NIST WTC Workshop

Building and Fire CodesBuilding and Fire CodesStephen S. Szoke, P.E.Stephen S. Szoke, P.E.Director of Codes and StandardsDirector of Codes and StandardsPortland Cement AssociationPortland Cement Association5420 Old Orchard Road5420 Old Orchard RoadSkokie, IL 60077Skokie, IL 60077847847--972972--90789078

NIST WTC Workshop

Just Another Government Just Another Government ReportReport

2005 2005 –– NIST WTC InvestigationNIST WTC Investigation2003 2003 –– FEMA/ASCE ObservationsFEMA/ASCE Observations1960 1960 –– 2005 2005 –– USFA Reports and USFA Reports and SpecificSpecific Recommendations for Recommendations for HighHigh--Rise ConstructionRise Construction

NIST WTC Workshop

Fire Codes and StandardsFire Codes and Standards

Building Code RequirementsBuilding Code Requirements–– International Code CouncilInternational Code Council–– National Fire Protection AssociationNational Fire Protection Association

Fire StandardsFire Standards–– American Society for Testing and American Society for Testing and 

MaterialsMaterials

NIST WTC Workshop

Fire StandardsFire Standards

ASTM E 119 Standard Test ASTM E 119 Standard Test Methods for Fire Tests of Building Methods for Fire Tests of Building Construction and MaterialsConstruction and Materials

NIST WTC Workshop

Time Temperature CurveTime Temperature CurveReal FiresReal Fires

Time

Tem

pera

ture

5 kg/m5 kg/m2 2 (1lb.ft(1lb.ft22))

100 kg/m100 kg/m2 2 (21 lb.ft(21 lb.ft22))

25 kg/m25 kg/m2 2 (5 lb.ft(5 lb.ft22))

ASTM E 119 Std CurveASTM E 119 Std Curve

NIST WTC Workshop

Safety FactorsSafety Factors

Structural Design Load FactorStructural Design Load Factor1.2 Dead + 1.6 Live Load1.2 Dead + 1.6 Live Load

Structural Design Resistance FactorStructural Design Resistance Factor0.60 to 0.85 concrete elements0.60 to 0.85 concrete elements

Overall Safety Factor of 1.8 to 2.7 Overall Safety Factor of 1.8 to 2.7 

NIST WTC Workshop

Safety Factor Applied to Safety Factor Applied to Real FiresReal Fires

Time

Tem

pera

ture

Real 5 kg/mReal 5 kg/m22

Real 100 kg/mReal 100 kg/m22100 kg/m100 kg/m2 2 with SFwith SF

5 kg/m5 kg/m2 2 with SFwith SF

NIST WTC Workshop

Various Combustible Various Combustible ContentContent

Time

Tem

pera

ture

PlasticPlasticTextileTextile

WoodWoodRubberRubber

NIST WTC Workshop

Real FiresReal Fires

Safety FactorsSafety FactorsComplicationsComplications–– Combustible content of assembliesCombustible content of assemblies–– Type of building contentsType of building contents–– Quantity of building contentsQuantity of building contents

Numerous TestsNumerous TestsHuge ExpenseHuge Expense

NIST WTC Workshop

Standard E 119Standard E 119

TimeTime--Temperature Curve may be unTemperature Curve may be un--conservative for engineering design.conservative for engineering design.

TimeTime--Temperature Curve could be Temperature Curve could be replaced by Heat Fluxreplaced by Heat Flux--Time CurveTime Curve

Reporting could be improvedReporting could be improvedMeasurements and equipment could be Measurements and equipment could be 

improved and more consistentimproved and more consistentStandardized testing apparatusStandardized testing apparatus

NIST WTC Workshop

Meeting Standard Test Meeting Standard Test RequirementsRequirementsMore robust systems initiallyMore robust systems initiallyNew designs of materials and New designs of materials and 

systems to meet the minimum systems to meet the minimum requirements of testsrequirements of tests

Need for a robustness component Need for a robustness component for all assembliesfor all assemblies

NIST WTC Workshop

Building Codes Building Codes RequirementsRequirements

Passive fire protection Passive fire protection requirementsrequirements–– Routinely relaxed over the last forty Routinely relaxed over the last forty 

yearsyears–– Routinely reduced for as economical Routinely reduced for as economical 

justification for sprinklersjustification for sprinklers

NIST WTC Workshop

Building Code Building Code RequirementsRequirements

Increases in cost for structural design Increases in cost for structural design and construction to resist seismic and construction to resist seismic forcesforcesIncreases in cost of energy Increases in cost of energy conservation with no direct relation to conservation with no direct relation to life safetylife safetyNo increases in costs for fire protection No increases in costs for fire protection and relaxation of requirements to and relaxation of requirements to justify expense of sprinklersjustify expense of sprinklers

NIST WTC Workshop

Building Code Building Code RequirementsRequirements

1968 1968 ChicagoChicago

WTC WTC TowersTowers

20032003IBCIBC

Columns, girders, Columns, girders, beams, trusses and beams, trusses and spandrels   spandrels   

Supporting floorsSupporting floorsSupporting roofsSupporting roofs

4 hr4 hr3 hr3 hr

3 hr3 hr2 hr2 hr

2 hr2 hr1 hr1 hr

Floor SystemsFloor Systems 3 hr3 hr 2 hr2 hr 2 hr2 hr

Roof SystemsRoof Systems 2 hr2 hr 1 hr1 hr 1 hr1 hr

NIST WTC Workshop

Major Burnout Without Major Burnout Without CollapseCollapse

2004 LaSalle Bank Building, 2004 LaSalle Bank Building, ChicagoChicago2001 90 West, New York 2001 90 West, New York 1991 One Meridian Plaza, 1991 One Meridian Plaza, Philadelphia (1973)Philadelphia (1973)1988 Interstate Bank Building, 1988 Interstate Bank Building, Los Angeles (1973)Los Angeles (1973)

NIST WTC Workshop

One Meridian PlazaOne Meridian Plaza

3 hour columns3 hour columns2 hour floors2 hour floorsConcrete and masonry shafts and Concrete and masonry shafts and stairwaysstairwaysBurned for 19 hoursBurned for 19 hoursSevere floor deflectionsSevere floor deflections

NIST WTC Workshop

LaSalle Bank BuildingLaSalle Bank Building

4 hour columns4 hour columns3 hour floors3 hour floorsBurned for 5Burned for 5--1/2 hours1/2 hoursCentral core of steel encased on Central core of steel encased on concrete and masonryconcrete and masonryMinimal floor deflectionsMinimal floor deflections

NIST WTC Workshop

Building Code Building Code RequirementsRequirements

Restore historic passive fire protection Restore historic passive fire protection requirementsrequirementsEliminate sprinkler trade offsEliminate sprinkler trade offs–– Hurricanes, earthquakes, other disruptions Hurricanes, earthquakes, other disruptions 

in water supplyin water supplyRequire redundancyRequire redundancy–– Alarms, sprinklers, and passive fire Alarms, sprinklers, and passive fire 

protectionprotectionCollapse resistanceCollapse resistance–– Design to permit total burnout without Design to permit total burnout without 

collapsecollapse

NIST WTC Workshop

Consideration of Other Consideration of Other Projects May Indicate:Projects May Indicate:

Robustness component is equally Robustness component is equally as important as fire enduranceas important as fire enduranceContinued trend for reduced Continued trend for reduced passive fire protection is not passive fire protection is not appropriateappropriateSprinkler tradeSprinkler trade--offs not offs not appropriate, redundancy is appropriate, redundancy is needed in highneeded in high--riserise

NIST WTC Workshop

Thank you!Thank you!Stephen S. Szoke, P.E.Stephen S. Szoke, P.E.Director of Codes and StandardsDirector of Codes and StandardsPortland Cement AssociationPortland Cement Association5420 Old Orchard Road5420 Old Orchard RoadSkokie, IL 60077Skokie, IL 60077847847--972972--90789078

- Building and Fire Codes
- Just Another Government Report
- Fire Codes and Standards
- Fire Standards
- Time Temperature CurveReal Fires
- Safety Factors
- Safety Factor Applied to Real Fires
- Various Combustible Content
- Real Fires
- Standard E 119
- Meeting Standard Test Requirements
- Building Codes Requirements
- Building Code Requirements
- Building Code Requirements
- Major Burnout Without Collapse
- One Meridian Plaza
- LaSalle Bank Building
- Building Code Requirements
- Consideration of Other Projects May Indicate:
- Thank you!