1. CE808: Structural Fire Engineering – Research Project
Impact of Design Fires on Performance of Steel Beams Under Fire Conditions
CE808: Structural Fire Engineering – Research Project
Megan Vivian
April 18th, 2008

2. History of ASTM E119 What you might not know…
ASTM E Swedish Curves Comparison SAFIR Analysis Conclusions
What you might not know…
American Society for Testing and Materials
First published in 1918
To specify a standard time-temperature curve for pass/fail criteria for structural elements
Designed to provide a comparative measure between structural members and building construction assemblies
Provide one factor in assessing fire performance
We’ve studied it and used it a lot this semester … but …

3. ASTM E119 Fire Curve The Good The Bad Easily reproduced
ASTM E Swedish Curves Comparison SAFIR Analysis Conclusions
The Good
Easily reproduced
Used as a standard for comparison
Provides good relation to building contents, materials of construction, and ventilation conditions
The Bad
Could be un-conservative for engineering design
Represents an intense fully developed fire within a building
Not always the scenario
Does not accurately model every fully developed fire
The development, growth, and decay of the fire depend upon the building contents, materials of construction, and ventilation conditions
Very simple and easy too use
But is it too simple?? Not well enough defined for specific cases?
Should only be used for comparison not as the only factor to determine fire performance (which is typically the case)

4. ASTM E119 Fire Curve The Good The Bad Easily reproduced
ASTM E Swedish Curves Comparison SAFIR Analysis Conclusions
The Good
Easily reproduced
Used as a standard for comparison
Provides good relation to building contents, materials of construction, and ventilation conditions
The Bad
Could be un-conservative for engineering design
Represents an intense fully developed fire within a building
Not always the scenario
Does not accurately model every fully developed fire
The development, growth, and decay of the fire depend upon the building contents, materials of construction, and ventilation conditions
Very simple and easy too use
But is it too simple?? Not well enough defined for specific cases?
Should only be used for comparison

5. Design Fire Curves Swedish Design Fire Curves
ASTM E Swedish Curves Comparison SAFIR Analysis Conclusions
Swedish Design Fire Curves
Published in 1970 by P. Jumppanen
Modeled to represent real fire curves
Derived from heat balance calculations
Use Kawagoe’s equation for burning rate of ventilation-controlled fires
Curves reflect the effects of changing fuel load and ventilation during the course of a real fire
Varying fuel loads and ventilation factors available
Scenarios
Model fires that reach post flashover and use all combustibles
Model fires that consider a slower fire with a longer duration
Model fires that follow a hydrocarbon fire (much hotter!!)

6. The Fire Curves
ASTM E Swedish Curves Comparison SAFIR Analysis Conclusions
Shown here is the standard ASTM curve
The few curves that reach post flashover
The curves that are slow growing and maintain lower temperatures
The curves that have short duration and quick cooling rates
The hydrocarbon fire curve

7. Thermal Analysis ASTM E119 Curve FV02100 Design Curve
ASTM E Swedish Curves Comparison SAFIR Analysis Conclusions
Used the same 2-hour rated protected steel beam for analysis with varying fire curves
ASTM E119 Curve
FV02100 Design Curve

8. Temperature Domain Failure
ASTM E Swedish Curves Comparison SAFIR Analysis Conclusions
For presentation only discuss temperature domain failures – did study the deflection criteria as well with structural analysis
Temperature at 2 hours in the lower flange of steel beam
If our temperature domain criteria is used at about 530°C … two curves fail the protected steel beam
ASTM is the fourth worst case scenario
One fire curve doesn’t even reach 120°C!

9. Maximum Temperatures Scenario Temperature (C) Hydrocarbon 559.5
ASTM E Swedish Curves Comparison SAFIR Analysis Conclusions
Scenario
Temperature (C)
Hydrocarbon
559.5
FV08800
533.5
FV12900
505.3
ASTM E119
469.2
FV08400
379.6
FV04200
318.8
FV02100
235.7
FV12225
167.7
FV08100
114.0
NIST WTC Workshop, Szoke

10. Conclusions
ASTM E Swedish Curves Comparison SAFIR Analysis Conclusions
ASTM E119 is useful for comparing performance between structural members and construction assemblies
To determine actual fire performance for a specific member or fire scenario, design fires should be considered
Can be completed with computer modeling (furnace testing would be very expensive)
Using most applicable curves - could run multiple tests to determine worse case scenarios
Even design fires cannot exactly match real fires
Difficulties measuring combustible content of assemblies and precise type or quantity of building contents
If the fire curve could be more properly modeled…
Safety factors could be improved upon
Huge impact on design and industry standards
How to make better fire curves…
Possibly use a heat-flux time curve to make a better model