An Introduction To Structural Fire Engineering - Course Notes 2014

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Course: Advanced Structural Steel Design
Section: Structural Fire Design
Revision: 0.2 – April 2014
By: RS Walls
UNIVERSITY OF STELLENBOSCH
ADVANCED DESIGN OF STRUCTURAL STEELWORK:
AN INTRODUCTION TO
STRUCTURAL FIRE ENGINEERING
POST-GRADUATE DESIGN COURSE
COURSE NOTES BY: RICHARD WALLS
COURSE COORDINATOR: DR. HENNIE DE CLERCQ
APRIL 2014

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ADVANCED DESIGN OF STRUCTURAL STEELWORK:
STRUCTURAL STEEL FIRE DESIGN COURSE NOTES
Introduction to the Course
Welcome to what is one of the first university courses in structural fire engineering in South Africa.
As a component of the Stellenbosch University Advanced Steel Design course it aims to provide an
introduction to fire engineering and how to apply this to building design.
The content of this course can only be considered a brief introduction to a highly complicated field.
However, fire engineering is rapidly gaining momentum around the world. In South Africa engineers
are signing off buildings daily saying that they comply with building code regulations but they may
either be (a) totally under-designed in terms of fire resistance, or (b) totally over-designed which
wastes large amounts of money.
Historically in this country fire engineering has been generally ignored at design time and then dealt
with by the architects or fire engineers afterwards, rather than the structural engineers getting involved
on the building side. However, building behaviour during a fire is most certainly a topic which
structural engineers should be addressing, as it forms part of our scope and training (when
supplemented by fire engineering guidelines).
Code Basis for the Course
Since South Africa does not properly address structural fire engineering in any of the SANS codes it
has been necessary to consult and provide code information from international documents. The main
documents that form the basis for this course are:
- Performance-based member design and heat transfer equations: The Canadian steel design
code CSA S16, along with its fire design Annex (Annex K). These guidelines may soon be
adopted in the latest version of the SA steel code (SANS 10162-1)
- Prescriptive design: British and European design guides. In the UK very good guidelines
have been published by the producers of fire protection materials as well as the steel
producers. The ECCS in Europe has also produced a number of guides.
- Fire loads, parametric curves and material behaviour: Eurocode (EN) documents. The
Eurocodes are the most technically advanced suite of design documents in the world,
covering numerous aspects in relation to fire engineering. However, they are also complicated
to apply and the design guidelines have a slightly different philosophy to our steel code.

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NOTE: The different codes used different nomenclature and symbols for various items. Be careful of
this.
Course Contents
This course is structured as follows:
1. An introduction to fire engineering
2. Discussions regarding structural fire design and approaches
3. Fire curves and heat transfer equations
4. Characterising the behaviour of steelwork at elevated temperatures
5. Member design at elevated temperatures
Tutorials are included with the design sections of the course. These must be completed and submitted
for marking according to the requirements of the course coordinator. The contents of this course will
be tested as part of the final exam.
Additional Reading and Resources
The following books are useful books for further information and advanced fire design details:
Design Guides and Books
Buchanan, A., 2001. Structural Design for Safety. New York: Wiley. (Covers a very wide scope)
CISC, 2010. CISC Commentary on CSA S16-09 Annex K Structural Design for Fire Conditions,
Ontario: Canadian Institute of Steel Construction.
ECCS, 2001. Model Code on Fire Engineering. First ed. Berne: European Convention for
Constructional Steelwork. (Very useful for performance based design, fire curves, etc.)
Franssen, J.-M. & Vila Real, P., 2010. Fire Design of Steel Structures. First ed. Berlin: European
Convention for Constructional Steelwork. (Very good for steel topics, composite not covered)
Lamont, S., 2001. PhD Thesis: The Behaviour of Multi-Storey Composite Steel Framed Structures in
Response to Compartment Fires. Edinburgh: University of Edinburgh. (Thorough explanations on
various topics are provided in the introductory chapters and is freely available online)
Lennon, T., 2011. Structural Fire Engineering. First ed. London: ICE Publishing. (Basic introduction
to fire engineering)
SCI, 1990. Fire Resistant Design of Steel Structures - A Handbook to BS 5950: Part 8. 1 Berkshire:
The Steel Construction Institute. (Free)
Prescriptive Design
ASFP, 2010. Fire protection for structural steel in buildings "The Yellow Book". 4th ed. Hampshire:
Association for Specialist Fire Protection. (Very comprehensive for prescriptive design)

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Tata Steel & BCSA, 2013. Steel Construction: Fire Protection, Tata Steel & British Constructional
Steel Assocaition (BCSA). (Basic pamphlet with design guidelines)
Software Tools
- Arcelor Mittal - Fire Calculations Download Centre, http://amsections.arcelormittal.com.
- Elefir-EN – Useful software for design of steel members considering standard or parametric
fire curves. It has been developed by the University of Liege and can be purchased.
- Slab Panel Method software. Produced by the University of Auckland and HERA, New
Zealand. Stellenbosch University is currently developing this for potential use in South
Africa. Other similar software includes MACS+, TSLAB etc.
Lecturer Contact Details:
Richard Walls – PhD Researcher, Stellenbosch University – Structural Engineer, BSM Baker –
Email: richardw@bsmbaker.co.za

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Table of Contents
1. Introduction to Fire Engineering.....................................................................................................1
1.1 What is Structural Fire Engineering........................................................................................2
1.2 What is a Fire and when does it Influence a Building?...........................................................3
1.3 The Effects of Fires on Society...............................................................................................3
1.4 The Role of the Structural Engineer .......................................................................................4
1.5 How to Protect Steelwork .......................................................................................................5
1.5.1 Passive Protection ...........................................................................................................5
1.5.2 Active Protection (sprinklers etc.)...................................................................................6
1.5.3 Compartmentation...........................................................................................................8
2. Structural Fire Design Approaches and Requirements .................................................................10
2.1 Prescriptive and Performance Based Design ........................................................................10
2.1.1 Historical Development of Design Methods.................................................................10
2.1.2 Prescriptive Design .......................................................................................................10
2.1.3 The “Yellow Book” and the “Euro-nomogram”...........................................................10
2.1.4 Performance Based Design ...........................................................................................10
2.1.5 Prescriptive vs. Performance-based Design..................................................................11
2.1.6 What is Failure? ............................................................................................................12
2.2 Building Requirements in a Fire...........................................................................................12
2.3 Loading at the Fire Limit State (FLS)...................................................................................15
3 Fire Curves and Heat Transfer Equations.....................................................................................17
3.1 Standard Fire Curves.............................................................................................................17
3.1.1 The Standard Fire..........................................................................................................17
3.1.2 The Hydrocarbon Fire...................................................................................................17
3.1.3 The External Fire ..........................................................................................................17
3.1.4 Discussion regarding the Standard Fires.......................................................................18
3.2 Parametric or Real Fires........................................................................................................19
3.2.1 Real Fire Curves............................................................................................................19

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3.2.2 Eurocode Parametric Curve Equations .........................................................................19
3.2.3 Thermal Inertia of Compartments.................................................................................23
3.2.4 Opening Factors............................................................................................................24
3.2.5 Comments on Fire Loading Conditions........................................................................24
3.2.6 Time Equivalence of Parametric Curves.......................................................................25
4. The Behaviour of Steel at Elevated Temperatures........................................................................30
4.1 The Thermal Response of Steelwork – Material Properties .................................................30
4.1.1 Elongation of structural and reinforcing steels .............................................................30
4.1.2 Specific Heat of Steelwork ...........................................................................................31
4.1.3 Thermal Conductivity ...................................................................................................31
4.2 Thermal Response of Steelwork – Structural Properties ......................................................32
4.3 Bolt and Connection Behaviour............................................................................................34
4.4 Heat Transfer Equations........................................................................................................35
4.4.2 The Ap/V Concept ........................................................................................................35
4.4.3 Unprotected Steelwork..................................................................................................36
4.4.4 Protected Steelwork ......................................................................................................37
5. Member Design for Fires..............................................................................................................41
5.1 Prescriptive Design ...............................................................................................................41
5.2 The “Yellow Book” ..............................................................................................................41
5.3 Euro-Nomogram ...................................................................................................................42
5.4 Design to the Canadian Steelwork Code – CSA S16 Annex K ............................................49
5.4.2 Tensile Resistance.........................................................................................................49
5.4.3 Compressive Resistance................................................................................................49
5.4.4 Bending Resistance.......................................................................................................50
5.4.5 Combined Axial Force and Flexure..............................................................................51
5.5 A Brief Introduction to Advanced Design Methods .............................................................52
6. References.....................................................................................................................................55

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1. Introduction to Fire Engineering
EXAMPLE 1: COURSE DESIGN EXAMPLE
To explain structural fire engineering we will be following a design example through this course to
explain the various topics covered. Imagine that you were designing the multi-storey building shown
below, and you were asked to sign it off as sufficient according to National Building fire regulations.
Figure 1.1: Layout of the design example building to be used in this course
At this point in time you might have no clue of what to do, but by the end of the course you will be
able to do the basics of structural fire design, namely:
1. Classify a building and determine the required fire rating of elements.
2. Do a quick design using prescriptive methods, or

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3. Generate a parametric time-temperature fire curve according to the building properties.
4. Calculate the heat transfer and maximum temperature of the steelwork.
5. Determine the steel mechanical properties at the elevated temperature.
6. Design the members using simple calculations according to the Canadian steel code.
7. Realise that you have already saved your client lots of money, but there are advanced fire
design methods out there which could save them even more money, but we just didn’t have
time to fully cover those.
1.1 What is Structural Fire Engineering
According to the Institute of Fire Engineering in the UK the definition of structural fire engineering
is:
"The application of scientific and engineering principles, rules (codes), and expert
judgement, based on an understanding of the phenomena and effects of fire and of the
reaction and behaviour of people to fire, to protect people, property and the
environment from the destructive effects of fire." (IFE, 2014)
Thus, at the end of the day the main aim of structural fire engineering is to primarily ensure the safety
of building occupants, with the protection of property and good as a secondary objective. However,
with the increasing influence of insurance companies in building development the protection of assets
is becoming more and more important.
Events such as the collapse of the World Trade Centre have increased the interest and rate of research
and interest in structural fire engineering worldwide in recent years. A report from the Federal
Emergency Management Agency (FEMA, 2002) which followed the World Trade Centre disaster
stated that: “The behaviour of the structural system under fire conditions should be considered as an
integral part of structural design.” Thus, it can be seen that the structural engineering industry is
slowly moving from prescriptive based methods towards rational structural fire engineering solutions,
whereby fire considerations are starting to become core issues rather than problems addressed as an
addendum. However, to consider all aspects of fire design is a complex and multi-disciplinary task,
typically left for specialists. It requires the consideration of “active and passive measures, movement
of smoke and fire, detection systems, fire safety management, structural response and risk analysis”
(Bailey, 2004).

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1.2 What is a Fire and when does it Influence a Building?
A fire can be described as the “process in which substances combine chemically with oxygen from the
air and typically give out bright light, heat, and smoke” (Oxford, 2014). This definition captures some
of the most important aspects that need to be addressed during a fire, namely: oxygen is used up
which can endanger the lives of people, smoke is produced which limits visibility and can cause
asphyxiation, and the heat generated can structurally affect buildings and reduce strength.
Many small, controlled fires occur within buildings each year such as those from candles, cigarettes or
braais (barbecues). These are typically of no concern to fire engineers unless they develop into fires
which can endanger personnel or damage property. As fires grow personnel life safety is typically at
risk long before structural stability is reduced, generally because of smoke generation and the
consumption of oxygen. Only once temperatures reach a few hundred degrees Celsius do they become
structurally significant (except when load bearing elements are combustible), and at this stage people
would have either been evacuated or be dead.
Fire Engineers (who historically have mainly been mechanical engineers in South Africa) generally
play a more important role in the early stages of fire development. They are required to design
ventilation systems, assess emergency exits, try to ensure compartmentation, design sprinkler and
other active fire prevention systems, and much more. In the case of larger and more expensive
buildings CFD (computational fluid dynamics) models of smoke flow may be created to try predict
smoke spread and design systems more efficiently.
1.3 The Effects of Fires on Society
In South Africa there were 410 deaths due to fires in 2011, which is significantly up from 192 deaths
in 2000 and 226 in 2001 (FPASA, 2013). A total of 37,721 recorded fires in the country caused an
estimated damage of R2.1bn during 2011, which does not even include indirect costs such as lost
production. In 2008 the UK experienced losses due to fire worth £1.3bn, which was up 16% from the
previous year (ASFP, 2010). In America the NFPA reports that there were 1.5 million fires in 2008,
with 35.5% being structural fires (States News Service, 2010), meaning that approximately 0.5
million building fires occurred in one year alone. Hence, in can be seen that across the world fires are
a great concern.
The following interesting facts regarding fires that have occurred in Europe are present by Twilt
(1994): (a) The likelihood of a person being killed in a car accident is 30 times higher than being
killed in a building fire. (b) In a survey of 5 European countries between 74% (Netherlands) and 85%
(France) of fatal fires occurred in domestic buildings. Hence, deaths in commercial and industrial
structures are fairly rare. (c) The cause of deaths in buildings due to heat and smoke is generally
between 74% (Germany) and 99% (Switzerland). Thus, very few deaths are caused by collapse or by

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people being burnt alive. (d) A survey showed that the monetary loss due to fires is in the order of
about 0.2-0.29% as a portion of Gross National Product. (e) Of the cost of damages to buildings and
businesses due to fires only between 21-32% is structural damage whereas the rest is due to stock and
indirect losses (productivity etc.).
Large fires generally gain high media attention and can become well known. Pictures of some well-
known building fires are shown below based on details from Engelhardt (2013).
Figure 1.2: Famous large building fires
1.4 The Role of the Structural Engineer
The Commission of the European Communities outlines the general requirements of construction
works subjected to fire conditions as:
 “the load bearing capacity of the construction can be assumed for a specific period of time,
 the generation of and spread of fire and smoke within the works are limited,
 the spread of fire to neighbouring construction work is limited,
 occupants can leave the works or be rescued by other means,
 the safety of rescue teams is taken into consideration.” (CEC, 1988)
Thus, it can be seen that a structural fire engineer should:
1. ensure structural stability and safety for a required length of time in a given fire,
2. design for compartmentation to limit fire spread,
Interstate Bank Building,
Los Angeles (1988)
This building burnt for 4
hours causing $50million
damage. Four floors were
destroyed.
Parque Central East Tower,
Caracas (2004)
Fire burned for 24 hours
across 17 stories. Up to 100
firefighters inside the
building. Firefighting
stopped after 12 hours due
to concerns regarding
structural collapse.

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3. consider evacuation routes and ensure that they are safe, and
4. allow for fire suppression by methods such as sprinklers or external fire brigades.
One major issue with fires is that their behaviour can be greatly affected by human interactions, which
makes the accurate prediction of fire spread and temperature more complicated. For instance,
Bontempi and Petrini (2010) highlight that if a warehouse has an internal fire and the building has all
its doors closed it will have a lower ultimate temperature than if the doors are left open, or if the doors
are opened after 5 minutes when a fire-fighting team arrives. Thus, in true rational design many fire
scenarios may need to be considered in a similar way to which various load cases should be
considered (dead + live, dead + wind etc.),
1.5 How to Protect Steelwork
1.5.1 Passive Protection
Figure 1.3: Market share in the UK of various fire protection systems (Tata Steel & BCSA, 2013)
Since this course revolves around structural steelwork it is important to know what options there are
for protecting structural steelwork. The main ways used are:
 Protective boards: these are usually gypsum-type boards which can be fastened around steel
sections. They are often cheaper than other products but can take time to install and cannot be
easily profiled to suit more complicated shapes.
 Spray-on products: numerous spray-on products have been developed to form a barrier to heat
transfer. They are normally applied more thickly than intumescent paints, but can be cheaper.
Often they are not aesthetically pleasing.
 Intumescent paints: these paints expand and char when heated to form a thick layer which
insulates the steelwork. They are very commonly used and can follow any shape. However,
they can be expensive.
 Concrete encasement, fire screens and other such systems can also be utilised.

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The market share of various protection systems in the UK is shown in Figure 1.3. To illustrate the
importance and impact that fire protection coatings can have on a project refer to Tables 1.1 and 1.2,
which provide prices for a local intumescent paint and spray-on vermiculite. Prices are for the supply
and installation of the protective coatings. For a UC 152x152x23 to obtain a 2hr fire rating it can be
seen that the price of the intumescent paint is almost 7 times the price of the steelwork! For a UC
305x305x137 the increase in cost to obtain a 1hr fire rating is about 14%. The thicknesses and costs
were determined by a local supplier. If an engineer could reduce those thicknesses using performance-
based design methods millions of Rands could be saved on larger projects (and this can be done!).
Fire Protection Costing
60min Fire Rating
Costing
120min Fire Rating
Costing
Section
Mass
(kg/m):
Ap/V
(m
-1
):
Steel Cost
(R/m):
Intumescent
Paint
Vermiculite
Spray
Intumescent
Paint
Vermiculite
Spray
UC 152x152x23 23.3 304 R 652.40 R 1,080.00 R 712.00 R 4,510.00 R 1,295.00
UC 203x203x46 46.2 205 R 1,293.60 R 705.00 R 950.00 R 4,610.00 R 1,730.00
UC 305x305x137 137 106 R 3,836.00 R 545.00 R 1,455.00 R 3,960.00 R 2,645.00
Table 1.1: Cost of fire protection coating to provide various fire resistance ratings for different sized columns
Fire Protection Product Thickness
60min Fire Rating DFT
(mm):
120min Fire Rating DFT
(mm):
Section
Mass
(kg/m):
Ap/V
(m
-1
):
Intumes.
Paint
Vermic.
Spray
Intumes.
Paint
Vermic.
Spray
UC 152x152x23 23.3 304 1.54 22 6 40
UC 203x203x46 46.2 205 0.75 22 4.43 40
UC 305x305x137 137 106 0.38 22 2.49 40
Table 1.2: Thickness of coatings to obtain various fire ratings.
1.5.2 Active Protection (sprinklers etc.)
In the ‘Model Code on Fire Engineering’ produced by the ECCS (2001) it is stated that fire safety
may be achieved using the following means: (a) fire prevention, (b) active or operational measures,
and (c) passive or structural measures. Active measures involve suppressing or preventing the growth
of the fire by an intervention with the likes of automatic sprinklers, a fire brigade, or suppression
systems.
The use of sprinklers in buildings has become standard practice in South Africa and around the world.
This is especially enforced by insurance companies who specify sprinkler requirements which go
beyond the protection of personnel to the protection of infrastructure, property and stock. International
insurance companies such as FMGlobal have very strict policies which dictate exactly how fire
protection is to be approached in various situations, which can also lead to very expensive firefighting
installations. However, the use of sprinklers does significantly reduce the chance of a structurally

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significant fire. In New Zealand no fully developed fire has ever occurred in a sprinklered, multi-
storey building under normal operating conditions (Feeney & Buchanan, 2000).
The effect of sprinklers on fire loads has been debated. In Eurocode 1 it is noted that the fuel load of a
building can be reduced by up to 60% when an automatic sprinkler system is installed. However, for
this to be applied factors such as a reliable water supply, supervision of control valves, regular
maintenance etc. need to be present. The American AISC 2005 Specification, Appendix 4, allows for
the same 60% reduction in fire loads due to sprinklers (Iqbal & Harichandran, 2010). In the UK fire
design is governed by Approved Document B of the Building Regulations (2007), which allows for a
reduction of 30 minutes in the fire resistance of members if sprinklers are installed.
The chance of a fire when active firefighting methods are in place is highlighted in Table 2.3 below.
From this it can be seen that the likelihood of a fully developed fire decreases from 10% to 2% when
a sprinkler system is installed.
Protection Method
Probability of fire
being out of control
Public fire brigade
Sprinkler
High standard fire brigade, combined with alarm system
Both sprinkler and high standard residential fire brigade
10-1
2 x 10-2
≤ 10-2
to 10-3
≤ 10-4
Table 2.3: The effect on the probability of fires due to active protection measures (Twilt, 1994)
In the 1960s in Fresno, California, fire regulations were changed which encouraged trade-offs
between active and passive fire protection methods, as discussed by Favre et al (1994). The change
permitted reductions of 50%, or 30 minutes, in fire resistances when an automatic sprinkler system
was installed. In many instances a sprinkler system could be installed in lieu of a 1-hour rated
building. Thus, in the major commercial and industrial areas the number of sprinkler protected
buildings went from 15-20% to 93% and 96% respectively during this period. Extensive research was
conducted 15 years before and after the change in regulations, with the results shown in Table 2.4
below. It can be seen that there was a 93.8% reduction in annual fire losses due to the extensive
introduction of sprinkler systems. This resulted in two of the three fire stations in the area being
relocated to elsewhere in the city and the city’s fire rating was improved, leading to insurance
benefits.
Years Total loss adjusted Loss per year to 1976 US dollars No. of fires
1954-69
1970-84
1,351,209
82,573
90,080
5,504
62
67
Table 2.4: Losses in Fresno, California, 15 years before and after a change in regulations which encouraged a change
to automatic sprinkler protection (Favre, et al., 1994)

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Comments from the Fire Fighting Industry regarding modifying Fire Ratings
In some international codes the fire rating on buildings can be reduced if measures such as sprinklers
are installed. However, Bevan Wolff, technical expert at the FPASA (Fire Protection Association of
SA), makes the following comment regarding active and passive structural protection systems in this
country:
“Passive protection measures are designed for the life of the building. Hence, if passive
measures rely on active protection measures then the active protection measures must
also be guaranteed for the life of the building”.
If the fire rating given to a building is reduced because of the presence of active protection measures
(sprinklers, inerting systems etc.) it must be ensured that these are maintained, tested and considered
for the life of the structure.
1.5.3 Compartmentation
A vital aspect that must be specifically considered during fire engineering design is that of
compartmentation. Compartmentation involves the division of fire zones to limit the spread of fire.
This is explicitly considered in building codes such as SANS 10400 by limiting the maximum
division area allowed in various occupancy categories. Dividing walls must be fire rated and retain
their integrity during a fire. Fire walls, fire doors and other methods are commonly used for this. For
multi-storey buildings BS 9999 makes the following recommendation:
In tall multi-storey buildings, it can be advisable for each storey to be a separate
compartment capable of resisting burn-out. This can protect occupants who might
have to exit past the fire storey when a fire is well developed, and can also protect fire
fighters who might have to work on storeys immediately above or below a fire when it
is well developed. (BSI, 2008)
Advanced design guides have started proposing details for maintaining compartmentation even when
floors deflect substantially through the use of systems such as deformable ceramic blankets (Clifton,
2013). If compartmentation is lost fires can spread throughout buildings causing large-scale damage,
as shown in the figure below. This 32-storey building burnt for 24 hours and had to be demolished
after the fire. The Great Fire of London, which devastated a large part of that city, helped identify the
fact that to prevent fire spread there needs to be sufficient separation between adjacent buildings
(Corus, 2004). This now forms part of international building codes and guidelines.

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Figure 1.4: Fire in the Windsor Building in Madrid, Spain, shown during and after the blaze (Engelhardt, 2013)

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2. Structural Fire Design Approaches and Requirements
2.1 Prescriptive and Performance Based Design
Before approaching the topic how structural design can be done it is important to discuss the different
approaches that engineers can take when doing designs. The two broad categories in which design can
be done are (a) prescriptive design, or (b) performance based or rational design. Often approaches
may fall somewhere between the two depending on how they are carried out.
2.1.1 Historical Development of Design Methods
Historically design has been done by considering members in isolation. Large furnaces were built to
test single beams and columns under load. It was found what temperature members failed at and
design methods were based upon this. Heating of members occurred according to the standard fire
(discussed below). In the past few decades significant advances have been made by considering entire
structural systems and realistic fires.
2.1.2 Prescriptive Design
Prescriptive design is basically the application of deemed-to-satisfy rules from codes to determine
what level of fire protection must be provided to structural elements. It does not consider structural
behaviour, considers little about loading conditions, fire temperatures and other such factors. The
guidelines presented in SANS 10400 building code are all prescriptive. The advantage of prescriptive
design is that it is quick to apply and check, and is generally conservative. However, the inherent
conservatism may lead to significant increases in the cost of fire protection systems.
2.1.3 The “Yellow Book” and the “Euro-nomogram”
In the UK a very good design guide for determining the thickness of protective materials when
designing steel members is the “Yellow Book” published by the Association for Specialist Fire
Protection (ASFP, 2010). It can be freely downloaded from www.asfp.org.uk. The European
Convention for Constructional Steelwork (ECCS) has published a number of publications on
steelwork in fires. In this course the Euro-Nomogram which has been produced to quickly determine
the thickness of protective coatings will be presented. Both this and the Yellow Book are semi-
prescriptive.
2.1.4 Performance Based Design
Performance based design involves the consideration of the actual behaviour of structural systems, the
development of heat in a fire, heat transfer, member fixities and other such factors. It can range from
being relatively simple to be highly advanced. For more expensive or critical structures the additional
time required to carry out detailed, advanced analyses may be justified.

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Figure 2.1 depicts the level of calculation and design required depending on what type of fire curves
and analysis models are utilised (Thomas, 1986). Simple methods can be used for single members and
standard fires, whereas advanced design methods are required for global structural behaviour and
parametric curves. As computer power and design software capabilities continue to increase it means
that advanced analyses can now be more commonly used in practice, and need not only be reserved
for critical structures or research.
Figure 2.1: Fire and response models for different fire curves and analysis models (Thomas, 1986)
2.1.5 Prescriptive vs. Performance-based Design
In a comparison of prescriptive and performance-based approaches in structural fire design Budny and
Giuliani (2010) note that the characteristics of prescriptive approaches are: (a) individual members are
checked rather than systems as a whole, (b) methods are typically simplified, (c) conventional fire
curves are used rather than real or natural fire curves, (d) no specialised engineering skills are
required, (e) it is easy to identify who is responsible, and (f) methods are typically not open to
technical innovation. Conversely, performance-based, or rational, design methods are characterised
by: (a) the stability of entire systems is addressed, (b) often well-defined design procedures are not
provided, (c) there is a greater computational effort and level of skills required, (d) designs can
potentially be more safe and economical, (e) a variety of fire situations can be considered, and (f)
modelling methods affect results.

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2.1.6 What is Failure?
A challenge with structural fire engineering is being able to define failure. Since it would be
acceptable for a structure to suffer some damage in a large fire it makes it very difficult to know what
fire limit state to design a building to. In some structures beams and columns have buckled during real
fires but floors remained in position such that people could get out and the structures didn’t collapse –
so would those be failures or not?
Various parameters for failure have been identified such as those given in BS 5950 Part 8 for:
- Beams: maximum deflection limited to span/20, or for deflections greater than span/30 the
rate of deflection must not exceed span2
/(9000 x member depth) [mm/min].
- Columns: Failure to support the applied load or a lateral deflection of 120mm.
- Insulating materials or floors: objects on the unexposed face must not combust. Temperature
on the unexposed side must be limited to 140°C (average) or 180°C (maximum).
- Integrity: boundaries required for compartmentation must not allow the passage of smoke or
flames from one compartment to another.
Tests are done relative to the standard fire.
2.2 Building Requirements in a Fire
The fire resistance rating (FRR) required for various buildings according to SANS 10400 is given in
the Table 2.1 below. From this it can be determined what level of fire rating is required.
Fire resistance requirements are usually measured according to the length of time a structure can
withstand a standard fire. This is typically defined as short, medium or long resistances corresponding
to times of 30, 60 and 120 minutes respectively. Tests have shown that often steel members can attain
15 minutes or more fire resistance without any protection (ASFP, 2010). It has been shown that some
structures such as open carparks generally don’t need passive protection and inherently satisfy fire
requirements.
It is very important to note that tests are referenced relative to the standard fire, as will be explained
in detail below. Both structural and non-structural elements need to be fire rated to ensure that they
are suitable for their application. Elements tested according to the various standards (SANS, BS, EN)
are required to satisfy load-bearing, integrity and insulation tests to obtain a specific fire rating. South
African fire resistance requirements will be discussed in detail below. Construction materials in this
country are tested according to the guidelines of SANS 10177-2.

13
By: RS Walls
These aforementioned time measures are meant to ensure that sufficient time is provided to allow for
the safe evacuation of a building. However, fire ratings in excess of these requirements may often be
stipulated by a company’s insurance provider to limit property and stock damage.
In theory a structure should be able to survive the full burnout of all combustible materials in it or in a
specified part of it (ECCS, 2001). The inherent levels of safety and structural stability in the event of a
fire are often not well defined, and in the case of a standard fire have little physical significance.
NOTE: As a structural engineer be very careful in terms of how buildings are classified, especially in
terms of warehouses. Developers will often try classify all their warehouses as occupancy type J3 to
bring down the cost of fire protection systems. However, many warehouses should actually be
classified as J2 or J1 depending on what is stored there.

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By: RS Walls
Type of occupancy
Class of
occupancy
Stability (min)
Single-
storey
building
Double-
storey
building
3 to 10
storey
building
11 storeys
and more
Basement
in any
building
Entertainment and public assembly A1 30 60 120 120 120
Theatrical and indoor sport A2 30 60 120 120 120
Place of instruction A3 30 30 90 120 120
Worship A4 30 60 90 120 120
Outdoor sport A5 30 30 60 90 120
High risk commercial services B1 60 60 120 180 120
Moderate risk commercial services B2 30 60 120 120 120
Low risk commercial services B3 30 30 90 120 120
Exhibition hall C1 90 90 120 120 120
Museum C2 60 60 90 120 120
High risk industrial D1 60 90 120 180 240
Moderate risk industrial D2 30 60 90 120 180
Low risk industrial D3 30 30 60 120 120
Plant room D4 30 30 60 90 120
Place of detention E1 60 60 90 120 120
Hospital E2 60 90 120 180 120
Other institutional (residential) E3 60 60 120 180 120
Medical facilities E4 30 30
Not
applicable
Not
applicable
120
Large shop F1 60 90 120 180 120
Small shop F2 30 60 120 180 120
Wholesalers' store F3 60 90 120 120 120
Office G1 30 30 60 120 120
Hotel H1 30 60 90 120 120
Dormitory H2 30 30 60 120 120
Domestic residence H3 30 30 60 120 120
Detached dwelling house H4 30 30 60
Not
applicable
120
Hospitality H5 30 30
Not
applicable
Not
applicable
120
High risk storage J1 60 90 120 180 240
Moderate risk storage J2 30 60 90 120 180
Low risk storage J3 30 30 90 90 120
Parking garage J4 30 30 30 90 120
NOTE 1 Unprotected steel may be used in the structural system of all single-storey and certain double-storey
buildings in spite of the fact that in many cases such structural members would not comply with the requirements of
this table. The practice is regarded as safe for all practical cases that are likely to occur in single-storey construction,
but the possible consequences of early distortion or collapse should be considered in the design of double-storey
buildings in order to be certain that escape routes will be able to serve their purpose for the required period.
Particular care should be exercised where thin sections are used or in "space-frame" type structures.
NOTE 2 A further problem arises in the application of the requirement of 4.2. Distortion or collapse of any structural
member should not cause loss of integrity or stability in any external wall facing a site boundary or another building
as this might lead to non-compliance with the safety distance requirement. Where such a situation occurs, it would
be necessary either to protect the steel to the extent required to attain the stability given in this table or to regard such
wall as being of type N for the purposes of 4.2.
Table 2.1: Fire resistance requirements for structural elements and components according to SANS 10400-T Table 6

15
By: RS Walls
EXAMPLE 2: FIRE RESISTANCE RATING
Q: Based on SANS 10400 requirements what FRR should be provided for the building shown in
Example 1?
A: From Table 2.1 the following can be derived:
- The building will be used for offices so is Class G1
- The building is between 3 and 10 storeys.
- Therefore, a 60 minute fire rating is required for the structure.
TUTORIAL 1: FIRE RATINGS
What occupancy class (A1, D3, etc.) and fire rating (30min, 60min) would you provide for the
following:
1. A single-storey Ster-Kinekor cinema complex.
2. A double-storey art gallery.
3. The basement of a hospital.
4. 12-storey building storing flammable products (though hopefully nobody would be foolish
enough to build such a structure).
If any of the above require interpretation of the table state what you have considered when providing
the fire rating. Note that ultimately it will be the fire engineers and fire chiefs who agree on these
requirements.
5. Go to YouTube and search for the video “Fire at Seven Dials” by BREVideoUK. Watch the
video and take note of how the steelwork has failed and also note general details regarding
fighting a fire. Submit a few sentences regarding what the main problem was that caused the
fire to spread throughout the building?
2.3 Loading at the Fire Limit State (FLS)
In the same way that live and wind loads can be reduced in certain load cases so can they also be
reduced when designing structures for fires. According to the Canadian fire design annex the load
combination to be adopted at the fire limit state is:
(2.1)
where:
G is the specified dead load
Ts is the effect due to expansion, contraction or deflection caused by temperature
changes due to the design fire. It can be taken as zero for statically determinate

16
By: RS Walls
structures or for structures that have sufficient ductility to allow for redistribution of
temperature forces before collapse. [Even though these guidelines have generally
been sufficient they must be carefully considered in some structures as forces caused
in members restrained from expanding can be significant].
α 1.0 for storage areas, equipment areas, and service rooms, 0.5 for other occupancies.
The Eurocode reduction factors are similar, but vary for some structures.
Q specified live load
In the above equation snow loads have not been listed as they typically do not apply in South Africa.
Fire loading is currently outside the scope of the South African loading code, SANS 10160, along
with other actions such as those on containment structures, bridges, towers and masts (Dunaiski, et al.,
2007). Thus, the inherent requirements of structures in South Africa cannot be identified relative to
existing codes. However, SANS 10160 does provide a philosophy for dealing with accidental loading
in Annex B of Part 1. Accidental loads are those which, according to SANS 10160 are “not
expected during the design life”, but when they do occur then structures should “not be
damaged to an extent disproportionate to the original cause of the abnormal event” (Retief &
Dunaiski, 2009). According to the aforementioned design philosophy structures should be categorised
depending on the consequence of their failure and then a design strategy can be picked accordingly
EXAMPLE 3: FIRE LOADING
Q: What load should be designed for at the ambient Ultimate Limit State (ULS) and at the Fire Limit
State (FLS) for the second floor column on Gridline B3 of the building in Figure 1.1? Assume that the
roof may be loaded in the future so the column may carry two full floors above it.
A: The loading can be determined as:
Permanent / Dead load:
Imposed / Live load:
ULS Loading
FLS Loading

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By: RS Walls
3 Fire Curves and Heat Transfer Equations
Before any structural element can be designed or fire rated it is necessary to have fire temperatures to
design against. This section discusses the historical development of time-temperature curves and their
current application.
3.1 Standard Fire Curves
The standard fire was proposed in 1918 and was not developed based on the response of elements to a
real fire, but rather what the authors considered a worst case time-temperature relationship between a
fire and a structure. It has now been adopted by numerous countries around the world with only minor
variation. Lennon (2011) considers it to be “enshrined in national, European and international
standards”. The main standards which govern the standard fire test are ASTM E119, ISO 834 and
NFPA 251. It is often referred to as the ISO 834 curve.
The standard fire does not consider a variety of factors which are known to affect fire behaviour such
as: fire source and load, ventilation characteristics and building properties. These curves can be
suitable for short duration fires, but typically for medium to long duration fires become inaccurate.
They have a steadily increasing temperature and do not consider a cooling phase or descending
branch.
3.1.1 The Standard Fire
For the standard ISO 834 fire the gas temperature in the firecell, θg, at a time t, in minutes, is given
by:
[°C] (3.1)
3.1.2 The Hydrocarbon Fire
For fires with a higher fuel energy content than considered for the standard fire, as might be found in
the petrochemical and associated industries, the hydrocarbon fire can be utilised:
[°C] (3.2)
3.1.3 The External Fire
For structures that might be subjected to the flames emerging from a building the less intense external
fire curve can be used, as given by:
[°C] (3.3)
A comparison of the above equations is given below.

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By: RS Walls
Figure 3.1: Graphical representation of commonly used fire curves
3.1.4 Discussion regarding the Standard Fires
Franssen and Vila Real have the following comment to make regarding the use of the standard fire
curve and analysing members in isolation:
“If the fire and mechanical model (an isolated element) are arbitrary and do not
represent the real situation, why should there be an attempt to create a more accurate
model by introducing the indirect effects of actions. As mentioned by Professor A.
Buchanan from Canterbury University in his talks, there must be a consistent level of
crudeness.” (Franssen & Vila Real, 2010)
They go on further to highlight the important fact that “The resistance of a structure to a nominal
fire should not be compared to the duration required for evacuation or intervention”. Simply
put, a one hour fire rating does not mean that a building will fall down after a fire burns in it for one
hour, and neither does it mean that people have an hour to evacuate. It simply means that the structure
can survive one hour of an arbitrary fire curve which has little resemblance for a real fire.
Furthermore, a real fire curve at one hour cannot be compared to one hour of a standard fire curve.
Great care must be taken when comparing fire resistance ratings between real and standard fires.
0
200
400
600
800
1000
1200
0 20 40 60 80 100 120
Gas
Temperature
(ºC)
Time (mins)
Standard
External
Hydrocarbon

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By: RS Walls
3.2 Parametric or Real Fires
3.2.1 Real Fire Curves
The development of temperature in a real fire is very different to that shown by the standard fire time-
temperature curve, as shown by the figure below. After ignition there is a slow period of growth until
flashover occurs. During the development of a fire a two-zone model is normally used which accounts
for the build-up of the heated upper zone and the cooler lower zone. The flashover point for a
compartment occurs when the gas temperature in the upper zone of the compartment reaches around
500-600ºC (Feasey, 1999), and it envelopes the cool bottom layer leading to a single zone situation.
At this point all combustible material in a compartment is burning, and is characterised by a rapid
temperature increase. Different models need to be applied for pre- and post-flashover behaviour.
Structural design is affected by the latter, but sprinkler activation, smoke movement models and
compartment tenability are governed by pre-flashover fires. As the fire progresses the fuel in the
compartment is consumed until the maximum temperature is reached, after which the fire starts to
cool down.
Figure 3.2: Typical development of gas temperature in a fire (Engelhardt, 2013)
It may seem counter-intuitive but the cooling phase can be as structurally dangerous as the heating
phase. When the structure heats up the beams expand, buckle and sag. When the structure cools down
tensile forces are induced in the members which have sagged, and this can lead to the failure of joints.
3.2.2 Eurocode Parametric Curve Equations
In Eurocode 1-1-2 (BSI, 2002) parametric fire curves which take into account a more realistic fire
behaviour are provided. These allow for the heating and cooling phases whilst considering the most
important factors affecting fire temperatures. They were developed based on the work in Europe by
Wickström (1985), and have now undergone 40 years of testing and validation relative to actual
building fires. They are typically valid for: (a) firecells up to 500m2
, and (b) for a maximum

20
By: RS Walls
compartment height of 4m. Going beyond these limits may require CFD modelling. The most
important parameters considered by any parametric curve are: (1) the fire load in the compartment, (2)
openings and ventilation conditions, and (3) the nature of the boundary walls and floors since they
either transmit heat from it or trap heat in the compartment.
(1) The basic temperature-time curve in the heating phase is given by:
[°C] (3.4)
where:
θg = gas temperature in the fire compartment [ºC]
t* = t.Γ [hours] (This can be considered as the time period modified by Γ to match the original
opening factor of 0.04/1160 utilised in calibration experiments) (3.5)
t = time [h]
Γ = (O/b)2
/(0.04/1160)2
√ with [J/m2
s1/2
K] – Thermal inertia of the firecell.
O = opening factor ( √ ) [m1/2
]
Av = area of ventilation openings [m2
]
h = height of ventilation openings [m]
At = total area of enclosure, including openings [m2
]
ρ = density of boundary enclosure [kg/m3
]
c = specific heat of boundary enclosure [J/kgK]
λ = thermal conductivity of the enclosure boundary [W/mK]
(2) The maximum temperature, θmax, that will be experienced in the heating phase will occur at
time tmax (which becomes t*
max when modified by Γ). If tmax occurs afters the limiting time, tlim,
then the limiting time is used instead. This is used to determine whether the fire is governed
by the fuel load or ventilation conditions. Note that at the change between the two conditions
an infinitely small change in parameters can cause a jump in theoretical results.
[( ) ] [h] (3.6)
[h] (3.7)
where:
qt,d = qf,d . Af / At (MJ/m2
) – This is the design fuel energy density of the whole compartment
relative to the total boundary area including floor, walls and roof. 50 ≤ qt,d ≤ 1000 [MJ/m2
]
tlim = 25min for slow growth fires, 20min for medium growth fires, and 15min for fast growth.
(3) If the limiting time is used for tmax then Γ must be modified. Hence, when tmax = tlim:
[h] (3.8)
with
where

21
By: RS Walls
NOTE: The original value of Γ must always be used for the cooling phase, but Γ is modified to Γlim
for only the heating phase. The limiting opening factor is applied for firecells with large openings
when all the air entering through the openings may not be used for combustion, and this slows down
the temperature increase rate.
(4) Under certain conditions Γlim needs to be multiplied by the factor k to account for mass
transfers which also limit the elevation of the temperature in the firecell:
When O > 0.04, and qt,d < 75, and b < 1160, then Γlim is modified by:
( ) ( ) ( ) (3.9)
(5) Once the maximum temperature has occurred the cooling phase is described by:
if [h] (3.10)
if [h] (3.11)
if [h] (3.12)
where
t* = t.Γ [h] (3.13)
[h] (3.14)
if , or , if (3.15)
(6) Fire Load Densities and Rate of Heart Release (RHR)
The design fire load qf,d can be calculated as follows:
[MJ/m2
] (3.16)
where
m is the combustion factor. For mainly cellulosic materials m = 0.8.
is the partial factor accounting for the risk based on the size of the compartment
is the partial factor accounting for the risk based on the type of occupancy
∏ is the differentiation factor taking into account the different active fire-
fighting measures available. (It is currently unclear whether this can be
applied in South Africa.)
qf,k is the characteristic fire load density per unit floor area [MJ/m2
]
Standard fire load densities are provided below for general occupancy requirements. An
extensive list of fire load densities accounting for numerous occupancy types have been
published by Buchanan (2001). Note that the 80% fractile value is typically used for design.
The fire load densities typically display a Gumbell probability distribution.

22
By: RS Walls
Occupancy:
Fire load densities qf,k [MJ/m2] Rate of Heat Release
Stand.
Deviation:
Average:
80%
Fractile:
Gumbell
Alpha:
Fire growth
rate:
tlim
[min]:
tα
[sec]:
RHRf
[kW/m2]:
Dwelling 234 780 948 0.0054782 Medium 20 300 250
Hospital (room) 69 230 280 0.018578 Medium 20 300 250
Hotel (room) 93 310 377 0.013784 Medium 20 300 250
Library 450 1500 1824 0.002849 Fast 15 150 500
Office 126 420 511 0.010174 Medium 20 300 250
School classroom 85.5 285 347 0.014993 Medium 20 300 250
Shopping centre 180 600 730 0.007122 Fast 15 150 250
Storage buildings * * * * * * * *
Theatre (cinema) 90 300 365 0.014243 Fast 15 150 500
Transport (public square) 30 100 122 0.04273 Slow 25 600 250
(*Depends highly on products stored so must be determined for each case.)
Table 3.1: Fire load densitities and rate of heat release values for different occupancies
The fire load density is the measure of all fuel available for burning per unit floor area of the firecell.
The table below summaries the most common qf,k values for various occupancies. Make sure that you
distinguish between the fire load density of the floor area, and the design fire load density relative to
the boundary area of a firecell: qt,d = qf,d . Af / At [MJ/m2
].
(7) and can be taken from the table below to account for the danger of fire activiation.
Compartment floor
area Af [m2
]
Danger of fire
activation,
Danger of fire
activation,
Example of occupancies
25 1.10 0.78 Artgallery, museum, swimming pool
250 1.50 1.00 Offices, residence, hotel, paper industry
2500 1.90 1.22 Manufacturer of machinery and engines
5000 2.00 1.44 Chemical laboratory, painting workshop
10000 2.13 1.66 Manufacturer of fireworks or paints
Table 3.2: Partial factors to account for the danger of fire activation depending on compartment floor area or
occupancy. Use linear interpolation between values.
(8) The fire load can be reduced when active firefighting measures are present. However, it must
be guaranteed that these measures are operational and well maintained. Typically in South
Africa trade-offs between active and passive fire protection measures are not allowed. Hence,
for this course use . The table below has been included for completeness and
potential future use. Reductions in fire load of up to 75% can be realised using this table.

23
By: RS Walls
Table 3.3: Differentiation factor accounting for various active fire protection systems, as proposed in various
European documents. The bottom row contains the proposed values in the European Research on the Natural Fire
Safety Concept document (NFSC). (ECCS, 2001)
3.2.3 Thermal Inertia of Compartments
The thermal inertia of a firecell plays an important role with regards to the amount of energy lost
whilst a fire is burning. The following table provides guidance for b values for various construction
materials:
Material:
λ – Thermal
Conductivity
[W/m.K]:
ρ –
Density
[kg/m
3
]:
cp – Specific
Heat
[J/kg.k]:
b – Thermal
inertia
[J/m
2
s
0.5
K]:
Brickwork 1.00 2000 1114 1521
CaSi-board 0.069 450 748 151.9
Cerablanket 0.035 128 800 59.9
Gypsum board 0.5 1150 1000 749
Light wt. conc. 1.0 1500 840 1122
Middle wt. conc. 1.0 2000 840 1296
Normal wt. conc. 2.0 2300 900 2034
Structural steel 54.0 7850 425 13422
Wood 0.10 450 1113 223
Table 3.4: Material properties at ambient temperature for various construction materials
For monolithic construction the value of b can be taken as:
√ [J/m2
s0.5
K] (3.17)
When different construction materials are used for the walls, floor and roof of a compartment then a
global thermal inertia is calculated for the firecell in respect to the area of each material (openings not
included):
∑
∑
[J/m2
s0.5
K] (3.18)

24
By: RS Walls
3.2.4 Opening Factors
The opening factor, O, accounts for the openings in the vertical walls of a compartment. It ranges
between 0.02 and 0.2, with higher values meaning more ventilation. It has been derived from
integrating the Bernoulli equation for pressure differences between the outside and inside, and is
calculated as:
√ [m0.5
] (3.19)
where
Av = area of ventilation openings [m2
]
h = height of ventilation openings [m]
At = total area of enclosure, including openings [m2
]
When there are several openings present an averaged, equivalent opening height, heq, is used:
√ [m0.5
] (3.20)
∑ [m] (3.21)
The estimated gas temperatures using the above equations are presented below for various opening
factor values ranging from 0.02 to 0.20. From this graph it can be seen that as the ventilation factor
increases the fires reach higher peak temperatures more quickly, but then has a much more rapid drop-
off. Such behaviour needs to be considered in structural design, especially for members with higher
thermal capacities.
Figure 3.3: Parametric fire curves according to EN1-1-3 for opening factors from 0.02 to 0.2. For this graph Af =
30m2
, At = 200m2
, b = 945 J/m2
s1/2
K, tlim = 20min and qf,d = 800 MJ/m2
3.2.5 Comments on Fire Loading Conditions
It should also be understood that in the same way that structures can have a variety of static load
combinations (dead + live, dead + wind, etc.) there could be a number of fire scenarios which
influence the loading. Petrini (2010) highlights that according to ISO/TS 16733 the following items
0
200
400
600
800
1000
1200
1400
0 50 100
θg
ºC
Time (min)
O=0.02
O=0.04
O=0.06
O=0.09
O=0.10
O=0.14
O=0.20

25
By: RS Walls
have to be specified to define an entire fire scenario: (a) fire source, (b) physical characteristics of the
combustible material, and (c) the growth rate of the fire and the peak fire temperature. For EN 1-1-2
curves a variety of fires may be obtained depending on whether windows are open or closed in a
building, if partition walls are removed or if the fire load density changes.
3.2.6 Time Equivalence of Parametric Curves
Research and experience have shown that the standard fire typically does not reflect real fires, as
discussed extensively above. However, since the majority of tests and ratings are done using the
standard fire it is necessary to provide ways to equate real fires to an equivalent standard fire. The
most popular methods are the CIB formula and the Eurocode formula (Nyman, 2002).
Eurocode Formula
The Eurocode time equivalent, te, to an ISO 834 standard fire is given by:
[mins] (3.22)
where the ventilation factor, wf, is given by:
( ) [ ] (3.23)
with
Hr is the compartment height [m]
ef is the design fire energy density, noted as qf.d above [MJ/m2]
Vertical ventilation ratio:
⁄ (3.24)
Horizontal ventilation ratio:
⁄ (3.25)
The vertical opening factor is:
(3.26)
CIB Formula
The CIB formula gives the equivalent fire time as:
[mins] (3.27)
Ventilation factor:
( )
(3.28)
Hv is the ventilation opening height, which we shall take as heq for multiple openings.

26
By: RS Walls
The CIB formula is more commonly used, but is only valid for compartments with vertical openings,
and cannot consider roof openings.
The kb and kc factors are obtained from the table below. Linear interpolation can be used between
values.
Formula: Term
b – Thermal inertia (J/m2
.s.K)
General
High
(> 2500)
Medium
(720-2500)
Low
(<720)
Eurocode kb 0.04 0.055 0.07 0.07
CIB kc 0.05 0.07 0.09 0.10
Table 3.5: Values of kc and kb for the CIB and Eurocode formulae (Nyman, 2002)
EXAMPLE 4: FIRE CURVES
QUESTION: For fire compartment of the building shown in Figure 1.1 do the following:
1. Generate a time-temperature fire curve according to EN 1-1-2.
2. Plot this curve against the standard fire curve.
3. Determine the equivalent fire rating of the curve generated.
The openings of the compartment are shown below. (Results have been calculated using a spreadsheet
with no rounding off until the final solution).
ANSWER 1.:
Compartment floor area:
Ventilation area, assuming all doors open and windows broken:
Total boundary enclosure area:

27
By: RS Walls
Wall area excl. openings:
A. Design fire load:
The compartment is used for offices, so according to the 80% fractile value of Table 3.1:
, and
The fire is cellulosic: .
By interpolating for in Table 3.2 based on the floor area:
For office use:
We will conservatively not account for active suppression systems:
B. Thermal inertia of the fire compartment:
According to Table 3.4: , and
∑
∑
C. Ventilation factor:
Since there are multiple openings, determine the equivalent opening height:
∑
√ √
D. Heating Phase:
The maximum temperature will occur at time tmax:
( ) ( ) ( ) ( )
, not required.
The maximum temperature experienced will be:
Calculate other time increments to provide ordinates on the graph.
E. Cooling Phase
Since:
. Therefore:
Temperature will return to ambient (20°C) at:

28
By: RS Walls
, or (from substituting and in the
equation above)
ANSWER 2:
From the above equations the following time-temperature curve has been produced.
Figure 3.4: Time-temperature curve for the firecell of Example 1, along with the standard fire curve
ANSWER 3:
a) For the Eurocode equation:
, by interpolating in Table 3.5 using
Vertical ventilation: ⁄ ⁄
Horizontal ventilation: ⁄ ⁄
Vertical opening factor:
Ventilation factor: [ ]
[ ]
Fire load:
Thus, the equivalent standard fire time is:
b) For the CIB equations:
, but interpolating in Table 3.5 using
( )
0
200
400
600
800
1000
1200
0 20 40 60 80 100 120
Temperature
(°C)
Time (min)
θg (degC): Std Fire

29
By: RS Walls
From these results it can be seen that the Eurocode and CIB equations calculate fairly different values.
However, it should be noted that both are significantly lower than the 60 minute fire rating required
by SANS 10400.
TUTORIAL 2: FIRE CURVES
i) Generate a time-temperature fire curve according to EN 1-1-2 for the following firecell:
A 10m x 5m library with a 3m inter-floor height.
The walls and ceiling are gypsum board, and the floor is light weight concrete.
1 Door: 1m x 2m high. 3 Windows: 2m x 2m.
ii) Determine the equivalent standard fire time using the EN and CIB equations.
*Note: This example has been put together to demonstrate a very hot fire. Most fires are
substantially cooler.
HINT: Use a 5 second time step when generating your curve so you can use the same
spreadsheet for the next tutorial.

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4. The Behaviour of Steel at Elevated Temperatures
Now that we know what type of fire can be used for design and what temperatures are experienced
with time it needs to be determined how steelwork will respond to these fire. In general the properties
of steel degrade with increasing temperature. By the time steelwork reaches 1200°C it behaves more
like spaghetti than a construction material.
4.1The Thermal Response of Steelwork – Material Properties
The equations from this section are provided in Part 1-2 of Eurocode 3.
4.1.1 Elongation of structural and reinforcing steels
The thermal elongation (Δl/l) which structural and reinforcing steels experience when at elevated
temperatures can be determined by:
for 20°C ≤ θa ≤ 750°C (4.1)
for 750°C < θa ≤ 860°C (4.2)
for 860°C < θa ≤ 1200°C (4.3)
where
θa is the length at 20°C of the steel member
is the elongation of the member induced by the temperature change
θa is the steel temperature
In simple calculation models the elongation can simply be taken as: . The value
of can be viewed as the elevated temperature coefficient of thermal expansion.
This behaviour is illustrated below. If steelwork is restrained from expanding it can introduce very
high forces within members which need to be considered (but are generally not).
Figure 4.1: Steel thermal elongation as a function of temperature
0
2
4
6
8
10
12
14
16
18
20
0 200 400 600 800 1000 1200
Δl/l
-
Steel
Elongation
(x10
-3
)
θa - Steel temperature (°C)

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4.1.2 Specific Heat of Steelwork
The specific heat of a steel, ca, is the amount of energy required to heat 1kg of the material by 1
degree Kelvin or Celsius. It is important because it greatly influences the rate at which steelwork heats
up. The equations for determining the specific heat are:
[J/kgK]
for 20°C ≤ θa ≤ 600°C
(4.4)
[J/kgK] for 600°C ≤ θa ≤ 735°C (4.5)
[J/kgK] for 735°C < θa ≤ 900°C (4.6)
[J/kgK] for 900°C < θa ≤ 1200°C (4.7)
In simple models the value can be taken as: ca = 600 J/kgK.
The graph of specific heat is shown below. The spike in the middle is due to a phase change in the
steelwork whereby additional energy is absorbed without an increase in the temperature of the
steelwork. This causes the non-linear graphs often observed in relation to steelwork.
Figure 4.2: Specific heat of steel as a function of temperature
4.1.3 Thermal Conductivity
The thermal conductivity of steelwork, λa, is the rate at which it transmits heat. This property also
influences the rate at which steelwork heats up during a fire. It is given by:
[W/mK] for 20°C ≤ θa ≤ 800°C (4.8)
[W/mK] for 800°C ≤ θa ≤ 1200°C (4.9)
In simple calculation models a constant value of W/mK can be used.
The graph of thermal conductivity against temperature is shown below. After the phase change the
thermal conductivity remains constant.
0
500
1000
1500
2000
2500
3000
0 200 400 600 800 1000 1200
c
a
-
Specific
Heat
(J/kgK)

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Figure 4.3: Thermal conductivity as a function of temperature
4.2Thermal Response of Steelwork – Structural Properties
Now it must be determined how the structural properties of steelwork vary with increasing
temperature. For this purpose the Eurocode guidelines will be used, since even the Canadian code
references the elevated temperature properties from the Eurocodes. The Eurocodes use the concept of
a reduction factor, k, which is multiplied by the original material property. The reduction factors given
below for steelwork at temperature θa are:
 ku,θ – Ultimate steel strength relative to yield strength.
 ky,θ – Reduction factor for the steel yield strength. A curve has been fitted to this data as
shown below.
 kE,θ – Reduction factor for the Young’s modulus. It is interesting to see that it reduces faster
than the yield strength.
 kp,θ – This applies to the end of the proportional limit stage of the stress-strain graph, i.e.
when the graph starts becoming non-linear. This is not commonly used in general design.
 k0.2p,θ – Reduction factor for the strength of hot-rolled and welded thin walled sections (Class
4 Sections). This accounts for local buckling. Generally Class 4 section behaviour at elevated
temperature is very complex.
From the table and graph below the strength and stiffness of steelwork at elevated temperatures can
quickly be determined. To assist with the use of spreadsheets various curves have been fitted to the
yield strength equation. The one below has been provided by Franssen and Vila Real (2010):
{ ( )}
⁄
(4.10)
0
10
20
30
40
50
60
0 200 400 600 800 1000 1200
λa
-
Thermal
conductivity
(W/mK)

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Figure 4.4: Reduction factors for various steel properties at elevated temperatures
Steel
temp. θa
Reductio factors at te perature θa relative to the value of fy or Ea at 20°C
ky,θ – Yield
Strength
kE,θ – You g’s
Modulus
kp,θ – Prop.
limit
ku,θ – Ultimate
Strength
k0.2p,θ – Class 4
Sections
20 °C 1.000 1.000 1.000 1.250 1.000
100 °C 1.000 1.000 1.000 1.250 1.000
200 °C 1.000 0.900 0.807 1.250 0.890
300 °C 1.000 0.800 0.613 1.250 0.780
400 °C 1.000 0.700 0.420 1.000 0.650
500 °C 0.780 0.600 0.360 0.780 0.530
600 °C 0.470 0.310 0.180 0.470 0.300
700 °C 0.230 0.130 0.075 0.230 0.130
800 °C 0.110 0.090 0.050 0.110 0.070
900 °C 0.060 0.068 0.038 0.060 0.050
1000 °C 0.040 0.045 0.025 0.040 0.030
1100 °C 0.020 0.023 0.013 0.020 0.020
1200 °C 0.000 0.000 0.000 0.000 0.000
NOTE: For intermediate values of the steel temperature linear interpolation may be used
Table 4.1: Reduction factors for steelwork at temperature θa according to EN 3-1-2
Sections should be classified in the same way as that done at ambient temperature according to SANS
10162-1. Only those which are considered to experience local buckling before reaching yield stress
are to have the Class 4 curve applied to them.
0.000
0.200
0.400
0.600
0.800
1.000
1.200
1.400
0 200 400 600 800 1000 1200
Reduction
Factor
Temperature (°C)
ku,θ = fu,θ / fy
ky,θ = fy,θ / fy
kE,θ = Ea,θ / Ea
kp,θ = fp,θ / fy
k0.2p,θ = f0.2p,θ / fy

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4.3Bolt and Connection Behaviour
Connections exhibit extremely complicated behaviour during a fire. This is a current topic of research
and beyond the scope of this course. However, the degradation of bolts and welds with increasing
temperature is shown below. It can be seen that the strength of connectors reduce faster than normal
structural steel. But, joints are often shielded by surrounding beams and have a much higher
concentration of mass so do not heat up as fast, and normally reach lower maximum temperatures.
Figure 4.5: Reduction factors for bolts (kb,θ) and welds (kw, θ) at elevated temperatures (EN 3-1-1)
Steel
te perature θa
Reduction Factor
Bolts - kb,θ Welds - kw,θ
20 °C 1.000 1.000
100 °C 0.968 1.000
200 °C 0.935 1.000
300 °C 0.903 1.000
400 °C 0.775 0.876
500 °C 0.550 0.627
600 °C 0.220 0.378
700 °C 0.100 0.130
800 °C 0.067 0.074
900 °C 0.033 0.018
1000 °C 0.000 0.000
1100 °C 0.000 0.000
1200 °C 0.000 0.000
Table 4.2: Reduction factors for bolts and welds at elevated temperatures (EN 3-1-1)
0.000
0.200
0.400
0.600
0.800
1.000
1.200
0 200 400 600 800 1000 1200
Reduction
Factor
Temperature (°C)
kw,θ
kb,θ

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4.4Heat Transfer Equations
4.4.2 AThe Ap/V Concept
An important concept to understand when using both prescriptive design methods and performance-
based design methods is that of the section factor, Am/V. When a steel member is encased this is
referred to as Ap/V. In older publications it used to be noted as Hp/A (heat perimeter per unit area). It
is calculated by:
(4.11)
The section factor is explained well and graphically shown in Section 5.1 of the Euro-nomogram, and
shown in Figure 4.6. The effect of different section factors is demonstrated below in Figure 4.7.
Stockier members have lower section factors and heat up less quickly.
Figure 4.6: Section factors depending on the protection material used and presence of a slab above.

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Figure 4.7: Heating curves for various beam sizes (Hp/A ratios) in a standard fire test (Corus, 2006)
4.4.3 Unprotected Steelwork
Since the Canadian code steelwork design guidelines are being adopted for member design it is
proposed that the Canadian heat transfer equations also be used, as will possibly be the case for the
next version of SANS 10162-1. However, the difference in results between the two codes is generally
less than a few percent to not a concern. Heat transfer equations for all codes are typically based upon
simplified, lumped mass transfer equations.
In a time period Δt the change in the temperature of unprotected steelwork is given by the
commentary on the Canadian CSA S16 (CISC, 2010) code as:
(4.12)
The coefficient of heat transfer, a, is:
(4.13)
where:
(4.14)
with symbols defined above as:
ac is the convective radiative heat transfer coefficient, approximated as 25W/mºC
ar is the radiative heat transfer coefficient (W/mºC)
cs is the specific heat of the steel (J/kgºC)
D is the exposed perimeter of the member (m)
M is the mass per unit length of the member (kg/m)
TF is the fire or gas temperature (ºC)
Ts is the steel temperature (ºC)
ΔT is the temperature rise in an unprotected section in the time period (°C)

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Δt is the time step, limited to 5 seconds for accuracy reasons (sec)
εF is a parameter accounting for the emissivity of the fire and view factor
The following guidelines are provided for estimating the emissivity factor:
Type of Assembly εf
Column, exposed on all sides 0.7
Floor beam: imbedded in the concrete floor slab,
with only bottom flange of beam exposed to fire
0.5
Floor beam, with concrete slab resting on top
flange of beam:
- Flange width : beam depth ratio ≥ 0.5 0.5
- Flange width : beam depth ratio < 0.5 0.7
Box girder and lattice girder 0.7
Table 4.3: Guidelines for estimating the emissivity factor
It should be noted that in this equation the rate of heat change is proportional to the difference in steel
and gas temperatures to the power of 4. Thus, there is a rapid increase in radiative heat transfer as the
temperature in a room rises.
4.4.4 Protected Steelwork
To reduce the rate at which steelwork temperature rises it is often advisable to protect steelwork with
various passive protection systems. These have discussed previsouly. The change in temperature
during the time period Δt for a protected steel member is given by:
When: (the thermal capacity of the insulation is much less than that of the steel
and can be ignored)
(4.15)
Otherwise (when the thermal capacity of the insulation must be considered):
[ ] (4.16)
where:
cp is the specific heat of the coating (J/kgºC)
ρp is the coating density (kg/m3
)
dp is the coating thickness (m)
kp is the thermal conductivity of the coating (W/mºC)

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EXAMPLE 5: HEAT TRANSFER EQUATIONS
QUESTION:
1) What temperature does the column on Gridline B3 and primary beam on Gridline B reach for
the fire curve generated in EXAMPLE 4:. Generate time-temperature curves to show the
behaviour. Consider the following for each member:
a. The member being bare steel.
b. Protection by being boxed out with 12mm gypsum board.
ANSWER 1:
a) Column of GL. B3 - Unprotected
i) For a UC 203x203x46 bare column: Ap / V = 205m-1
(Section 5.2, Euro-Nomogram).
(useful conversion equation)
ii) εF = 0.7 for a column exposed on all sides.
iii) Time increment to be used: 5 seconds.
iv) At the first time increment: TF = 45.1°C, from Example spreadsheet.
Thus, the temperature at the end of the first time period is: 20.14°C. The remaining
steps have been carried out to generate the graph below.
b) For the cladded column:
ii) Perimeter of the boxed out section
iii) For gypsum board: cp = 1700 J/kgºC. ρp = 800kg/m3
. dp = 0.012m. kp = 0.20W/m°C.
iv) 32640. Thus, equation (4.16) must be used.
[ ] [ ]
The remainder of the calculations have been carried out as shown in the graph below.
Maximum temperatures – Unprotected: 837.6°C
- Protected: 582.4°C

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Figure 4.8: Temperatures of the protected and unprotected UC 203x203x46 column.
ANSWER 2:
a) Primary Beam on Gl. B, unprotected:
i) For a UB 533x210x82 bare column: Ap / V = 180m-1
ii) Flange width : beam depth = 210 / 533 = 0.39 < 0.5, so εF = 0.7
b) Perimeter of the boxed out section:
iii) Ap / V = 120m-1
See the curves below for the temperature.
Maximum temperatures – Unprotected: 827.32°C
- Protected: 562.3°C
Figure 4.9: Temperatures of the protected and unprotected UC 533x210x82 beam.
0
100
200
300
400
500
600
700
800
900
1000
0 20 40 60 80 100 120
Temperature
(°C)
Time (min)
EN 1-1-2 Fire
Unprotected
Protected
0
100
200
300
400
500
600
700
800
900
1000
0 20 40 60 80 100 120
Temperature
(°C)
Time (min)
EN 1-1-2 Fire
Unprotected
Protected

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TUTORIAL 3: HEAT TRANSFER EQUATIONS
Using the fire curve that you generated from the last tutorial generate time-temperature graphs and
determine the maximum temperatures for a UC 305x305x97 grade S355JR exposed on all sides in the
firecell with:
a) No passive fire protection.
b) 24mm vermiculite boards, boxing out the entire section.
Submit a graph showing the temperature development with time.

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5. Member Design for Fires
5.1Prescriptive Design
The simplest rules available for the prescriptive design of steelwork occur in SANS 10400. The
thicknesses of coatings are given to provide certain fire resistances. These guidelines will not be
considered as there are a number of fairly simple guides which provide much better design
information.
5.2The “Yellow Book”
A guide to consider for passive protection fire design is the “Yellow Book” published by the
Association for Specialist Fire Protection (ASFP, 2010) (available free at www.asfp.org.uk). The
design is based upon limiting the temperature of steelwork to the “critical temperature” as listed
below, which depends on the load ratio. The critical temperature is defined as “The temperature at
which failure of the structural steel element is expected to occur against a given load level”. Example
6 below is taken from the Yellow Book to illustrate how coating thickness might be determined.
EXAMPLE 6: YELLOW BOOK FIRE PROTECTION

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Table 5.1: Limiting temperatures for the design of protected steelwork according to the "Yellow Book" (ASFP, 2010)
5.3Euro-Nomogram
Another good resource for determining the thickness of passive protection is the Euro-Nomogram
published by the ECCS. It is contained on the following pages. It can be freely downloaded after
registering online with the ECCS as part of the document “Explanatory Document for ECCS No 89 -
Euro-Nomogram - Fire Resistance of Steel Structures” (ECCS, 1999).
Examples are given in the Nomogram regarding how to use it.

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EXAMPLE 7: COATING THICKNESS TO THE EURO-NOMOGRAM
QUESTION: Determine the thickness of boxed out gypsum boards required to give the column from
the previous example a 60 minute fire rating (SANS 10400).
ANSWER: For the profile Ap/V = 138.1m-1
(140 in the Euro-Nomogram). The column is exposed on
all 4 sides and is important for overall stability, so K = 1.2.
From the Red Book the strength of a UC 203x203x46 with a 4m effective length: Cr = 1067kN.
Thus, using the fire load from Example 3 of 551kN, the degree of utilisation is:
Now to go the Nomogram: Enter the graph on the left at . Go up to K=1.2. On the right
enter the Nomogram at a fire resistance of 60 min. Go up to meet the line projected across from
K=1.2. From this we approximately get:
By substituting the gypsum board value we get: dp = 20.5mm.
Thus, an approximately 20mm thick board will be sufficient.
TUTORIAL 4: EURO-NOMOGRAM COATING THICKNESS
Determine the thickness of passive protection for a UC 305x305x97 of grade S355JR requiring 60min
fire rating. Consider it to be important for stability. Vermiculite boards will be used to fully box out
the column, which is exposed on all sides.
5.4Design to the Canadian Steelwork Code – CSA S16 Annex K
5.4.2 Tensile Resistance
The tension resistance of a member is determined in the same way that it is done an ambient
temperature, but with the reduced yield strength of members.
5.4.3 Compressive Resistance
The compressive resistance at temperature T is given by:
( )
(5.1)

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√ √ (5.2)
with:
d equals 0.6
n equals 1.34 for general steelwork
Figure 5.1 shows the failure stress for columns when at ambient temperature, 500°C and 800°C. It can
be seen that the strength of members degrades very quickly with increasing temperature.
Figure 5.1: Compressive failure stress of columns according to CSA S16
5.4.4 Bending Resistance
The resistance of a member in bending under lateral-torsional buckling is given as:
( ) (5.3)
where
Ck 0.12
Mp(T) is the plastic moment at elevated temperature, T
Mu(T) is the elastic critical load at elevated temperature T, given by:
√ (5.4)
where
ω2 is a factor to account for the bending moment shape. This can be taken as defined in
Table 5.4 of the Red Book.
(5.5)
For a fully restrained beam the resistance can simply be calculated as the plastic or elastic section
modulus (depending on what class it is) multiplied by the reduced yield strength of the steelwork.
0
50
100
150
200
250
300
350
0 50 100 150 200
Cr(T)/A
-
Failure
Stress
(MPa)
KL/r - Slenderness Ratio
20°C
500°C
800°C

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The lateral-torsional buckling resistance of a UB 406x178x54 is shown in the figure below.
Figure 5.2: Lateral-torsional buckling resistance of a UB 406x178x54 beam at different temperatures
5.4.5 Combined Axial Force and Flexure
Beam-columns are to be designed in the same manner as done at ambient temperature with the
reduced member capacities as defined above.
EXAMPLE 8: CANADIAN STEEL DESIGN EXAMPLE
QUESTION: Check the design capacity of the UC 203x203x46 column in the fire compartment at
the fire limit state. Obtain maximum temperatures from Example 5, considering both the protected
and unprotected member.
ANSWER:
Obtain the reduction factor for fy and E from Table 3.5 by interpolation.
UC 203x203x46
Details:
Maximum
Temperature:
ky,θ: kE,θ:
fy((T)
(MPa):
E(T)
(GPa):
Bare steel 837.6°C 0.091 0.082 32.3MPa 16.4GPa
Protected –
12mm gypsum
582.4°C 0.525 0.361 186.4MPa 72.2GPa
√ √
( )
0
50
100
150
200
250
300
350
400
450
0.0 2.0 4.0 6.0 8.0 10.0
Mr
-
Bending
resistance
(kNm)
KL - Effective length (m)
20°C
500°C
800°C

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Using the same equations: for the protected member. Thus, the column is
insufficient for the 551kN load calculated earlier for the FLS.
However, note that for the Eurocode the effective length can be reduced to 0.5 of the original because
of the cool columns above and below acting as fixities. For the top floor of a building a factor of 0.7
should be used. If an effective length of 0.5L is used the resistance will increase to around 674kN for
the protected member. This would be sufficient for resistance.
TUTORIAL 5: STEEL RESISTANCES
QUESTIONS:
1) Determine the capacity of a UC305x305x97 grade S355JR column which is 5m long and at
750°C. What would the capacity be is the effective length was halved as per the Eurocodes for
columns between intermediate floors in buildings?
2) Determine the bending resistance of a 5m long UB 406x140x39 grade S355JR beam at
650°C. Consider the beam to be unbraced along its full length, so the effective length can be
taken as 1.0. The beam carries a UDL and is simply-supported.
5.5A Brief Introduction to Advanced Design Methods
Significant advances have been made in structural fire engineering since the series of full-scale fire
tests done at BRE’s Large Building Test Facility at Cardington from 1993 to 2003 (European Joint
Research Program, 1999). In these tests a purpose-built 8 storey building was progressively burnt
down to investigate the behaviour of steel and composite buildings at elevated temperatures.
The tests demonstrated that the interaction between members has a significant effect on overall
structural fire behaviour (Lennon, 2011). It is interesting to note that during none of the tests
structural collapses were observed, even when the atmosphere temperature reached 1200ºC, and the
temperature of exposed steel beams reached 1150ºC (Bailey, 2002). Current design codes (BS5950-8,
EN1994-1-2) predicted that the beams would fail at temperatures of around 680ºC, showing that
practice does not fully match codes at this stage. Figure 5.3 shows a photo of failed beams and a
buckled column as observed at the Cardington tests. The floor deflections were substantial but the
floors exhibited catenary-type tensile behaviour which greatly enhanced the capacity of the floors, as
shown in Figure 5.4.

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Figure 5.3: Failed column and beams at the Cardington fire tests (Lamont, 2001)
Figure 5.4: Large deflections observed in the composite floors during the Cardington tests (Lamont, 2001)
Following on from the Cardington tests various design methods have been produced, along with
software to carry out the analyses. The general principle behind these methods is to protect the
primary beams and columns in a structure, but allow the secondary beams to fail in case of a fire. This
can result in substantial savings, where up to 50% of beams do not need passive protection.
Figure 5.5 shows the typical layout and failure mechanism observed in a composite when it fails
during a fire.

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Figure 5.5: Layout for the SPM. The typical crack pattern associated with the inelastic, large-deflection behaviour of
composite slabs at elevated temperatures is shown
Some of the software systems that have been produced for composite fire design include:
SPM: SPM stands for the Slab Panel Method and has been developed by Prof. Charles Clifton
and HERA in New Zealand. It is currently being investigated at Stellenbosch University and
could be introduced as a viable design method for South Africa.
TSLAB: This is a spreadsheet that has been developed in the UK by the Steel Construction
Institute (SCI) and is based upon Bailey’s tensile membrane design method for composite
structures
MACS+: MACS+ is a package freely distributed by Arcelor Mittal and its name stands for
Membrane Action of Composite Structures in Case of Fire (Vassart & Zhao, 2012). It used to be
known as FRACOF and has also been built upon Bailey’s (2002) membrane action method for
designing composite slabs. Cellular and protected steel supporting beams can be considered. It
has many similarities to the SPM software.

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6. References
ASFP, 2010. Fire protection for structural steel in buildings "The Yellow Book". 4th ed. Hampshire:
Association for Specialist Fire Protection.
Bailey, C., 2002. Structural fire design of unprotected steel beams supporting composite floor slabs.
Sao Paulo, II CICOM II International Conference on Steel Construction .
Bontempi, F. & Petrini, F., 2010. Fire induced collapses in structures: Basis of the analysis and
design. London, Taylor and Francis, pp. 685-690.
BSI, 2001. BS 7974: Application of fire safety engineering principles to the design of buildings - Code
of practice, London: British Standards Institute (BSI).
BSI, 2002. BS EN 1991-1-2:2002: Eurocode 1: Actions on structures - Part 1-2: General Actions -
actions on structures exposed to fire, London: British Standards Institute (BSI).
BSI, 2005a. BS EN 1992-1-2:2005: Eurocode 2: Design of concrete structures – Part 1-2: General –
Structural fire design, London: British Standards Institute (BSI).
BSI, 2005b. BS EN 1993-1-2:2005: Eurocode 3: Design of steel structures – Part 1-2: General –
Structural fire design, London: British Standards Institute (BSI).
BSI, 2005c. BS EN 1994-1-2:2005: Eurocode 4: Design of composite steel and concrete structures –
Part 1-2: General – Structural fire design. London: British Standards.
BSI, 2008. BS 9999:2008. Code of practice for fire safety in the design, management and use of
buildings, London: British Standards Institute (BSI).
Buchanan, A., 2001. Structural Design for Safety. New York: Wiley.
Budny, I. & Giuliani, L., 2010. A comparison between prescriptive- and performance-based
approaches in fire safety design of structures. Rome, La Sapienza.
CEC, 1988. Construction Product Directive, dated 21.12.1988. Official Journal of the European
Commission, L40(12), p. 89/106/EEC.
CISC, 2010. CISC Commentary on CSA S16-09 Annex K Structural Design for Fire Conditions,
Ontario: Canadian Institute of Steel Construction.
Clifton, G., 2013. Cost-effective fire resistant multi-storey steel structures. Johannesburg, SAISC.
Corus, 2004. Fire design for steel structures: Engineered for safety and economy. Scunthorpe: Corus
Construction & Industrial.
Corus, 2006. Fire resistance of steel-framed buildings. North Lincolnshite, Corus Construction and
Industrial.
CSA, 2009. CSAS16-09 Design of steel structures, Toronto: Canadian Standards Association.
Dunaiski, P., Retief, J. & Goliger, A., 2007. Proposed new South African loading code SANS 10160,
Pretoria: CSIR.
ECCS, 1999. Explanatory Document for ECCS No 89 'Euro-Nomogram' Fire Resistance of Steel
Structures, Brussels: European Convention for Constructional Steelwork.
ECCS, 2001. Model Code on Fire Engineering. First ed. Berne: European Convention for
Constructional Steelwork.
Engelhardt, M. D., 2013. Lecture Notes: Introduction to Structural Fire Engineering. Notes ed.
Austin: University of Texas at Austin.
European Joint Research Program, 1999. The behaviour of multi-storey steel framed buildings in fire,
Rotherham: British Steel plc.

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Favre, J.-P., Fontana, M. & Hass, R., 1994. Optimal Fire Safety through Modern Engineering
Approaches. Luxembourg, European Convention for Constructional Steelwork, pp. 21-54.
Feasey, R., 1999. MSc Thesis: Post-flashover design fires. Christchurch: University of Canterbury.
Feeney, M. & Buchanan, A., 2000. Accounting for Sprinkler Effectiveness in Performance Based
Design of Steel Buildings, Christchurch: The University of Canterbury.
FEMA, 2002. World Trade Centre Building Performance Study: Data Collection, Preliminary
Observations and Recommendations., New York: Federal Emergency Management Agency.
FPASA, 2013. Fire Stats 2011. Fire Protection, Volume June, pp. 37-51.
Franssen, J.-M. & Vila Real, P., 2010. Fire Design of Steel Structures. First ed. Berlin: European
Convention for Constructional Steelwork.
IFE, 2014. The Institution of Fire Engineers. [Online]
Available at: http://www.ife.org.uk/FAQs
[Accessed 18 March 2014].
Iqbal, S. & Harichandran, R., 2010. Capacity Reduction and Fire Load Factors for Design of Steel
Members Exposed to Fire. Journal of Structural Engineering, ASCE, 136(December), pp. 1554-1562.
ISO, 1999. ISO 834 Fire-resistance tests -- Elements of building construction. Parts 1-12, Geneva:
International Organization for Standardization.
Lamont, S., 2001. PhD Thesis: The Behaviour of Multi-Storey Composite Steel Framed Structures in
Response to Compartment Fires. Edinburgh: University of Edinburgh.
Lennon, T., 2011. Structural Fire Engineering. First ed. London: ICE Publishing.
Lennon, T., Moore, D., Wang, Y. & Bailey, C., 2007. Designers' guide to EN1991-1-2, EN1992-1-2,
EN1993-1-2 and EN1994-1-2. 1 ed. London: Thomas Telford.
Nyman, J., 2002. MSc Thesis: Equivalent Fire Resistance Ratings of Construction Elements Exposed
to Realistic Fire. Christchurch: University of Canterbury.
Oxford, 2014. Oxford Dictionaries. [Online]
Available at: www.oxforddictionaries.com/definition/english/fire
[Accessed 02 Fabruary 2014].
Petrini, F., 2010. Numerical analyses for Performance-Based Fire Engineering (PBFE). London,
Taylor & Francis, pp. 711-714.
Retief, J. & Dunaiski, P., 2009. The Limit States Basis of Structural Design for SANS 10160-1. In: J.
Retief & P. Dunaiski, eds. Background to SANS 10160. Stellenbosch: SUN MeDIA, pp. 25-55.
SABS, 2005. SANS 10162-1:2005. The structural use of steel. Part 1: Limit-state design of hot-rolled
steelwork, Pretoria: South African Bureau of Standards.
SABS, 2005. SANS 10177-2: Fire testing of materials, components and elements used in buildings
Part 2: Fire resistance test for building elements, Pretoria: South African Bureau of Standards.
SABS, 2010. SANS 10400: The application of the National Building Regulations. Part T: Fire
protection., Pretoria: South African Bureau of Standards.
SABS, 2011. SANS 10160: Basis of structural design and actions for buildings and industrial
structures, Pretoria: South African Bureau of Standards.
SABS, 2011. SANS 10162-2:2011 The structural use of steel. Part 2: Cold-formed steel structures,
Pretoria: SABS.
States News Service, 2010. Michigan State Universty Hosts International Conference in Structural
Fire Engineering, East Lansing, MI: Biography In Context.

An Introduction To Structural Fire Engineering - Course Notes 2014

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