prEN 1992-1-2

Eurocode 2 – Design of concrete structures – Part 1-2: Structural fire design

1.1   Scope of prEN 1992 1 2
(1)   This document deals with the design of concrete structures for the accidental situation of fire exposure and is intended to be used in conjunction with prEN 1992 1 1 and EN 1991 1 2. This document identifies differences from, or supplements to, normal temperature design.
(2)   This document applies to concrete structures required to fulfil a loadbearing function, separating function or both.
(3)   This document gives principles and application rules for the design of structures for specified requirements in respect of the aforementioned functions and the levels of performance.
(4)   This document applies to structures, or parts of structures, that are within the scope of prEN 1992 1 1 and are designed accordingly.
(5)   The methods given in this document are applicable to normal weight concrete up to strength class C100/115 and lightweight concrete up to strength class LC50/60.
1.2   Assumptions
(1)   In addition to the general assumptions of prEN 1990 the following assumptions apply:
-   the choice of the relevant design fire scenario is made by appropriate qualified and experienced personnel or is given by the relevant national regulation;
-   any fire protection measure taken into account in the design will be adequately maintained.

Eurocode 2: Bemessung und Konstruktion von Stahlbeton- und Spannbetontragwerken - Teil 1-2: Allgemeine Regeln - Tragwerksbemessung für den Brandfall

1.1   Anwendungsbereich von prEN 1992 1 2
(1) Dieses Dokument behandelt die Bemessung von Betontragwerken für den Sonderlastfall Brandeinwirkung und ist in Verbindung mit prEN 1992 1 1 und prEN 1991 1 2 anzuwenden. Dieses Dokument enthält abweichende und zusätzliche Regelungen zu den Bemessungsregeln für Tragwerke bei normaler Temperatur.
(2) Dieses Dokument gilt für Betontragwerke, die Funktionen der Tragfähigkeit und/oder des Raumabschlusses erfüllen müssen.
(3) Dieses Dokument enthält Prinzipien und Anwendungsregeln im Hinblick auf die Tragwerksbemessung zur Erfüllung von festgelegten Anforderungen bezüglich der vorstehend genannten Funktionen und Leistungskriterien.
(4) Dieses Dokument gilt für Tragwerke oder Teile von Tragwerken die in den Anwendungsbereich von prEN 1992 1 1 fallen und entsprechend bemessen sind.
(5) Die in diesem Dokument angegebenen Verfahren gelten für Normalbeton bis zur Festigkeitsklasse C100/115 und für Leichtbeton bis zur Festigkeitsklasse LC50/60.
1.2   Annahmen
(1) Zusätzlich zu den allgemeinen Annahmen nach prEN 1990 gelten die folgenden Annahmen:
-   die Wahl des maßgebenden Bemessungsbrandszenarios erfolgt durch angemessen qualifiziertes und erfahrenes Personal oder wird in der maßgebenden nationalen Vorschrift angegeben;
-   jede bei der Bemessung berücksichtigte Brandschutzmaßnahme wird ausreichend instandgehalten.

Eurocode 2: Calcul des structures en béton - Partie 1-2: Règles générales - Calcul du comportement au feu

1.1   Domaine d’application de la prEN 1992 1 2
(1)   Le présent document s’applique au calcul des structures en béton en cas d’exposition accidentelle au feu et est destiné à être utilisé conjointement avec la prEN 1992 1 1 et la prEN 1991 1 2. Ce document identifie les différences ou les éléments supplémentaires par rapport au calcul aux températures normales.
(2)   Ce document s’applique aux structures en béton devant remplir une fonction porteuse, une fonction séparatrice ou les deux.
(3)   Ce document donne des principes et des règles d’application pour le calcul des structures en vue de satisfaire aux exigences spécifiées, selon les fonctions et niveaux de performance susmentionnés.
(4)   Ce document s’applique aux structures, ou aux parties de structures, qui relèvent du domaine d’application de la prEN 1992 1 1 et qui sont calculées en conséquence.
(5)   Les méthodes indiquées dans ce document sont applicables au béton de densité normale présentant une classe de résistance jusqu’à C100/115 et au béton léger présentant une classe de résistance jusqu’à LC50/60.
1.2   Hypothèses
(1)   Outre les hypothèses générales de la prEN 1990, les hypothèses suivantes s’appliquent :
-   le choix du scénario de calcul pertinent pour l’incendie est effectué par un personnel qualifié et expérimenté ou est donné par la réglementation nationale pertinente ;
-   toute mesure de protection contre l’incendie prise en compte dans le calcul sera maintenue de manière adéquate.

Evrokod 2: Projektiranje betonskih konstrukcij - 1-2. del: Splošna pravila - Projektiranje požarnovarnih konstrukcij

General Information

• Status: Not Published
• ICS: 91.010.30 - Technical aspects
• ICS: 91.080.40 - Concrete structures
• Technical Committee: CEN/TC 250 - Structural Eurocodes
• Drafting Committee: CEN/TC 250/SC 2 - Eurocode 2: Design of concrete structures
• Current Stage: 4599 - Dispatch of FV draft to CMC - Finalization for Vote
• Start Date: 19-Dec-2022
• Due Date: 26-Aug-2022
• Completion Date: 19-Dec-2022
• Mandate: M/515 - Mandate for amending existing Eurocodes and extending the scope of structural Eurocodes
• Ref Project: oSIST prEN 1992-1-2:2021 - Eurocode 2: Design of concrete structures - Part 1-2: General rules - Structural fire design

Relations

• Revises: EN 1992-1-2:2004 - Eurocode 2: Design of concrete structures - Part 1-2: General rules - Structural fire design
• Effective Date: 18-Jan-2023

Standards Content (Sample)

SLOVENSKI STANDARD
oSIST prEN 1992-1-2:2021
01-december-2021
Evrokod 2: Projektiranje betonskih konstrukcij - 1-2. del: Splošna pravila -
Projektiranje požarnovarnih konstrukcij

Eurocode 2: Design of concrete structures - Part 1-2: General rules - Structural fire

design

Eurocode 2: Bemessung und Konstruktion von Stahlbeton- und Spannbetontragwerken -

Teil 1-2: Allgemeine Regeln - Tragwerksbemessung für den Brandfall

Eurocode 2: Calcul des structures en béton - Partie 1-2: Règles générales - Calcul du

comportement au feu
Ta slovenski standard je istoveten z: prEN 1992-1-2
ICS:
13.220.50 Požarna odpornost Fire-resistance of building
gradbenih materialov in materials and elements
elementov
91.010.30 Tehnični vidiki Technical aspects
91.080.40 Betonske konstrukcije Concrete structures
oSIST prEN 1992-1-2:2021 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN 1992-1-2:2021
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oSIST prEN 1992-1-2:2021
DRAFT
EUROPEAN STANDARD
prEN 1992-1-2
NORME EUROPÉENNE
EUROPÄISCHE NORM
September 2021
ICS 91.010.30; 91.080.40 Will supersede EN 1992-1-2:2004
English Version
Eurocode 2: Design of concrete structures - Part 1-2:
General rules - Structural fire design

Eurocode 2: Calcul des structures en béton - Partie 1- Eurocode 2: Bemessung und Konstruktion von

2: Règles générales - Calcul du comportement au feu Stahlbeton- und Spannbetontragwerken - Teil 1-2:

Allgemeine Regeln - Tragwerksbemessung für den
Brandfall

This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee

CEN/TC 250.

If this draft becomes a European Standard, CEN members are bound to comply with the CEN/CENELEC Internal Regulations

which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.

This draft European Standard was established by CEN in three official versions (English, French, German). A version in any other

language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC

Management Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,

Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,

Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and

United Kingdom.

Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are

aware and to provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without

notice and shall not be referred to as a European Standard.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels

© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 1992-1-2:2021 E

worldwide for CEN national Members.
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oSIST prEN 1992-1-2:2021
prEN 1992-1-2:2021 (E)
Contents Page

European foreword ...................................................................................................................................................... 4

0 Introduction ...................................................................................................................................................... 5

1 Scope .................................................................................................................................................................... 8

1.1 Scope of prEN 1992-1-2 ................................................................................................................................ 8

1.2 Assumptions ..................................................................................................................................................... 8

2 Normative references .................................................................................................................................... 8

3 Terms, definitions and symbols ................................................................................................................ 9

3.1 Terms and definitions ................................................................................................................................... 9

3.2 Symbols .............................................................................................................................................................. 9

4 Basis of design ................................................................................................................................................ 14

4.1 General rules .................................................................................................................................................. 14

4.2 Nominal fire exposure ................................................................................................................................. 14

4.3 Physically based fire exposure ................................................................................................................ 15

4.4 Actions .............................................................................................................................................................. 15

4.5 Design values of material properties .................................................................................................... 15

4.6 Verification methods ................................................................................................................................... 16

4.7 Member analysis ........................................................................................................................................... 16

4.8 Analysis of parts of the structure ............................................................................................................ 16

4.9 Global structural analysis .......................................................................................................................... 17

4.10 Detailing ........................................................................................................................................................... 17

4.11 Spalling ............................................................................................................................................................. 17

4.12 Protective layers ........................................................................................................................................... 17

5 Material properties ...................................................................................................................................... 17

5.1 General.............................................................................................................................................................. 17

5.2 Concrete thermal properties .................................................................................................................... 18

5.2.1 Emissivity coefficient ................................................................................................................................... 18

5.2.2 Thermal conductivity .................................................................................................................................. 18

5.2.3 Specific heat .................................................................................................................................................... 18

5.2.4 Density .............................................................................................................................................................. 19

5.3 Mechanical properties ................................................................................................................................ 20

5.3.1 Concrete ........................................................................................................................................................... 20

5.3.2 Reinforcing steel ........................................................................................................................................... 23

5.3.3 Prestressing steel .......................................................................................................................................... 25

6 Tabulated design data ................................................................................................................................. 26

6.1 General.............................................................................................................................................................. 26

6.2 General design rules .................................................................................................................................... 27

6.3 Columns ............................................................................................................................................................ 29

6.3.1 General.............................................................................................................................................................. 29

6.3.2 Method A .......................................................................................................................................................... 30

6.3.3 Method B .......................................................................................................................................................... 32

6.4 Walls .................................................................................................................................................................. 33

6.4.1 Non load-bearing walls (partitions)....................................................................................................... 33

6.4.2 Load-bearing solid walls ............................................................................................................................ 33

6.5 Tensile members ........................................................................................................................................... 34

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6.6 Beams ................................................................................................................................................................ 35

6.6.1 General ............................................................................................................................................................. 35

6.6.2 Simply supported beams exposed to fire on one, two or three sides ........................................ 36

6.6.3 Continuous beams exposed to fire on one, two or three sides ..................................................... 37

6.6.4 Beams exposed on all sides ....................................................................................................................... 39

6.7 Slabs ................................................................................................................................................................... 39

6.7.1 General ............................................................................................................................................................. 39

6.7.2 Simply supported slabs .............................................................................................................................. 40

6.7.3 Continuous solid slabs ................................................................................................................................ 40

6.7.4 Flat slabs .......................................................................................................................................................... 41

6.7.5 Ribbed slabs.................................................................................................................................................... 41

7 Simplified design methods ........................................................................................................................ 43

7.1 General ............................................................................................................................................................. 43

7.2 Temperature profiles .................................................................................................................................. 43

7.2.1 General ............................................................................................................................................................. 43

7.2.2 Basic solution for one side exposure ..................................................................................................... 43

7.2.3 Walls, slabs and rectangular cross-sections ....................................................................................... 45

7.2.4 Circular cross-sections ............................................................................................................................... 47

7.3 Structural analysis ....................................................................................................................................... 48

7.3.1 General ............................................................................................................................................................. 48

7.3.2 Reduction of cross-section ........................................................................................................................ 48

7.3.3 Bending ............................................................................................................................................................ 51

7.3.4 Bending and axial load ............................................................................................................................... 53

7.3.5 Shear and torsion ......................................................................................................................................... 57

8 Advanced design methods ......................................................................................................................... 58

8.1 General ............................................................................................................................................................. 58

8.2 Thermal analysis .......................................................................................................................................... 59

8.3 Mechanical analysis ..................................................................................................................................... 59

8.4 Validation of advanced design methods ............................................................................................... 60

9 Detailing ........................................................................................................................................................... 60

9.1 General ............................................................................................................................................................. 60

9.2 Detailing of reinforcing and prestressing steel ................................................................................. 60

9.3 Detailing of members .................................................................................................................................. 60

9.4 Joints.................................................................................................................................................................. 62

9.5 Connections .................................................................................................................................................... 62

9.6 Fire protection systems .............................................................................................................................. 62

10 Rules for spalling .......................................................................................................................................... 63

Annex A (normative) Properties at high temperature of Steel Fibres Reinforced Concrete .......... 65

Annex B (informative) Recycled Aggregate Concrete Structures ............................................................. 66

Annex C (normative) Buckling of columns under fire Conditions ........................................................... 67

Bibliography ................................................................................................................................................................. 75

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oSIST prEN 1992-1-2:2021
prEN 1992-1-2:2021 (E)
European foreword

This document (prEN 1992-1-2:2021) has been prepared by Technical Committee CEN/TC 250

“Structural Codes”, the secretariat of which is held by BSI. CEN/TC 250 is responsible for all Structural

Eurocodes and has been assigned responsibility for structural and geotechnical design matters by CEN.

This document is currently submitted to the CEN Enquiry.
This document will supersede EN 1992-1-2:2004 and its amendments and corrigenda.

The first generation of EN Eurocodes was published between 2002 and 2007. This document forms part

of the second generation of the Eurocodes, which have been prepared under Mandate M/515 issued to

CEN by the European Commission and the European Free Trade Association.

The Eurocodes have been drafted to be used in conjunction with relevant execution, material, product

and test standards, and to identify requirements for execution, materials, products and testing that are

relied upon by the Eurocodes.

The Eurocodes recognize the responsibility of each Member State and have safeguarded their right to

determine values related to regulatory safety matters at national level through the use of National

Annexes.
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oSIST prEN 1992-1-2:2021
prEN 1992-1-2:2021 (E)
0 Introduction
0.1 Introduction to the Eurocodes

The Structural Eurocodes comprise the following standards generally consisting of a number of Parts:

— EN 1990, Eurocode: Basis of structural and geotechnical design
— EN 1991, Eurocode 1: Actions on structures
— EN 1992, Eurocode 2: Design of concrete structures
— EN 1993, Eurocode 3: Design of steel structures
— EN 1994, Eurocode 4: Design of composite steel and concrete structures
— EN 1995, Eurocode 5: Design of timber structures
— EN 1996, Eurocode 6: Design of masonry structures
— EN 1997, Eurocode 7: Geotechnical design
— EN 1998, Eurocode 8: Design of structures for earthquake resistance
— EN 1999, Eurocode 9: Design of aluminium structures
—

The Eurocodes are intended for use by designers, clients, manufacturers, constructors, relevant

authorities (in exercising their duties in accordance with national or international regulations),

educators, software developers, and committees drafting standards for related product, testing and

execution standards.

NOTE Some aspects of design are most appropriately specified by relevant authorities or, where not specified,

can be agreed on a project-specific basis between relevant parties such as designers and clients. The Eurocodes

identify such aspects making explicit reference to relevant authorities and relevant parties.

0.2 Introduction to EN 1992 Eurocode 2

(1) EN 1992 applies to the design of buildings, bridges and civil engineering structures in plain,

reinforced and prestressed concrete. It complies with the principles and requirements for the safety and

serviceability of structures, the basis of their design and verification that are given in

prEN 1990:2021 Basis of structural and geotechnical design.

(2) EN 1992 is only concerned with the requirements for resistance, serviceability, durability and fire

resistance of concrete structures. Other requirements, e.g. concerning thermal or sound insulation, are

not considered.
(3) EN 1992 is subdivided into the following parts:

— Part 1-1: General rules and rules for buildings, bridges and civil engineering structures

— Part 1-2: Structural fire design
— Part 4: Fastenings
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oSIST prEN 1992-1-2:2021
prEN 1992-1-2:2021 (E)
0.3 Introduction to prEN 1992-1-2

(1) prEN 1992-1-2 describes the requirements and rules for the structural design of buildings exposed

to fire.

(2) prEN 1992-1-2 is intended for clients (e.g. for the formulation of their specific requirements),

designers, contractors and relevant authorities.

(3) The general objectives of fire protection are to limit risks with respect to the individual and society,

neighbouring property, and where required, environment or directly exposed property, in the case of fire.

(4) The fire parts of the Structural Eurocodes deal with specific aspects of passive fire protection in

terms of designing structures and parts thereof for adequate load bearing resistance and for limiting fire

spread as relevant.

(5) Required functions and levels of performance can be specified either in terms of nominal

(standard) fire resistance rating, generally given in national fire regulations or by referring to fire safety

engineering for assessing passive and active measures, see prEN 1991-1-2.
(6) Supplementary requirements concerning, e.g.:
— the possible installation and maintenance of sprinkler systems,
— conditions on occupancy of building or fire compartment,

— the use of approved insulation and coating materials, including their maintenance,

are not given in this standard, because they are subject to specification by the competent authority.

0.4 Verbal forms used in the Eurocodes

The verb “shall" expresses a requirement strictly to be followed and from which no deviation is permitted

in order to comply with the Eurocodes.

The verb “should” expresses a highly recommended choice or course of action. Subject to national

regulation and/or any relevant contractual provisions, alternative approaches could be used/adopted

where technically justified.

The verb “may” expresses a course of action permissible within the limits of the Eurocodes.

The verb “can” expresses possibility and capability; it is used for statements of fact and clarification of

concepts.
0.5 National annex for prEN 1992-1-2

National choice is allowed in this standard where explicitly stated within notes. National choice includes

the selection of values for Nationally Determined Parameters (NDPs).

The national standard implementing prEN 1992-1-2 can have a National Annex containing all national

choices to be used for the design of buildings and civil engineering works to be constructed in the relevant

country.

When no national choice is given, the default choice given in this standard is to be used.

When no national choice is made and no default is given in this standard, the choice can be specified by a

relevant authority or, where not specified, agreed for a specific project by appropriate parties.

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oSIST prEN 1992-1-2:2021
prEN 1992-1-2:2021 (E)
National choice is allowed in prEN 1992-1-2 through the following clauses:
— 4.5 (1)
— 4.7 (1)
— 9.2 (1)
— 10 (10)

The National Annex can contain, directly or by reference, non-contradictory complementary information

for ease of implementation, provided it does not alter any provisions of the Eurocodes.

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oSIST prEN 1992-1-2:2021
prEN 1992-1-2:2021 (E)
1 Scope
1.1 Scope of prEN 1992-1-2

(1) This document deals with the design of concrete structures for the accidental situation of fire

exposure and is intended to be used in conjunction with prEN 1992-1-1 and prEN 1991-1-2. This

document identifies differences from, or supplements to, normal temperature design.

(2) This document applies to concrete structures required to fulfil a loadbearing function, separating

function or both.

(3) This document gives principles and application rules for the design of structures for specified

requirements in respect of the aforementioned functions and the levels of performance.

(4) This document applies to structures, or parts of structures, that are within the scope of

prEN 1992-1-1 and are designed accordingly.

(5) The methods given in this document are applicable to normal weight concrete up to strength class

C100/115 and lightweight concrete up to strength class LC50/60.
1.2 Assumptions

(1) In addition to the general assumptions of prEN 1990 the following assumptions apply:

— the choice of the relevant design fire scenario is made by appropriate qualified and experienced

personnel or is given by the relevant national regulation;

— any fire protection measure taken into account in the design will be adequately maintained.

2 Normative references

The following documents are referred to in the text in such a way that some or all of their content

constitutes requirements of this document. For dated references, only the edition cited applies. For

undated references, the latest edition of the referenced document (including any amendments) applies.

NOTE See the Bibliography for a list of other documents cited that are not normative references, including those

referenced as recommendations (i.e. in ‘should’ clauses), permissions (‘may’ clauses), possibilities ('can' clauses),

and in notes.
EN 1363-2, Fire resistance tests — Part 2: Alternative and additional procedures
prEN 1990:2021, Eurocode: Basis of structural and geotechnical design

prEN 1991-1-2:2021, Eurocode 1: Actions on structures — Part 1-2: General actions — Actions on

structures exposed to fire

prEN 1992-1-1:2021, Eurocode 2: Design of concrete structures — Part 1.1: General rules and rules for

buildings

, Eurocode 1: Actions on structures — Part 1-7: General actions — Accidental actions

EN 1991-1-7:2006
1) Under revision.
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prEN 1992-1-2:2021 (E)
3 Terms, definitions and symbols
3.1 Terms and definitions

For the purposes of this document, the terms and definitions given in prEN 1990, prEN 1991-1-2 and

prEN 1992-1-1 and the following apply.
3.1.1
axis distance

distance between the axis of the reinforcing bar and the nearest edge of concrete

3.1.2
critical temperature of reinforcement

temperature of reinforcement at which loadbearing failure of the member in fire situation is expected to

occur at a given stress level
3.1.3
maximum stress level

for a given temperature, the stress level at which the stress-strain relationship of steel is truncated to

provide a yield plateau
3.1.4
part of structure
isolated part of a structure with appropriate support and boundary conditions
3.1.5
fire protection material

any material or combination of materials applied to a structural member for the purpose of increasing its

fire resistance
3.1.6
reduced cross-section

cross-section of the member used in structural fire design when parts of the cross-section with assumed

zero strength and stiffness are removed
3.1.7
spalling

fire induced spalling of concrete consists of the breaking off of layers or fragments of concrete from the

surface of a structural element

Note 1 to entry: Depending on the severity of the phenomenon, it may or may not influence the performance of

the structural member.
3.2 Symbols
For the purposes of this document, the following symbols and units apply.
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oSIST prEN 1992-1-2:2021
prEN 1992-1-2:2021 (E)
3.2.1 Latin upper case letters
Refer to

A Cross-sectional area of longitudinal reinforcement at axis distance 7.3.4.2 (4), Annex B

a from the column’s most compressed side

A Cross sectional area of longitudinal reinforcement at axis distance a 7.3.4.2 (4), Annex B

from the column’s tensile/least compressed side
A Provided cross-sectional area of longitudinal reinforcement in the 7.3.3.2 (4)
st,prov
tension chord

Ast,req Required cross-sectional area of longitudinal reinforcement in the 7.3.4.2 (4)

tension chord for the design at ambient temperature according to
prEN 1992-1-1
A Required cross-sectional area of reinforcement for ultimate limit 6.2 (3)
s,prov
state according to prEN 1992-1-1
A Provided area of reinforcement 6.2 (3)
s,req
E Design effect of actions in fire situation
d,fi
E Slope of the linear elastic range in the stress-strain relationship of 5.3.2.1
s,θ
reinforcing steel
E Slope of the linear elastic range in the stress-strain relationship of 5.3.3.1
p,θ
prestressing steel
F Resisting compression force of longitudinal reinforcement at axis 7.3.4.2 (4)
sd,0,fi
distance a from the column’s most compressed side
F Resisting tensile force of longitudinal reinforcement at axis 7.3.4.2 (4)
sd,1t,fi
distance a from the column’s tensile side
F Resisting compression force of longitudinal rein
...