Comments on NIST Recommendation 

T. D. Lin*

NIST -

WTC Disaster Conference, Septemb

* Research Professor

Fire Research LaboratoryNational Cheng K

ung University, Taiwan
NIST Recommendation Nos. 5

NIST Recommendation Nos. 5

Recommendat Recommendation No. 5 on No. 5NIST Recommends That The Technical Basis for The Ce

NIST Recommends That The Technical Basis for The Ce

for F

ire Resistance Testing of Co re Resistance Testing of Component mponents, Assemblies, a

s, Assemblies, a

be Improved through a National Effort. be Improved through a National Effort.Recommendat Recommendation No. 7 on No. 7

NIST Recommends NIST Recommends The Nationwide A The Nationwide Adoption and Use of 

doption and Use o

Frame Approach to Fire Resistance Ratings Frame Approach to Fire Resistance RatingsRecommendat Recommendation No. 9 on No. 9NIST Recommends The Recommends The Development of Performance Ba

Development of Performance Ba

and Code Provisions as an Alternative to Current Prescri and Code Provisions as an Alternative to Current Prescrip

Methods. Tools, Guidelines, and Methods. Tools, Guidelines, and Test Methods Necessary 

Test Methods Necessary 

The Fire Performance of The Stru The Fire Performance of The Structure should Form a Wh

cture should Form a Wh
Early Fire Resistance Investigatio

Early Fire Resistance Investigatio

In 1920s In 1920s 

National Bureau of Standards (NBS) Conducted B

National Bureau of Standards (NBS) Conducted B

Tests of Specially Construct Tests of Specially Constructed Buildings of 16x30

d Buildings of 16x30

30x60x9 ft. The Reports were 30x60x9 ft. The Reports were Publi

shed in 1922 a

hed in 1922 a

Started in 1925 Started in 1925 

NBS Fire Tested Sixty 8 S Fire Tested Sixty 8’-

9

” High R/C Columns o

High R/C Columns o

Square and Circular X Square and Circular X

-Sections Designed in Sections Designed in Acco

Acco

Prescriptive Code Developed based on The Worki

Prescriptive Code Developed based on The Worki

Fire Tests were Carried out Following The ASTM 

Fire Tests were Carried out Following The ASTM 

Test Data were Used to Determ Test Data were Used to Determine Structural Fire 

ine Structural Fire 

as Required by The Prescriptive Codes as Required by The Prescriptive Codes
Revisions of ACI Revisions of ACI

-318 C

1941 

- 2005 14 Revisions were Made 14 Revisions were Made

1941 

- 1971 The Working Stress Theory (WS

The Working Stress Theory (WS

1963 

- 1971 Shifting from 1971 Shifting from WST to Strength D

WST to Strength D

1971

- Present Present The Strength Design Theory has b

The Strength Design Theory has b

ACI 318 Refers F ACI 318 Refers Fire Safety Desig

re Safety Desig

“Standard Method for F “Standard Method for Fire Resist

re Resist

and Masonry Constructi and Masonry Construction Asse

on Asse
Impact of ACI Code Chan

Impact of ACI Code Cha

 Columns Designed Based on SDT are Thinne

Columns Designed Based on SDT are Thinne

Companion Columns Designed Following W

Companion Columns Designed Following W

 Thinner Columns Generally Ha Thinner Columns Generally Have Weaker Fi

ve Weaker Fi

 Building Officials Questioned Fire Resistanc

Building Officials Questioned Fire Resistanc

Designed in Accordance with SDT Designed in Accordance with SDT

 PCA & NRC were Asked to Update Column 

PCA & NRC were Asked to Update Column 
The Joint PCA/NRC Column 

The Joint PCA/NRC Column 

Program, 1980 Program, 1980 

- 2000

 Fire Tests of 40 Columns; 12 Fire Tests of 40 Columns; 12’-

9

” High, Various X High, Various X

with Carbonate, with Carbonate, Siliceous, Lightweight, and High 

 Siliceous, Lightweight, and High 

 Columns were Designed, Cast, Cured at PCA Fire 

Columns were Designed, Cast, Cured at PCA Fire 

Shipped to NRC in Ottawa Shipped to NRC in Ottawa

 Columns were Fire Tested at NR Columns were Fire Tested at NRC Fire Laborator

C Fire Laborator

Furnace Equipped with a 1000 ton Hydraulic Syst

Furnace Equipped with a 1000 ton Hydraulic Syst

 Results were Publi Results were Publi

shed in PCA and NRC Publi hed in PCA and NRC Publica

ca

U

sed to Determine Structural ed to Determine Structural Fire Ra Fire Ratings of Colu

tings of Colu

by Prescriptive Code by Prescriptive Code

 Average Cost for Each Test was approximately US 

Average Cost for Each Test was approximately US 
PCA/NIST Fire Tests of Concr

PCA/NIST Fire Tests of Concr

and Slabs and Slabs 1970’s to 1980 s to 1980

 Programs Programs 

were partial ere partially F

unded by nded by NBS and Tests NBS and Tests 

w

ere Conducte re Conducted at 

d at 

Using Its Large Floor and Beam Furnaces Furnaces Equipped with Ap Equipped with Appropriate 

propriate 

 A Dozen of 18X14 ft Flat, Pan n of 18X14 ft Flat, Pan-Joist, and Waffle Concrete Slabs were Te

, and Waffle Concrete Slabs were T

Determine Structural Fire Rati Determine Structural Fire Ratings of Different Slab Type ngs of Different Slab Types and Effect o

s and Effect o

Restrai Restraints. The Test Data were Publ ere Published in PCA Publ ished in PCA Publication and ACI 

 More Than a Dozen of More Than a Dozen of 40 ft Long Rec 40 ft Long Rectangular, T, Double lar, T, Double-T Concrete 

Tested to Determine Structural Fire Ratings of Different Tested to Determine Structural Fire Ratings of Different Beam Types In

Beam Types I

of One End Continuity and Two End Continuity. Results were Publishe

 The Same Results The Same Results 

were Used to De ere Used to Develop Rational Design of Rein velop Rational Design of Reinforced 

forced 

Members for Fire Resistance. Members for Fire Resistance. The Engineeri The Engineeri

ng Principles g Principles 

were Publish

ish

Safety Journal, Safety Journal, 1986

 Published Data were Used by ished Data were Used by Designers, Engineers, and Designers, Engineers, and Buildin Building Offici

g Offici

 A Special Project Invol A Special Project Involving Flex ng Flexural and Shear Behaviors of Beams in F

in F

Carried Out by PCA and The res rried Out by PCA and The result w

as Publis s Published by NBS. hed by NBS. GCR-87-53

 The Average Cost Per Tes The Average Cost Per Test w

as approxim s approxim

ately $25,000. tely $25,000.
Standard Fire Test Proce

ASTM E-119, ISO-834, CEN/TC127, DIN10JISA1304, and CNS-12514 Cross References Resulted to almost Identica

Furnace Sizes Time-Temp. Curves, Exceedingly CoSpecimen Dimensions Support Conditions, ?ableLoad ApplicationsEnd Point Criteria, ?able
Support Conditions: A-6.1.2 of IS

 The Areas of Supports are to be Protected 

The Same Degree as Provided in Practice

 Positioning Supports outside Furnace is a 

Laboratory Practice in U. S. and Abroad

 Fire Test must be Terminated when a Lar

Collapse Becomes ImminentWhy: To Protect Instrumentation and Fac



Tests without Support Areas Exp

 Failures Occur in The Fire Exposed Regio The Beam/Column Joint (Critical as Descr

FEMA & NIST Reports) was not Included 

 Since Element Fire Tests do not Cover The 

Specimen Their Structural Fire Ratings neCarefully Evaluated



Comments on PCA/NRC Colu

 All Tests were Conducted Following The ASTM  Columns were Subjected to Fire on 4 sides and  Top and Bottom Ends (~ 1 Ft. ) were not Expos Few were Subjected to Same Fire Exposure and 

Concentric/Eccentric Load

 Test Data Represent Structural Fire Ratings of  But The Same Data have been Used to Assess S

Ratings of Edge and Corner Columns 

 The Validity of Such Applications is Theoretica

The Next Slide Explains The Reason Why
Explanation Explanation

 Edge & Corner Co Edge & Corner Columns are Exposed to Fire on 3 

lumns are Exposed to Fire on 3 

respectively respectively

 Uneven Circumferential Temperature Distributio

Uneven Circumferential Temperature Distributio

1. To Cause Greater Thermal Stresses on The 

1. To Cause Greater Thermal Stresses on The 

2. To Increase Load Eccentric 2. To Increase Load Eccentricity and Results 

ity and Results 

Bending Moment Bending Moment 

3. To Induce Buckling Failures of Concrete or 

3. To Induce Buckling Failures of Concrete or 

The Buckling Failure of Exterior Columns 

The Buckling Failure of Exterior Columns 

Engulfed Stories and Triggered Collapses o

is a Good Example is a Good Example 
Confusing End Point Criteria of A

Confusing End Point Criteria of A

1. Heat Transm 1. Heat Transmission 

– When Temperature Rise on 

When Temperature Rise on 

Surface Reaches 250 F Average or Surface Reaches 250 F Average or 325 F at a Sing

325 F at a Sing

Point is Met Point is Met

2. Steel Temperature 2. Steel Temperature 

– When The Temperatures of 

When The Temperatures of 

(including the Structure Steel) or Prestress Steel R

(including the Structure Steel) or Prestress Steel R

F respectivel F respectively, The End Point is Met y, The End Point is Met

3. Structural End Point 3. Structural End Point 

– When a Structural Failur

When a Structural Failur

Imminent, The End Point Imminent, The End Point is met. is met.

Note:

The Term “Fire Rating” has been The Term “Fire Rating” has been Commonly Use

mmonly Use

Elapse Time of a Fire Test with Elapse Time of a Fire Test without Identifying wh

out Identifying wh

Based upon Seems Co Based upon Seems Confusing because, Heat Tran

nfusing because, Heat Tran

Structural Failure are Two Diffe Structural Failure are Two Different Physical rent Physical Beh

 Beh

Rating and Structural Fire Rating may be of App

Rating and Structural Fire Rating may be of App

Use in Performance Based Codes Use in Performance Based Codes
Where Does Performance Based C

Where Does Performance Based C

 The Con The Concept of P cept of Performance Ba erformance Bas

ed Cod

e Emerged before 1980 Emerged before 1980

 NIS

T Recommends Th Recommends That Structural at Structural Fire Resis Fire Resis

tances Should be 

ances Should b

Performance Objectives Performance Objectives 

 Code Officials Recognize Th Code Officials Recognize The Need for Fire Safety Designs Em

 for Fire Safety Designs Em

 The First Version of “I The First Version of “I

C

C Performance Code for Buildings an

mance Code for Buildings an

Jointly Published by BOCA, Jointly Published by BOCA, ICB

O, a

nd SBCCI in 20 I in 2001

 The P

B

C Legal R Legal Responsibility Sh sponsibility Sharing among E ing among E

ngineering Fir

gineering Fir

Building Officials is in T Building Officials is in T

he General Public Interest e General Public Interest

 The T

rend of P end of Performance Based rformance Based Cod

e Applicat Application to Fire Saf

ion to Fire Saf

 Fire Tes Fire Tes

ts of Beam-Column Frames will Serve T mn Frames will Serve T

he P

B

C Purpo
Structural Fire Safety Studies i

 Architecture and Building Research Institu Recognizes

The Need for Beam/Column

Fr

Built a B/C Furnace Equipped with a 2000

 The Planning, Design, and Construction T The Cost was Approximately U.S.$ 2 Mil
The ABRI B/C Furn

The ABRI B/C Furn

 The Furnace Measures 7 m High, 4.95 m Wide, 8.9

The Furnace Measures 7 m High, 4.95 m Wide, 8.9

 It is Equipped with Sophisticated It is Equipped with Sophisticated Heati

ng, Loading

g, Loading

Acquisition Systems Acquisition Systems 

 A 2000

-ton Actuator is Located Directly Underneat

ton Actuator is Located Directly Undernea

 An Expensive Exha pensive Exhaust

-Air Purification Unit was In

Air Purification Unit was In

EPA Air Quality Control Requirement Air Quality Control Requirement

 National Science Co National Science Council of Taiw uncil of Taiwan and ABRI hav

an and ABRI hav

Research Projects Research Projects
The Newly Constructed A

Beam-Column Furnac
Engineering Consideration on FInterior, Edge, and Corner Beam-Column the Roof, Mid-Height, and Ground Floor 
Possible Beam-Column Comb

Concrete Frames Concrete Frames Steel Frames Steel Frames

1. Normal weight concrete beams, slabs, 1. Normal weight concrete beams, slabs, 

and columns and columns

1. H-steel for beams 

steel for beam

2. Normal weight concrete columns/beams 2. Normal weight concrete columns/beams

and lightweight concrete slabs and lightweight concrete slabs

2. H-steel for colum

steel for colum

3. High strength concrete columns and 3. High strength concrete columns and 

normal weight concrete beams and slabs normal weight concrete beams and slabs

3. Box column and 

3. Box column and 

4. High s 4. High strength concrete columns, normal rength concrete columns, normal 

weight concrete beams, and lightweight weight concrete beams, and lightweightconcrete slabs concrete slabs

4. SRC columns and 

4. SRC columns and 

5. F

R

P-sheltered concrete systems sheltered concrete systems 5. SRC columns and 

5. SRC columns an

6. C

omposite beam

7. Durability of fire 

7. Durability of fire 

At Least 40 Tests Will Be Needed for A Decent The Estimated Cost is US$2 Millions
Another B/C Furnace Is Under Des

Another B/C Furnace Is Under Des

Fire Research Laboratory of National Cheng Kung Un

Fire Research Laboratory of National Cheng Kung Un

Build a Beam/Column Furnace Equipped with 5 Actu

Build a Beam/Column Furnace Equipped with 5 Actu

Generating a Total Load of ~ 1000 tons. Generating a Total Load of ~ 1000 tons. 

The Uniqueness of The De The Uniqueness of The Design Involves The Ca Involves The Capabilit

pabilit

Load or a Combination of Axial Load, Moments Load or a Combination of Axial Load, Moments in O

 in O

and a Twist Moment to Enhance Th and a Twist Moment to Enhance The Flexibility of Te

e Flexibility of Te

Reaction F Reaction Forces and Unbalance Moments on X rces and Unbalance Moments on X

-

Y

-Z A

Z A

Base can be Controll Base can be Controlled and Measured through The Us

ed and Measured through The Us

Available High Speed Software a Available High Speed Software and Data Acquisition 

nd Data Acquisition 

a Big Step forward from The Century Old Fire Test M

a Big Step forward from The Century Old Fire Test M

The Next Slide Shows The Concep The Next Slide Shows The Conceptual Loading System

tual Loading System

Construction Contract was Signed Construction Contract was Signed in June, 2005 and T

 in June, 2005 and T

will be Signed Separately Later. will be Signed Separately Later.
Conceptual Beam/Column Load

Conceptual Beam/Column Load

Twist Moment

Unbalance M Unbalan

Specimen:

Simulating Edge Column

AN

Actuator fLoad

Actuator for Axial Load and Moment

Eccentr

c
Conclusion

 Performance-Based Codes Demands Structural Fire  NIST Recommends Structural Frame Te Structural Frame Tests for Fire 

sts for Fire 

Ratings Ratings

 The Current Structural Fire Test Procedures should 

through National and International Efforts 

 Fire Tests of Beam/Column Frames shall Open a N Test Data will be Needed in Designing Fire Safety o Fire Tests of Structural Frames may Exceed $30,00 Domestic and International Collaborations will be L Collaborations Offer Opportunity for Tech Exchang
Suggestions for Collaborative 

Suggestions for Collaborative 

 Structural Fire Tests of Co Structural Fire Tests of Corner, Edge, and Interior Be

rner, Edge, and Interior Be

Experimental Program shall be Designed Focusing on High be Designed Focusing on High-Rise Buildings 

Rise Buildings 

an International Co an International Committee

 Rational Designs for Fire Safety Rational Designs for Fire Safety of Concrete and Ste

 of Concrete and Ste

Engineering Pri Engineering Principles shall ciples shall be Developed by St be Developed by Structural/ ructural/Fire Safety Engi Fire Safety Enginee

ne

Data. Th Data. The Task sh e Task shall be Supe all be Supervised by The Same Co rvised by The Same Committee

 Software for Rational Designs Software for Rational Designs of Fire Safety Building

 of Fire Safety Building

Computer Programs Computer Programs shall be Dev all be Dev

eloped from loped from Rational Design Theory Rational Design Theory throu

and Numerical Experts. The Wo and Numerical Experts. The Work shall be Supervised by rk shall be Supervised by The Same Co The Same Comm

mm

 Software for Building Fire Eval Software for Building Fire Evaluation incl uation including Bom

uding Bom

The Developed Software The Developed Software shall then be Expanded shall then be Expanded to Cov

er Terror E r Terror Explosion

plosion

shall be Supervised by The shall be Supervised by The Same Co Same Committee and Fire Prot mmittee and Fire Protection Experts (F

xperts (F

** The above Menti The above Mentioned Subjects a oned Subjects are conceivably within PBC Requiremen

Ultimate Objective of This Conf Ultimate Objective of This Conference, ”Fire Safety Inves ce, ”Fire Safety Investigation of Th

n of Th

Disaster” as well Disaster” as well
Wu Ni Non Wu Ni Non 

Thank You Thank You

For questions, please contact: For questions, please contact: tdlin

@a