Structural fire design - eurocodes.fi fire... · CONCRETE part 1.2 structural fire design EC3 - part 1.1 general rules SC 3 STEEL ... Background and Applications NDP for Structural

EUROCODESBackground and Applications

“Dissemination of information for training” workshop 18-20 February 2008 Brussels

Structural fire design Organised by European Commission: DG Enterprise and Industry, Joint Research Centre with the support of CEN/TC250, CEN Management Centre and Member States

Wednesday, February 20 – Palais des Académies Structural fire design Roi Baudoin room

9:00-9:30 General presentation of Eurocode Fire Parts

J. Kruppa CTICM

9:30-10:15 Eurocode 1 - 1.2 Action in case of fire T. Lennon BRE

10:15-10:30 Coffee

10:30-11:45 Eurocode 2 - 1.2 concrete structures T. Hietanen RT Betonikeskus

11:45-13.00 Eurocode 3 - 1.2 steel structures L. Twilt TNO

13:00-14:30 Lunch

14:30-15:45 Eurocode 4 - 1.2 composite structures J. B. Schleich University of Liege

15:45-16:00 Coffee

16:00-17:00 Eurocode 5 - 1.2 timber structures H. Hartl University Innsbruck J. Fornather Austrian Standards Institute

17:00-17:45 Eurocode 9 - aluminium alloys structures

N. Forsén Multiconsult

17:45-18:00 Discussion and close All workshop material will be available at http://eurocodes.jrc.ec.europa.eu

GENERAL PRESENTATION OF EUROCODE FIRE PARTS

J. Kruppa

CTICM

Brussels, 18-20 February 2008 – Dissemination of information workshop 1

Background and ApplicationsEUROCODES

Structural Fire Designaccording to Eurocodes

Joël KRUPPACTICM

Coordinator CEN TC 250 / Horizontal Group "FIRE"


EUROCODESBackground and Applications ESSENTIAL REQUIREMENTS

SAFETY in CASE of FIREconcerning the construction work :

Load bearing capacity of the construction can be assumed for a specific period of timeThe generation and spread of fire and smokewithin the works are limitedThe spread of fire to neighbouring construction works is limitedThe occupants can leave the works or berescued by other meansThe safety of rescue teams is taken intoconsideration


EUROCODESBackground and Applications HARMONISATION of ASSESSMENT METHODS

To prove compliance with Essential Requirements :

Tests + extended applications of resultscalculation and/or design methodscombination of tests and calculations



EUROCODES for STRUCTURAL FIRE DESIGN

Fire parts within :

EC 1 : ACTIONS on STRUCTURES

EC 2 : CONCRETE STRUCTURESEC 3 : STEEL STRUCTURESEC 4 : COMPOSITE STRUCTURESEC 5 : TIMBER STRUCTURESEC 6 : MASONRYEC 9 : ALUMINIUM ALLOYS STRUCTURES



CEN TC 250 – Sub-Committeesinvolved in Fire Safety

part 1.2actions incase of fire

EC1- part 1.1General actions

SC 1ACTIONS

part 1.2structuralfire design

EC2 - part 1.1general rules

SC2CONCRETE



SC 3STEEL



SC4COMPOSITE



SC5TIMBER



SC6MASONRY



SC9ALUMINIUM

TC 250Structural Eurocodes

HORIZONTAL GROUP "FIRE"


EUROCODESBackground and Applications NDP for Structural Fire Design

Selection thermal actions nominal firesparametric fire (simple fire models)advanced fire models

Some coefficients for load combinationDefault value for reduction factor for the

design load level in fire situationUse of advanced calculation modelsSome material propertiesUse of informative annex on simple

calculation method


EUROCODESBackground and Applications EC1 – 1.2 : Actions in case of fire

2.1 General(1) A structural fire design analysis should take

into account the following steps as relevant :selection of the relevant design fire scenarios,determination of the corresponding design fires,calculation of temperature evolution within the structural members,calculation of the mechanical behaviour of the structure exposed to fire.


EUROCODESBackground and Applications Various Steps for Assessments

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Mechanical behaviourat elevated temperatures

Heat Transfer to structural elements

Fire Development and propagation

Structural schematisation

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or

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Time (min)

Vert

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∆V



2.2 Design fire scenario(1) To identify the accidental design situation, the relevant design fire scenarios and the associated design fires should be determined on the basis of a fire risk assessment.(2) For structures where particular risks of fire arise as a consequence of other accidental actions, this risk should be considered when determining the overall safety concept.(3) Time- and load-dependent structural behaviour prior to the accidental situation needsnot be considered, unless (2) applies.


EUROCODESBackground and Applications Real scale fires



2.3 Design fire(1) For each design fire scenario, a design fire, in a fire compartment, should be estimated according to section 3 of this Part.(2) The design fire should be applied only to one fire compartment of the building at a time, unless otherwise specified in the design fire scenario.(3) For structures, where the national authoritiesspecify structural fire resistance requirements, it may be assumed that the relevant design fire is given by the standard fire, unless specified otherwise .


EUROCODESBackground and Applications ISO fire versus "natural" fires

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ISO NAT - 1

NAT - 2 NAT - 3



2.4 Temperature Analysis(1)P When performing temperature analysis of a member, the position of the design fire in relation to the member shall be taken into account.(2) For external members, fire exposure through openings in facades and roofs should be considered.(3) For separating external walls fire exposure from inside (from the respective fire compartment) and alternatively from outside (from other fire compartments) should be considered when required.



2.4 Temperature Analysis (cont'd)

(4) Depending on the design fire chosen in section 3, the following procedures should be used :

with a nominal temperature-time curve, the temperature analysis of the structural members is made for a specified period of time, without any cooling phase;NOTE 1 The specified period of time may be given in the NationalRegulations or obtained from Annex F following the specifications of the National Annex.with a fire model, the temperature analysis of the structural members is made for the full duration of the fire, including the cooling phase.NOTE 2 Limited periods of fire resistance may be set in the National Annex.



2.5 Mechanical Analysis

(1)P The mechanical analysis shall be performed for the same duration as used in the temperature analysis.

(2) Verification of fire resistance should be in the time domain:tfi,d ≥ tfi,requ

or in the strength domain:Rfi,d,t ≥ Efi,d,t

or in the temperature domain:Θd ≤ Θcr,d

wheretfi,d design value of the fire resistancetfi,requ required fire resistance timeRfi,d,t design value of the resistance of the member in the fire situation at time tEfi,d,t design value of the relevant effects of actions in the fire situation at time tΘd design value of material temperatureΘcr,d design value of the critical material temperature



EUROCODES 2 to 6 and 9

parts 1. 2


EUROCODESBackground and Applications PARTS on STRUCTURAL FIRE DESIGN

The parts dealing with structural fire resistance in EC2 to EC6 & EC9 have the following layout:

General (scope, definitions, symbols and units)Basic principles (performances requirements, design values

of material properties and assessment methods)Material properties (strength and deformation and thermal

properties)Assessment methodsConstructional details (if any)Annexes (additional information)


EUROCODESBackground and Applications Requirements

2.1.1 General

(1)P Where mechanical resistance in the case of fire is required, concrete structures shall be designed and constructed in such a way that they maintain their load bearing function during the relevant fire exposure.(2)P Where compartmentation is required, the elements forming the boundaries of the fire compartment, including joints, shall be designed and constructed in such a way that they maintain their separating function during the relevant fire exposure. This shall ensure, where relevant, that:

integrity failure does not occur, see EN 1991-1-2insulation failure does not occur, see EN 1991-1-2thermal radiation from the unexposed side is limited.

Exemple from EC2-1.2



2.1.1 General (cont'd)

(3)P Deformation criteria shall be applied where the means of protection, or the design criteria for separating elements, require consideration of the deformation of the load bearing structure.(4) Consideration of the deformation of the load bearing structure is not necessary in the following cases, as relevant:

the efficiency of the means of protection has been evaluated according to […], the separating elements have to fulfil requirements according to nominal fire exposure.




2.1.3 Parametric fire exposure

(2) For the verification of the separating function the following applies, assuming that the normal temperature is 20°C:

the average temperature rise of the unexposed side of the construction should be limited to 140 K and the maximum temperature rise of the unexposed side should not exceed 180 K during the heating phase until the maximum gas temperature in the fire compartment is reached;the average temperature rise of the unexposed side of the construction should be limited to ∆θ1 and the maximum temperature rise of the unexposed side should not exceed ∆θ2 during the decay phase.

Note: The values of ∆θ1 and ∆θ2 for use in a Country may be found in its National Annex. The recommended values are ∆θ1 = 200 K and ∆θ2 = 240 K.



EUROCODESBackground and Applications Background for ∆θ1 = 200 K

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Seperating element for I 30 :+210 K at 49 min.

Separating element for I 120:+187 K at 181 min

Standard fire

Unexposed side of the separating element

+ 140 K

Experimentations carried out in the 80s ("Investigating the unexposed surface temperature criteria of standard ASTM E 119", by K. J. Schwartz and T.T. Lie, Fire technology, vol 21, N0 3, August 1985): - concluded the self-ignition temperatures of ordinary combustibles, in contact with unexposed surface of separating element are in excess of 520 °F (271°C),- suggested to use 400°F (222 K) for average temperature rise and 450°F (250 K) for maximum temperature rise at any point

1

2


EUROCODESBackground and Applications Material Properties

2.3 Design values of material properties

(1)P Design values of mechanical (strength and deformation) material properties Xd,fi are defined as follows:

Xd,fi = kθ Xk / γM,fi

Xk characteristic value of a strength or deformation propertykθ reduction factor for a strength or deformation property dependent on temperatureγM,fi partial safety factor for the relevant material property, for the fire situation

(2)P Design values of thermal material properties Xd,fi are defined as follows:

Xd,fi = Xk,θ /γM,fi or Xd,fi = γM,fi Xk,θ

Xk,θ value of a material property in fire designγM,fi partial safety factor for the relevant material property, for the fire situation.

Note 1: The value of γM,fi for use in a Country may be found in its National Annex. The recommended value is: γM,fi = 1,0

Note 2: If the recommended values are modified, the tabulated data may require modification




Verification method :BASIC PRINCIPLE

Load-bearing function of a structure shall be assumed for the relevant duration of fire exposure t if :

Ed,t, fi ≤ Rd,t, fiwhere :

Ed,t, fi : design effect of actions (Eurocode 1 part 1.2)

Rd,t, fi : design resistance of the structure attime t



Various possibilities for analysis of a structure

member analysis (mainly when verifying

standard fire resistance requirements)

analysis of parts of the structure

global structural analysis

Schematisation of the structure


EUROCODESBackground and Applications Member Analysis

(1) The effect of actions should be determined for time t = 0 using combination factors ψ 1,1 or ψ1,2 according to EN 1991-1-2 Section 4.

(2) As a simplification to (1) the effects of actions may be obtained from a structural analysis for normal temperature design as:

Ed,fi = ηfi Ed

Where

Ed is the design value of the corresponding force or moment for normal temperature design, for a fundamental combination of actions (see EN 1990);

ηfi is the reduction factor for the design load level for the fire situation.


EUROCODESBackground and Applications ηfi

assumptions: γGA = 1,0, γG = 1,35 and γQ = 1,5.

Note 2: As a simplification a recommended value of ηfi = 0,7 may be used.



EUROCODESBackground and Applications Member Analysis (cont'd)

(4)Only the effects of thermal deformationsresulting from thermal gradients across the cross-section need be considered. The effects of axial or in-plane thermal expansions may be neglected.

(5) The boundary conditions at supports and ends of member, applicable at time t = 0, are assumed to remain unchangedthroughout the fire exposure.



EUROCODESBackground and Applications Global structural analysis

(1)P When global structural analysis for the fire situation is carried out, the relevant failure mode in fire exposure, the temperature-dependent material propertiesand member stiffnesses, effects of thermal expansions and deformations (indirect fire actions) shall be taken into account.


EUROCODESBackground and Applications Assessment methods

covering both thermal model and mechanical model

HD

∆ θ a , t = p p

p a a

g , t a , tλρ

θ θφ

A / V

d c

( - )( 1 + / 3 )

t∆ - ( e φ / 1 0 - 1 ) ∆ θ g , t

tabulated data

simple calculation models

advanced calculation models

standard fire

resistance

dimensi

on

Minimum dimensions [mm]

[min] axis distanc

e

Possible combinations of a (average axis distance) and bmin (width of

beam)

Web thickness

R 30 bmin 80 120 160 200 80 a 25 15 10 10

R 60 bmin 120 160 200 300 100 a 40 35 30 25

R 90 bmin 150 200 250 400 100 a 55 45 40 35

R 120 bmin 200 240 300 500 120 a 65 55 50 45

R 180 bmin 240 300 400 600 140 a 80 70 65 60

R 240 bmin 280 250 500 500 160 a 90 80 75 70


EUROCODESBackground and Applications Data on fire protection systems

Membrane protection

TS 13381-1 : horizontal membranesENV 13381 -2 : vertical membranes

Fire protection to :

ENV 13381 -3 : concrete membersENV 13381 -4 (& -8 ?) : steel membersENV 13381 -5 : concrete/profiled steel sheetENV 13381 -6 : concrete filled hollow steel columnsENV 13381 -7 : timber members


EUROCODESBackground and Applications Possible Design Procedures

Project Design

Performance-Based Code(Physically BasedThermal Actions)

Prescriptive Regulation(Thermal Actions given

by a Nominal Fire)

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Standard time-temperaturecurveHydrocarbon fire

External fire


EUROCODESBackground and Applications Possible Design Procedures (cont’d)

Prescriptive Regulation(Thermal Actions given

by a Nominal Fire)

Member analysisAnalysis of part of the structure

Analysis of the entire structure

Tabulated data Simple calculationmodels

Mechanicalactions at boundaries

Selection of mechanical actions


Advanced calculationmodels

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Standard time-temperaturecurveHydrocarbon fire

External fire


EUROCODESBackground and Applications Possible Design Procedures (cont’d)

Performance-Based Code

Simple calculationmodels

Advanced calculationmodels

Member analysisAnalysis of part of the structure

Analysis of the entire structure


Selection of mechanical actions


Fire development Model 0

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EUROCODESBackground and Applications ISO Concept vs FSE* Approach

ultimate and "deformation" limit states

mainly ultimate load bearing capacity

mechanical model

thermal gradient in 2 , 3 directions

uniform temperature over the whole surface

heat transfertmodel

part of structure with interaction between elements

isolated elements

structural model

all design fires 300°C @120min 1300°C @ 20min …And cooling phase

ISO-fire1100°C @ 120min

fire model

FSE* ApproachISO – concept(current approach)

Model

* : Fire Safety Engineering



EUROCODE 1 - 1.2 ACTION IN CASE OF FIRE

T. Lennon BRE

1



Eurocode 1: Actions on structures – Part 1-2: General actions – Actions on structures

exposed to fire

Tom LennonPrincipal Consultant, BRE, UK


EUROCODESBackground and Applications Scope of presentation

Introduction to structural fire engineering design

Section 3 Thermal actions for temperature analysis3.2 Nominal temperature-time curves3.3 Natural fire models

Section 4 Mechanical actions for structural analysis4.2 Simultaneity of actions4.3 Combination rules for actions

Annex A Parametric time-temperature curvesAnnex B Thermal actions for external membersAnnex C Localised firesAnnex D Advanced fire modelsAnnex E Fire load densitiesAnnex F Equivalent time of fire exposureAnnex G Configuration factor

Worked example – Equivalent time of fire exposure


EUROCODESBackground and Applications Introduction to structural fire engineering design

Why structural fire engineering?

What is structural fire engineering design?

How do we do it?


EUROCODESBackground and Applications Structural fire engineering design – Do we need it?

Existing body of data

Tried and tested solutions

Accepted levels of safety and reliability

Tabulated data generally conservative



Structural fire engineering design – Do we need it? –YES!

Levels of safety unknownDegree of conservatism unknownNo account of interaction between structural

elementsNo account of alternative load carrying

mechanismsNo account of alternative modes of failure


EUROCODESBackground and Applications Structural fire engineering design – Do we need it? – YES!

Complex structures not covered by existing regulatory requirement – “fire engineering may be the only suitable approach”

Provides for a more rational approach to the design of buildings for fire if undertaken as part of an overall fire safety strategy

Change of use or renovation of existing structure – possible increased fire resistance requirement, removal of existing means of ensuring fire resistance

Uncertainties in existing prescriptive approach

2



Structural fire engineering design – what is it?

Time

FLASHOVER Natural fire curve

Tem

pera

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Ignition - Smouldering Heating Cooling

Standard fire curve

Life safety Structural damage – risk of collapse – structural fire engineering only concerned with this phase of the fire



Performance-Based Code (Physically based Thermal Actions)

Selection of Simple or Advanced Fire Development Models

Prescriptive Rules (Thermal Actions by Nominal Fire

Calculation of Mechanical Actions at Boundaries

Member Analysis

Project Design

Analysis of Part of the Structure

Analysis of Entire

Structure


Selection of Mechanical

Actions

Advanced Calculation

Models

Simple Calculation

Models If available


Member Analysis

Analysis of Part of the Structure

Analysis of Entire

Structure


Selection of Mechanical

Actions

Advanced Calculation

Models

Simple Calculation

Models If available

Tabulated Data

General - Design Procedures


EUROCODESBackground and Applications Structural fire design procedure

Structural fire design procedure takes into account:

Selection of relevant design fire scenariosDetermination of corresponding design firesCalculation of temperature within the

structural membersCalculation of mechanical behaviour of the

structure exposed to fireEN1991-1-2 is principally concerned with the

first two above. Fire parts of the material codes cover the remaining two.


EUROCODESBackground and Applications Consider relevant design fire scenario

Building fire / tunnel fire / petrochemical fireLocalised fire / fully developed fireIdentification of suitable compartment

size/occupancy/ventilation condition for subsequent analysis – representative of “reasonable worst case scenario”

The choice of the design fire scenario will dictate the choice of the design fire to be used in subsequent analysis.

The choice of a particular fire design scenario should be based on a risk assessment taking into account the likely ignition sources and any fire detection/suppression systems available.


EUROCODESBackground and Applications Choose appropriate design fire

For fully developed post-flashover building (compartment) fires the usual choice is between nominal and natural fire exposures

Nominal fires are representative fires for the purposes of classification and comparison but bear no relationship to the specific characteristics (fire load, thermal properties of compartment linings, ventilation condition) of the building considered

Natural fires are calculation techniques based on a consideration of the physical parameters specific to a particular building.


EUROCODESBackground and Applications Modelling compartment fires

In compartment fires it is often assumed that the whole compartment is fully involved in the fire at the same time and the same temperature applies throughout. Such a scenario is the basis of a one zone model.

Two zone models exist in which the height of the compartment is separated into two gaseous layers each with their own thermal environment

Three zone models exist in which there is a mixed gas layer separating the upper and lower gas levels

Computational Fluid Dynamics (CFD) may be used to analyse fires in which there are no definite boundaries to the gaseous state. This type of analysis would be suitable for very large compartments such as airport terminals, atria and sports stadia. It is often used to model smoke movement.

3


EUROCODESBackground and Applications Post-Flashover Fire Models

In a compartment flashover occurs when sustained flaming from combustibles reach the ceiling and the temperature of the hot gas layer is between 550°C and 600°C.

After flashover the rate of heat release will increase rapidly until it reaches a maximum value for the enclosure. To simplify design, the growth period between the onset of flashover and the maximum heat release rate is usually ignored and it may be assumed that when flashover occurs the rate of heat release instantaneously increases to the maximum value set by the available air.


EUROCODESBackground and Applications Section 3 Thermal actions for temperature analysis

Thermal actions are given by the net heat flux:

rnetcnetnet hhh ,,&&& +=

Convective heat flux

Radiative heat flux


EUROCODESBackground and Applications 2.2 Nominal temperature-time curves

Standard temperature-time curve

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945ºC

θg = 20+log10345(8t+1)


EUROCODESBackground and Applications Nominal fire curves

Other nominal curves include:Smouldering fire curve

“Semi-Natural” fire curve

External fire exposure curve*

Hydrocarbon curve*

Modified hydrocarbon curve

Tunnel lining curves – RWS/RABT

* Included in the Eurocode


EUROCODESBackground and Applications External fire temperature-time curve

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Θg = 660(1 – 0.687e-0.32t – 0.313e-3.8t) + 20

Temperature constant after 22 mins at 660ºC



Hydrocarbon temperature-time curve

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EUROCODESBackground and Applications 2.3 Natural fire models

Natural fire models are based on specific physical parameters with a limited field of application

For compartment fires a uniform temperature distribution as a function of time is generally assumed

For localised fires a non-uniform temperature distribution as a function of time is assumed


EUROCODESBackground and Applications Natural fire models

Simplified fire models – compartment fires

Any appropriate fire model may be used considering at least the fire load density and the ventilation conditions

The parametric approach in Annex A of the code is one example of a simplified natural fire model



Simplified fire models – external members

For external members the radiative heat flux should be calculated from the sum of the radiation from the compartment and from the flames emerging from the opening

An example of a simplified calculation method for external members is given in Annex B of the Code



Simplified fire models – localised fires

In many cases flashover is unlikely to occur. In such cases a localised fire should be considered.

Annex C presents an example of a procedure for calculating temperatures in the event of a localised fire


EUROCODESBackground and Applications Section 4 Mechanical actions for structural analysis

If they are likely to occur during a fire the same actions assumed for normal design should be considered.

Indirect actions can occur due to constrained expansion and deformation caused by temperature changes within the structure caused by the fire.



INDIRECT thermal actions should be considered. EXCEPT where the resulting actions are:

recognized a priori to be negligible or favourable.

accounted for by conservatively chosen models and boundary conditions or implicitly considered by conservatively specified fire safety requirements.

5



The indirect actions should be determined using the thermal and mechanical properties given in the fire parts of EN1992 to EN1996 and EN1999.

For member design subjected to the standard fire only indirect actions arising from the thermal distribution through the cross-section needs to be considered.



Actions considered for ‘normal’ design should also be considered for fire design if they are likely to act at the time of a possible fire.

Variable actions should be defined for the accidental design situation, with associated partial load factors, as given in EN1990.



Simultaneous action with other independent accidental actions does not need to be considered

Additional actions (i.e partial collapse) may need to be considered during the fire exposure

Fire walls may be required to resist horizontal impact loading according to EN1363-2



When indirect actions do not need to be considered, and there is no prestressing force, the total design action (load) considering permanent and the leading variable action is given by;

( )∑≥

+1

11211j

,k,,j,k Qor""G ψψ

The use of ψ1,1 or ψ2,1 is defined in the National Annex



The values of ψ1,1 and ψ2,1 are given in Annex A of EN1990:2002


EUROCODESBackground and Applications Mechanical actions for structural analysis

As a simplification, the effect of actions in the fire conditioncan be determined from those used in normal temperature design

dfid,fit,d,fi EEE η==

d

t,d,fifi R

E=ηWhere

6


EUROCODESBackground and Applications Annex A Parametric Temperature-Time Curves

EN 1991-1-2 Annex A- Parametric Equation

θg = 1325(1-0.324e-0.2t*-0.204e-1.7t*-0.472e-19t*)where t* = t.Γ

and Γ = (O/b)²/(0.04/1160)²O is the opening factor

and b relates to the thermal inertia √(ρcλ)Where ρ = density (kg/m³)c = specific heat (J/kgK)

Λ = thermal conductivity (W/mK)


EUROCODESBackground and Applications Parametric equation (contd)

O = opening factor Av√h/At (m½)

Av = area of vertical openings (m²)

h = height of vertical openings (m)

At = total area of enclosure – walls, ceiling and floor including openings (m²)


EUROCODESBackground and Applications Parametric Equation

Scope of Equation

- 0.02 ≤ O ≤ 0.2 (m½) (lower limit of 0.01 in UK NA)- 100 ≤ b ≤ 2000 (J/m² s½ °K)- Af ≤ 500m² (No restriction in UK NA)

- mainly cellulosic fire loads- maximum compartment height = 4m (No restriction in UK NA)- concept of limiting duration (20 minutes for offices)


EUROCODESBackground and Applications EC1 Parametric exposure

Cooling phaseΘg = θmax – 625(t*-t*max.x) for t*max ≤ 0.5Θg = θmax – 250(3-t*max)(t*-t*max.x) for t*max < 2Θg = θmax – 250(t*-t*max.x) for t*max ≥ 2

Where t*max = (0.2x10-3. qt,d/O).ΓAnd tmax = maximum of (0.2x10-3. qt,d/O) and tlimWith tlim = 25 minutes for slow fire growth rate,

20 minutes for medium fire growth rate and 15 minutes for fast fire growth rate



comparison between EC1 parametric calculation and measured values

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Time temperature curves

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Average temperature TEST 2Parametric time temperatureISO curve

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Annex B Thermal actions for external members – Simplified calculation method

Allows for the determination of:

Maximum temperatures of a compartment fire

The size and temperatures of the flames emerging from the openings

Radiation and convection parameters

Takes into account effect of wind through inclusion of forced draught and no forced draught calculations


EUROCODESBackground and Applications Annex C Localised fires

Where a fully developed fire is not possible the thermal input from a localised fire source to the structural member should be considered.

Annex C provides one possible method – The UK NA specifies an alternative methodology based on existing National information


EUROCODESBackground and Applications Annex D Advanced Fire Models

Annex D sets out general principles associated with advanced fire models (One zone, two zone or CFD)

There is no detailed guidance and such methods should only be used by experts


EUROCODESBackground and Applications Annex E Fire load densities

Annex E presents a method for calculating design fire load densities based on characteristic values from survey data for different occupancies

The characteristic values are modified according to the risk of fire initiation and the consequence of failure related to occupancy and compartment floor area

Active fire safety measures are taken into account through a reduction in the design fire load density

This approach is not accepted in the UK NA


EUROCODESBackground and Applications Annex F Equivalent time of fire exposure

Provides a quick and easy method of relating a real fire exposure to an equivalent period in a standard fire resistance furnace

Mainly based on work on protected steel specimens

Recent analysis extended the use of the concept to unprotected steel for low fire resistance periods



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Atmosphere(fire)

Atmosphere(furnace)

Steel(fire)

Steel(Furnace)

8


EUROCODESBackground and Applications Time equivalent – calculation methods

CIB W14: te = qf c wLaw: te = kL/√(AvAt)Pettersson: te = 0.067qf(Av√h/At)-½

EC1: te,d = qf,d kb wf

Where qf,d = design fire load densitykb = factor to take into account the

thermal properties of the enclosurewf = ventilation factor to take into

account vertical and horizontal openings



Time equivalent – what is it? How does it work? How do you do it?

Worked example – fire compartment within an office buildingGeometric data

0Area of horizontal opening (roof light) Ah

3.6Height of compartment H (m)

2Height of ventilation opening h (m)

7.2 (3.6m wide by 2m high)

Ventilation area Av (m²)

36 (6m x 6m)Floor area (m²)



Time equivalent – thermal properties

76.8520PlasterboardWalls

36520PlasterboardFloor

362280ConcreteRoof

Area (m²)Thermal inertia (b value –J/m²s½K)

MaterialElement


EUROCODESBackground and Applications Time equivalent worked example

te,d = (qf,d.kb.wf)kc

Where qf,d = design fire load density (MJ/m²)

kb is a factor dependent on thermal properties of the lining materialsAnd wf is a ventilation factor given by:

wf = (6/H)0.3 [0.62 + 90(0.4-αv)4] in the absence of vertical openingsWhere H is the height of the compartment (m) and αv = Av/Af

kc = factor dependent on material = 1.0 for protected steel



Time equivalent worked example

0.07 (0.09)b<720

0.055 (0.07)720≤b≤2500

0.04 (0.055)b > 2500

kb (min.m²/MJ)b = (ρcλ)½

(J/m²s½K)




347 (360)School classroom

511 (570)Office

377 (400)Hotel

280 (350)Hospital

948 (400)Dwelling

Characteristic fire load density (MJ/m²) 80% fractile

Occupancy

9




qf,d = 570 MJ/m²

wf = 0.863 (αv = 0.2)

kb = 0.07 (b = 945 (Σ(bjAj/Aj))

kc = 1.0 (protected steel beam)

te,d = 570 x 0.863 x 0.07 = 34 minutes therefore 60 minutes fire protection would be appropriate


EUROCODESBackground and Applications Time equivalent – important questions to ask

Have sensitivity studies been carried out on % glazing removed during the fire. Breaking of glass during a fire is very difficult to predict. In reality the ventilation area will vary with time during the fire process.

What value has been used for the fire load density

What confidence is there in the final configuration of the compartment linings? In the absence of definite data then a figure of kb = 0.09 should be used (UK National Annex)


EUROCODESBackground and Applications Annex G Configuration Factor

Text book information on general principles for radiative heat transfer

Specific guidance for external members



Thank you for your attention!

EUROCODE 2 - 1.2 CONCRETE STRUCTURES

T. Hietanen RT Betonikeskus

1



EN 1992-1-2Fire design of concrete structures

Tauno HietanenFinnish Concrete Industry Association

convenor of Project Teams- ENV 1992-1-2- EN 1992-1-2




• Sections 1 and 2 General, Basis of design • Section 3 Material properties• Section 4 Design procedures

– Simplified calculation method 4.2, Annex A, B and E– Shear, torsion and anchorage 4.4 and Annex D– Spalling 4.5

• Section 5 Tabulated data– Annex C

• Section 6 High strength concrete


EUROCODESBackground and Applications Project Team

Dr. Yngve Anderberg Fire Safety Design AB Sweden- fire design consultant

Dr.Ing. Nils Erik Forsén Multiconsult AS Norway - structural design consultant

Mr. Tauno Hietanen Concrete Industry Association Finland- concrete industry and standardization Convenor

Mr. José Maria Izquierdo INTEMAC Spain- research institute, especially fire damages

Mr. Alain Le Duff CSTB France- fire research institute

Dr.-Ing. Ekkehard Richter TU Braunschweig Germany - fire research institute

Mr. Robin T. Whittle Ove Arup & Partners United Kingdom- structural design consultant, Technical secretary

and National Technical Contacts


EUROCODESBackground and Applications Technical background

• CEB Bulletins ”Fire design of concrete structure”, latest No 208 July 1991

• EC 2:Part 10, 1990, prepared for the Commission by experts J.C, Dotreppe (B), L. Krampf (D), J. Mathez(F)– including material properties harmonized between

EC 2, 3 and 4• ENV 1992-1-2 November 1995

– and national comments on ENV• Project Team started the revision 1999 and prEN

was approved for Formal Vote 2002


EUROCODESBackground and Applications Scope of EN 1992-1-2

(5)P This Part 1-2 of EN 1992 applies to structures, or parts of structures, that are within the scope of EN 1992-1-1 and are designed accordingly. However, it does not cover:- structures with prestressing by external tendons- shell structures

(6)P The methods given in this Part 1-2 of EN 1992 are applicable to normal weight concrete up to strength class C90/105 and for lightweight concrete up to strength class LC55/60.Additional and alternative rules for strength classes above C50/60 are given in section 6.


EUROCODESBackground and ApplicationsSummary of alternative verification methods given in EN 1992-1-2

NONOGlobal structural analysis

•Only the principles are given

•Temperature profiles given for Standard fire only

NOAnalysis of part of the structure

YES

YES•Standard fire and parametric fire

YES•Data given for Standard fire only

Member analysis

Advanced calculation methods

Simplified calculation methods

Tabulated data

2


EUROCODESBackground and Applications Resistance to Fire CE-marking

National fire regulations:

- Required class - or fire resistance time

Parametric fire: - Fire resistance

time

Nominal fire:

- European REI (M) classification

Fire parts of Eurocodes:- Tabulated data- Simplified calculation- Advanced calculation

EN 13501-2 Classification standard

EN 1363, EN 1365

Fire tests

CE marking

REI (M)




• Sections 1 and 2 General, Basis of design• Section 3 Material properties• Section 4 Design procedures





EUROCODESBackground and Applications Section 3 Material properties

• Strength and deformation properties in Section 3 are given for simplified and advanced calculation methods

• Strength reduction curves for Tabulated data (in Section 5) and Simplified calculation methods (in Section 4) are derived from material properties in section 3

• Thermal properties are given in Section 3 for calculation of temperature distribution inside the structure

• Material properties for lightweight concrete are not given due to wide range of lightweight aggregates

– this does not exclude use of lightweight aggregate concrete, see e.g. Scope and Tabulated data

• Strength and deformation properties are applicable to heating rates similar to standard fire curve (between 2 and 50 K/min)

• Residual strength properties are not given


EUROCODESBackground and Applications Concrete compressive strength

0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0,8

0,9

1

0 0,005 0,01 0,015 0,02 0,025

strain εc [-]

ratio

of s

treng

thfc,

Θ/fc

k [-]

100 °C

300 °C

500 °C

700 °C

20 °C


EUROCODESBackground and Applications Concrete: Stress-strain relationship

Mathematical model and parameters fc,θ, εc1,θ and εcu1,θαCC = 1,0 in fire design

σ

εc1,θ εcu1,θε

fc,θfc,θ

εc1,θ εcu1,θ

3

θ,1cθ,1c

θ,c

2

3

ε+ε

f

ε

ε


EUROCODESBackground and Applications Strength reduction of concrete

• The same strength reduction values are given for simplified calculation methods in Section 41. Siliceous concrete2. Calcareous concrete

0 ,8

1

0

1 0 ,6

0 ,2

0 ,4

1 0002 00 800400 120 00 600

k c(θ )

θ [°C ]

2

3



Reinforcing and prestressing steel:Stress-strain relationship

• Mathematical model and parameters fsp,θ, fsy,θ and Es,θ

σ

ε sp,Θ ε sy,Θ ε st,Θ ε su,Θ ε

fsy,Θ

fsp,Θ

Es,θ


EUROCODESBackground and Applications Reinforcing steel strength

0

0,2

0,4

0,6

0,8

1

0 0,002 0,004 0,006 0,008 0,01 0,012 0,014 0,016 0,018 0,02

strain εs [-]

ratio

of s

treng

th

fs, /

fyk [-

]

500°C

600°C

700°C

800°C

20°C - 400°C

hot rolled reinforcing steel fyk = 500 N/mm2

1000°C

strength at 0.2% proof strain


EUROCODESBackground and Applications Strength reduction of reinforcing steel

Strength reduction for simplified calculation methods in Section 4• Class N (normal)

Curve 1 : Tension reinforcement (hot rolled) for strains εs,fi ≥ 2% Curve 2 : Tension reinforcement (cold worked) for strains εs,fi ≥ 2% Curve 3 : Compression reinforcement and tension reinfor-cement for strains εs,fi < 2%

0,8

1

0

1

2

3

0,6

0,2

0,4

1000200 800400 12000 600

ks(θ )

θ [°C]


EUROCODESBackground and Applications Strength reduction of steel

Strength reduction for simplified calculation methods in Section 4• Class X: recommended only when there is experimental evidence


EUROCODESBackground and Applications Reinforcing steel Class X

Class X was proposed by Finland because initial testing of steel strength at elevated temperatures is required in Finnish standard

FINNISH NA:• Class X may be used with following additional conditions: • Strength properties at elevated temperatures are determined by applying

standard SFS-EN 10002-5.• Strength properties of reinforcing steel at elevated temperatures are subject to

initial type testing at temperatures 300 °C, 400 °C, 450 °C, 500 °C and 550 °C.• Requirements for 0,2 % proof strength Rp0,2 are given in table 3.2-FI, where

fyk is nominal yield strength or 0,2 % proof stress of the reinforcing steel at room temperature.

• Table 3.2-FI: 1 Strength requirements of reinforcing steel at elevated temperatures


EUROCODESBackground and Applications Reference curve for Tabulated data in Section 5

1. Reinforcing steel θcr = 500˚C 0,6 stress level

2. Prestressing bars θcr = 400˚C 0,55 stress level

3. Prestressing wires and strands

θcr = 350˚C 0,55 stress level

4


EUROCODESBackground and Applications Strength reduction of prestressing steel

Strength reduction is given by fpy,θ / (βfpk) and fpp,θ / (βfpk), where β is NDP

• Class A:

• Class B: β = 0,9


EUROCODESBackground and Applications Background for Class A

Common new proposal from the University of Liege and CERIB for the general and simplified models for the mechanical properties of prestressing steel (wires and strands) at elevated temperatures,

September 12th 2003


EUROCODESBackground and Applications Strength reduction of prestressing steel

Strength reduction for simplified calculation methods in Section 4


EUROCODESBackground and Applications Thermal properties

• Specific heat of concrete, u is moisture % by weight


EUROCODESBackground and Applications Thermal properties

• Thermal conductivity of concrete, NDP between upper and lower limit


EUROCODESBackground and Applications Background for thermal conductivity

• Project Team EN 1992-1-2 made a lot of calibrations to temperatures measured in fire tests of typical concrete structures, and the lower limit fits very well

• Design rules for steel-concrete composite structures (mainly including heavy steel sections) seem to be calibrated to the upper limit

• A compromise was made on TC 250 level: NDP between upper and lower limit

• EN 1992-1-2, 3.3.3:• Note 2: Annex A is compatible with the lower limit. The

remaining clauses of this part 1-2 are independent of the choice of thermal conductivity. For high strength concrete, see 6.3.

5









EUROCODESBackground and Applications Design methods

• advanced calculation methods for simulating the behaviour of structural members, parts of the structure or the entire structure, see 4.3– only principles are given, no detailed design rules

• simplified calculation methods for specific types of members, see 4.2– Annex B.1 “500°C isotherm method”

developed by Dr Yngve Anderberg, earlier published in Sweden and in CEB Bulletins

– Annex B.2 “Zone method”developed by Dr Kristian Hertz, earlier published in Denmark and in ENV 1992-1-2

• detailing according to recognised design solutions (tabulated dataor testing), see Section 5

• Shear, torsion and anchorage; spalling; joints


EUROCODESBackground and Applications Simplified calculation method

• 500°C isotherm method

• Zone method • • •

Concrete with temperature below 500°C retains full strength and the rest is disregarded

Cross section is divided in zones. Mean temperature and corresponding strength of each zone is used

This method is more accurate for small cross sections than 500°C isotherm method

500°C

kc(θ1)

kc(θ2)kc(θ3)

M kc(θM)


EUROCODESBackground and Applications 500°C isotherm method

• Determine the 500°C isotherm and the reduced width bfi and effective depth dfi

• Determine the temperature of reinforcing bars and the reduced strength

• Use conventional calculation methods


EUROCODESBackground and Applications Temperature profiles

x (mm)0 10 20 30 40 50 60 70 80 90 100

300

200

0

400

600

800

1000

1200 θ ( C)

1100

900

700

500

100

R30 R60 R90

R120

R180

R240

• Temperature distribution in the cross section can be calculated from the thermal properties

• Annex A of EN 1992-1-2 gives temperature profiles for slabs, beams and columns


EUROCODESBackground and Applications Simplified calculation method for beams and slabs

• Annex E• Simplified method to calculate bending capacity for predominantly

uniformly distributed loads• This is some kind of extension of Tabulated data

6


EUROCODESBackground and Applications Shear, torsion and anchorage

Annex D (informative)• Shear failures due to fire are very uncommon. However, the

calculation methods given in this Annex are not fully verified.• For elements in which the shear capacity is dependent on the

tensile strength, special consideration should be given where tensile stresses are caused by non-linear temperature distributions


EUROCODESBackground and Applications Calculation for shear

The reference temperature θ p should be evaluated at points P along the line ‘a -a’ for the calculation of the shear resistance. The effective tension area A may be obtained from EN 1992-1 (SLS of cracking).

a

a aa aa

P P P

A


EUROCODESBackground and Applications Spalling of normal strength concrete

CALCULATION METHODS TABULATED DATADefine exposure class ↓

↓ ↓ Explosive spalling is coveredX0 or XC1 (dry) other by minimum requirements

↓ ↓ No further check neededMoisture content ≤ 3

%Yes

≤ 3 %←

Is moisture contentknown

↓ No, or yes but > 3 %↓

OK Yes←

Avoid spalling bymore accurate as-

sessment

Moisture content, type of aggre-gates, permeability of concrete,

heating rateNo↓

OKYes←

Has the correct be-haviour been checked

by tests

No→

Assume loss of cover andcalculate R

Solid slabs OK,some beams OK


EUROCODESBackground and Applications Falling off of normal strength concrete

Shall be minimised or taken into account

c ≥ 70 mm No → OK↓Yes

Tests to showthat falling of

does not occur

Yes→

OK

No↓

Provide sur-face rein-forcement









EUROCODESBackground and Applications Scope of Tabulated data

(1) This section gives recognised design solutions for the standard fireexposure up to 240 minutes. The rules refer to member analysis.

Note: The tables have been developed on an empirical basis confirmed by experience and theoretical evaluation of tests. The data is derived from approximate conservative assumptions for the more common structural elements and is valid for the whole range of thermal conductivity in 3.3. More specific tabulated data can be found in the product standards for some particular types of concrete products or developed, on the basis of the calculation method in accordance with 4.2, 4.3 and 4.4.

(2) The values given in the tables apply to normal weight concrete (2000 to 2600 kg/m3, made with siliceous aggregates.If calcareous aggregates or lightweight aggregates are used in beams or slabsthe minimum dimension of the cross-section may be reduced by 10%.

(3) When using tabulated data no further checks are required concerning shear and torsion capacity and anchorage details.

(4) When using tabulated data no further checks are required concerning spalling, except for surface reinforcement.

7


EUROCODESBackground and Applications Tabulated data - General

Tabulated data are based on a reference load level ηfi = 0,7, unless otherwise stated in the relevant clauses.Note: Where the partial safety factors specified in the National Annexes of EN 1990 deviate from those indicated in 2.4.2, the above value ηfi = 0,7 may not be valid. In such circumstances the value of ηfi for use in a Country may be found in its National Annex.

For walls and columns load level ηfi or degree of utilisation µfiis included in the tables

Linear interpolation between the values in the tables may be carried out


EUROCODESBackground and Applications Load level and degree of utilisation

ACTIONS RESISTANCES

Ed

withγF

Ed,fi

withγF,fiandψfi

Rd

withγM

time Ed × ηfi = Ed,fi Rd Rd,fi ηfi = load level µfi = Ed,fi / Rd = degree of utilisation takes into account if the structure is not fully loaded


EUROCODESBackground and Applications Tabulated data – main principle

bmin

a

Check minimum dimensions of concrete cross section and axis distance to steel

Axis distance is nominal value, no need to add tolerance

Axis distance is given for reinforcing steel (θcr = 500ºC), to be increased for prestressing steel (bars 10 mm, strands and wires 15 mm)

θcr = 500ºC is derived from load level 0,7 divided by partial factor for reinforcement γs = 1,15 → σs,fi/fyk = 0,60

For prestressing strands and wires θcr = 350ºC and σs,fi/fp0,1k = 0,55(Ed,fi = 0,7 Ed, fp0,1k/fpk = 0,9, γs = 1,15)


EUROCODESBackground and Applications Tabulated data in EN 1992-1-2

For beams and slabs degree of utilisation may be taken into account by following simple rule:

a) Calculate the actual steel stress

b) Evaluate the critical temperature using reference curve for steel strength

c´) Adjust the minimum axis distance by 1 mm for every 10˚C difference in temperature

f AEσE A

yk s,reqd,fis,fi

d s,provs

(20 C) = x x

γ°

σs,fi /fyk = 0,4

Tcr = 580˚C, ∆a = - 8 mm


EUROCODESBackground and Applications Tabulated data for columns

• Completely revised• Two optional methods are given

– Method A is derived from test results, but field of application is limited to buckling length ≤ 3 m and first order eccentricity ≤0,15h to 0,4h (depending on the National Annex)

– Method B is based on calculations, it is more conservative and many interpolations are needed. Limitations for normative table:eccentricity ≤ 0,25h and λfi ≤ 309 pages of tables in Annex C


EUROCODESBackground and Applications Parameters for columns

In Method A degree of utilisation:

µfi = NEd.fi /NRd

In Method B load level is defined as:

n = N0Ed,fi /(0,7(Ac fcd + As fyd))

Slenderness, lo,fi- upper floor 0,7 l- intermediate floor 0,5 l

l 0,7 l 0,5 l

Eccentricity

8


EUROCODESBackground and Applications Method A for columns

Minimum dimensions (mm) Column width bmin/axis distance a of the main bars

Column exposed on more than one side Exposed on one side

Standard fire

resistance

µ fi = 0.2 µ fi = 0.5 µ fi = 0.7 µ fi = 0.7 1 2 3 4 5

R 30

R 60

R 90

R 120

R 180

R 240

200/25

200/25

200/31 300/25

250/40 350/35

350/45**

350/61**

200/25

200/36 300/31

300/45 400/38

350/45** 450/40**

350/63**

450/75**

200/32 300/27

250/46 350/40

350/53

450/40**

350/57** 450/51**

450/70**

-

155/25

155/25

155/25

175/35

230/55

295/70 ** Minimum 8 bars For prestressed columns the increase of axis distance according to 5.2. (5) should be noted.


EUROCODESBackground and Applications Method B for columns

Standard

fire

Mechanical reinforcement

Minimum dimensions (mm). Column width bmin/axis distance a

resistance ratio ω n = 0,15 n = 0,3 n = 0,5 n = 0,7 1 2 3 4 5 6

R 30

R 60

R 90

R 120

R 180

R 240

0,100 0,500 1,000

0,100 0,500 1,000

0,100 0,500 1,000

0,100 0,500 1,000

0,100 0,500 1,000

0,100 0,500 1,000

150/25* 150/25* 150/25*

150/30:200/25*

150/25* 150/25*

200/40:250/25* 150/35:200/25*

200/25*

250/50:350/25* 200/45:300/25* 200/40:250/25*

400/50:500/25* 300/45:450/25* 300/35:400/25*

500/60:550/25* 450/45:500/25* 400/45:500/25*

150/25* 150/25* 150/25*

200/40:300/25* 150/35:200/25* 150/30:200/25*

300/40:400/25* 200/45:300/25* 200/40:300/25*

400/50:550/25* 300/45:550/25* 250/50:400/25*

500/60:550/25* 450/50:600/25* 450/50:550/25*

550/40:600/25* 550/55:600/25* 500/40:600/30

200/30:250/25*

150/25* 150/25

300/40:500/25* 250/35:350/25* 250/40:400/25

500/50:550/25* 300/45:550/25* 250/40:550/25*

550/25*

450/50:600/25 450/45:600/30

550/60:600/30 500/60:600/50 500/60:600/45

600/75 600/70 600/60

300/30:350/25* 200/30:250/25* 200/30:300/25

500/25*

350/40:550/25* 300/50:600/30

550/40:600/25* 550/50:600/40 500/50:600/45

550/60:600/45 500/60:600/50

600/60

(1) 600/75

(1)

(1) (1) (1)

* Normally the cover required by EN 1992-1-1 will control. (1) Requires width greater than 600 mm. Particular assessment for buckling is required.


EUROCODESBackground and Applications Simple calculation for method A

R = 120 ((Rηfi + Ra + Rl + Rb + Rn )/120)1,8

( )

+

+−=

ωαωµηcc

fifi /85,0)1(00,183R

Ra = 1,60 (a – 30)Rl = 9,60 (5 – lo,fi)Rb = 0.09 b’Rn = 0 for n = 4 (corner bars only)

= 12 for n > 4a = axis distance to the longitudinal steel bars (mm); 25 mm ≤ a ≤80 mml0,fi = effective length of the column under fire conditions; 2 m ≤ l0,fi ≤6 m;b’ = 2Ac/ (b+h) for rectangular cross-sections = φ col for circular cross-sections (mm) ;

200 mm ≤ b’ ≤ 450 mm; h ≤ 1,5 b.ω = mechanical reinforcement ratio at normal temperature condi-tions

cdc

yds

fAfA

=

αcc = coefficient for compressive strength (see EN 1992-1-1)


EUROCODESBackground and Applications 300 x 300 a = 35

0

30

60

90

120

150

180

0 1 2 3 4 5 6

Buckling length (m)

R (m

in)

eta,fi = 0,5 > 4 bars eta,fi = 0,5 "4 bars" eta,fi = 0,3 > 4 bars eta,fi = 0,3 4 bars


EUROCODESBackground and Applications Walls

• Tabulated data as in ENV• Fire walls have been added

– Classification M, to be used only if there are national requirements

– Data taken from DIN standard


EUROCODESBackground and Applications Beams, slabs, tensile members

• In principle the same as in ENV• Some numerical values have been checked, e.g.

– Rule for increase of axis distance in I-beam web (validity of expression 5.10)

– Three classes for I-beam web thickness (NDP)– Minimum width of continuous beams– Flat slab thicknesses have been checked (to more conservative

direction)

9









EUROCODESBackground and Applications Strength reduction of high strength concrete

• Large scatter in strength, composition of concrete has big influence


EUROCODESBackground and Applications HSC strength reduction is NDP

0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0,8

0,9

1

0 100 200 300 400 500 600 700 800

Temperature

Stre

ngth

redu

ctio

n

Class 1Class 2Class 3


EUROCODESBackground and Applications HSC Tabulated data

Increase of minimum cross section by factor

Class 1 Class 2

- Walls and slabs exposed on one side

1,1 1,3

- Other structural members 1,2 1,6 Increase of axis distance by factor 1,1 1,3 Note: Factors are recommended values, and may be modified in National Annex Factor for axis distance in Class 2 seems to be too high, and it should not depend on the strength reduction


EUROCODESBackground and Applications HSC simplified calculation

km Moment capacity reduction factors for beams and slabs Class 1 Class 2 Beams 0,98 0,95 Slabs exposed to fire in the compres-sion zone

0,98 0,95

Slabs exposed to fire in the tension side, hs ≥ 120 mm

0,98 0,95

Slabs exposed to fire in the tension side, hs = 50 mm

0,95 0,85


EUROCODESBackground and Applications Spalling of HSC

• Up to C80/95 and silica fume content less than 6 % rules for normal strength concrete apply

• In other cases at least one of the following methods:– A: A reinforcement mesh with a nominal cover of 15 mm. This

mesh should have wires with a diameter ≥ 2 mm with a pitch ≤50 x 50 mm. The nominal cover to the main reinforcement should be ≥ 40 mm.

– B: A type of concrete for which it has been demonstrated (by local experience or by testing) that no spalling of concrete occurs under fire exposure.

– C: Protective layers for which it is demonstrated that no spalling of concrete occurs under fire exposure

– D: Include in the concrete mix more than 2 kg/m3 of monofilament propylene fibres.

10


EUROCODESBackground and Applications Background documentation

• Project Team has written ”Main background document” describing main changes to ENV

• It refers to other numbered documents called BDA (Background Document Annex)

• These documents have been delivered to CEN/TC 250/SC 2.

End of presentation

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on

s

TN

O C

entr

e for

Fire R

esearc

h2

L. T

wilt

Febru

ary

2005

Fir

e D

esig

n S

teel

Str

uctu

res-

Intr

od

ucti

on

Co

nte

nts

�In

tro

ductio

n

�H

isto

rical re

vie

w�

Fire D

esig

n o

f S

teel S

tructu

res: m

ain

ro

ute

�D

esig

n p

roce

dure

s�

Litera

ture

Bru

sse

ls,

18

-20

Fe

bru

ary

20

08

–D

isse

min

atio

n o

f in

form

atio

n w

ork

sho

p3

EU

RO

CO

DE

SB

ac

kg

rou

nd

an

d A

pp

licati

on

s

TN

O C

entr

e for

Fire R

esearc

h3

L. T

wilt

Febru

ary

2005

Pro

ject

Team

EC

3-1

.2

Mem

bers

hip

�N

iels

An

ders

en

(DK

)

�M

ari

o F

onta

na

(CH

)�

Jean-M

arc

Fra

nssen

(B)

�D

avid

Moore

(UK

)

�C

hristo

ph

He

inem

eyer

(secre

tary

)(D

)

�Le

en

Tw

ilt(c

onven

or)

(NL)

Fir

e D

esig

n S

teel

Str

uctu

res -

Intr

od

ucti

on

Bru

sse

ls,

18

-20

Fe

bru

ary

20

08

–D

isse

min

atio

n o

f in

form

atio

n w

ork

sho

p4

EU

RO

CO

DE

SB

ac

kg

rou

nd

an

d A

pp

licati

on

s

TN

O C

entr

e for

Fire R

esearc

h4

L. T

wilt

Febru

ary

2005

His

tori

cal re

vie

w

�19

95

Rele

ase E

NV

vers

ion o

f E

C3-1

.2�

19

99

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rt o

f con

vers

ion E

NV

�E

N�

20

01

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bili

ty o

f prE

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20

03

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ent

of

EN

vers

ion b

y S

C3

Fir

e D

esig

n S

teel

Str

uctu

res -

His

tory

Euro

codes

: B

ack

gro

und &

Appli

cati

ons

Str

uct

ura

l F

ire

Des

ign:

EC

3-1

.2 S

teel

Str

uct

ure

s

Bru

ssel

s, F

ebru

ary

2008 2

L. T

wil

t

TN

O C

entr

e fo

r F

ire R

esea

rch

The N

ether

lands

Bru

sse

ls,

18

-20

Fe

bru

ary

20

08

–D

isse

min

atio

n o

f in

form

atio

n w

ork

sho

p5

EU

RO

CO

DE

SB

ac

kg

rou

nd

an

d A

pp

licati

on

s

TN

O C

entr

e for

Fire R

esearc

h5

L. T

wilt

Febru

ary

2005

Co

nvers

ion

fro

m E

NV

� ��E

N

�C

EN

MS

’s involv

ed

19

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om

ments

receiv

ed

�e

ditori

al

10

8�

tech

nic

al

10

6�

legal

3+

---

--to

tal:

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17

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e D

esig

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tru

ctu

res -

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tory

Em

phasis

on m

odific

ation E

NV�

EN

vers

ion

Bru

sse

ls,

18

-20

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bru

ary

20

08

–D

isse

min

atio

n o

f in

form

atio

n w

ork

sho

p6

EU

RO

CO

DE

SB

ac

kg

rou

nd

an

d A

pp

licati

on

s

TN

O C

entr

e for

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esearc

h6

L. T

wilt

Febru

ary

2005

0

20

40

60

80

10

0

12

0

nu

mb

er

1

main

issu

e

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ll c

om

ments

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de

finitio

ns

Ba

sic

princip

le &

rule

s

Mate

ria

l pro

petie

s

Str

uctu

ral fire

desig

n

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nexe

s

Co

mm

en

ts p

er

main

issu

e

Fir

e D

esig

n S

tru

ctu

res -

His

tory

Bru

sse

ls,

18

-20

Fe

bru

ary

20

08

–D

isse

min

atio

n o

f in

form

atio

n w

ork

sho

p7

EU

RO

CO

DE

SB

ac

kg

rou

nd

an

d A

pp

licati

on

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TN

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entr

e for

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esearc

h7

L. T

wilt

Febru

ary

2005

Glo

bal se

t u

p o

f E

C3-1

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enera

l�

sco

pe,

definitio

ns, sym

bols

etc

.�

Basic

princip

les a

nd r

ule

s�

perf

orm

ance

re

quir

em

ents

(e.g

.. d

efo

rmatio

n

cri

teri

a),

asse

ssm

ent

meth

ods e

tc.

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ate

ria

l pro

pert

ies

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erm

al &

mech

anic

al (s

teel a

nd p

rote

ctio

n)

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tructu

ral fire

desig

n�

sim

ple

& a

dva

nced

calc

ula

tio

n m

od

els

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nn

exes

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e D

esig

n S

teel

Str

uctu

res –

Main

ro

ute

Bru

sse

ls,

18

-20

Fe

bru

ary

20

08

–D

isse

min

atio

n o

f in

form

atio

n w

ork

sho

p8

EU

RO

CO

DE

SB

ac

kg

rou

nd

an

d A

pp

licati

on

s

TN

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entr

e for

Fire R

esearc

h8

L. T

wilt

Febru

ary

2005

Resis

tan

ce t

o f

ire -

Ch

ain

of

even

tsR

esis

tan

ce t

o f

ire -

Ch

ain

of

even

ts

4:

Therm

al

response

tim

e

R

5:

Mechanic

al

response

6: P

ossib

le

colla

pse

tim

e

Θ

2: T

herm

al action

3: M

echanic

al actions

Loads

Ste

el

colu

mns

1: Ig

nitio

n

Fir

e D

esig

n S

teel

Str

uctu

res –

Main

ro

ute

Euro

codes

: B

ack

gro

und &

Appli

cati

ons

Str

uct

ura

l F

ire

Des

ign:

EC

3-1

.2 S

teel

Str

uct

ure

s

Bru

ssel

s, F

ebru

ary

2008 3

L. T

wil

t

TN

O C

entr

e fo

r F

ire R

esea

rch

The N

ether

lands

Bru

sse

ls,

18

-20

Fe

bru

ary

20

08

–D

isse

min

atio

n o

f in

form

atio

n w

ork

sho

p9

EU

RO

CO

DE

SB

ac

kg

rou

nd

an

d A

pp

licati

on

s

TN

O C

entr

e for

Fire R

esearc

h9

L. T

wilt

Febru

ary

2005

Th

erm

al re

sp

on

se

Basic

s

Th

erm

al re

sp

on

se

Basic

s

DV

: (s

ho

wn f

or

1dir

ection o

nly

)

yy

xx

zz

qq

+ ∆

q

∆q

/ ∆

x +

∆(ρ

c pΘ

) /

∆t

= 0

bou

nd

ary

co

nd

itio

n:

inco

min

g/o

utg

oin

g

flux a

t surf

ace:

hnet,

tot

initia

l con

ditio

n:

roo

m t

em

pera

ture

0)

()

(=

∂∂∂

∂+

∂

∂

xxΘ

t

Θcp

λρ

q =

λλ∆Θ

/ ∆

x

heat

bala

nce

Fouri

er’s law

Fir

e D

esig

n S

teel

Str

uctu

res –

Main

ro

ute

Therm

al conduction (

= λ

)

Therm

al capacity (

= ρ

·cp)

Bru

sse

ls,

18

-20

Fe

bru

ary

20

08

–D

isse

min

atio

n o

f in

form

atio

n w

ork

sho

p1

0

EU

RO

CO

DE

SB

ac

kg

rou

nd

an

d A

pp

licati

on

s

TN

O C

entr

e for

Fire R

esearc

h10

L. T

wilt

Febru

ary

2005

Th

erm

al co

nd

ucti

vit

y

Ste

el vs. co

ncre

te

Th

erm

al co

nd

ucti

vit

y

Ste

el vs. co

ncre

te

tem

pera

ture

[°C

]

thermal Conductivityλ[W/mK]

010

20

30

40

50

60

0200

400

600

800

1000

1200

ste

el

concre

te

Fir

e D

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n S

teel

Str

uctu

res –

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ro

ute

Bru

sse

ls,

18

-20

Fe

bru

ary

20

08

–D

isse

min

atio

n o

f in

form

atio

n w

ork

sho

p1

1

EU

RO

CO

DE

SB

ac

kg

rou

nd

an

d A

pp

licati

on

s

TN

O C

entr

e for

Fire R

esearc

h11

L. T

wilt

Febru

ary

2005

Th

erm

al cap

acit

y

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el vs. co

ncre

te

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erm

al cap

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y

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el vs. co

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te

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n

0123456789

0200

400

600

800

1000

1200

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ture

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thermalcapacity [MJ/m3K]

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el

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te

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ture

Fir

e D

esig

n S

teel

Str

uctu

res –

Main

ro

ute

Bru

sse

ls,

18

-20

Fe

bru

ary

20

08

–D

isse

min

atio

n o

f in

form

atio

n w

ork

sho

p1

2

EU

RO

CO

DE

SB

ac

kg

rou

nd

an

d A

pp

licati

on

s

TN

O C

entr

e for

Fire R

esearc

h12

L. T

wilt

Febru

ary

2005

temperature [oC]tim

e [

min

]

060

120

800 0

400

Th

erm

al re

sp

on

se

Ste

el b

eam

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ncre

te s

lab

(2D

)

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erm

al re

sp

on

se

Ste

el b

eam

/co

ncre

te s

lab

(2D

)

Fir

e D

esig

n S

teel

Str

uctu

res –

Main

ro

ute

Euro

codes

: B

ack

gro

und &

Appli

cati

ons

Str

uct

ura

l F

ire

Des

ign:

EC

3-1

.2 S

teel

Str

uct

ure

s

Bru

ssel

s, F

ebru

ary

2008 4

L. T

wil

t

TN

O C

entr

e fo

r F

ire R

esea

rch

The N

ether

lands

Bru

sse

ls,

18

-20

Fe

bru

ary

20

08

–D

isse

min

atio

n o

f in

form

atio

n w

ork

sho

p1

3

EU

RO

CO

DE

SB

ac

kg

rou

nd

an

d A

pp

licati

on

s

TN

O C

entr

e for

Fire R

esearc

h13

L. T

wilt

Febru

ary

2005

Mech

an

ical re

sp

on

se

Basic

s

�T

heory

of

Ap

plie

d M

ech

anic

s�

Bern

ouill

i�

ε to

t=

εth

erm

+ ε

σ⇒

coeff

icie

nt

of

therm

al elo

ngation (

αth

erm

)⇒

constitu

tive r

ela

tio

nsh

ips s

teel, c

on

cre

te,

…

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ldm

odels

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rmation c

apacity

�…

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edu

ce

d s

tre

ngth

& s

tiff

ness a

t ele

vate

d

tem

pera

ture

Em

phasis

on u

ltim

ate

sta

te a

naly

sis

Fir

e D

esig

n S

teel

Str

uctu

res –

Main

ro

ute

Bru

sse

ls,

18

-20

Fe

bru

ary

20

08

–D

isse

min

atio

n o

f in

form

atio

n w

ork

sho

p1

4

EU

RO

CO

DE

SB

ac

kg

rou

nd

an

d A

pp

licati

on

s

TN

O C

entr

e for

Fire R

esearc

h14

L. T

wilt

Febru

ary

2005

Mech

an

ical

pro

pert

ies o

f ste

el at

ele

vate

d

tem

pera

ture

s(q

ualita

tive)

str

ain

[%

]

str

ess [N

/mm

2]

f y,θ

‘ ‘

str

ess s

train

re

lation

s

tem

pera

ture

[C

]

400

ff yy, ,

θθ=

k

= k

θθ·· ff

y,20

y,20

ky

θθ

str

ength

red

uction f

acto

r

f y,2

0

f y,2

0

f y,θ

+-

θ20

°C

Note

s:

-unlim

ite

d d

efo

rmatio

n c

ap

acity

-“

+ “

= “

-”

Fir

e D

esig

n S

teel

Str

uctu

res –

Main

ro

ute

Bru

sse

ls,

18

-20

Fe

bru

ary

20

08

–D

isse

min

atio

n o

f in

form

atio

n w

ork

sho

p1

5

EU

RO

CO

DE

SB

ac

kg

rou

nd

an

d A

pp

licati

on

s

TN

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entr

e for

Fire R

esearc

h15

L. T

wilt

Febru

ary

2005

Mech

an

ical re

sp

on

se

Pri

ncip

le

failu

re a

t t f

for:

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Ed

Θ

with:

RΘ

: re

sis

tance

at

t m

Ed

Θ:

actio

n e

ffect

at

t m

t f:

resis

tan

ce

to f

ire

note

: t f

dep

en

ds a

.o.

on

the “

ga

p”

betw

een

Rd20 a

nd E

dΘ

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tim

et f

t f

Ed

Θ

Rd2

0

“gap”

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e D

esig

n S

teel

Str

uctu

res –

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ro

ute

Bru

sse

ls,

18

-20

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bru

ary

20

08

–D

isse

min

atio

n o

f in

form

atio

n w

ork

sho

p1

6

EU

RO

CO

DE

SB

ac

kg

rou

nd

an

d A

pp

licati

on

s

TN

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entr

e for

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h16

L. T

wilt

Febru

ary

2005

0

0.2

0.4

0.6

0.81

1.2

02

00

40

06

00

80

01

00

01

20

0

tem

pe

ratu

ur

[0C

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=>

Reductiefactor [-] ==>

Vlo

eig

ren

s S

taa

l

E-m

od

ulu

s S

taa

l

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ks

terk

te B

eto

n

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od

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eto

n

Red

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on

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str

en

gth

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tiff

ness

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ele

vate

d t

em

pera

ture

s

Fir

e D

esig

n S

teel

Str

uctu

res –

Main

ro

ute

Euro

codes

: B

ack

gro

und &

Appli

cati

ons

Str

uct

ura

l F

ire

Des

ign:

EC

3-1

.2 S

teel

Str

uct

ure

s

Bru

ssel

s, F

ebru

ary

2008 5

L. T

wil

t

TN

O C

entr

e fo

r F

ire R

esea

rch

The N

ether

lands

Bru

sse

ls,

18

-20

Fe

bru

ary

20

08

–D

isse

min

atio

n o

f in

form

atio

n w

ork

sho

p1

7

EU

RO

CO

DE

SB

ac

kg

rou

nd

an

d A

pp

licati

on

s

TN

O C

entr

e for

Fire R

esearc

h17

L. T

wilt

Febru

ary

2005

050

100

150

200

250

300 0

20

40

60

80

100

120

140

tim

e (m

in)

deflection(mm)

test

calc

ula

tion

Calc

ula

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ste

st

Sim

ula

ted failu

re m

ode

Failu

rem

ode

in test

Cellu

lar

ste

el beam

Fir

e D

esig

n S

teel

Str

uctu

res –

Main

ro

ute

So

urc

e:E

fecti

sF

ran

ce (

CT

ICM

)

Fir

e D

esig

n S

teel S

tru

ctu

res

Po

ten

tial o

f E

C3-1

.2

Bru

sse

ls,

18

-20

Fe

bru

ary

20

08

–D

isse

min

atio

n o

f in

form

atio

n w

ork

sho

p1

8

EU

RO

CO

DE

SB

ac

kg

rou

nd

an

d A

pp

licati

on

s

TN

O C

entr

e for

Fire R

esearc

h18

L. T

wilt

Febru

ary

2005

Str

uctu

ral fi

re d

esig

n p

roced

ure

sT

yp

e o

f m

od

els

�S

imple

calc

ula

tio

n m

odels

�b

eam

s�

com

pre

ssio

n m

em

bers

�N

only

�N

& M

�te

nsio

n m

em

bers

�A

dvance

d c

alc

ula

tio

n m

od

els

�T

ests

for

ind

ivid

ual m

em

bers

only

!

Fir

e D

esig

n S

teel

Str

uctu

res –

Desig

n

Bru

sse

ls,

18

-20

Fe

bru

ary

20

08

–D

isse

min

atio

n o

f in

form

atio

n w

ork

sho

p1

9

EU

RO

CO

DE

SB

ac

kg

rou

nd

an

d A

pp

licati

on

s

TN

O C

entr

e for

Fire R

esearc

h19

L. T

wilt

Febru

ary

2005

Sim

ple

calc

ula

tio

n m

od

els

Co

ncep

ts

�“R

esis

tance”

conce

pt

�“C

ritical te

mpera

ture

”co

ncept

Fir

e D

esig

n S

teel

Str

uctu

res –

Desig

n

Bru

sse

ls,

18

-20

Fe

bru

ary

20

08

–D

isse

min

atio

n o

f in

form

atio

n w

ork

sho

p2

0

EU

RO

CO

DE

SB

ac

kg

rou

nd

an

d A

pp

licati

on

s

TN

O C

entr

e for

Fire R

esearc

h20

L. T

wilt

Febru

ary

2005

Sim

ple

calc

ula

tio

n m

od

els

“R

esis

tan

ce”

co

nce

pt

�“C

om

pre

ssio

n m

em

bers

”(N

, N

& M

):pro

ce

dure

diffe

rentfr

om

ro

om

tem

pera

ture

pro

ce

dure

s�

“Be

am

s”

and

“te

nsio

n m

em

bers

”:pro

ce

dure

sim

ilar

to r

oom

te

mpera

ture

pro

ce

dure

s

Fir

e D

esig

n S

teel

Str

uctu

res –

Desig

n

Euro

codes

: B

ack

gro

und &

Appli

cati

ons

Str

uct

ura

l F

ire

Des

ign:

EC

3-1

.2 S

teel

Str

uct

ure

s

Bru

ssel

s, F

ebru

ary

2008 6

L. T

wil

t

TN

O C

entr

e fo

r F

ire R

esea

rch

The N

ether

lands

Bru

sse

ls,

18

-20

Fe

bru

ary

20

08

–D

isse

min

atio

n o

f in

form

atio

n w

ork

sho

p2

1

EU

RO

CO

DE

SB

ac

kg

rou

nd

an

d A

pp

licati

on

s

TN

O C

entr

e for

Fire R

esearc

h21

L. T

wilt

Febru

ary

2005

“R

esis

tan

ce”

co

nce

pt

Illu

str

ati

on

fo

r th

e b

uc

kli

ng

re

sis

tan

ce N

b,fi,

Θ,R

d

�

with

�bucklin

g c

oeffic

ient

�im

perf

ection c

oeff.

�re

l. s

lendern

ess r

atio

Fir

e D

esig

n S

teel

Str

uctu

res –

Desig

n

…(1

)

…(a

)

yy

fiR

dfi

bf

kA

NΘ

=,

,,

χ

22

1

θθ

θλ

ϕϕ

χ−

+=

fi

5,0

,,

]/

[θ

θθ

λλ

Ey

kk

=

…(b

)

Note

: -

ϕΘ

depends on s

teel gra

de a

nd λ

Θ

-λ

Θdepends o

n tem

pera

ture

]2

1[

21

θλ

θλ

αθ

ϕ+

+=

…(c

)

Bru

sse

ls,

18

-20

Fe

bru

ary

20

08

–D

isse

min

atio

n o

f in

form

atio

n w

ork

sho

p2

2

EU

RO

CO

DE

SB

ac

kg

rou

nd

an

d A

pp

licati

on

s

TN

O C

entr

e for

Fire R

esearc

h22

L. T

wilt

Febru

ary

2005

Bu

cklin

g c

urv

es a

t ele

vate

d t

em

pera

ture

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0.0

0.5

1.0

1.5

2.0

2.5

3.0

Lam

da r

el(

Tcri

t)

Nu(T) / Npl(T)

New

S50

0

New

S35

5

New

S23

5

EN

V 1

993

Fir

e D

esig

n S

teel

Str

uctu

res –

Co

nvers

ion

Bru

sse

ls,

18

-20

Fe

bru

ary

20

08

–D

isse

min

atio

n o

f in

form

atio

n w

ork

sho

p2

3

EU

RO

CO

DE

SB

ac

kg

rou

nd

an

d A

pp

licati

on

s

TN

O C

entr

e for

Fire R

esearc

h23

L. T

wilt

Febru

ary

2005

Bu

cklin

g c

urv

es

Desig

n a

id

λ(2

0°C

) 4

00°C

500°C

600°C

700°C

800°C

0.0

1.0

00

1.0

00

1.0

00

1.0

00

1.0

00

0.1

0.9

27

0.9

31

0.9

24

0.9

17

0.9

34

0.2

0.8

60

0.8

69

0.8

53

0.8

36

0.8

75

0.3

0.7

94

0.8

10

0.7

84

0.7

57

0.8

20

0.4

0.7

28

0.7

50

0.7

15

0.6

79

0.7

64

0.5

0.6

63

0.6

90

0.6

46

0.6

03

0.7

08

0.6

0.5

98

0.6

29

0.5

79

0.5

31

0.6

51

0.7

0.5

35

0.5

69

0.5

15

0.4

66

0.5

93

0.8

0.4

76

0.5

11

0.4

56

0.4

08

0.5

35

0.9

0.4

22

0.4

56

0.4

03

0.3

57

0.4

81

1.0

0.3

74

0.4

06

0.3

56

0.3

14

0.4

30

1.1

0.3

32

0.3

62

0.3

16

0.2

77

0.3

84

1.2

0.2

96

0.3

23

0.2

80

0.2

45

0.3

43

1.3

0.2

64

0.2

89

0.2

50

0.2

18

0.3

07

1.4

0.2

37

0.2

59

0.2

24

0.1

95

0.2

75

1.5

0.2

13

0.2

33

0.2

01

0.1

75

0.2

48

1.6

0.1

92

0.2

11

0.1

82

0.1

58

0.2

24

1.7

0.1

75

0.1

91

0.1

65

0.1

43

0.2

04

1.8

0.1

59

0.1

74

0.1

50

0.1

30

0.1

85

1.9

0.1

45

0.1

59

0.1

37

0.1

19

0.1

69

2.0

0.1

33

0.1

46

0.1

26

0.1

09

0.1

55

Fir

e D

esig

n S

teel

Str

uctu

res –

Desig

n

χ(

Θ,c

rit

)fo

r S

235

Bru

sse

ls,

18

-20

Fe

bru

ary

20

08

–D

isse

min

atio

n o

f in

form

atio

n w

ork

sho

p2

4

EU

RO

CO

DE

SB

ac

kg

rou

nd

an

d A

pp

licati

on

s

TN

O C

entr

e for

Fire R

esearc

h24

L. T

wilt

Febru

ary

2005

“R

esis

tan

ce”

co

nce

pt

Illu

str

ati

on

fo

r m

om

en

t c

ap

acit

y M

fi,Θ

,Rd

�U

niform

tem

pera

ture

dis

trib

ution:

�N

on u

niform

tem

pera

ture

dis

trib

ution*)

:

with:

ky,Θ

=str

ength

reduction facto

r

A =

ste

el are

a

κ1,

κ2

= adapta

tion facto

rs for

non u

niform

tem

pera

ture

dis

trib

ution

Fir

e D

esig

n S

teel

Str

uctu

res –

Desig

n

Rd

yR

dfi

Mk

MΘ

Θ=

,,

,…

(1)

…(2

)2

1,

,,

/κ

κR

dy

Rd

fiM

kM

ΘΘ

=

*) O

nly

for

cla

ss 1

, 2 c

ross s

ections; an “

exact”

calc

ula

tion is a

lso a

llow

ed

Euro

codes

: B

ack

gro

und &

Appli

cati

ons

Str

uct

ura

l F

ire

Des

ign:

EC

3-1

.2 S

teel

Str

uct

ure

s

Bru

ssel

s, F

ebru

ary

2008 7

L. T

wil

t

TN

O C

entr

e fo

r F

ire R

esea

rch

The N

ether

lands

Bru

sse

ls,

18

-20

Fe

bru

ary

20

08

–D

isse

min

atio

n o

f in

form

atio

n w

ork

sho

p2

5

EU

RO

CO

DE

SB

ac

kg

rou

nd

an

d A

pp

licati

on

s

TN

O C

entr

e for

Fire R

esearc

h25

L. T

wilt

Febru

ary

2005

Fir

e D

esig

n S

teel

Str

uctu

res –

Desig

n

Efi,d

/Rfi,d

,Θ=

fy,Θ

/fy

= k

y,Θ

(= µ

Θ)

0

200

400

600

800

1000

1200

00,2

0,4

0,6

0,8

11,2

stre

ng

th-r

ed

ucti

on

fa

cto

r (=

uti

lisa

tio

n)

steel temperature

“C

riti

cal te

mp

era

ture

”co

nc

ep

tB

asic

s

�U

tilis

ation

facto

r µ

Θin

tem

pera

ture

dom

ain

:

�S

trength

reduction f

acto

r as function s

teel te

mpera

ture

with:

Θ=

ste

el te

mpera

ture

ky,

Θ=

str

ength

reduction facto

rµ

Θ=

utilis

ation

facto

r

Bru

sse

ls,

18

-20

Fe

bru

ary

20

08

–D

isse

min

atio

n o

f in

form

atio

n w

ork

sho

p2

6

EU

RO

CO

DE

SB

ac

kg

rou

nd

an

d A

pp

licati

on

s

TN

O C

entr

e for

Fire R

esearc

h26

L. T

wilt

Febru

ary

2005

ste

p 1

: dete

rmin

e m

echanic

al re

sponse µ

a⇒

Θcrit

ste

p 2

: dete

rmin

e therm

al re

sponse ⇒

Θa

ste

p 3

: dete

rmin

e fir

e r

esis

tance ⇒

fire

res.

Θ,

µ0

Sta

ndard

Fire c

urv

e

fire

res.

utilis

ation f

acto

r

Θa

Θcrit

tim

e

ste

p 1

ste

p 2

ste

p 3

Θa

ste

el te

mp.

“C

riti

cal te

mp

era

ture

”co

nc

ep

t

Desig

n p

roc

ed

ure

Fir

e D

esig

n S

teel

Str

uctu

res –

Desig

n

Bru

sse

ls,

18

-20

Fe

bru

ary

20

08

–D

isse

min

atio

n o

f in

form

atio

n w

ork

sho

p2

7

EU

RO

CO

DE

SB

ac

kg

rou

nd

an

d A

pp

licati

on

s

TN

O C

entr

e for

Fire R

esearc

h27

L. T

wilt

Febru

ary

2005

with

Am

is e

xposed s

urf

ace a

rea m

em

ber

[m2/m

]

V is volu

me m

em

ber

[m

3/m

]

Kshis

“shadow

”fa

cto

r

… …

0

)(

)(

=∂

∂∂∂

+∂

∂

x

xΘ

t

θc

λρ

boundary

& initia

l

conditio

ns

td

hc

/VA

&d

net

,

aam

ρd Θ

a=

Fir

e D

esig

n S

teel

Str

uctu

res –

Desig

n

Th

erm

al re

sp

on

se s

tee

l ele

men

t

Un

ifo

rm t

em

pera

ture

dis

trib

uti

on

“shadow

”fa

cto

r is

new

in E

N v

ers

ion

ks

h

Bru

sse

ls,

18

-20

Fe

bru

ary

20

08

–D

isse

min

atio

n o

f in

form

atio

n w

ork

sho

p2

8

EU

RO

CO

DE

SB

ac

kg

rou

nd

an

d A

pp

licati

on

s

TN

O C

entr

e for

Fire R

esearc

h28

L. T

wilt

Febru

ary

2005

Sh

ad

ow

eff

ect

Eff

ect

sh

ap

e s

teel p

rofi

le

�S

ha

do

w e

ffect ca

use

d b

y lo

cal shie

ldin

g o

fir

radia

tive

hea

t tr

ansfe

r, d

ue t

o s

ha

pe

of

ste

el

pro

file

, e

.g.:

shadow

effect

no s

hadow

effect

�H

ence:

�-p

rofile

s, shadow

eff

ect: y

es

�-p

rofile

s, shado

w e

ffect: n

o

Fir

e D

esig

n S

teel

Str

uctu

res –

Desig

n

Euro

codes

: B

ack

gro

und &

Appli

cati

ons

Str

uct

ura

l F

ire

Des

ign:

EC

3-1

.2 S

teel

Str

uct

ure

s

Bru

ssel

s, F

ebru

ary

2008 8

L. T

wil

t

TN

O C

entr

e fo

r F

ire R

esea

rch

The N

ether

lands

Bru

sse

ls,

18

-20

Fe

bru

ary

20

08

–D

isse

min

atio

n o

f in

form

atio

n w

ork

sho

p2

9

EU

RO

CO

DE

SB

ac

kg

rou

nd

an

d A

pp

licati

on

s

TN

O C

entr

e for

Fire R

esearc

h29

L. T

wilt

Febru

ary

2005

Sh

ad

ow

eff

ect

Bare

vs. in

su

late

d s

tee

l p

rofi

les

�W

ithout

therm

al ra

dia

tio

n,

no s

ha

do

w e

ffect,

h

ence:

�bare

pro

file

s, shadow

eff

ect: y

es

�in

sula

ted p

rofile

s, shadow

effect: n

o

Fir

e D

esig

n S

teel

Str

uctu

res –

Desig

n

Bru

sse

ls,

18

-20

Fe

bru

ary

20

08

–D

isse

min

atio

n o

f in

form

atio

n w

ork

sho

p3

0

EU

RO

CO

DE

SB

ac

kg

rou

nd

an

d A

pp

licati

on

s

TN

O C

entr

e for

Fire R

esearc

h30

L. T

wilt

Febru

ary

2005

Sh

ad

ow

eff

ect

Su

mm

ary

�U

npro

tecte

d p

rofile

s:

�-p

rofile

s:

�-p

rofile

s:

�In

sula

ted

pro

file

s:

�“a

ll”pro

file

s:

with: [A

m/V

] is section facto

r[A

m/V

]bo

xis

b

ox v

alu

e o

f section facto

r

kshadow

= 0

.9 [A

m/V

] box/[A

m/V

]

kshadow

= 1

kshadow

= 1

Fir

e D

esig

n S

teel

Str

uctu

res –

Desig

n

Bru

sse

ls,

18

-20

Fe

bru

ary

20

08

–D

isse

min

atio

n o

f in

form

atio

n w

ork

sho

p3

1

EU

RO

CO

DE

SB

ac

kg

rou

nd

an

d A

pp

licati

on

s

TN

O C

entr

e for

Fire R

esearc

h31

L. T

wilt

Febru

ary

2005

Sim

ple

calc

ula

tio

n m

od

els

Gen

era

l d

esig

n c

on

sid

era

tio

ns

�C

on

nectio

ns

�C

lassific

ation

cro

ss-s

ections

Fir

e D

esig

n S

teel

Str

uctu

res –

Desig

n

Bru

sse

ls,

18

-20

Fe

bru

ary

20

08

–D

isse

min

atio

n o

f in

form

atio

n w

ork

sho

p3

2

EU

RO

CO

DE

SB

ac

kg

rou

nd

an

d A

pp

licati

on

s

TN

O C

entr

e for

Fire R

esearc

h32

L. T

wilt

Febru

ary

2005

Fir

e d

esig

n c

on

nec

tio

ns

Deem

ed

to

sa

tisfy

co

nd

itio

ns

�F

ire

pro

tection

not sm

alle

r th

an m

em

ber

�U

tiliz

atio

n less th

an m

em

ber

Note

: fo

r calc

ula

tion m

eth

od r

efe

r to

Annex

D

Fir

e D

esig

n S

teel

Str

uctu

res –

Desig

n

Euro

codes

: B

ack

gro

und &

Appli

cati

ons

Str

uct

ura

l F

ire

Des

ign:

EC

3-1

.2 S

teel

Str

uct

ure

s

Bru

ssel

s, F

ebru

ary

2008 9

L. T

wil

t

TN

O C

entr

e fo

r F

ire R

esea

rch

The N

ether

lands

Bru

sse

ls,

18

-20

Fe

bru

ary

20

08

–D

isse

min

atio

n o

f in

form

atio

n w

ork

sho

p3

3

EU

RO

CO

DE

SB

ac

kg

rou

nd

an

d A

pp

licati

on

s

TN

O C

entr

e for

Fire R

esearc

h33

L. T

wilt

Febru

ary

2005

Cla

ssif

ica

tio

n o

f cro

ss

-sec

tio

ns

Old

ru

le (� ��

EN

V)

�B

ord

er

line

valu

es f

or

b/t

:(b

/t)b

ord

er,

Θ=

εΘ

(b/t

)bord

er,

20

with:

εΘ=

[(2

35/f

y)(k

E,θ/k

y,θ

)]0.5

*)

*) follo

ws d

irectly fro

m r

oom

tem

pera

ture

rule

stem

pera

ture

depende

nt

�C

onse

que

nces?

?

Fir

e D

esig

n S

teel

Str

uctu

res –

Desig

n

Bru

sse

ls,

18

-20

Fe

bru

ary

20

08

–D

isse

min

atio

n o

f in

form

atio

n w

ork

sho

p3

4

EU

RO

CO

DE

SB

ac

kg

rou

nd

an

d A

pp

licati

on

s

TN

O C

entr

e for

Fire R

esearc

h34

L. T

wilt

Febru

ary

2005

Cla

ssif

ica

tio

n o

f cro

ss

secti

on

sC

on

seq

uen

ces

“o

ld”

rule

�T

em

pera

ture

d

ep

en

de

ncy

�H

ence

�cla

ssific

ation “

unsta

ble

”�

analy

sis

com

plic

ate

d

0

0.2

0.4

0.6

0.81

1.2

0200

400

600

800

1000

1200

tem

pera

ture

[C

]

εΘ

εΘaccord

ing to o

ld r

ule

appro

xim

ation: new

rule

no

t

pra

ctica

l

Fir

e D

esig

n S

teel

Str

uctu

res –

Desig

n

Bru

sse

ls,

18

-20

Fe

bru

ary

20

08

–D

isse

min

atio

n o

f in

form

atio

n w

ork

sho

p3

5

EU

RO

CO

DE

SB

ac

kg

rou

nd

an

d A

pp

licati

on

s

TN

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s

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10

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Lit

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EUROCODE 5 - 1.2 TIMBER STRUCTURES

H. Hartl University Innsbruck

J. Fornather

Austrian Standards Institute



Structural fire design Eurocode 5-1.2

Timber structures

Hans Hartl

University Innsbruck / Austria

[email protected]

Your logo


EUROCODESBackground and Applications Structural fire design – timber - sections

7 Chapters :

1. General2. Basis of design3. Material properties4. Design procedure for mechanical properties5. Design procedure for wall and floor assemblies6. Connections7. Detailing

[email protected]


EUROCODESBackground and Applications Structural fire design – timber - annexes

6 Annexes :

A : (informative) Parametric fire exposureB : (informative) Advanced calculation modelsC : (informative) Load-bearing floor joists and wall

studs in assemblies whose cavities are completely filled with insulation

D : (informative) Charring of members in wall and floor assemblies with void cavities

E : (informative) Analysis of the separating function of wall and floor assemblies

F : (informative) Guidance for users of this Eurocoe Part

[email protected]


EUROCODESBackground and Applications Structural fire design – timber - verification

2.4 Verification methods2.4.1 GeneralEd,fi ≤ Rd,t,fi2.4.2 Member analysis

Ed,fi =ηfiEd ηfi = f(Gk, Qk, γ, ψ)

[email protected]


EUROCODESBackground and Applications Structural fire design – timber – R&D

Some research work has been carried out:

Such as in the fields of• Material properties and resistances • Some Design procedures for mechanical resistance• and others which will be subject to the following paper

Still more R&D has to be done

This will partially be covered by the following project:

[email protected]


EUROCODESBackground and Applications Structural fire design - FireInTimber

FireInTimber – Partners and countries:SP Trätek – Sweden VTT – FinnlandTUM, DGfH – Germany BPU, CSTB FranceTreSenteret – Norway BRE – UKHFA, UIBK, TUW – Austria ETH Zuerich – SwitzerlandResand – Estonia

European industry: CEI-Bois / [email protected]


EUROCODESBackground and Applications Structural fire design – timber - FireInTimber

Expected results:

• Analytical design concepts for load-bearing timber structures under fire conditions

• New models for load-bearing solid wood cross laminated panel and light weight structures during fire exposure

• Performance principles of connections at fire exposure

• Guidance on joints between wall and ceiling elements and on fire stops within structures

[email protected]



Expected results:

• Critically reviewed novel innovative products and summary of new knowledge for product development

• The first European wide guideline on the fire safe use of wood in buildings.

[email protected]



FireInTimber :

• a new project within the European WoodWisdom-Net framework

• with 14 participants from 9 countries• the project has started in November 2007 and will

be finalised by the end of 2009 • It is supported by industry through the European

initiative BWW and public funding organisations.

[email protected]


EUROCODESBackground and Applications Structural fire design – timber – EN 1995 – 1.2

Eurocode 5, part 1 . 2 :

In the following paper today’s status as well as up to date findings will be presented by JochenFornather.

Thank you very much for your attention!

[email protected]



Structural fire design Eurocode 5-1.2

Timber structures

Jochen Fornather

Austrian Standards Institute

[email protected]


EUROCODESBackground and Applications Scope of EN 1995-1-2

EN 1995-1-2• shows the design of timber structures for

the accidental situation of fire exposure• to be used in conjunction with EN 1995-1-1

and EN 1991-1-2.• only identifies differences from, or

supplements normal temperature design.• deals only with passive methods of fire

protection• applies to building structures with load-

bearing function and/or separating function


EUROCODESBackground and Applications Design procedure (1)


EUROCODESBackground and Applications Design procedure (2)

Annex A:Charring rates and charring depths


EUROCODESBackground and Applications Basis of design (1)

Basic requirements• mechanical resistance• fire compartmentation• deformation criteria

Requirements (R, E, I) concerning• nominal fire exposure• parametric fire exposure

same as EN 1991-1-2

Actionssee EN 1991-1-2

• emissivity coefficient of wood surfaces: e = 0,8



Design values of material properties and resistances



Design values of material properties and resistances



Verification methods


EUROCODESBackground and Applications Material properties

Mechanical properties• simplified methods for cross section and timber frame

members in wall and floor assemblies completely filled with insulation

• advanced calculation methods.Thermal properties

Charring (depth)• for all surfaces of wood and wood-based panels directly

exposed to fire, • for surfaces initially protected from exposure and

charring occurs during the relevant time of fire exposure.


EUROCODESBackground and Applications Material properties: Charring (1)

Surfaces unprotected throughout the time of fire exposure•one-dimensional charring

•notional charring

dchar,0





Charring for panels with other densities than ρ = 450 kg/m3 and smaller thickness hp = 20 mm

Example:OSB – panel: ρk = 700 kg/m³hp = 20 mm ßo,ρ,t = 0,72 mm/minhp = 12 mm ßo,ρ,t = 0,93 mm/min



Surfaces of beams and columns initially protected from fire exposure•the start of charring is delayed until time tch;•charring may commence prior to failure of the fire protection, but at a lower rate than the described charring rates until failure time tf of the fire protection;•after failure time tf of the fire protection, the charring rate is increased above the shown values until the time tadescribed below;•at the time ta when the charring depth equals either the charring depth of the same member without fire protection or 25 mm whichever is the lesser, the charring rate reverts to the described value.



Surfaces of beams and columns initially protected from fire exposure



Surfaces of beams and columns initially protected from fire exposure


EUROCODESBackground and Applications Design procedures for mechanical resistance

Simplified rules for determining cross-sectional properties - Reduced cross-section method

kmod,fi = 1,0

k0: unprotected surface

k0: intial protected surface



Simplified rules for determining cross-sectional properties - Reduced properties method

kmod,fi = f (ρ/Ar and strength, stiffness)

•apply only to rectangular cross-sectionsof softwood exposed to fire onthree or four sides and •round cross-sections exposed along their whole perimeter.

kmod,fi (t equal or greater 20 min):



Simplified rules for analysis of structural members and components

General– Compression perpendicular to the grain may be disregarded.– Shear may be disregarded in rectangular and circular cross-

sections.Beams, columns

– bracing fails should be consideredMechanically jointed members

– reduction in slip moduli in the fire situation shall be taken into account

Bracings



Advanced calculation methods• for determination of the mechanical resistance

and the separating function shall provide a realistic analysis of structures exposed to fire,

• based on fundamental physical behaviour to lead to a reliable approximation of the expected behaviour of the relevant structural component under fire conditions.


EUROCODESBackground and Applications Design procedures for wall and floor assemblies

Analysis of load-bearing function• shall be designed for fire exposure on both

sides at the same time.

Analysis of separating function• take into account the contributions of different

material components and their position in the assembly.


EUROCODESBackground and Applications Connections (1)

•applies to connections between members under standard fire exposure, for fire resistances not exceeding 60 min.

Connections with side members of woodSimplified rules - unprotected connections



Connections with side members of woodSimplified rules - unprotected connections•greater tdfi is possible (not more than 30 min) by increasing the following dimensions by afi:

–the thickness of side members,–the width of the side members,–the end and edge distance to fasteners.

•kflux = 1,5



Connections with side members of woodSimplified rules - protected connections



Connections with side members of woodAdditional rules for connections with internal steel plates



Connections with side members of woodReduced load methodUnprotected wood

Protected wood



Connections with external steel plates•unprotected•protected

Simplified rules for axially loaded screws•design resistance of the screws•conversion factor η


EUROCODESBackground and Applications Detailing

Walls and floors•Dimensions and spacings

•Detailing of panel connections

•Insulation

•Other elements



Thank you very much for your attention!

Contact:[email protected]

EUROCODE 9 - ALUMINIUM ALLOYS STRUCTURES

N. Forsén

Multiconsult

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CO

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3

00,

120,

200,

290,

520,

921,

001,

00H

342)

EN

AW

-505

2

00,

100,

190,

370,

660,

870,

931,

00H

141)

EN

AW

-500

5

00,

390,

580,

821,

001,

001,

001,

00O

EN

AW

-500

5

00,

130,

190,

310,

570,

981,

001,

00H

34E

N A

W-3

004

550

350

300

250

200

150

100

20

Alu

min

ium

allo

y te

mpe

ratu

re C

Tem

per

Allo

y

Rat

ios

k o,θ

for a

lum

iniu

m a

lloys

at e

leva

ted

tem

pera

ture

fo

r up

to 2

hou

rs th

erm

al e

xpos

ure

perio

d

Brus

sels

, 18-

20 F

ebru

ary

2008

–D

isse

min

atio

n of

info

rmat

ion

wor

ksho

p11

EUR

OC

OD

ESB

ackg

roun

d an

d A

pplic

atio

nsEC

9 –

1.2

: Alu

min

ium

str

uctu

res

-fire

00,

060,

110,

230,

500,

750,

901,

00Lo

wer

lim

it va

lues

550

350

300

250

200

150

100

20

Alu

min

ium

allo

y te

mpe

ratu

re C

Low

er li

mits

of th

e 0,

2% p

roof

str

engt

h ra

tios

k o,θ

for

alum

iniu

m a

lloys

at e

leva

ted

tem

pera

ture

for u

p to

2

hour

s th

erm

al e

xpos

ure

perio

d

Brus

sels

, 18-

20 F

ebru

ary

2008

–D

isse

min

atio

n of

info

rmat

ion

wor

ksho

p12

EUR

OC

OD

ESB

ackg

roun

d an

d A

pplic

atio

nsEC

9 –

1.2

: Alu

min

ium

str

uctu

res

-fire

055

0

28 0

0040

0

37 8

0035

0

47 6

0030

0

54 6

0025

0

60 2

0020

0

65 1

0015

0

67 9

0010

0

69 3

0050

70 0

0020

Mod

ulus

of

elas

ticity

, Eal

,θ(N

/mm

²)

Alu

min

ium

allo

y te

mpe

ratu

re,θ

(°C

)

Mod

ulus

of e

last

icity

of a

lum

iniu

m a

lloys

at e

leva

ted

tem

pera

ture

for a

two

hour

ther

mal

exp

osur

e pe

riod,

E al

,θ

EURO

CO

DES

Bac

kgro

und

and

appl

icat

ion

Wor

ksho

p Br

usse

ls 1

8-20

Feb

ruar

y 20

08

Nils

E F

ORS

ÉN M

ultic

onsu

lt AS

, Nor

way

4

Brus

sels

, 18-

20 F

ebru

ary

2008

–D

isse

min

atio

n of

info

rmat

ion

wor

ksho

p13

EUR

OC

OD

ESB

ackg

roun

d an

d A

pplic

atio

nsEC

9 –

1.2

: Alu

min

ium

str

uctu

res

-fire

0

0,1

0,3

0,4

0,5

0,6

0,7 0

0,2

0,8

1,0

0,9

500

400

300

200

100

6061

-T6

6063

-T5

E

6063

-T6

6082

-T6

6082

-T4

θ al /

°C

k o,θ

E al,θ

E al

3004

-H34

Brus

sels

, 18-

20 F

ebru

ary

2008

–D

isse

min

atio

n of

info

rmat

ion

wor

ksho

p14

EUR

OC

OD

ESB

ackg

roun

d an

d A

pplic

atio

nsEC

9 –

1.2

: Alu

min

ium

str

uctu

res

-fire

•Th

e N

27 d

ocum

ent i

s av

aila

ble

at th

is w

ork

shop

•R

efer

s in

tern

atio

nal t

est d

ata

•Su

mm

ariz

es th

e m

ain

back

grou

nd fo

r the

str

engt

h da

ta g

iven

in E

C9

Part

1.2

Brus

sels

, 18-

20 F

ebru

ary

2008

–D

isse

min

atio

n of

info

rmat

ion

wor

ksho

p15

EUR

OC

OD

ESB

ackg

roun

d an

d A

pplic

atio

nsEC

9 –

1.2

: Alu

min

ium

str

uctu

res

-fire

OB

SER

VE T

HA

T

•St

reng

th d

ata

are

base

d on

the

0,2

proo

f str

ess

-onl

y •

Mod

ulus

of e

last

icity

is g

iven

the

sam

e te

mpe

ratu

re d

epen

dent

redu

ctio

n fa

ctor

for a

ll al

loys

•N

o st

ress

-str

ain

rela

tions

hips

are

giv

en fo

r the

pl

astic

rang

e•

The

mod

ulus

of e

last

icity

in th

e cr

itica

l te

mpe

ratu

re ra

nge

is re

lativ

ely

less

redu

ced

com

pare

d to

the

stre

ngth

redu

ctio

n•

Hig

h te

mpe

ratu

re c

reep

is n

ot e

xplic

itly

give

n

Brus

sels

, 18-

20 F

ebru

ary

2008

–D

isse

min

atio

n of

info

rmat

ion

wor

ksho

p16

EUR

OC

OD

ESB

ackg

roun

d an

d A

pplic

atio

nsEC

9 –

1.2

: Alu

min

ium

str

uctu

res

-fire

MA

TER

IAL

PRO

PER

TIES

-TH

ERM

AL

Ther

mal

str

ain

Com

pare

:

Alu

min

ium

at 2

00 °C

: 0,0

044,

ste

el a

t 500

°C: 0

,006

75, a

lso:

Ela

stic

ity

mod

ulus

less

than

for s

teel

–re

stra

int l

oads

cor

resp

ondi

ngly

less

EURO

CO

DES

Bac

kgro

und

and

appl

icat

ion

Wor

ksho

p Br

usse

ls 1

8-20

Feb

ruar

y 20

08

Nils

E F

ORS

ÉN M

ultic

onsu

lt AS

, Nor

way

5

Brus

sels

, 18-

20 F

ebru

ary

2008

–D

isse

min

atio

n of

info

rmat

ion

wor

ksho

p17

EUR

OC

OD

ESB

ackg

roun

d an

d A

pplic

atio

nsEC

9 –

1.2

: Alu

min

ium

str

uctu

res

-fire

200

600

800

1000

1200 0

400

500

400

300

200

100

0θ a

l / °C

c al /

(J/k

g°C

)

Spec

ific

heat

Brus

sels

, 18-

20 F

ebru

ary

2008

–D

isse

min

atio

n of

info

rmat

ion

wor

ksho

p18

EUR

OC

OD

ESB

ackg

roun

d an

d A

pplic

atio

nsEC

9 –

1.2

: Alu

min

ium

str

uctu

res

-fire

alum

iniu

m

Ther

mal

cap

acity

–in

com

paris

on…

..

Brus

sels

, 18-

20 F

ebru

ary

2008

–D

isse

min

atio

n of

info

rmat

ion

wor

ksho

p19

EUR

OC

OD

ESB

ackg

roun

d an

d A

pplic

atio

nsEC

9 –

1.2

: Alu

min

ium

str

uctu

res

-fire

Con

duct

ivity

in c

ompa

riso

n

050100

150

200

250

2050

100

150

200

250

300

350

400

450

500

Tem

pera

ture

C

W/m K

Ste

elAl

umin

ium

Brus

sels

, 18-

20 F

ebru

ary

2008

–D

isse

min

atio

n of

info

rmat

ion

wor

ksho

p20

EUR

OC

OD

ESB

ackg

roun

d an

d A

pplic

atio

nsEC

9 –

1.2

: Alu

min

ium

str

uctu

res

-fire

OB

SER

VE T

HA

T

•A

lum

iniu

m h

as a

con

duct

ivity

sign

ifica

ntly

hig

her t

han

that

of s

teel

–be

nefic

ial w

rtdi

strib

utio

n of

hea

t inp

ut•

The

heat

cap

acity

(per

m3 )

is s

omew

hat l

ower

com

pare

d to

that

of s

teel

, how

ever

, loo

king

at g

iven

str

uctu

res

(alu

min

ium

vs

stee

l) w

ith th

e sa

me

func

tion,

the

heat

ca

paci

ty is

abo

ut th

e sa

me

beca

use

defle

ctio

n co

ntro

l of

ten

gove

rns

the

desi

gn fo

r an

alum

iniu

m s

truc

ture

.

EURO

CO

DES

Bac

kgro

und

and

appl

icat

ion

Wor

ksho

p Br

usse

ls 1

8-20

Feb

ruar

y 20

08

Nils

E F

ORS

ÉN M

ultic

onsu

lt AS

, Nor

way

6

Brus

sels

, 18-

20 F

ebru

ary

2008

–D

isse

min

atio

n of

info

rmat

ion

wor

ksho

p21

EUR

OC

OD

ESB

ackg

roun

d an

d A

pplic

atio

nsEC

9 –

1.2

: Alu

min

ium

str

uctu

res

-fire

The

non-

linea

r tra

nsie

nt th

erm

al a

naly

sis

•So

lutio

n of

Fou

rier's

equ

atio

n by

FEM

•Th

erm

al p

rope

rtie

s of

insu

latio

n pr

oduc

t m

ore

sign

ifica

nt th

an th

ose

of a

lum

iniu

m

(c(θ

), λ

(θ))

wrt

resu

lts•

Exam

ple:

I be

am in

sula

ted

with

100

mm

R

ockw

ool1

10kg

/m3

Brus

sels

, 18-

20 F

ebru

ary

2008

–D

isse

min

atio

n of

info

rmat

ion

wor

ksho

p22

EUR

OC

OD

ESB

ackg

roun

d an

d A

pplic

atio

nsEC

9 –

1.2

: Alu

min

ium

str

uctu

res

-fire

Brus

sels

, 18-

20 F

ebru

ary

2008

–D

isse

min

atio

n of

info

rmat

ion

wor

ksho

p23

EUR

OC

OD

ESB

ackg

roun

d an

d A

pplic

atio

nsEC

9 –

1.2

: Alu

min

ium

str

uctu

res

-fire

Fire

pro

tect

ion

mat

eria

ls

•Th

e pr

oper

ties

and

perf

orm

ance

of f

ire p

rote

ctio

n m

ater

ials

use

d in

des

ign

shou

ld b

e as

sess

ed a

s to

ve

rify

that

the

fire

prot

ectio

n re

mai

ns c

oher

ent a

nd

cohe

sive

to it

s su

ppor

tthr

ough

out t

he re

leva

nt fi

re

expo

sure

. •

The

verif

icat

ion

of th

e pr

oper

ties

of p

rote

ctio

n m

ater

ials

is g

ener

ally

per

form

ed b

y te

sts.

Pr

esen

tly th

ere

are

no E

urop

ean

stan

dard

for

test

ing

of s

uch

mat

eria

ls in

con

nect

ion

with

al

umin

ium

str

uctu

res.

An

illus

trat

ion

of s

uch

test

ap

plic

able

to fi

re p

rote

cted

ste

el s

truc

ture

sis

gi

ven

in E

NV

1338

1-4.

Brus

sels

, 18-

20 F

ebru

ary

2008

–D

isse

min

atio

n of

info

rmat

ion

wor

ksho

p24

EUR

OC

OD

ESB

ackg

roun

d an

d A

pplic

atio

nsEC

9 –

1.2

: Alu

min

ium

str

uctu

res

-fire

Obs

erve

For f

ire p

rote

cted

str

uctu

res

the

inte

grity

of th

e in

sula

tion

syst

em is

th

eore

tical

ly le

ss c

halle

nged

as lo

ng

as th

e st

rain

leve

lsar

e ke

pt a

t a

mod

erat

ele

vel (

as fo

r alu

min

ium

, pr

ovid

ed th

at h

igh

tem

pera

ture

cre

epdo

es n

ot b

ecom

e si

gnifi

cant

) th

roug

hout

the

fire

expo

sure

EURO

CO

DES

Bac

kgro

und

and

appl

icat

ion

Wor

ksho

p Br

usse

ls 1

8-20

Feb

ruar

y 20

08

Nils

E F

ORS

ÉN M

ultic

onsu

lt AS

, Nor

way

7

Brus

sels

, 18-

20 F

ebru

ary

2008

–D

isse

min

atio

n of

info

rmat

ion

wor

ksho

p25

EUR

OC

OD

ESB

ackg

roun

d an

d A

pplic

atio

nsEC

9 –

1.2

: Alu

min

ium

str

uctu

res

-fire

Stru

ctur

al fi

re d

esig

n

E fi,d≤

Rfi,

d,t

•Te

nsio

nm

embe

rsan

d be

ams:

”Str

aigt

hfo

rwar

d”•

Col

umns

: Red

uctio

nfa

ctor

1,2

to ta

keac

coun

tofh

igh

tem

pera

ture

cree

p

Brus

sels

, 18-

20 F

ebru

ary

2008

–D

isse

min

atio

n of

info

rmat

ion

wor

ksho

p26

EUR

OC

OD

ESB

ackg

roun

d an

d A

pplic

atio

nsEC

9 –

1.2

: Alu

min

ium

str

uctu

res

-fire

Cla

ssifi

catio

n of

cro

ss-s

ectio

ns

•In

a fi

re d

esig

n si

tuat

ion,

cro

ss-s

ectio

ns m

ay b

e cl

assi

fied

as fo

r nor

mal

tem

pera

ture

desi

gn a

ccor

ding

to

6.1

.4 in

EN

199

9-1-

1.•

This

rule

is b

ased

on

the

sam

e re

lativ

e dr

op in

the

0,2

% p

roof

str

engt

h an

d m

odul

us o

f ela

stic

ity. I

f th

e ac

tual

dro

p in

mod

ulus

of e

last

icity

is ta

ken

into

acc

ount

acc

ordi

ng to

Fig

ure

2, th

e cl

assi

ficat

ion

of th

e se

ctio

n ch

ange

s, a

nd a

larg

er

capa

city

val

ue o

f the

sec

tion

can

be c

alcu

late

d.

The

Nat

iona

l Ann

exm

ay g

ive

prov

isio

ns to

take

th

is in

to a

ccou

nt.

•C

onfe

r Bac

kgro

und

docu

men

t N26

Brus

sels

, 18-

20 F

ebru

ary

2008

–D

isse

min

atio

n of

info

rmat

ion

wor

ksho

p27

EUR

OC

OD

ESB

ackg

roun

d an

d A

pplic

atio

nsEC

9 –

1.2

: Alu

min

ium

str

uctu

res

-fire

RES

ISTA

NC

E

Tens

ion

mem

bers

Nfi,

t,Rd

= ∑

Aik o

,θ,if o/γ M

,fior

N

fi,θ,

Rd

= k o

,θN

Rd

(γM

x/γM

,fi)

Bea

ms

Mfi,

t,Rd

= ∑

Aiz i

k o,θ

,if o/γ M

,fior

Mfi,

t,Rd

= k o

,θm

axM

Rd

(γM

x/γM

,fi)

(acc

ordi

ngly

for t

orsi

onal

bend

ing

and

shea

r)

Col

umns

Nb,

fi,t,R

d=

k o,θ

,max

Nb,

Rd

(γM

1/1,2

γ M,fi)F

acto

r1,2

; Cre

epN

ote

also

poss

ible

to re

duce

buck

ling

leng

th, a

s in

EC

3 P

art 1

.2, t

hesa

me

met

hod

is g

iven

Brus

sels

, 18-

20 F

ebru

ary

2008

–D

isse

min

atio

n of

info

rmat

ion

wor

ksho

p28

EUR

OC

OD

ESB

ackg

roun

d an

d A

pplic

atio

nsEC

9 –

1.2

: Alu

min

ium

str

uctu

res

-fire

Furt

herm

ore:

•Lu

mpe

d m

ass

met

hod

for t

empe

ratu

re c

alcu

latio

n as

for s

teel

, for

unp

rote

cted

(mod

erat

e ra

diat

ion)

an

d pr

otec

ted

(ver

ified

test

dat

a ne

eded

) alu

min

ium

st

ruct

ures

, (no

w F

EM is

mor

e su

ited,

com

petit

ive)

•A

dvan

ced

calc

ulat

ion

met

hods

onl

y m

entio

ned

by

prin

cipl

e, m

ust b

e ba

sed

on c

ompr

ehen

sive

stu

dies

an

d ve

rifie

d m

ater

ial m

odel

s•

Hea

t tra

nsfe

r to

exte

rnal

stru

ctur

al a

lum

iniu

m

mem

bers

: Mat

eria

l ind

epen

dent

(ex

emis

sivi

ty)

stea

dy-s

tate

mod

el a

s fo

r ste

el

EURO

CO

DES

Bac

kgro

und

and

appl

icat

ion

Wor

ksho

p Br

usse

ls 1

8-20

Feb

ruar

y 20

08

Nils

E F

ORS

ÉN M

ultic

onsu

lt AS

, Nor

way

8

Brus

sels

, 18-

20 F

ebru

ary

2008

–D

isse

min

atio

n of

info

rmat

ion

wor

ksho

p29

EUR

OC

OD

ESB

ackg

roun

d an

d A

pplic

atio

nsEC

9 –

1.2

: Alu

min

ium

str

uctu

res

-fire

Sum

mar

y

-EC

9 Pa

rt 1

.2 o

ffers

a p

ragm

atic

and

pra

ctic

al

appr

oach

to d

esig

n fo

r fire

resi

stan

ce o

f al

umin

ium

str

uctu

res

-Th

e pr

otec

tion

syst

em re

pres

ents

a m

ain

part

of t

he fi

re re

sist

ance

con

cept

-A

ppro

ved

and

verif

ied

ther

mal

dat

a

c(θ)

, λ(θ

) for

use

with

FEM

are

nee

ded

from

th

e fir

e in

sula

tion

indu

stry

-In

tegr

ity o

f pro

tect

ion

syst

ems

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