PROPOSED CEN STANDARD IN COMPARISON WITH ISO FOR THE ASSESSMENT OF THE FIRE BEHAVIOUR OF MASONRY. Chrístiane Hahn

Size: px

Start display at page:

Download "PROPOSED CEN STANDARD IN COMPARISON WITH ISO FOR THE ASSESSMENT OF THE FIRE BEHAVIOUR OF MASONRY. Chrístiane Hahn"

Oswin Sanders
5 years ago
Views:

1 PROPOSED CEN STANDARD IN COMPARISON WITH ISO FOR THE ASSESSMENT OF THE FIRE BEHAVIOUR OF MASONRY 1 ABSTRACT Chrístiane Hahn Up to now the assessment of fire behaviour of masonry walls is done according to national standards or even only to national judgement. Because of the attempt to open the European market the work on harmonising the standards started. This paper presents the work for the assessment of fire behaviour of masonry that is presently done in the CEN committies CEN/TC 127 "Fire Resistance Testing of Building Elements", CEN/TC 250 SC 6 PT 7 "Structural Fire Design for Masonry" and also explains the concept that is wrítten down in the "Interpretative Document".Finally a comparison with ISO will dose this subject. 2 INTRODUCTION To get the European market started harmonised standards are necessary. For realizing the decisions for harmonisation the European standard organisation CEN was asked by the European commission to set up harmonised standards. For the work technical commities with working groups (WG) and task groups (TG) were founded. For the dead line the complet standards should be finished. The work for the international standards (ISO) is still done parallel in some cases. But mainly the work is done according to the Vienna agreement. New european standards shall be set up and shall replace the national standards after a certain transitional períod o Keywords: Masonry; Fire Assessment; CEN Standards; European Market. Dip!.-Ing., Deputy head of the fire department Institute for Building Materials, Solid Construction and Fire Protection Technical University Braunschweig Germany Te!. int Institut für Baustoffe, Massibau und Brandschutz Beethovenstr. 52 D Braunschweig Fax int

2 3 BLANKET CLAUSE FOR FlRE PROTECTION 3.1 Construction Product Directive The European commission set the blanket clause for fire protection in the "Construction Product Directive" as follows: "The construction works must be designed and built in such a way that in the event of an outbreak of fire : the loadbearing capacity of the construction can be assummed for a specific period of time, the generation and spread of fire and smoke within the works are limited, the spread of the fire to neighbouring construction works is limited, occupants can leave the works or be rescued by other means, the safety of the rescue teams is taken into consideration." The requirements itself which are necessary to fulfill this blanket clause are defined in the "Interpretative Document for the Essential Requirement - Safety in Case of Fire" (Last version complete, uly 1993). 3.2 Interpretative Document The general requirements, the concept and the basis for fire protection are described. It is differentiated between loadbearing and non-loadbearing building elements with separating or non-separating function. Therefore wall typs are defined The criteria for the evaluation of the building components are as follow : R : Loadbearing criterion Structures shall maintain their loadbearing function during the relevant fire exposure E : Integrity criterion Defines the ability of a separating member (wall) to prevent passage of flames and hot gases during the relevant fire exposure I : Thermal insulation Defines the ability of a separating member (wall) to prevent excessive transmission of heat during the relcvant fire exposure W : Radiation criterion Defines the insulation of a separating member on the basis of the radiation emitted during the relavant fire exposure M : Mechanical criterion Structures shall maintain their loadbearing capacity and their integrity under mechanical impact during the relevant fire exposure 1464

3 4 CEN/TC General CEN/TC 127 works on the assessment of fire behaviour. CEN/TC 127 started working in 1991 and set up a very tight time table for producing the standards for the buiiding elements. Nearly ali standards were supposed to be ready for stage 41 - public presentation for the 6 manth inquiry - at the end af 1992, but there is a deiay. Provisonal mandates were handed out mainiy to ad hoc groups. Additionally, work was given to EGOLF - European Group of Laboratories for Fire - to reach the above mentianed aim. CENITC 127 Fire safety in buildings Working groups Arbeits-Gruppen WG1 WG 2 sd hoc group 1 Non-combustibility Harmonized test European reaction of INichtbrennbarkeit) preparation and fire classification sd hoc group 2 translation of national Ignitability classifications (Europãische (Endzündberkeitl ~ Klassifizierung des I sd hoc group 3 I Probenvorbereitungen Brandverhaltens von Flcor coverings und Übertragung von Baustoffen) IBodenbelãgel nationalen Klassifi zierungen) I sd hoc group 4 Roof tests (Bedachungenl Figure 1: Overview CEN/TC 127 l I ad hoc gtoup 5 Door and shutter assemblies (Feuerschutzabschlüsse) I sd hoc group 6 Penetration seals (Abschottungen) I sd hoc grcup 7 Strategy (Str8tegie I ed hoc group 8 Smoke IRauch) I sd hoc group 9 Partitions (Trennwãndel ed hoc group 10 Additional requirements (zus ãtzliche Anforderungen) l ed hoc group 11 Damper. ventilation ducts ILüftungsleitun gen ) ~ I I 1465

4 4.2 CEN standardisation for masonry Ad hoc group 9 "Partition" set up the standard for testing ali types of walis including masonry. This group started oniy on non-ioadbearing internai walis with separating function. Additional tasks are non-ioadbearing externai walis with or without separating function, Ioadbearing internai and externai walis, both with or without separating function, and facades now. Masonry is used for ali of these types. "> 100 > 100 "> 100 ~,--_----"I -~-",4'f.-""-"---=:----'-<:L~r~1=f--j tragende Lr,/ raumabschliebende direction of floor span AuBenwande loadbearing separating outside walls Balken (Stürze) lintels tragende, nicht raumabschliebende AuBenwande loadbearing non separating outside walls Stützen (Mauerwerkspfeiler) columns tragende, nicht raumabschliebende Innenwande! Deckenspannrichtung direction of flol~or~s~p~a~n ---:E~::::::=== nichttragende Trennwânde loadbearing non-separating inside walls non loadbearing partitions tragende, raumabschliebende Innenwand loadbearing, separating inside wall Figure 2: WalI types (exampie) 1466

5 For ali of these wall types single papers wiu be set up as folow : EN YYY 1 General requirements for - Part 1: General testing and Fire Resistance Testing performance requirements EN YYY 2 Fire Resistance Testing - Part 1: Partitions of Nonloadbearing Elements - Part 2a: External walls - Part 2b: Facades EN YYY 3 Fire Resistance Testing - Part 1: Internal walls of Loadbearing Elements - Part 2: External walls EN YYY 5 Contribution to Fire Resist- - Part 6: Applied protection ance of Structural Members to masonry eements EN QQQ 1 Material Properties at - Part 1: General requirement High Temperatures - Part 4: Masonry CEN/TC 127 defines the basis for fire protection and sets up the testing standard for the assessment. Depending on the building element the test methodes are defined very detailed. For example the loading system or the mechanical impact are defined exactly. Furnace Figure 3: Loading system Hydraulic ---+\ acks 1467

6 Sectional Elevation \ Release Equipment.' l";ll... :: ~ ~. ~,.\ \~, -1'. ~ack l e.t-. 8renner I o '<:~../. 8 25,I, gj~ l l ~L M z~. Komplextrennwand 1.000Nm Brandwand 3000 Nm "' kg Lead Shot O.K.F. Halle Hydraulic acks 1500~ Figure 4: Mechanical impact The background for these precize definitions is that test results ali over Europe will be accepted. Up to now clients have to test in each European country, if they need the assessments because test results achieved in other countries will not be accepted. The intemational standardization (ISO) oniy describes the general concept up to now, Details are not given. Within EGOLF - European Group of Laboratories for Fire - there was a group working on protection of masonry -cladding, piaster, etc, 5 CEN/TC 250 SC General CEN/TC 250 SC 6 PT 7 works on the "Structural Fire Design of Masonry". The revised version of EC 6 part 10 wiu be presented in une The basis for this paper is Eurocode 6 part 10 [1]. 1468

7 PT 7 StNctuta' Fire Quion Figure 5: Overview CEN/TC CEN/TC 250 SC 6 PT 7 This paper defines the possibilities to assess the fire behaviour of masonry. On principie there will be 3 equal ways as follow: - Testing the masonry wall according to CEN/TC Assessment according to tabulated data - Assessment by calculation * simplified calculation method * general calculation method The revised version wiu only present tabulated data for the assessment of fire behaviour of masonry. Tables for each wall type will be set up although it is rather difficult to mix test results from different countries with different types of units and loading. Contrary to ali other building materials, i.e. concrete, there exists no calculation method for assessing the fire behaviour of masonry up to now. Further details to the paper will be given at the presentation because at that time a redrafted version will exist. 6SUMMARY The general blanket for fire protection according to the "Construction Product Directive" and the "Interpretative Document" for the harmonized European market is presented. The testing methods for the assessement of fire resistance for masonry are drafted in CEN/TC 127. Essential requirements are summarized. The work is very 1469

8 detailed in contrast to the ISO-work. CEN/TC 250 SC 6 PT 7 is presented. It is necessary to start a European discussion to be able to finalize this paper during the 3 year testing period. Up to now it is rather unsatisfactory. REFERENCES: [1] Haseltine, B., Hahn, Chr., Waldum, Alf: Eurocode 6, part 10: "Structural Fire Design for Masonry", Draft

Fire classification of construction products and building elements

ÖNORM EN 13501-2 Edition: 2008-01-01 Fire classification of construction products and building elements Part 2: Classification using data from fire resistance tests, excluding ventilation services Klassifizierung