BS ISO TR 12470-1998 Fire resistance tests Guidance on the application and extension of results《防火试验 试验结果的应用和扩展指南》.pdf

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1、BRITISH STANDARD BS ISO/TR 12470:1998 Fire resistance tests Guidance on the application and extension of results ICS 13.220.50BSISO/TR12470:1998 This British Standard, having been prepared under the direction of the Health and Environment Sector Board, was published under the authority of the Standa

2、rds Board and comes into effect on 15 October1998 BSI 06-1999 ISBN 0 580 30627 5 National foreword This British Standard reproduces verbatim ISO/TR12470:1998 and implements it as the UK national standard. The UK participation in its preparation was entrusted by Technical Committee FSH/22, Fire resis

3、tance tests, to Subcommittee FSH/22/2, Interpolation and extrapolation of test results, which has the responsibility to: aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK int

4、erests informed; monitor related international and European developments and promulgate them in the UK. A list of organizations represented on this subcommittee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications

5、referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions o

6、f a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, theISO/TR title page, p

7、ages ii to iv, pages 1 to40, an inside back cover and aback cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Amendments issued since publication Amd. No. Date CommentsBSISO/TR

8、12470:1998 BSI 06-1999 i Contents Page National foreword Inside front cover Foreword iii Text of ISO/TR 12470 1ii blankBSISO/TR12470:1998 ii BSI 06-1999 Contents Page Foreword iii Introduction 1 1 Scope 1 2 Common factors 2 2.1 Manufacture and materials 2 2.2 Moisture content 3 2.3 Increasing size 3

9、 3 Loadbearing elements 3 3.1 Beams 4 3.2 Columns 5 3.3 Floors 6 3.4 Walls 8 4 Non-loadbearing elements 9 4.1 Vertical partitions 9 4.2 Ceiling membranes (Horizontal partitions) 11 4.3 Doors Hinged and pivoted leaves 12 4.4 Lift landing doors Centre opening and two-speed lift landing doors 15 4.5 Ro

10、lling shutters 17 4.6 Glazed elements 18 5 Components contributing to the fire resistance of elements 20 5.1 Suspended ceilings 20 5.2 Insulating systems 23 6 Service installations 24 6.1 Ducts 24 6.2 Dampers 26 6.3 Penetration seals 27 7 Future evolution 28 7.1 Improvement of testing methodologies

11、28 7.2 Mathematical modelling of thermal and mechanical response 30 7.3 Expert system based upon the use of performance coefficients 31 Annex A (normative) Summary of general practices in various countries as far as interpolation and extrapolation are concerned 34 Annex B (informative) Current pract

12、ices in various countries 37 Annex C (informative) Bibliography Inside back cover Figure 1 33 Table A.1 Extrapolation 35 Table A.2 Extrapolation 36 Table A.3 Interpolation 37 Descriptors: Buildings, construction, fire protection, structural members, building elements, fire tests, test results, exten

13、sions, rules (instructions).BSISO/TR12470:1998 BSI 06-1999 iii 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 com

14、mittees. 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

15、International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. The main task of technical committees is to prepare International Standards, but in exceptional circumstances a technical committee may propose the publication of a Technical Report of one of the foll

16、owing types: type 1, when the required support cannot be obtained for the publication of an International Standard, despite repeated efforts; type 2, when the subject is still under technical development or where for any other reason there is the future but not immediate possibility of an agreement

17、on an International Standards; type 3, when a technical committee has collected data of a different kind from that which is normally published as an International Standard (“state of the art”, for example). Technical Reports of types1 and2 are subjected to review within three years of publication, t

18、o decide whether they can be transformed into International Standards. Technical Reports of type3 do not necessarily have to be reviewed until the data they provide are considered to be no longer valid or useful. ISO/TR12470, which is a Technical Report of type2, was prepared by Technical Committee

19、ISO/TC92, Fire safety, Subcommittee SC2, Fire resistance. The primary objective of this Technical Report is to produce a harmonized approach to the extension of results obtained from fire resistance tests performed according to the time-temperature curve as given in ISO834-1. Such an approach is usa

20、ble by writers of fire testing standards to assist with the preparation of harmonized “field of direct application” statements. In addition it is of assistance to fire safety engineers/consultants who either need to establish the extended field of application of a tested construction, to establish w

21、hether a similar untested element would be expected to satisfy the test criteria where the variations between the tested and untested constructions are significant, or produce the rules governing the application. The guidance as to whether the application can be extended is given in three forms. In

22、the simplest form a rule may be used which may be based upon sound scientific facts or even just custom and practice. For quantifiable aspects it identifies where fire engineering calculations may be used. Where judgement needs to be exercised, it identifies the factors that need to be considered. T

23、he guidance given also allows a designer or the enforcing authority to assess the fire resistance of an element when it is of a size that cannot be tested due to the physical limitations of testing furnaces. Whether this is a valid use of this guidance document will depend upon the philosophy of a p

24、articular countrys regulations and the way they use fire resistance tests in their building codes. In a complex building where the behaviour can only be established from first principles, a greater understanding of the limitations applying to a test result is critical. Structural elements such as be

25、ams, girders, columns and floors are generally designed by using calculation methods applicable at room temperature and each element is more or less different from one another. These structural elements also need calculation methods that assess their fire behaviour and it is important that these are

26、 correlated by tests. Annex A forms an integral part of this Technical Report. Annex B and Annex C are for information only.iv blankBSISO/TR12470:1998 BSI 06-1999 1 Introduction Fire resistance tests on building components are necessary to establish their behaviour against pre-determined criteria wh

27、en exposed to a representative fully developed fire and to provide information that may be used in determining the fire safety level of buildings. For several decades people have accepted by means of test results only, the possibility of grading the components. Now, due to the improvement of knowled

28、ge and the sophistication of buildings, it is necessary to be able to give a more accurate assessment of the components used in buildings. Because of the cost of the tests and the size limitations of the testing furnaces, it is not possible for any given building element to be tested at all of its v

29、arious sizes or designs. As a consequence we need rules or even better mathematical models for predicting, from test results, the behaviour of elements which are changed in size, design and/or application. The performance of these elements is adjudged as a separate consideration and only against sta

30、ndard heating conditions as defined in ISO834-1. Even with the knowledge available to assess the behaviour of a given constructional element, whatever its design or its size, we will still be a long way from establishing the real behaviour of a building in a real fire. The philosophy of only grading

31、 elements into different fire resistance categories may not give any indication about how the element behaves when heated. By studying and assessing the data from fire resistance tests, it will be possible, using the guidance within this Technical Report, to obtain a basic understanding of the influ

32、ence of the main parameters on the element performance during a fire resistance test. In practice, tests can give much useful information which can be used for interpolation and extrapolation of the results. In the following, all of these assessments will be based on the one hand on the standard tim

33、e/temperature conditions and, on the other hand, on isolated elements with no interaction with the adjacent elements. Also ageing and weathering are not covered here. This Technical Report is divided in two parts: guidance on direct use and extended application of test results for various elements u

34、sed in buildings; the parameters which would be assessed by rules, calculation or only expert judgements are discussed. future 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

35、can be used by experts to give their judgement, expert systems which could take into account the interaction of various factors in an assessment. In addition Annex A and Annex B give an overview of current practices in various countries as far as application and extension of fire resistance test res

36、ults are concerned. It is mentioned where agreement could be found and where more efforts have to be made for harmonization. Annex C gives additional reading. 1 Scope Direct and extended applications of test results are the two possible ways to ensure that a modified element will have a good possibi

37、lity of obtaining the same fire rating as that of the original tested specimen. In both cases these applications refer only to the fire rating that the building element can expect to reach if it were to be tested in a furnace according to the standard fire used for the reference test. For each type

38、of element of construction, the application of test results will be considered under two sub-headings. a) Direct application: this section identifies the modifications that can be made to the design of the tested element without reducing its fire rating. These possible modifications are based on obv

39、ious knowledge and do not need further evaluation. In every case it is, at least, assumed that the basic materials used for the tested sample will not be changed. The results obtained from tests performed using standard configurations are valid for the field of application derived from that configur

40、ation, regardless of any specific advice given in the following chapters. b) Extended application: this will require in every case an assessment by a fire expert either in developing rules of application or evaluating the results of fire engineering calculations or making a judgement. In every case

41、it will 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.BSISO/TR12470:1998 2 BSI 06-1999 A judgement is the result of a qualitative process, normally carried o

42、ut by experts. Judgements are used to justify a change of design or method of construction which may use, for example, empirical data derived from tests, established physical properties, hot and cold state calculations, a knowledge of fire exposure, fire behaviour and response of the construction, e

43、ither in isolation or in combination. 1) Rules of application: these would be applied universally even by persons without expertise in fire as part of the “field of application” of the test result for a given family of products. These rules may require cold state calculation. The quantification of t

44、hese rules would be agreed universally based upon validated experience related to generic constructions or components. This could cover size changes, number of joints, size of glazing etc. Throughout this Technical Report the clauses covering rules frequently express the acceptable change in terms o

45、f un-quantified percentages indicated by the letter “X” and an appropriate suffix. This allows national code authorities to insert their own acceptable limits which will relate to their established fire safety philosophy. Authorities are encouraged to support the necessary research towards internati

46、onally harmonized validated value. 2) Fire engineering calculations: these would be used by an expert in giving advice but will mainly be restricted to the properties indicated below: non-loaded elements: this would be restricted to the calculation of temperature rise and deflection of “simple” comp

47、onents and elements; loaded element: in addition to the properties permitted for non-loaded elements, calculation at elevated temperature could be permitted for the load-bearing capacity for well-documented materials (steel, concrete, etc.) and for statically determined elements. In every case the c

48、alculation models used by the experts, whatever their source (purchased from software manufacturers or developed in the institution) have to be fully validated by comparison with existing test results and by sensitivity analysis of the various parameters. 3) judgements: for a test result to be extra

49、polated to cover changes outside those for which calculations or written rules are applicable, the result may still apply subject to some expert judgement being made. The section on judgements highlights the matters that need to be considered and to be explained by the body or person responsible for making such judgements. Generally, components of a construction element could be changed, provided it can be shown that this does not reduce the fire resistance. It must be demonstrated that the interaction of a new component with other components