific research: from localities determined by the purpose of the research, and
mentioned in the design-report of the tests;
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ISO 22157-1:2004(E)
From each locality, the selection, marking, etc., of the different consignments, and all the details of the various
clumps and culms, shall be reported.
5.2 Selection
Bamboo culms shall be selected from various clumps in the standing condition, by a qualified person who can
identify the species and understand the various implications involved in conversion and testing. Whenever
necessary and convenient, the testing authority shall inspect the locality before felling.
For scientific research, the culms selected for testing shall be sound and free from any defects, and shall be
representative of average dominant bamboo culms of the locality. For commercial tests, they must fairly
represent the total population that is to be used for construction purposes, even if the entire population has its
drawbacks. Broken, damaged and discoloured bamboos shall be discarded.
The required number of culms shall be randomly selected from different clumps, blocks and compartments.
For commercial tests, they shall be of the same mature age group.
Immediately after selection, the bamboo may be marked “T” in the standing condition, at breast height, and
the testing authority shall be informed of the locality, so that further special instructions, if any, may be
considered.
5.3 Felling, marking and conversion
Before felling, one ring shall be marked at a height of one metre from the ground with white or black paint, and
the following data shall be recorded:
 the name of the species (botanical and local);
 the name of the locality;
 the number of clumps and culms selected;
 the age of the culms;
 details about the marks on the culms;
 number of nodes between ground level and the ring of paint;
 date of felling and of despatch;
 signature.
Also before felling, each culm shall be marked at a distance of about 0,25 m above the ring of paint; if digits 6
or 9 are used, these shall be underlined.
The culms shall be felled according to good local practice, but the ring of paint shall be kept on the culm. In
the horizontal position the culm shall be divided into parts to be used for tests or to be thrown away. The parts
to be used shall be marked with a ring at the lower end, and the mark of the culm shall be repeated on each
part. Also, a mark regarding the position in the culm shall be added, indicating “bottom”, “middle” or “top”,
each being 1/3 of the usable part of the culm. The height of these parts in the culm shall be recorded, in
metres, from the level where the culm has been felled. Only then shall the culm be divided into parts.
5.4 Despatch
Material should be despatched as early as possible, preferably within two weeks after felling. In case it is not
possible to send the material immediately, the material shall be stored in a shady place, protected from rain,
and free of contact with the soil. If a risk of cracking exists, the ends can be covered with coal tar, paraffin wax
or varnish, or any other appropriate cover.
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ISO 22157-1:2004(E)
If the tests are meant for commercial purposes, specimens shall be tested in air-dry conditions. In the case of
scientific research, tests might be done on green specimens, in which case the specimens shall be
despatched immediately. As bamboo is highly susceptible to attack by destroying agents in many countries, it
may need prophylactic treatment to keep it intact during despatch, transit and storage.
All the details of a particular consignment shall be rechecked and signed and dated by the dispatcher. The
details shall be sent along with the documents of the consignments.
5.5 Receipt and storage of the bamboo culms
On receipt of the material by the testing authority, the particulars of identification of the various culms shall be
checked, and a proper record shall be kept.
The bamboo culms shall be stored for as short a duration as possible, in such a way that no deterioration shall
take place.
5.6 Marking and conversion into test specimens
Specimens shall be cut for the various tests, and suitable markings (e.g. project number, consignment number,
culm number, etc.) shall be made for complete identification of each specimen.
The sequence of tests shall be such as to eliminate, as far as possible, changes due to storage and weather
conditions, which might affect the comparison of results.
The number of specimens in each test shall not be less than twelve.
5.7 Test report
The test report shall include the following information:
a) the name and address of the laboratory, the date, and the name of the responsible researcher;
b) a reference to this part of ISO 22157, and to applicable national standards;
c) details of the test specimens, as mentioned in 5.3;
d) temperature and air humidity in the laboratory;
e) equipment used, and any other information which may influence the use of the test results;
f) the test results, including the values of moisture content and the mass per volume, the actual dimensions,
moduli and/or strength values, mode of failure, and any other information which may influence the use of
the test results (e.g. position along the culm);
g) details about the statistical treatment of the test results, including the methods used and the results
obtained; the accuracy of a mean value shall be half the standard deviation, and the accuracy of a
standard deviation shall be half its own standard deviation;
h) data about the adjustment to a 12 % moisture content, if applicable.
6 Moisture content
6.1 Scope
This clause specifies a method for determining the moisture content of bamboo for physical and mechanical
tests.
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ISO 22157-1:2004(E)
6.2 Principle
Determination, by weighing, of the loss in mass of the test piece on drying to constant mass. Calculation of the
loss in mass as a percentage of the mass of the test piece after drying.
6.3 Apparatus
6.3.1 Balance, with an accuracy of 0,01 g.
6.3.2 Equipment capable of drying bamboo to an absolutely dry condition, e.g. an electric oven.
6.3.3 Equipment to ensure the retention of moisture in the test pieces, e.g. flasks with ground-glass
necks, and stoppers.
6.4 Preparation of test pieces
Test pieces for determination of moisture content shall be prepared immediately after each mechanical test.
The number of test pieces shall be equal to the number of test pieces for the physical or mechanical test. The
form shall be like a prism, approximately 25 mm wide, 25 mm high and as thick as the wall thickness. The test
pieces shall be taken near to the place of failure, and stored under conditions which ensure that the moisture
content remains unchanged.
6.5 Procedure
The test pieces shall be weighed to an accuracy of 0,01 g, and then dried in an oven at a temperature of
103 ± 2 °C.
After 24 h, the mass shall be recorded at regular intervals of not less than 2 h. Great care shall be taken to
prevent any change in moisture content between removal from the oven and subsequent determinations of
the mass.
The drying shall be considered to be complete when the difference between the successive determinations of
the mass does not exceed 0,01 g.
6.6 Calculation and expression of results
The moisture content MC of each test piece shall be calculated as the loss in mass, expressed as a
percentage of the oven-dry mass, using the following formula:
mm−
o
MC=×100
m
o
where
m is the mass of the test piece before drying;
m is the mass of the test piece after dr
...