Fire-resistance tests -- Guidance on the application and extension of results from tests conducted on fire containment assemblies and products

This document explains a methodology to determine the applicability of the results of fire resistance tests to actual applications. It is applicable to those loadbearing and simple vertical and horizontal separating elements for which there is an ISO standard test procedure based upon the ISO 834 series for determining the fire resistance of a representative sample of the construction proposed for use in a specific building or just for general use. These elements are: —   loadbearing elements; —   non-loadbearing elements: —   partitions: —   stud construction partitions; —   composite panel/SIPS partitions; —   ceiling membranes (horizontal partitions): —   jointed ceilings; —   composite panel ceilings. Direct and extended applications of test results are the two possible ways to ensure that a modified element has an acceptable probability of obtaining the same fire rating as that of the original tested specimen. In both cases, these applications generally refer only to the fire rating that the building element can expect to reach if it, or a representative sample of it, were to be tested in a furnace according to the standard fire test conditions used in the reference test. One of the most common variations is in respect of the size of the element in use. Fire resistance testing furnaces have size restrictions and as a consequence, there is little confidence that the result obtained on an element of construction tested in accordance with the standard methods will behave in a similar manner when installed in the final building. This document does not provide guidance on the application and extension of results arising from testing carried out on door and window assemblies, linear gaps or service penetration seals, which is covered in ISO/TR 12470-2. For some, but not all of the critical parameters, a summary of the possible influences is incorporated in the given examples.

Essais de résistance au feu -- Recommandations pour l'application et l'extrapolation des résultats d'essais réalisés sur les produits et assemblages d'endiguement du feu

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Publication Date
22-Nov-2017
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6060 - International Standard published
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21-Oct-2017
Completion Date
23-Nov-2017
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TECHNICAL ISO/TR
REPORT 12470-1
First edition
2017-11
Fire-resistance tests — Guidance
on the application and extension
of results from tests conducted on
fire containment assemblies and
products —
Part 1:
Loadbearing elements and vertical
and horizontal separating elements
Essais de résistance au feu — Recommandations pour l'application
et l'extrapolation des résultats d'essais réalisés sur les produits et
assemblages d'endiguement du feu —
Partie 1: Éléments porteurs et éléments horizontaux et verticaux de
séparation
Reference number
ISO/TR 12470-1:2017(E)
ISO 2017
---------------------- Page: 1 ----------------------
ISO/TR 12470-1:2017(E)
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© ISO 2017, Published in Switzerland

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ii © ISO 2017 – All rights reserved
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ISO/TR 12470-1:2017(E)
Contents Page

Foreword ..........................................................................................................................................................................................................................................v

Introduction ................................................................................................................................................................................................................................vi

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 2

3 Terms and definitions ..................................................................................................................................................................................... 2

4 Principles of the field of application ................................................................................................................................................ 4

4.1 Direct application ................................................................................................................................................................................. 4

4.2 Extended application ......................................................................................................................................................................... 4

4.2.1 Rules of extended application .............................................................................................................................. 5

4.2.2 Calculations and computer programs used in extended applications ............................... 5

4.2.3 Judgements in extended applications ............................................................................................................ 5

4.3 Project specific application .......................................................................................................................................................... 5

5 Common factors which influence the field of application of all elements ................................................6

5.1 Manufacture and materials .......................................................................................................................................................... 6

5.1.1 General...................................................................................................................................................................................... 6

5.1.2 Direct application ............................................................................................................................................................ 6

6 Loadbearing elements .................................................................................................................................................................................... 6

6.1 Walls ............................................................................................................................................................................................................... 7

6.1.1 General...................................................................................................................................................................................... 7

6.2 Direct application ................................................................................................................................................................................. 7

6.2.1 Common parameters of all forms of wall construction .................................................................. 7

6.2.2 Extended application ................................................................................................................................................... 9

6.3 Floors............................................................................................................................................................................................................11

6.3.1 General...................................................................................................................................................................................11

6.3.2 Direct application .........................................................................................................................................................11

6.3.3 Extended application ................................................................................................................................................13

7 Non-loadbearing elements .....................................................................................................................................................................15

7.1 Vertical partitions ..............................................................................................................................................................................15

7.1.1 General...................................................................................................................................................................................15

7.1.2 Direct application .........................................................................................................................................................15

7.1.3 Extended application ................................................................................................................................................16

7.2 Horizontal “partitions” ceiling membranes ................................................................................................................20

7.2.1 General...................................................................................................................................................................................20

7.2.2 Direct application .........................................................................................................................................................20

7.2.3 Extended application ................................................................................................................................................21

8 Evolution of testing and summary of quantifiable approaches ........................................................................25

8.1 Improvement of testing methodologies .........................................................................................................................25

8.1.1 Existing test methods ..............................................................................................................................................26

8.1.2 Test using reduced-size specimen (reduced-scale test) .............................................................27

8.1.3 Selection of the specimen ......................................................................................................................................27

8.2 Mathematical modelling of thermal and mechanical response .................................................................28

8.2.1 Level 1 — Numerical regression analysis ...............................................................................................28

8.2.2 Level 2 — Graphical approach ..........................................................................................................................28

8.2.3 Level 2 — 3D interpolation .................................................................................................................................28

8.2.4 Level 3 — Physical equation analysis .........................................................................................................29

8.2.5 Level 4 — Finite element methods ...............................................................................................................29

8.2.6 Level 5 — Integrated interactive analysis ...............................................................................................30

8.3 Expert system based upon the use of performance coefficients...............................................................30

8.3.1 Concept .................................................................................................................................................................................30

8.3.2 Establishing the coefficients ...............................................................................................................................31

8.3.3 Obtaining benefit from excess performance .........................................................................................31

© ISO 2017 – All rights reserved iii
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ISO/TR 12470-1:2017(E)

Annex A (informative) Principles of using expert judgement to establishing to the extended

field of application ...........................................................................................................................................................................................32

Bibliography .............................................................................................................................................................................................................................39

iv © ISO 2017 – All rights reserved
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ISO/TR 12470-1:2017(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.

The procedures used to develop this document and those intended for its further maintenance are

described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the

different types of ISO documents should be noted. This document was drafted in accordance with the

editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).

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. Details of

any patent rights identified during the development of the document will be in the Introduction and/or

on the ISO list of patent declarations received (see www.iso.org/patents).

Any trade name used in this document is information given for the convenience of users and does not

constitute an endorsement.

For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and

expressions related to conformity assessment, as well as information about ISO's adherence to the

World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following

URL: www.iso.org/iso/foreword.html.

This document was prepared by Technical Committee ISO/TC 92, Fire safety, Subcommittee SC 2, Fire

containment.
A list of all parts in the ISO 12470 series can be found on the ISO website.
© ISO 2017 – All rights reserved v
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ISO/TR 12470-1:2017(E)
Introduction

Fire resistance tests on building components are necessary to establish their behaviour against pre-

determined criteria when exposed to a representative fully developed fire and to provide information

that may be used in determining the fire safety of buildings. For several decades, people have accepted,

by means of test results only, the possibility of grading the components. Now, due to the enhancement

of our knowledge and the complexity of buildings, it is necessary to be able to give a more accurate

assessment of the components used in buildings, particularly with the growth of the use of functional

approaches to designing fire safe structures.

The need to understand how the element will perform at a different size, with different levels of

restraint, etc. is vital when applying the results of the fire tests in a life safety situation, especially

those where the fire safe solution has been generated using fire safety engineering techniques rather

than using a code compliant solution. This does not negate the need to predict any changes that may

result from changes to the test construction when complying with building code solutions, but these

codes may themselves provide solutions that take into account the influence or impact of changes, and

indeed the guidance given in this document may be used by the code writers to produce such guidance.

Even with the knowledge available to assess the behaviour of a given constructional element, whatever

its design or its size, we will still be some distance away from establishing the complete behaviour of a

building in a real fire.

The philosophy of only grading elements into different fire resistance categories may not give any

indication about how the element actually behaves when heated. By studying and analysing the data

from fire resistance tests, it will be possible, using the guidance within this document, to obtain a

basic understanding of the influence of the main parameters on the element performance during fire

resistance tests.

In practice, tests do give much useful information which can be used for interpolation and extrapolation

of the results.

The original version of ISO/TR 12470 was published by ISO/TC 92/SC 2 in 1998. This Technical Report

provided a methodology identifying how the results of fire resistance tests carried out in the standard

furnaces could be modified to apply to the elements as they may be used in practice. In some cases, the

results of the test may need to be reduced to reflect any increases in the degree of difficulty that the

final application represents or alternatively, modifications/enhancements may need to be made to the

construction in order to maintain the performance level(s).

In the intervening years since the original Technical Report was prepared, a greater understanding has

developed as to what the changes are likely to be and how they may be quantified. Some of the work in

Comité Européen de Normalisation (CEN) has aided this process and in particular, the principles given

in Annex A remained unpublished by CEN but were developed in one of the technical Work Groups of

CEN/TC 127. This revision represents the current state-of-art in respect of the objectives of the original

1998 version of ISO/TR 12470.

In this document, all assessments of extended application are based on standard time/temperature

conditions and on isolated elements, with no interaction with the adjacent elements.

Also, ageing and weathering are not covered.
The ISO/TR 12470 series is published in two parts:
Part 1: Loadbearing elements and vertical and horizontal separating elements;

Part 2: Fire resistant door assemblies, glazing, services and service penetration.

vi © ISO 2017 – All rights reserved
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ISO/TR 12470-1:2017(E)
This document is divided into two sections:

— Guidance on direct and extended application of test results for various elements used in buildings,

the major parameters of which would be assessed by calculation or expert judgements based upon

the methodology and discipline given in Annex A.
— Current state-of-art and possible evolution:

— improvement of testing methodologies to give a better prediction of the performance of various

sizes and designs of a given element;
— mathematical modelling which can be used by experts to give their judgement;

— expert systems which could take into account the interaction of various factors in an assessment.

© ISO 2017 – All rights reserved vii
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TECHNICAL REPORT ISO/TR 12470-1:2017(E)
Fire-resistance tests — Guidance on the application
and extension of results from tests conducted on fire
containment assemblies and products —
Part 1:
Loadbearing elements and vertical and horizontal
separating elements
1 Scope

This document explains a methodology to determine the applicability of the results of fire resistance

tests to actual applications.

It is applicable to those loadbearing and simple vertical and horizontal separating elements for

which there is an ISO standard test procedure based upon the ISO 834 series for determining the fire

resistance of a representative sample of the construction proposed for use in a specific building or just

for general use. These elements are:
— loadbearing elements;
— non-loadbearing elements:
— partitions:
— stud construction partitions;
— composite panel/SIPS partitions;
— ceiling membranes (horizontal partitions):
— jointed ceilings;
— composite panel ceilings.

Direct and extended applications of test results are the two possible ways to ensure that a modified

element has an acceptable probability of obtaining the same fire rating as that of the original tested

specimen. In both cases, these applications generally refer only to the fire rating that the building

element can expect to reach if it, or a representative sample of it, were to be tested in a furnace according

to the standard fire test conditions used in the reference test.

One of the most common variations is in respect of the size of the element in use. Fire resistance testing

furnaces have size restrictions and as a consequence, there is little confidence that the result obtained

on an element of construction tested in accordance with the standard methods will behave in a similar

manner when installed in the final building.

This document does not provide guidance on the application and extension of results arising from

testing carried out on door and window assemblies, linear gaps or service penetration seals, which is

covered in ISO/TR 12470-2.

For some, but not all of the critical parameters, a summary of the possible influences is incorporated in

the given examples.
© ISO 2017 – All rights reserved 1
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ISO/TR 12470-1:2017(E)
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 834 (all parts), Fire resistance tests — Elements of building construction
ISO 13943, Fire safety — Vocabulary
3 Terms and definitions

For the purposes of this document, the terms and definitions given in ISO 834 (all parts) and

ISO 13943 apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— IEC Electropedia: available at http://www.electropedia.org/
— ISO Online browsing platform: available at http://www.iso.org/obp
3.1
direct application

application that identifies the modifications that can be made to the design of the tested element

without reducing its fire rating

Note 1 to entry: These possible modifications are based on obvious knowledge and do not need further evaluation.

In every case, it is at least assumed that the basic material(s) used for the construction of the tested sample will

not be changed.

Note 2 to entry: Direct application defines the variation(s) in the construction and the limits of use for the

element which, without further analysis, are covered by the result of a test in accordance with the ISO 834 series.

Direct application is arrived at by the application of simple rules (3.4) that are known, or considered by the fire

community, to give equal or improved fire resistance performance by the users. The rules can be applied by non-

fire experts.

Note 3 to entry: Only results from one test report can be used when considering a change of an element. Any

combination and use of two or more tests reports or other technical sources should be regarded as extended

application (3.2) and hence dealt with accordingly.
3.2
extended application

application that generally requires an assessment by a fire expert either in developing rules (3.4) of

application for more general application by others, or evaluating the results of fire engineering

calculations, or for making a judgement in specific cases

Note 1 to entry: In every case, it should be taken into consideration that extended application may take into

account the difference between the result of the original test and the fire resistance required for the untested

element.

Note 2 to entry: Extended application defines and specifies the variations in the construction and establishes

the limits of use for an element that has been tested according to the appropriate ISO standard, based upon an

analysis by fire experts. The extended application can use the results from one or more test reports and can

be based upon rules, calculations and expert judgement (3.6). As a result of the extended application, the fire

resistance classification of an element with respect to defined performance characteristics may be maintained,

increased or decreased when used in practice.
2 © ISO 2017 – All rights reserved
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ISO/TR 12470-1:2017(E)
3.3
project specific application

application that uses a mixture of established validated calculations/computer models (if they exist and

are appropriate) together with judgements made by suitably qualified persons (normally a professional

badged engineer or a corporate member of a learned professional body)

Note 1 to entry: Because the application will, in these circumstances, require an understanding of both the

structural response and the fire dynamics of the building in question, it is inevitable that the solution will involve

an element of fire safety engineering.
3.4
rule

quantitative factor (3.9) that can be applied to the result of tests when defining the limits of application

for which justification exists as a result of research and testing

Note 1 to entry: Rules are primarily used in determining the direct application (3.1) of the result as its application

does not generally require specialist knowledge.

Note 2 to entry: It is anticipated that these rules be established by the specialist (or ad hoc) groups preparing

the specific standards based upon public domain knowledge and developed by industry consortia or trade

associations for specific elements for which the members have appropriate interest and knowledge, particularly

in Europe initially. After some experience, the results of calculations and judgements may become rules.

3.5
calculation in support of extended application

calculation method that can be applied to one or more parameters of a tested construction and which

are based on existing physical laws or which have been empirically validated and which form part of

the process of defining the extended application (3.2)

Note 1 to entry: If this term has a definition elsewhere, then it should be used but possibly modified to include

this specific use.
3.6
expert judgement

qualitative process performed by fire experts when the complexity of the influence is beyond the

scope of rules (3.4), to establish the resultant effect of a variation in one or more parameters, on the

classification awarded
3.7
construction parameter

aspect of the design and construction of an element that may be varied and which may result in a

change in the fire resistance performance, e.g. a change in one or more of the dimensions of a stud in a

stud framed separating element
3.8
thermal and mechanical parameter

aspect of the conditions of a test that may vary in practice and influence the classification system given,

e.g. the pressure differential that will exist at the top of a larger element than existed at the top of the

specimen when tested
3.9
factor

one of the possible variations that may be applied to a parameter, e.g. a change in the stiffness as a

result of a dimensional change in the member or a component within the element
3.10
factor influence

one of the potential causes of a change in the fire resistance recorded by test, with respect to one or

more of the criteria, when a factor (3.9) is changed, e.g. an increase in the loadbearing capacity R as a

result of an increase in stiffness
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ISO/TR 12470-1:2017(E)
4 Principles of the field of application

The field of application from the result of a fire resistance test has at least three possible components:

(1) direct application, (2) extended application and (3) project specific application.

The process of determining the direct application and extended application of the fire resistance

rating of a tested construction normally assumes that the performance is evaluated against the

temperature/time and differential pressure conditions given in the appropriate ISO fire resistance

testing standard (based upon the ISO 834 series or the national, regional equivalent), as this is generally

what is referenced in national prescriptive legislation. The variations between the tested specimen and

the “as-built” construction will therefore be restricted to:
— variations in the size of the construction;
— variations in the materials and methods of construction;
— variations in the restraint and fixity;
— variations in the load carried (if any).

In this situation, only the constructional parameters given in A.2.2 need to be taken into account.

In practice, there will be a need to predict the performance of a structure when it is exposed to

different fire exposure conditions, in terms of the temperatures reached after certain durations and

with greater or lesser pressure differentials. Generally, the parameters will be analysed by means of

a fire engineering analysis which is outside of the scope of this document, but the parameters listed in

A.2.1 may be appropriate for use in an expert judgement analysis of these characteristics.

For each type of element of construction, the application of test results will be considered under three

conditions: (1) direct application, (2) extended application and (3) project specific fields of application.

Changes in materials and methods of construction can have significant influences on the fire resistance.

Because the advice and recommendations are common to all elements, those aspects are dealt with

separately under 5.1 to avoid repetition. The user of this document should consider these aspects

in all applications of results whether direct applications, extended applications, or project specific

applications.
4.1 Direct application

The direct application will normally involve the application of “rules” that are given as part of the test

standard or in a document directly associated with the test standard. It requires no knowledge of the

process of determining the fire resistance other than an understanding of the criteria and the general

terminology.

Where there is more than one change in any proposed construction/installation, two “direct

application” rules should not be applied automatically and the two should be compared as part of an

extended application.
4.2 Extended application

Determining the extended application of the fire resistance is a more complex matter and will generally

need to be undertaken by “experts” who understand the mode of failure and the factors that lead to such

a failure. There are three common methods used by practitioners to establish the extended application

of the fire resistance of elements of construction and these are:
— application of locally validated rules, especially within Europe;
— use of estab
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