NBSIR 75-674/)

Building Associated Fire ProblemsReport of Meeting CIB.

W14, April 1-5, 1974

A. F. Robertson, D. Gross and R. B. Williamson

Center for Fire Research

Institute for Applied Technology

National Bureau of Standards

Washington, D. C. 20234

March 1975

U.S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS

NBSIR 75-674

BUILDING ASSOCIATED FIRE PROBLEMSREPORT OF MEETING CIB,

W14, APRIL 1-5, 1974

A. F. Robertson, D. Gross and R, B. Williamson

Center for Fire Research

Institute for Applied Technology

National Bureau of Standards

Washington, D. C. 20234

March 1975

Working Committee Document

For Official Distribution

Not for Reference

U.S. DEPARTMENT OF COMMERCE, Frederick B. Dent, Secretary

NATIONAL BUREAU OF STANDARDS, Richard W. Roberts. Director

Contents

Page

1. INTRODUCTION 1

2. PLENARY MEETING. . 2

3. GROUP MEETINGS A

k. VISIT TO FIRE LABORATORY 16

5. REPORT SESSION AND CONCLUSIONS 17

APPENDIX 20

BUILDING ASSOCIATED FIRE PROBLEMS -- REPORT OF MEETING CIB, WU,

APRIL 1-5, 197^

A. F. Robertson, D. Gross and R. B. Williamson

This report summarizes discussions which took place at

the recent meeting of Commission WlA of CIB. About of the more than 100 documents related to fire problems were con- sidered at the meeting. It was agreed that current trends in

building construction and furnishing materials present new forms of fire hazard which warrant increased attention. While

progress was evident in methods for analyzing fire endurance

performance of structural building elements it seems desirable

to place greater emphasis on the fire gas hazard as a cause of

fire casualties. A symposium is planned on methods for managing

gas movement and disposal during building fires. A state-ofthe-art paper is also planned to review and document current

work on the influence of fire gases on animals and humans. It was noted that the smoke production characteristics of furnishing items may present serious problems and must be considered

in any attempt to control smoke during building fires.

Key words: CIB; codes; Commission Wl^; fire endurance; fire

gases; fires; fire tests; growth; models; smoke.

1. INTRODUCTION

The 11th meeting of Commission WlA of Conseil International du

Batiment pour la Reserche, L'Etude et la Documentation (CIB) was held at

the Braunschweig Technical University. Professor Pierig welcomed the

delegates, Annex I, and gave a brief history of the University which now

has about 7,300 students. Professors are expected to spend about one- half of their time on research. Professor Kordina was introduced as the

host and Chairman of the meeting. Dr. Thomas introduced the agenda,

Annex II, and asked for revision of the report of his comment on fire

load surveys to make more evident his concern that several countries are collecting information which will not be useful in design of new buildings

This was accepted and no further revisions proposed. A brief review was made of activities proposed in that report for future action. Many of

these had been implemented although others had not been accomplished.

Some of the latter included:

a. a symposium on concrete spalling, possibly in connection

with a meeting of the Federation International P recon t ra i n te

(FIP) , and

b. meetings to explore the means for coordinating statistical

work relating to building fires.

1
New developments were reported:

a. It was noted that two building material associations (CECM & FIP/CEB) were on the verge of publishing model structural codes.

It was proposed that CIB might review these and comment on their

merit and general applicability as performance criteria for all

mater i a 1 s

b. Dr. Thomas indicated that there was pressure from the CIB

Governing Board for Commission U]k to produce more tangible out-

- - puts. There were comments that Commission Wl^ could improve its

overall effectiveness by development of reviews of the literature

and recommendations on appropriate fire safety procedures or

' requirements. The delegates were asked to remember this in preparation of the reports of their groups.

Dr. Thomas then indicated his recommendation for classifying the papers

into four groups as indicated in Annex III.

I. Structural (Fire Endurance)

II. General Fire Considerations

III. Smoke and Reaction to Fire

IV. Papers of General Interest

It was proposed that the latter group of papers be presented and discussed in plenary session. This was agreed and the discussions are sum- marized below.

2. PLENARY MEETING

Dr. Thomas, continued as Chairman of this meeting, to discuss papers

of general interest to all delegates. Papers 72/71 and 7/7^ were presented by Dr. Berl. These are the Annual reports for 1972 and 1973 of • the fire program underway and the Johns Hopkins Applied Physics Laboratory.

Four major thrusts were briefly mentioned:

a. fire casualty studies,

b. mechanism of chemical inhibition,

c. means for assisting fire department operations, and

d. fire science training.

Only the first of these was discussed in any detail. Their findings

showed that about 80 percent of the fire victims examined in the State of

Maryland had carboxyhemag lob i n contents high enough to explain the fatality

(in the absence of any other cause). Mention was made of the prevalence

of prior heart trouble and alcohol as aggravating the problem. In 10

percent of the fatalities, the cause of death could not be determined.

In reply to questions, it was reported that oxygen deficiency was not a

2
likely cause for the fatalities so far studied, and that approximately 100

of 120 lives might have been saved if a sensitive CO detector/alarm had

been present.

Mr. Maroni presented his paper \2/7^^ on the large-scale burn tests

of panels and assemblies of foamed plastic insulation for interior lining

of buildings. He emphasized that small-scale bench-top tests were inadequate

for prediction of the foam behavior under severe fire exposure. Even fire

retardant treated foams showing low tunnel ratings may be unsafe unless

additional fire safety measures such as sprinklers are arranged to protect

the occupancy. The film showing fire tests of large corner wall assemblies

was shown. Considerable interest was evident in the study.

Mr. Nice reviewed paper 11l~Jk. This involves a report of the first

phase of a three-year study of furniture fire problems.

This work is discussed in detail in the report of Group III. The

interest feature of this work was the comprehensive aspect of the ignition source and materials being investigated. They, like we, find that smoldering ignition of foams can be enhanced when a cotton fabric is placed

between the foam and the ignition source.

Mr. Keough presented his paper 31/7^- This is similar to Tjllk and

involved use of 16 textile and plastic coated upholstery covering materials

alone and with 6 different cushion backing materials. The tests used

included: Austrailian Standard AS1530 part 2-1973. a vertical flammability

test using a match-like ignition flame source; AS-30 part 111-1970, the

Early Fire Hazard Test which assesses ignition, spread of flame, heat

evolved and smoke developed; a radiant ignition test involving a hot wire

to pilot ignition, irradiance levels of 20, 32 and 50 KW/m^ were used.

Duration of flaming and smoldering following ignition were observed as well

as depth of burning penetration. It was concluded that:

a. Penetration of cover and cushion backing material by small

ignition sources was affected by type of cover material.

Wool fabrics showed best performance.

b. With small ignition sources PVC coated fabrics showed resist- ance to penetration. This was not observed for polyurethane

coated fabrics.

c. With high radiant exposures the properties of the backing

material override those of the cover. The cushion materials

may be listed in the following order of increasing hazard:

1 . mi nera 1 wool

2. compact wool waste and hair felt,

3. cotton floe and polyurethane foam, and

k. sponge rubber.

The number indicates CIB/WlA paper No. 12 of the year 1974 (see complete

title in Annex III at end of paper).

3
Professor Williamson reviewed his paper 2k/1k "Impact of Contents

of Building Fires." The presentation was primarily through use of movies

and slide projection photographs of corner, "^/k room and baby crib fire

tests. The main thrust was that the planned introduction of a wide variety

of plastic furniture building finish and other occupancy items present a serious new hazard to the public. It was stated that many of these items can be ignited and propagate fire from a match or other small ignition

source. It was further suggested that since the ratio of heat of combustion

to heat of vaporization, or "B" number, of plastics was higher by a factor

of about 2.5 than that of wood, the former may represent a more flammable

type of fuel. Since paper 2h/Jk is not complete, Williamson requested

comments from any who had suggestions. It was evident that many delegates were concerned about problems related with plastic home furnishings items.

Dr. Stolp of Netherlands emphasized the need for an analytical model

to relate ignition and other reaction to fire properties to the fire

behavior of various products.

Dr. Thomas introduced document kO/Jk "The early stages of fire growth

In a compartment." This describes the cooperative study of fire growth

and development in a model compartment. He reported that the document

could be considered as the draft manuscript of a second paper to be published soon on compartment fires. Any comments would be appreciated. The

work reported indicates that the time for flame spread to involve all the

fuel within the compartment is:

1. not significantly affected by compartment shape and only

slightly by fuel continuity and compartment ventilation, and

2. does depend on position of ignition, fuel height, stick spacing,

and compartment lining.

Professor Pettersson reviewed document hlljk "Principles of Fire

Engineering Design" authored by Wittereen and Twilt of TNO. He reported

that this was the first of five documents that would be required to cover

the subject and forms one chapter of a building design text or proposed

code for the Commite European du Construction Metal lique (CECM)

This discussion completed the first days work. The three groups were assigned rooms for their work during the next day and a half. The

reports of these three groups are included in Annex I V . We elaborate on these further only to the extent that supplementary material was discussed

which has not been either adequately reported in Annex IV or is not available in a document circulated.

3. GROUP MEETI NGS

This section of the report presents information on discussions which

took place during the three simultaneous group meetings above and beyond

that included in Annex IV.

k
A. Group I (Mr. Malhotra, Chairman)

The main discussion items were: 1) correlation of furnaces, 2) design

of structures (concrete, steel), 3) properties of materials, k) model tests

and large-scale tests, and 5) structural codes and philosophy of structural

f i re protect i on

1. Correlation of Furnaces - An analysis was made by Dr. Van Keulen

and Dr. Stolp in Document Al/7^(NL) of the i nter 1 abora tory data on the

heat flux to a wall during the standard time-temperature exposure in a fire endurance test. Due to damage or evaporation of the gold layer on the heat flux meter, distinctions between radiative and convective heat

transfer could not be made. The largest differences occurred in the first

15 minutes. By 60 minutes the differences between furnaces were of the same order as the variation in a given furnace. The results from the

NBS furnace fell within the main band of results from all other laboratories (3 labs in Germany, 1 each in the Netherlands, Australia and U.K.).

0 20 AO 60 80

~T" I KA E_ I (min)

OF MEDUkKS* OF e»M«^D3 OF OTHC(^

5
There was considerable discussion on (a) the importance of radiation

(from hot gases versus walls) particularly between oil versus gas-fired

furnaces (however, the test results did not show startling differences);

and on (b) the influence of the thermal conductivity of the furnace bricks.

For the NBS furnace, it was reported that the heat input was nearly equally

divided among (a) the convective heat transfer to the walls, (b) the radiative heat transfer to the walls, and (c) the heat carried out by the

exhaust gases. The preparation of a guide report on a method for evaluating heat balance In a furnace was assigned as a task for Mr. Gross (NBS),

Mr. Keough (Australia) was assigned the task of recommending a procedure

for achieving greater uniformity in the radiation characteristics of fur- naces .

2. Design of Structures - Dr. Jarosz of the Polish Institute of

Building Technology, Warsaw, described fire tests on loaded prestressed

concrete L-beam girders 18 metres long and prestressed concrete roof panels

12 metres long. These tests were conducted to verify the conventional

method of calculating fire resistance based on the "minimum cover" method.

Since there were no gas or oil furnace facilities available, the tests were

performed by burning wood in a "provisional fire chamber." The standard

time-temperature curve was approached but not reached. A structural load was applied using additional concrete slabs.

Explosive spalling of concrete caused early collapse of the roof

panels (21 to 28 minutes) presumably due to the limited curing (approximately 3 to 6 months). Explosive spalling in the web (8 cm thick) of the

girders also occurred. Considerable background information on this effect

is available in reports by Meyer-Ottens

Additional discussions were held on calculation of the fire perfor- mance of concrete structural elements. Mr. Anderberg of Sweden described

calculations and tests on concrete slabs restrained against end rotation

but permitted to move longitudinally (Document 22/73S) . He illustrated

how collapse of a structure could occur during the cooling phase, sometimes several hours after the end of heating. A more complete paper will

be published on these predictive techniques.

ActUAL M645l((^^/AE«-5

Top ^e'tNR ioo't.

6
On the subject of steel structures, the Rudolphi and Knublauch (BAM)

model for predicting heat transfer through an insulated layer over steel was briefly described (Document 17/73D). Comparisons were made between

small and large-scale furnace test results using a scaling factor involving

the profile factor ratio F/U where F is the steel cross-sectional area and

U is the perimeter surface of the assembly. Additional attention was given

to the influence of creep, the significance of critical temperature, and

the use of deflection criteria in the discussions of papers by Lie and

Stanzak and by Wakamatsu.

Mr. Thor (Document ^3/7^5) showed that rate of loading had a large

effect on stress particularly at high temperatures; this is a measure of

creep strain. A mid-span deflection failure criterion based on RyanRobertson (1/800 L2/Q) was stated to be more appropriate than deflection

rate, but this was questioned by Malhotra and by Meyer-Ottens (based on approximately 60 tests at Braunschweig).

The behavior of a multi-story steel framed structure exposed to fire was the subject of a paper by Saito (Document 38/7^J), briefly discussed

by Professor Kawagoe) . It was estimated that instability due to thermally

induced deformation could result when steel temperatures exceeded 150°C.

3. Properties of Materials - Mr. Malhotra summarized briefly discussions which had taken place on the subject of concrete spalling among

experts from Germany (Meyer-Ottens), Netherlands, and the U.K. (Malhotra,

Dougall, Sullivan). Dr. Meyer-Ottens' thesis paper is completed and a short summary will be circulated to members. Both parts, i.e., (a) Theory

and Results of 120 Tests, and (b) Thesis, will be published by the German

Association for Concrete Structures this year.

Mr. Kalos from Greece (Document 26/7'+G) discussed the effect of car- bonization which might lead to severe spalling in aged concrete. Since

subsurface cracking and porosity increase with age, the loss of water vapor

will tend to limit pore clogging and subsequent spalling (no spalling if

total moisture content is less than 2-1/2?^).

The question of planning a conference on concrete spalling was discussed and it was decided to leave the decision up to the CIB Plenary Group

with the thought that expansion of the topic and collaboration with other

societies (RILEM/FIP, CEB) could be considered.

Anderberg and The 1 andersson (Document 23/73S) have done considerable

work on measuring and analyzing the stress and deformation characteristics

of concrete at high temperatures. Using concrete specimens in torsion at

high temperatures, twist angle data were obtained under constant and transient temperature-creep conditions. Creep was classified into instantaneous

elastic (and plastic) creep, basic creep, and transitional creep.

7
I vis rAKfrA>i^cOs

Dr. Schneider has performed similar experiments at Braunschweig in

which he varied one component, kept one component constant, and measured

the third component (stress, temperature, strain). This work will be

presented at the May 197^ ' P meeting in New York.

4. Model Tests and Large-Scale Tests - Mr. Twilt described several

studies involving reduced scale tests on columns and on braced and unbraced

frames. The objective in the first study (Document 48/7^NL) was to determine the effect of the rate of heating on the creep and load bearing capacity

of steel columns. The heating rates, which ranged from 5 to 50°C per minute, had very little effect for the model beams and columns, and it was

felt that the history of heating may not affect prior performance greatly.

In the study of frames (Document kS/JkHL) , the principal conclusions were that (a) thermal expansion (i.e., comparing insulated versus uninsulated beams) had no significant effect on the critical temperature for the

frame, and (b) the critical frame temperature is higher than the critical

temperature for single columns. It was stated that full-scale verification

was needed. A question was raised as to the applicable slenderness ratio

to use and the interpretation of the relatively better performance of the

uninsulated frame.

At the present time, Mr. Magnusson is monitoring a series of fullscale tests on the load bearing capacity of axially restrained steel

columns at Metz. This work is sponsored jointly by CECM and the Swedish

Building Research Council. Excellent agreement was noted between the

measured and predicted collapse temperatures and failure loads.

In an extensive paper (Document 3^/7^^), Dr. Knublauch showed how to

model the fire-induced temperature field created on the outside of a building with a model structure in which the story height was one-half

metre. Using wood cribs scaled to give a burning rate proportional to

the 5/2 power of the linear dimensions (for ventilation-controlled fires),

experiments were carried out with steel columns placed in several positions in front of the window. It was concluded that steel column protection

was only needed on one side and that normal unprotected steel columns could

be overloaded. _o
5. Structural Codes - Various international committees are preparing

sturctural codes for concrete and steel based on different approaches. It was felt that the CIB Commission could help to ensure a harmony of codes

by studying code proposals, advising committees of the latest Information,

and pointing out areas of needed research. Professor Kordina raised several basic technical questions, but insufficient time was available for

d i scuss i ons

a. Should building codes require residual strength for

structural elements?

b. How can codes be altered to define the fire performance of

the complete structure where codes currently consider only

individual members?

c. Should codes continue to be based on standard fires and

standard fire loads, or should they address the individual

situation, i.e., fire loads, geometry, thermal properties,

ventilation, time-temperature curve, and finally fire performance?

Harmathy suggested that we should consider "designing the fire"

instead of designing fire protection for a hypothetical fire. He argued

that fire spread through doors and building openings by radiation and con- vection was more realistic than heat conduction through a structure leading

to u 1 1 imate col lapse

B. Group I I (Professor R. 8. Williamson, Chairman)

The group divided the discussion into three broad categories: 1) the

analysis of fully developed compartment fires, 2) the optimum design and

specification of fire safe buildings, and 3) recommendations to commission

Wl^ concerning possible actions in Group ll's sphere of interest.

1 . The analysis of fully developed compartment fires - Document

16/73(C) "A New Look at Compartment Fires, Part I and Part M" by

T. Z. Harmathy. The author began by noting that he would include some points made in two recent publications which had not yet been circulated

to this commission. These documents are entitled "Design Approach to Fire

Safety in Buildings," recently published in Progressive Architecture and

"Designers' Option: Fire Resistance or Ventilation," to be presented at

the 6th Congress of CIB in Budapest during October 197^- In the Document

16/73(C) the author started with sections on the basic burning characteristics of cellulosic materials. He follows this with a theoretical model

which is used as the basis for two equations that describe the rate of

burning in the two regimes of compartment fires, namely: fue 1 -surf ace- controlled and the ventilation-controlled regimes. By examining these

relations, the author drew a number of conclusions. First, the worst con- ditions with respect to high temperature occurs at or just before the

"critical point" where the rate of burning is already maximum and the rate

of the flow of fresh air into the room is still relatively low. He pointed

out in his theory, however, that a substantial portion of the fuel load

9
burns outside the room of origin. This means that the ventilation con- trolled fires are hotter and longer than the corresponding fue 1 -surfacecontrolled fires where excess air is available to dilute the fire gases

and carry larger portions of these out of the compartment prior to their

complete combustion.

The design recommendations contained in the two new papers are based

on the concept that larger ventilation openings can be provided with a high degree of reliability to be open in a fire situation. This design

approach moves away from the classic concept that the destructive potential

of a fire is solely dependent on the amount of combustible material In the

fire compartment. Dr. Harmathy indicates that from his analysis the transition from ventilation control to fuel surface control takes place when the

air flow rate into the compartment is 1.8 kg/s per m^ of the surface area

of fuel. He recommends that the designer can choose opening dimensions

which are larger than necessary to supply this critical air flow and thus

control the expected fire to burn out within the original fire compartment

in 30 minutes or less. He discussed some of the possible drawbacks such

as unexpectedly high fire loads, passage of fire through doors or other

openings in the walls, ceiling or the exterior of the building and finally

the late involvement of the fire designer in the planning stage of the

bu i 1 d i ng

Document kl/J^iS) "A Discussion of Compartment Fires" by Sven Erik

Magnusson and Sven The 1 anderson . The authors highlighted the similarities

and the differences between their approach and that presented in the previous document. They note that their approach also shows a less severe

fire at higher ventilation and they indicate the increased performance

of steel structures at high ventilation using the Swedish building regulations. They point out that perhaps the greatest differences in the two

approaches is that they calculate their results on the basis that all of

the fuel burns inside the fire compartment while Harmathy's analysis under

certain conditions of fuel load and ventilation shows a relatively large

portion of the fuel burning outside the original compartment.

They noted that the evolution of heat during the most intense phase

of the fire is in close agreement with that predicted by Harmathy. The

differences lie in the energy release during the decay period while

Harmathy believes it has burned outside of the fire compartment in these

specific cases. The common occurrence of flames outside the window of fire

compartments supports Harmathy's contention, while the continued evolution

of heat during the decay period supports Magnusson and The 1 anderson . It also seems likely that endothermic characteristics of cellulosic fuel are probably ended at about the time the decay period starts, and thus, the

relative contribution may be greater.

Document 39/7^(UK) "The Effect of Crib Porosity and Recent CIB

Experiments" by P. H. Thomas. The author indicated that the most important

aspect of the paper was the identification of three types of conditions in

crib experiments; one, where fuel porosity is controlled, a second, where

surface of the fuel was dominant, and finally, a third area where ventilation in the compartment was most important. Dr. Thomas believed that

10
the fuel porosity controlled situations are probably not very important for

most actual fire conditions.

In more general terms, he noted that the most important aspect of a fully developed compartment fire is the quantity of air flowing into the

compartment. The previous papers both take account of this factor, but it was Dr. Thomas' opinion that it could be used as a more central parameter

in the structure of the analysis. He noted that the heat evolution curves were extremely sensitive to other factors such as feedback of energy to

fuel bed which cannot be scaled easily. He presented briefly the concept

of the mass transfer, sometimes known as the B-number (the ratio of heat

generated by a unit mass of fuel to the energy necessary to drive it into

the vapor phase) and indicated that a detailed knowledge of these factors

is necessary to understand the rate of heat evolution inside and outside

the compartment. The use of air flow is potentially a much easier concept

since it is required for all of the combustion within the compartment.

Document 21/7^(USA) "Modeling of Vented Enclosure Fires" by

Paul A. Croce, Factory Mutual Research Corporation, was briefly described

by Mr. Williamson. This work is in progress and it was noted that it was

in general agreement with that presented by Dr. Thomas. The group encouraged the program and hopes to see a more complete paper at its next meeting

Dr. Thomas discussed this paper further on Wednesday morning and it is hoped

that we will hear more of the work before the next meeting.

L. Nilsson discussed the papers introduced. He stated that a recent

report by P. H. Thomas and Nilsson points out that another regime, that is

the crib poros i ty reg i me , ought to be involved. To study the different

regimes about 350 tests have been performed and about 100 of these tests

theoretically analyzed. Different combinations of the following parameters

have been studied:

2

1. the fire load a; 17-5 ^ q ^ 87-5 MJ/m enclosing surface area

of the f i re ce 1 I ,

1 / 2 2. the opening factor a/T/A^ , 0.020 < a/T/A^ < 0. 1 U m ,

3. the piling (jletjisity of the fire load expressed by tijie

^ poros i ty

factor (j) cm ' defined by Gross. 0 . 1 1) S 1 • I cm '

,

h. the stick thickness b of the fuel 10 ^ b < 50 mm, and

5. the thermal properties of the enclosing construction of the

f i re ce 1 1 .

In the tests the temperature-time curve, burning rate, radiation, and

smoke density have been measured.

The computer program proposed by Sven The landersson and Sven-Erik

Magnusson has been used with the experimentally measured temperature-time

curve to yield the energy-time curve released during the burning.

II
The results indicate that instead of two different fires, that is

fuel-bed and ventilation-controlled fires you have to talk about six

regimes, that is for easy burning cribs:

1. fuel -bed controlled fires,

2. ventilation-controlled fires,

,3- a transition zone between them (and for fires also, depending on

. the cr i b)

h. combination of fuel bed - and crib-controlled fire,

5- combination of ventilation and crib-controlled fire, and

6. combination of fuel bed - ventilation crib-controlled fire.

The report gives equations to determine six important points on the

energy-time curve which makes it possible to sketch this curve with sufficient accuracy in practical design. The equations take into account the

parameters described above.

In the report an effort is also made to find a crib carefully defined

which gives an equivalent fire as for real furniture in a compartment.

2 . Optimum Design and Specification of Fire Safe Buildings - Document 25/73 (UK) "Passive and Active Fire Protection - The optimum

Combination" by R. Baldwin and P. H. Thomas. Dr. Thomas presented a short description of the paper and noted that there were some situations

where it was clearly best to use either an active or a passive protection

system because the alternate was too expensive. There are also situations

where either approach is too expensive, but the most interesting situation

lies in the region where the two approaches are competitive. This introduces the concept of "trade-offs" and he discussed this philosophy at some

length. This combination runs through all of the design concepts discussed

below.

Document 2k/73 (S) "Principles of Fire Engineering Design and Fire

Safety of Tall Buildings" by Professor Pettersson. The author notes that

this was a review paper presented at the International Conference on Tall

Buildings held in August of 1972. In this paper he reviewed the available

framework for a functional design approach to tall buildings. He describes

the General Services Administration's (USA) "Decision tree" approach.

Professor Pettersson commented that this system was good in that it made

engineers think in an overall fire safety way. In addition, it gives a framework for understanding where we should put our research effort.

Mr. Harmathy commented that in the "Decision tree" approach, the

designer must rely on the state-of-the-art at the time he or she makes

the final design choices. The continuing research effort will refine our understanding and the code of practice must be geared to a changing set

of choices at specific locations in the decision tree.

Document kk/lk (S) "The Connection Between a Real Fire Exposure and

the Heating Conditions According to Standard Fire Resistance Tests, With

Special Reference to Steel Structures" by 0. Petterson. The author described the whole document of which this contribution is the second chapter.

12
He than went on to describe the contents of the paper. The most significant point was the clear reliance on an equivalent time based on actual

steel temperature rather than the more traditional area-under-the-curve

concept (discussed in Document 23/7^)-

Document hjllk "Principles of Fire Engineering Design" by J. Witterveen

and L. Twilt. This paper was discussed in the complete Commission Wl^t

meeting on Monday and may be discussed again on Thursday.

Document 22/7^ (USA) "Fire Safety Criteria and Tests for Dwellings - Pre-f 1 ashover" by R." B. Williamson describes a restatement of existing

fire safety requirements and some criteria and tests in a new form. The

author noted that it was an early draft and he welcomed any suggestions or comments. Dr. Thomas indicated that the inclusion of feedback and research

into the traditional scheme of control requirements and criteria assumed

a dynamic system.

Document 2}>/lU (USA) "Fire Safety Criteria and Tests for Dwellings - Post-f lashover ."• A special report by Mr. Vytenis Babrauskas on the general

topic of compartment fires was submitted in place of the above named document.

The report discussed the bases of our understanding of fully developed fires

in compartments.

Document Ik/Jk (USA) "Impact of Centents on Building Fires" by

P. S. Klitgaard and R. B. Williamson. This paper describes some of the new hazards represented by the large growth of plastics in buildings for

furniture and other large content items. Mr. Williamson noted that the

criteria for fire propagation in 22/7^+ could be used to control these

hazards to some extent. The role of plastics in the fully developed fire was discussed earlier.

3 . Recommendations to Commission Wl^ concerning possible actions

in Group II 's sphere of interest - The Group II discussion

centered on the design and control of buildings in a changing society.

It was noted that there are a number of organizations engaged in trade-off

schemes and it was decided to make the recommendation to the entire Commission WlA that a draft document be circulated prior to our next meeting

which identified the general principles of fire safety. This might include

a methodology of approached trade-off as well as other topics.

C. Group I I I (Dr. Robertson, Chairman)

The papers in this group were classified under the following subjects:

1) fire behavior of plastics and textiles, 2) measuring the fire hazard,

3) fire gas movement in buildings, and growth and spread of fires.

It is suggested that the reader review Annex !V for the main report

of discussion of these subjects. Some points of further interest developed at the meeting are reported here.

13
Dr. Kawagoe in discussing the time available for escape when fires

develop described recent Japanese thinking on this subject which had been

developed on the basis of plume theory. If one has

a large room in which a smokey fire develops, the time at which various

stages of smoke development occur in the room may be described by:

for the cases of point source and area fire, respectively

t is the time to various levels of smoke accumulation,

Q is the smoke production rate assumed equal to the burning rate, and

r is the radius of the fire

Thus, the time required for smoke to fill various fractions of the room height can be illustrated by the diagram above. The curved lines

represent the conditions for a fire that grows rapidly in size while smoke

fills the room. This, of course, is only illustrative, but does seem to

provide a means for visualizing smoke movement and spread.

Later during discussion of papers 13/7^ and IA/7A on combustion rate

calorimetry studies in USA, a description was provided of a burn out room

for a similar purpose. The room has been built in Dortmund and comprises

a roughly cubical compartment of about 2 metres dimension.

lit
The steel plate is used to measure the thermal impact of the enclosure

walls when items are burned in the room. This is compared with the equivalent time for the standard time-temperature curve, as defined in ISO R 83^, required to match the heat input to the steel plate. An "m" factor,

which is defined in the proposed German Standard DIN 18230 for industrial

buildings, appears to denote the time ratios for the two tests. This

factor is proposed as a way of defining the contribution of the building

contents in terms of its composition and form. A paper on this development

was presented by W. Halpaap in Switzerland last fall. There was considerable discussion about this work. The point was made that m would not be

a material property but would be a function of surface to volume ratio of

the item burned. The basic idea of course is to measure the relative

thermal impact of a burning item on the enclosure walls and ceiling and,

thus, define the fire endurance performance which should be designed into

the structure.

In discussion of the review paper 6/7^ on toxic species in combustion

gases. Dr. Berl emphasized the importance of CO as the main fire gas hazard

observed to date. He indicated that he personally considered it very

unlikely that phosgene could be present as a serious hazard. This position

was taken both because of its instability at high temperatures and the

very low equilibrium concentrations at low temperatures.

In connection with this point Dr. Robertson suggested an experiment

with animals or humans in the sleeping mode to determine whether they would

be awakened by an irritating gas. If they were awakened this might provide a means for alerting occupants of a building when fire occurs.

During discussions of smoke movement in buildings Dr. Kawagoe described an air-inflated portable barrier through which a man can climb, but

which closes automatically and maintains a smoke seal in any passageway in

wh i ch it is i ns ta 1 1 ed

In connection with discussion of paper 15/7^ on the NBS corridor fire

tests. Dr. Stolp of Netherlands described a series of tests they had

conducted on ten or more floor covering materials. The geometrical and

air flow conditions differed appreciably from the NBS arrangement.

15
Their tests were run by igniting one of several cribs in the burn room at

the end of a corridor. It usually required about 20 min to involve all

the cribs. The floor coverings included wood, linoleum and a wide variety

of carpeting materials. Various combinations of these were used on burn

room, cross corridor, and main corridor length. In most instances fire

spread along the floor only 3 to ^ metres. As a result they have concluded

that when there is no need for concern with more severe burn exposure.

Dr. Stolp also described a series of crib fire extinguishment tests.

For these tests the crib was placed in a compartment under various ventilation conditions and water applied uniformly over the top of the crib.

Observations were made of crib weight loss, water application rate as a function of time. They also plan similar experiments with as an inerting

agent. We plan to correspond with Stolp and get more information on this

s tudy

At the Institute for Building Materials and Reinforced Concrete in

Braunschweig, the following activities were observed:

a. A fire endurance test of a suspended ceiling ^ung from a steel

beam and concrete floor (loaded to 1,600 Kg/M ) over a large

undivided area. Furnace pressure was maintained at 1.0 to 1.2 mm wg , A subsequent test will involve the addition of a 60-min

rated dividing partition in the furnace with fire exposure on one side only. The test to be run until thermal failure of the

partition occurs and then fire exposure will be applied to the

full specimen length.

b. Explosive spalling of a loaded concrete section representing

the 8 cm thick web of a concrete beam. The concrete had 3%

moisture by weight, the load was 1^0 kilotons/cm and fire

exposure was applied to both sides. As previously predicted by

Meyer-Ottens , explosive spalling occurred at 17 to 18 minutes.

c. Fire tests on safes, including drop tests.

VISIT TO FIRE LABORATORY

16
d. Measurements of the high temperature properties of concrete

carried out by Dr. Schneider. In a very comprehensive volume

entitled "On the Dynamic Loss of Strength Reactions in Standard

Concrete at High Temperatures," published at Braunschweig in

December 1973, Dr. Schneider summarized analytical and experimental

studies on thermal and mechanical properties, as well as X-ray

analysis of concretes involved in fire.

e. Construction was underway on a new $1 million building to house

a large L-shaped furnace capable of fire endurance testing of

columns, girders, beams, floors, and combination column/beams

and wa 1 1 /f 1 oors

This new furnace will be 8.80 metres long. Maximum distributed floor

load is planned for 90 tons plus a concentrated column load of ^00 tons.

By closing off the horizontal section, a column up to 5-5 metres may be

tested. Lateral loads and moments may be applied to beams and floors and

braced (restraint) or unbraced conditions can be simulated. Column deflections will be measured optically. Professor Kordina stated that no attempt

was made to supersede or compete with the fire furnace at Metz. A preliminary prediction calculation has already been made by Mr. Haksever on

the fire performance of a rigid L-frame of reinforced concrete with hinged

supports and no displacement at ends.

5. REPORT SESSION AND CONCLUSIONS

A report session was held at the end of the meeting, during which

each of the three groups summarized their discussions. Since these are covered in the draft reports included in Annex I V there is no need to

repeat them here.

A brief resume of the conclusions reached at the meeting may be

summarized as follows:

1. It was proposed that CIB would serve a most useful purpose

reviewing and commenting on the merit and applicability of

codes being currently developed by two different building

material associations CECM and FIP/CEB.

by

mode 1

2. Task Groups were identified to:

a. develop a procedure for characterizing the heat balance and

radiation characteristics of fire endurance furnaces,

b. develop new methods for design of concrete and steel frame

s t ructu res , c. participate in a proposed FIP symposium on fire damage

including spalling and repa i rab i 1 i ty of concrete structures,

and

d. prepare a state-of-the-art paper including future research

needs on physical and thermal properties of materials at

high temperature.

17

3. The expected introduction of polymeric materials as substitutes

for more conventional building and furnishing materials requires

a review of their behavior during fires and consideration of the

validity of existing test methods for evaluating fire safety.

k. A paper is planned to discuss the basic fire research objectives

as they apply to building problems (structural and occupant

safety)

5. Increased recognition should be given to the importance of fire

gases as a threat to building occupant safety.

6. Commission Wl4 should encourage a symposium on the subject

"Building Design Techniques to Control Gas and Smoke Movements

du r i ng F i res

. '

7. A survey paper should be prepared to review and document current

work on the influence of fire gases and smoke on animals and

humans

8. There is need for increased emphasis on study of:

a. early warning of occupants when a fire occurs,

b. study of human behavior when alerted to a fire,

c. characteristic times of fire phenomena as a determinant

of f i re safety , and

d. improved reaction to fire test methods.

9. It was generally agreed that because of the quantity of smoke

and gases resulting from burning even small quantities of

building finish or furnishing items, a great need exists for

the development and utilization of special means for the control

of fire gases and smoke during building fires.

19
Append i x

20
ANNEX I

o. PROF. DR.-ING. KARL KOROINA • TECHNISCHL UNIVERSITAT BRAUNSCHWEIG

Lehfituhl furSlahlbcton- und Mosjivbou • Inilitut (ur Boi/stolfkunde und Stahlbeloiibau

Liste der angemeldeten Teilnehner zur Tagung der CIB-Kommission UG 1

in Braunschweig, 1

. -5 • '* • 197'<

Australien

Belgi en

Kanada

Danemark

England

Finnland

Frankreich

Griechenland

J apan

Niederlande

Neuseeland

Norvegen

Polen

Mr. Keough

Mr. Minne

Mr. Harmathy

Mr. Aegidius

Mr. Malhotra

Mr. Nice

Mr. Thooas

Mr. Oksanen

M. Adam

M. Arnault

M. Bellisso n

M. Cabret

Mr. Kalos

Mr. Kavagoe

Mr. Stolp

Mr. Twilt

Mr. Witteveen

Mr. Kenna

Mr. Bakke

Mr. Landr^

Mr. Jarosz

Experimental Building Station

Chatswood

LaboratoriuB voor Annvending

der Brandstof f en , Gent

National Research Council

of Canada, Ottawa

National Institute of Materials

Testing, Kopenbagen

Fire Research Station,

Borehamvood

dito

dito

Technical Research Centre of

Finland, Otaniemi

S.N . B.A.T. I . , Paris

Centre Technique Industriel

de la Construction, Puteaux

Centre Scientifique et Technique

du BStiment, Paris

dito

The Technical Chamber of Greece

Atben

Building Research Institute,

Tokio

Institute TNO for Building

Materials and Building Structure.'

Rijswijk

dito

dito

Building Research Association

of New Zealand, Wellington

Fire Research Laboratory,

Universitat Trondheim

dito

Instytut Techniki Budowlane j

Warscbau

I k*t'M- V 'It r Hi. j » I //H^

21
-2-

Schweden *

Ung arn

USA

Mr. Anderberg

Mr. BengtsBon

Mr. Hagglund

Mr . Magnus son

M.r Nilsson

Mr. Pettersson

Mr. Sjojin .

'

Mr. Thel anders son

Mr. Thor

Mr . Tolstoy

Mr. bdeen

Mr . Kovacs

Mr. Berl

Mr. Gross

Mr. Hacker

Mr. Maroni

Mr. Padnofsky

Mr. Robertson

Mr. Williamson

Division of Structural Mechanics

and Concrete Construction, Lund

Swedish Fire Protection Ass.,

Stockholm

The Research Institute of the

Swedish National Defence,

Stockholm

Division of Structural Mechanics

and Concrete Construction, Lund

Dito

di to

The Research Institute of the

Swedish National Defence,

Stockholm

Division of Structural Mechanics

and Concrete Construction, Lund

Swedish Institute of Steel

Construction, Stockholm

National Swedish Institute for

Materials Testing, Stockholm

Division of Building Materials,

Stockholm

Institute for Quality Control

of Building, Budapest

Johns Hopkins University

National Bur of Stds, Wash., D.C. BatteHe

Factory Mutual

NASA

National Bureau of Standards , Washington

University of California,

Berkeley

Deut s chl and die Herren

Bechtold

Becker

Fischer

Gliis i ng

Institut fiir Baustof f kunde und

Stahlbetonbau , Braunschweig

BASF Ludvigshafen

Staatl. Mater i alpriifungsamt

Dortmund

Bundesanstalt fur Mat er i alprii f unc

Ber 1 i n

22
-3-

Deutschland Haks ever

Klingelhof er

Klingsch

Knublauch

Kordi na

Frau Krampf

Meyer-Ottens

Rudolphi

Schneider

Stanke

Teichen

Tei chgraber

Wes che

Westhof

Institut fiir Baustof f kunde

und Stahlbetonbau , Braunschweig

Staatl. Mat er i al prij f ungE amt

Dortmund

Institut fiir Baustof f kunde und

Stahlbetonbau, Braunschweig

Bundesanstalt fiir Materialpriifung Berlin

Institut fiir Baustof f kunde und

Stahlbetonbau, Braunschweig

Institut fiir Baustof f kunde

und Stahlbetonbau, Braunschweig

dito

Bundesanstalt fiir Materialpriifung Berlin

Institut fQr Baus toff kunde und

Stahlbetonbau, Braunschweig

Bundesanstalt fiir Materialpriifung Berlin

Otto Graf - Inst i tut , Stuttgart

Institut fiir Holzf orschung , Miinchen

Institut fiir Baustof f kunde und

Stahlbetonbau, Braunschweig

Staatl. Mat er i alpr ii f ungsamt

Dortmund

23
ANNEX II

CIB COMMISSION V^A

Programine for 11th Meeting

Sunday. 31 Msurch 1930 .

Monday, 1 April

0900

1200

Lunch

13.30

17.00

Tuesday

0900

1200

Arrive in Braunschweig.

Drinks and snackB for pau-ti r ipantB and ladies at the Hotel DeutcheB-Haue

At University Rooms - (a) Opening of Meeting in Room 2 in basement

of the wing SchleinitzBtrasse entrance in

Pockel BstraBse

(b) Acceptance of record of 10th Meeting

(c) Election of officers for meeting

Report presented by Co-ordinator of developments

within CIB, its relations with other bodies amd

consequences for V)14. DiscuBsion of tasks and

methods of working. Divide into groups.

At University Rooms

Lunch

13.30

17.00

Croup diBcusBions

'Wednesday

0900

1200

Afternoon

Lvenin^

riiursday

0900

At University Rooms

Group discussion and preparation of group reports

Visit to fire section of Technische Universit'a't

(Details to be announced)

Commission dinnei

(Details to be announced)

Presentation of reports from groups and full W14

discussion. At University Rooms

1200

Friday

Lunch

13.30

17.00

0900

1200

Final discussion

Future activities of W14. Arrangements for next meetinr Other hunmeFS.

2k
- 2 -

Friday afternoon and evening EacurBion for participantc and ladled

(Details to be announced later)

(a small charge may need to te made if expentseu

prove to be too hi^)

Lunch (Monday to Friday) ie available at the

"Mensa" about 5 minutes ' walk from the meeting.

During morning and afternoon Session coffee will

be served.

CIB/iOOO/1'^/23F

25
ANNEX 1 1 I

CIB COMMISSION W14

COMPLETE LIST OF PAPERS CIRCULATED TO DELEGATES SINCE

JHE MAY 1972 MEETING IN STOCKHOLM

CIB CTF/7-L'Ai(C)

* Clb CTF/7 V-2(S)

* CIB CTF/7^/53(UK)

CiB CTF/7 :V34(C)

CIB CTF/7.V55(C)

^*

CIB CTF/72/56(J)

• :v!- < iVl2/57(J)

CIB CTF/72/58(J)

CIB CTF/72/59(J)

CIE CTF/7^/(:'0(j)

CIB CTF/72/6i(j)

CX?, (:TF/fV/t2(J)

CIB CTF/72/63(J)

CIB CTF/7 2/64 (J)

CIB CTF/72/65(J)

Remote meaaurement of large deflections in fire tests.

Some essential material properties connected to a differentiated fire engineering design.

Report of the Tenth Meeting of CIB Commission.

Sweden 15-19 May 1972

A numerical procedure to calculate the temperature

of protected steel columns exposed to fire. 1972

Bibliography of Fire Research Problems in Japan.

(1961-1971) 1972

Visibility through smoke. (Part 2. Visibility of

monochromatic signs through smoke). Japan 1971

Study on injurious properties of combustion products

of building materials at initial stages of fires.

Japan 1971

Propagation of Combustion in Solid Materials, Part III. Temperature distribution in a smouldering rod.

Japan 1968

Some statistical features on extinction of small

diffusion flame cf burning liquid with sprays of

several salt solutions. Japan 1968

Experimental study on behaviour of smoke flow and

smoke-proofing of escape routes. Japan I969

Visibility through fire smoke. Japan 1970

Characterisation of smoke-motion in the building

fire (1) On the flow pattern of smoke through the

corridors and staircases. Japan 1970

Model experiments on a smoke tower Part III. Japan 1971

Characterisation on factor in estimating fire-hazard

by furnace-test based on the patterns in the modelling

of fire for the classification of organic interior

building materials. Part I Japan 1971

The characterisation on the mode of combustion and

smoke evolution of organic materials in fire Part II. Japan 1972

26
CIB CTF/72/66(LJK)

CIB CTF/72/67(UK)

CIB CTF/72/68(d)

CIB CTF/72/69(b)

TS-* CIB CTF/72/70(CA)

CIB CTF/7 2/71 (USA)

• CIB/W14/V73(C)

CIB/W14/2/73(F)

CIB/w14/3/73{UK)

CIB/WI 4/4/7 3(C)

CIB/Wi4/5/73(D)

ClB/wi4/6/73(C)

CIE/w 14/7/7 3 (L^)

CIB/W 14/8/7 3(C)

CIB/WI 4/9/7 3(^)

CIB/W14/10/73(UK)

CIB/W14/11/73(Lj'K)

CIB/WI4/1 2/73(0)

Fully-developed fires in Single Compartments - A co-operative research programme of the Conseil

International du Batiment. United Kingdom 1^2

Extreme Value Theory and fire resistance.

United Kingdom 1972

Uber Ausfuhrung and Aussagcfahigkeit des

Normbrandversuches nach DIN 4102 B.A.M. Germany 1972

La resistance au feu des portes - "The Fire

resistance of doors". Belgium 1972

Venting fires through rocfs. Experimental fires

in an aircraft hanger. Australia 1972

Fire problems Program Annual. Summary Report

July 1971 - June 1973. USA 1972

Calculation of the fire resistance of reinforced

concrete columns. August 1972

Etudes de Viei 1 1 issement Accelere de Produits

Ignifuges du Commerce Francais. France 1972

The behaviour of people in fires.

United Kingdom 1972

Contribution of insulation in cavity walls to propagation of fire. Canada October 1972

Baulicher Brandschutz .

Fire and The Civil Ehgineer. Ottawa 1972

Fire problems of pedestrian malls. Part 2. Large scale experiments with a shaft vent. United Kingdom 1972

Thermal degradation of cellulose and levoglucosanThe effect of inorganic salt. Ottawa 1972

Brandverhalten von raumabschliessenden Bauteilen.

1972

Behaviour of building structures.

Extract from "A complete guide to fire and buildings"

Report of the neeting at Institute TNO for building

materials and building structures. Delft, The

Netherlands on January 29-30 1973.

Combustion products of polymeric materials containing

nitrogen in their chemical structure.

27
CIB/W14/13/7^(C)

CIB/WU/14/?3(C)

•:IB/W14/15/T3(D)

11 • CIB/w14/16/73(c)

* CIB/W14/1 7/7 3(D)

% • CIE/W14/1B/73(UK)

CIB/W14/19/73(C)

CIB/W14/20/73(S)

% CIB/W14/21/73(S)

• •:IB/W14/22/73(S)

1 • CIB/W14/l3/'/i(S)

CIB/W14/24/73(S)

iT* CIB/w14/25/73(UK)

CIB/w14/26/73(L'K)

ClB/W14/27/73(UK)

CIB/W14/2e/73(UK)

CIB/w14/29/73{UK)

Ident) l ication of CIS-4, 5-E)poxy-2-Pentenal

from I^rolysis of H, PO treated cellulose.

February 1973

Thermal properties of selected masoniy unit

concretes. February 1973

Brandrisike elektrisher Leitungen and

Installationen in Wanden. Berlin April 1973

A new look at compartment fires. Parte I and

II. Ottawa 1972

Unterauchl ingen fur ein Prufverfahren zur Bemessung der Brandschutzbekleidung von Stalzletutzen.

The problems of pedestrian precincts - Part 3« The smoke production of sprinklered fires (low

water pressure). United Kingdom June 1973

An improved hydraulic heat flow simulator.

Effect of high temperatures on tensile strength

of concrete. Sweden 1972

Fire Research and Building. Sweden 1971

Fire-exposed hyperstatic concrete structures.

Sweden 1973

Stress and deformation characteristics of concrete

at high temperatures. 1. General discussion and

a critical review of literature. Sweden 1973

Principles of fire engineering design and fire

safety of tall buildings. Sweden 1973

Passive and active fire protection - The optimum

combination. United Kingdom 1973

A method of evaluating life for economic purposes.

United Kingdom 1972

Fire tests on air-supported structure.

United Kingdom 1972

The economics of accident prevention - Explosions.

United Kingdom 1973

Collected summaries of Fire Research Notes. United Kingdom 1972

- 3 -

28
CIB/W14/i/74(C)

-r1 » CIB/w14/2/74(c)

CIB/W14/3/74(c)

CIB/W1 4/4/74 (CA)

CIB/W14/5/74(USA)

CIB/W1/1/6 /74^USA)

CIB/W14/7/74(USA

ClB/W14/8/74(L'SA)

CIB/WI4/9 /74 (USA)

CIB/W14/10/74(USA

CIB/WI4/I 1/74 (USA

CIB/WI4/I 2/74 (USA

Ui.« CIB/WI4/ 13/74 (USA

CIB/W14/14/74(U3A

IS-. CIB/WI4/1 5/74 (USA

CIB/WI4/I 6/74 (USA

ISC. CIB/W14/17/74(USA

CIB/WI4/1 8/74 (USA

CIB/WI4/19/74 (USA

CIB/WI 4/20/74 (USA,

Design of concrete masonry walls for fire

endurance. 1973

Fare resi&tance of protected steel columns.

Prediction of fire endurance of concrete slabs.

1973

Control of smoke from fire In an air conditioned

building Australia.

The accumulation of gases on an upper floor

during fire buildup.

Survey of toxic species evolved in the pyrolysis

and combustion of polymers.

Annual summary report 1972-3

Topical report survey and evaluation of U.S.

National fire death statistics.

Topical report sample survey of Maryland fire

fatality data.

Loss prevention data insulated steel deck.

Loss prevention data high rise buildings.

Large scale fire tests of rigid cellular plastic

wall and roof insulations.

Development of a heat release rate calorimeter.

An experimental method for evaluating fire

hazard

NBS corridor fire testsj iherg:,' and radiation

models

E'/aluation of a pressurized stairwell smoke control

system for a 12 story apartment building.

Report of fire tests on flexible connections in

HVAC systems.

Radiative energy transfer from Gaseous diffusion

flames

Exting'jishment of radiation augmented plastic fires

b; water sprays.

Calculation of response time of ceiling mounted

fire detectors.

- 4 -

29
^* CIB/W14/21/74(USA)

'^^ • CIB/W14/22/74('-'Sa)

't » CIB/W14/ 774(USA)

c:e/wi4/24/74(usa)

Cy2/W 14/25/74 (USA)

, CIB/W14/26/74(G)

^* c:b/wi 4/27/74 (UK)

CIB/W14/28/74(CA)

CIB/W14/29/74(C)

i * CIB/W14/30/74(B)

1^"^* CIB/W14/31/74(CA)

1^ • CIB/V; 14/32/74(1)

CIB/wi4/33/74(D)

1 • CIB/W14/34/74(D)

CIB/W1 4/35/74 (D)

CIE/WI 4/36/74 (D)

X • ClB/Wl4/37/74(J) ^ * cib/w 14/38/74 (J)

CIB/wi4/39/74(LTC)

CIB/W14/40/74(UK)

Modeling of vented enclosure fires.

Fire safety criteria and tests for dwellings

preflashover.

Fire safety criteria and tests for dwellings

postf lashover

Impact of contents on building fires.

A full-scale fire program to evaluate new furnishings and textile materials developed

by NASA.

Influence of the carbonisation of the concrete on the

jxplosive spalling under fire conditions.

Athens 1973

Fire hazards of plastics in furniture and furnishingsj

Ignition studies. United Kingdom 1974

Fire behaviour of pipe instalation.

Australia 1973

Prediction of fire endurance of concrete masonry

walls.

La resistance au feu des portes.

Fire properties of some commonly used upholstry

materials. TH 44/153/412 Australia

Comraensurability problems m fire endurance

testing. Ottawa 1973

Das Brandverhalten von HotZBtutzen unter

Druckbeanspru Chung.

Uber das Brandgeschehen von der fassade lines

brennenden Gebaudes unter besonderer Berucksichtigung

der feuerbean-spruchung von aussenstutzen.

Verhalten von Baustoffen im feur.

Untersuchungen zum brandverhaten.

l)esign of fire cover on steel structures.

Fire reaistance design for steel structures.

The effect of crib porosity and recent CIB experiments.

(Available at meeting)

The early stages of fire growth in a compartment.

A co-operative research programme of the CIB.

(Available at meeting)

- 5 -

30
I * CIB/W14/41/74(N)

II IV * CIB/WlA/42/74(S)

I * CIB/WlA/43/74(S)

II * CIB/W14/44/74(S)

CIB/W14/45/74(S)

I CIB/WI4/46/74 (B)

II IV CIB/W14/47/74(NED)

I CIB/W14/48/74(NED)

I CIB/W14/49/74(NED)

CIB/W14/5n/74(N)

Comparison of heat transfer In several wall

furnaces

A discussion of compartment fires.

Deformations and critical loads of steel

beams under fire exposure conditions.

The connection between a real fire and the

heating conditions according to standard fire

resistance tests, with special application to steel structures.

Probalistic analysis of structural fire safety.

La Raslstance an fen de poulous an beton arine.

Principles of fire engineering design.

On the behavior of steel columns at elevated

temperatures

Oriented small scale model tests on the stability

of braced and unbraced frames at elevated

temperat ures

Analysis of combustion products from polystyrene

polyurethane , polyurethane and polyvinyl

chloride and also combustion gases from pinewood and spruce.

31
ANNEX IV CIB-WG 1 1» - Meeting, April 197'*, Braunschweig

Report of Group I - Structural Protection

The following delegates part i c i pat ed -i n the discussion:

Messrs. Malhotra (Chairman).

Klingsch (Secretary)

Parti cipants : Stolp Netherlands

Gross - V . . - ' USA

Jar OS 2 Poland

K a 1 o s Greece

Schneider G e many

Kordina Germany

Twilt Netherlands

Magnusson Sweden

Thelanders son Sweden

Arnault France

Be 1 1 i 3 son . France

Pet t er s son Sweden

Ande r be rg Sweden

Thor Sweden

Fischer Germany

St anke Germany

Knublauch Germany

Bi erbauer Germany

Haksever Germany

Keough Australia

Kenna New Zealand

Bakke Norway

Harmathy Canada

Kaw agoe Japan

The group divided its discussion into the following items:

1. Correlation of furnaces (32/7U, k\/Jh)

2. Design of structures

a) concrete (1/73, 6U/TU, 22/73, note by Mr. Jarosz)

b) steel (17/73, 2/7"*, 37/7h, 1*3/7'*)

c) others

3. Properties of materials (23/73 , 26/7'*, note on spalling by the

cbai rman

1* . Model tests and large scale tests ('*8/7'*, '*9/7'*, 3'*/7'*) 5. Structural codes, philosophy of structural fire protection (11/73)

6. Proposals for tasks, output etc.

32
-2-

1. Correlation of furnacea

Mr. Stolp presented bis document containing the final report on the

laboratory exercise on the correlation of vertical furnaces in ten

different laboratories using the TNO developed heat-f luxmeter . The date

when examined showed that in many cases the gold facing had been

damaged and hence it was not always possible to make a distinction

between the radiative and the convective heat transfer, It was nevertheless obvious that the biggest differences occur in the first

30 minutes but when the walls of the furnace are sufficially lost

the differences are considerably reduced. By 60 minutes the differences

between furnaces were of the same order as the variation in a given

furnace

Mr. Harmathy in his paper outlined an analytical method of evaluating the heat-balance of a furnace from a knowledge of the total

heat input, heat absorbed by the furnace walls and heat lost by the

fluegases. Mr. Gross bad used this technique and found that in his

furnace the surface temperature of the SIPOREX-wall and the refractory blocks was about the same and assuming that convective heat

transfer was proportional to the gas temperature and the radiative

, th heat transfer to the gas temperature to the «» power, the heat

loss to furnace walls, the specimen and the exhaust gases was equal

and 1/3 of the total heat input.

Mr. Kcough pointed out that the major part of differences were caused

by building furnaces with refractory materials having widely differing thermal characteristics. One solution would be to line all

furnaces with a low density and low conductivity material (such as

B & W 28 or M.I. 28 blocks). From his experience this will enable

the furnace walls to acquire gas temperatures after 13 minutes

or so become radiative; it will further more decrease some of the

effects due to different fuels and make the environment in the

furnace similar to that in a fire even for short duration tests.

It was agreed that the group will produce a guide to this topic

(see item ^ )

33
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2. Design of Structures -(a) ^ oncret eMr. Jarosz i^ave details of tests on prestressed concrete I-section

beams and concrete-slabs in a building using wood as fuel. The

web of the beam suffered severe damage by spalling causing it to

fail prcmaturaly. Difficulties were also expected with the adhesion of plaster to the smooth concrete surface. Mr. Harmathy

spoke on Mr. Lie's paper which describes a numerical approach to

establishing the fire resistance of reinforced concrete columns by

establishing heat transfer into concrete, reduction in strength

of concrete and steel and increase in the slenderness ratio.

Mr. Pettersson had experienced; some difficulties in correlating

some test data to a numerical technique without taking full account

of short time creep and physical damage which concrete may suffer.

Mr. Anderberg described tests on slabs restrained against rotational

movement at both ends but without any longitudinal restraint.

Moments at the supports and in midspan varied not only during the

heat-period but often suffered the maximum alteration in the coolingdown phase, sometimes a few hours after the end of heating. This

indicates the possiblity of collapse of a concrete structure after

the main severiV of the fire had been passed.

The discussion showed progress that was being made in finding

numerical solutions to predict the behaviour of simple structural

el erne nt s .

(b) - steel

Mr. STanke described a model developed in BAM to predict heat transfer through and isulating coating to a steel plate representing a column. Comparisons were made with full scale tests and relationships

derived between steel temperature and the duration of exposure

taking into account, s t eeljt hi cknes s , properties of the encasement

and the factor F/U (F is steel cross section and U the perimeter

surface of the section).

3k
A paper by Dr. Lie dealt with deriving empirical relationships

to predict the temperature of steel section when different encasements

were provided. Mr. Pettersson informed the group that a document

was under preparation in Sweden which will deal with the design of

protected and unprotected steel structures on the basis of theoretical

fire exposure conditions which take into account the characteristics

of compartments and the heating and the cooling phase of the fire.

It was hov«ver felt that the present information on thermal properties

of elements was inadequate which prevented accurate solutions to

be provided.

Mr. Wakamatsu's paper dealt with the same topic and gave a computer

programme which has been developed. Mr. Twilt found that the buckling

curves used were different from those in Mr. Lie's paper.

Mr. Thor gave a detailed account of experiments to establish

stress /strain curves for mild steel at different temperatures and

under different rates of loading. As the shape of the curves altered

at high temperatures he doubted the wisdom of using 0,2? proofstress

as a basis for estimating the stability. Tests on steel beams

shoved that midspan deflection was a useful criterion of failure

2 and a limiting deflection of 1/800 of span divided by the depth

of the section was appropriate. On the other hand some tests

carried out at Braunschweig for the ECSS had shown that the rate

of deflection was a better measure of stability.

Mr. Kawagoe described Mr. Saito's paper which analysed the likely

behaviour of a multi-storey steel framed structure. It appeared

that if steel temperatures were to exceed 1^0°C the deformation

caused by thermal expansion may cause instability.

(c) - Others

Note was made of the interesting series of tests undertaken in

Belgium on a number of doors.

35
-5-

3. P roperties of materials

Mr. Malhotra in a brief note gave account of discussions which

had taken place in the spalling of concrete since the last meeting.

A few experts from Germany, Netherlands and UK met to discuss

their findings and future activities relative to this problem.

Mr. Mey er-Ottens ' paper was to be presented by the German

Association of concrete structures and will be circulated to members.

Mr. Kalos presented an account of his views based on information

on the charges that take place in carbonaceous concretewith age.

He felt that clogging of the pores 10 to 20 mm below surface could

lead to more severe spalling in old concrete. Mr. Mey er-Ottens

experience led him to believe that sub-surface cracking will help

relieve the pressure and no serious effect may occur in practice.

The panel considered the question of holding a conference, seminar

or symposium on the topic of spalling. There was agreement that

this topic should be dealt with as a part of a general discussion

on predicting fire damage to concrete and its repairability

Mr. Gross asks the plenary session to seek collaboration with

other organisations such as FIP, CEB, RILEM etc. for holding such

a conference preferably at the time of some other international

meeting.

Mr. Thelandersson presented the results of his work on the stress

and deformation characteristics of concrete at high temperatures

and highlighted the differences that occurred under constant and

transient t emper at ure - c reep conditions. Data had been obtained on concrete specimens tested under torsion at high temperatures.

More recently s t r e s s / s t r ai n relationships with compression tests

had also been examined and a report was under preparation.

Mr. Schneider describes some experiments of a simular type undertaken at Braunschweig and he found many similarities between his

results and those obtained at Lund.

36
-6-

Mr. Schneider supported by Nr. Pettersson suggested that need

for obtaining data on. propert ies of aaterials at high temperatures

vas kueh that its absence would seriously hinder the prediction

of behaviour of structures of sixes and complexity vbich cannot be

tested with our present equipment. Document 72/52 had provided

a list of needs and these should be carefully examined to plan

future work .

U. Model tests and large scale scale tests (U8/7l», ^9/7U, 3k/lk).

Mr. Tvilt described a series of model scale tests on columns and

braced and unbraced frames. Effect of rate of heating on structural

properties of steel, particularly creep, vas examined. Mid-span

deformation of pin-jointed columns was measured at different

temperatures. In tests on frames vertical deformation of beams

was not significantly affected by the rates of heating used.

Although creep is an important factor it was felt that in practical

eases the history of heating may not have a significant effect on performance

In the frame tests there was no significant effect of the thermal

expansion of beam on the critical temperature. Critical temperatures

for columns were the same or higher as determined by tests on a single unit

Mr. Harmatby pointed out the variation in rates of heating and

stress levels vbich occur in real fires, hence there would be

need for full scale verification. Mr. Kordina felt that for

slender/, rat 1 o of 72 uninsulated beams and columns gave better

performance than insulated one^twhicb needed to be explained in

any future report .

Mr. Magnusson gave some advance information on a study he had

undertaken on the loadbearing capacity of fire exposed steel columns

with axial restraint. The analytical approach used, with step by

step computation of flexural rigidity, has been confinned in full

scale tests on 18 columns carried out at Metz (Project sponsored

jointly by CCCM and Swedish Building Association). The mathematical

model had reproduced with great accuracy the experimental set up

37
-7-

at Metz. The range of failure temperatures vaa between 2^0 and

68o''c. A report will be available shortly.

Mr. Knublauch bad been able to aodel the temperature field created

on the outside of a building on a 1/2 m storey height structure.

This was achieved by controlling the burning rate of gases. such

thatthe rates of burning were related by a power law of 5/2.

This was found to be the case for ventilation controlled fires

only. Experiments were carried out on steel columns placed in

various positions in front of the window and it was found that

generally one face was exposed to more severe conditions than

others and normal unprotected steel columns could be overloaded.

Mr. Harmathy felt that the height of the compartment could be

factor in establishing the shape and height of flames outside

the window.

Structural Codes

The chairman described activity in various international committees

and associations which will shortly lead to the issue of structural

codes on concrete and steel based on quite different concepts.

It was important to ensure there was harmony in different codes

and the CIB Commission could play an important role in this

connection. Both Mr. Pettersson and Mr. Kordinawere wholeheartedly

in favour of ensuring unanimity of approach even though the

contribution maybe only modest at this stage. The plenary session

was asked to take necessary action to cover the following aspects

either singly or together as appropriate.

1 . Scrutinizing of codes before publication

2. Advising code committees on latest knowledge

3. Adopting a long term role of producing data on structural

fire protection including philosophy.

38
6 . Taaks

The 'diBcussion had led to the identification of areas where an output was possible which would be of help to various International

and national organizations and those engaged in the fire safety

field. All oi the tasks were not equal in importance and on some only a state of the art type of statement could be made.

1. Correlation of furnaces « (a) A method of evaluating the heat balance of a furnace

(Mr. Gross - abt 6 months)

(b) Uni fy i ng rad i at i ve characteristics of furnaces

(Mr. Keough - abt 6 months)

2. Design of structures

(a) Stimulating the behaviour of concrete beams and solumns

(b) ditto for protected and unprotected steel beams and columns

(Mr. Magnusson and a colleague from Braunschweig , 6 to 12 months)

(c) Evaluating the behaviour of frames

(Mr. WitteveenC ? ) , Mr. Sullivan(T) - a state of the-artpaper in 6 to 12 months).

3. Properties of materials

(a) Spalling of concrete and arrangement of a symposium on

'the prediction of fire damage to concrete and its

repai rab i 1 i t y

' (Mr. Malhotra through Mr. Thomas)

(b) The state of art on the effect of high temperatures on properties of structural materials

c ) Future needs

b,C.i Mr. Fetters son and Mr. Harmathy - 12 to 2h months)

It. Guide lines to indicate relationship between micro and macro

fire tests (should be discussed at the next meeting).

^. Structural codes, advice, scrutiny andlongtime needs

( phi losophy

(Messrs. Pettersson, Kordina, Witteveen and Malhotra).

39
REPORT OF GROUP 2 - GEJJERAL FIRE CONSIDERATIONS

The following delegates participated In the discussions:

Prof. R.B. Williamson (Chairman and secretary)

Mr. T.Z. Harmathy

C Mr. F. Hoffmann

Mr. H.G. Kllngelhofer

Mr. S.E. Magnusson

Mr. L. Nllsson

Prof. 0. Pettersson

Mr. S. Thelanderson

Dr. P.H. Thomas

Mr. R. Bechtold

This was the first meeting of this group and the first order of business

was to look over the papers assigned for Its review. The group divided the

discussion Into three broad categories of the analysis of fully developed

compartment fires, the optimum design and specification of fire safety In

bulldlr.gs and finally to make recormiendatlons to the whole Commission Vlk

concerning possible actions In group 2's sphere of interest.

1. The analysis of fully developed compartment fires

The group began Its discussion by hearing a short presentation of each docu

ment by its author or someone from the same "country. The meeting was quite

informal and there was continuous discussion within the group.

Document 16/73{C) "A New Look at Compartment Fires, Part I and Part II" by

T.Z. Harraathy starts with a discussion of the empirical burning characteristics of cellulosic materials in general and wood cribs In particular. The

paper then presents an analysis which contains one equation to describe the

rate of burning in the fuel-surface-controlled regime and another equation

In the ventilation controlled regime. Several conclusions were reached

concerning choices of parameters. M. Harraathy then discussed how this

^0
- 2 -

analysis suggested design proceeduresthat might reduce the Import of fully

developed fires on buildings.

Document 42/Y4(S) "A Discussion of Compartment Fires" by S.E. Magnusson

and S. Thelandersson. The Authors presented the discussion by highlighting

the similarities and differences between their approach and that presented

In the previous document l6/73(C). The discussion was very extensive and

many members of the group entered Into Issues.

Document (UK) "The Effect of Crib Porosity and Recent C.I.B. Experiments"

by P.H. Thomas and Document 2\/Jk (USA) "Modeling of Vented Enclosure Fires" by

P.A.Croce were discussed together and found to present consistent Information.

In the discussion on fully developed compartment fires the differing

approaches of Mssr .Harmathy , Magnusson and Thelanderson were discussed in some detail after presentations by the authors. The group points out all theories

so far available rely somewhere on experimental data uncorrelated by theory

and almost exclusively based on wood fuels. The conventional heat balance

equations are approximations in that they adopt empirically the "best"

values for calorific value or net rate of heat release. This does not detract

from the value of these theories so long as they only apply to wood. If the

role of feed back to the fuel (to provide its effective "latent heat" to go

from the solid to gas phase) is important one might expect It to be responsible for considerable differences between pasties and wood. Because when

heat release in the room is controlled by the air flow In ventilation con- trolled fires the primary difference in fully developed fires would be manifest in the extrem£il flame outside the compartment and In the transition between ventilation and fuel controlled fires, probably raising the value of

the ventilation paraiDeter at which it occurs. This makes it less likely

that a plastic fire Is fuel controlled.

Mr. Nllsson and Mr. Thomas pointed out that their recent work, based on considerations simlliar to those of Heskestad and Croce (CIB Wl4 21/74 USA), can

be used to identify areas where the porosity of the fuel bed Itself (as

opposed to the surface area) led to departures from the well established

^1
- 3 -

verrtllation and fuel surface controlled regimes. This could account for some of the scatter to which Harmathy had drawn attention In one earlier

discussion in the group.

2. Optimum Design and Specification of Fire Safety in Buildings

Document 25/73 (UK) "Passive and Active Fire Protection - The optimum

Combination" by R. Baldwin and P.H. Thomas. Dr. Thomas presented a short

description of the paper and noted that there were some situations where it was clearly best to use either an active or a passive protection system

because the alternate was too expensive. There are also situations where

either approach Is too expensive, but the most Interesting situation lies

In the region where the two approaches are competitive. This Introduces

the concept of "trade-offs" and he discussed this philosophy at some length.

This combination runs through all of the design concepts discussed below.

Document 24/73 (S) "Principles of Fire Engineering Design and Fire Safety

of Tall Buildings" by Prof. Pettersson. The author noted that this was a review paper presented at the International conference on Tall Buildings

held In August of 1972. In this paper he reviewed the available framework

for a functional design approach to tall buildings. He describes the

General Services Administration's (USA) "Decision tree" approach.

Prof. Pettersson commented that this system was good In that it made

engineers think in an overall fire safety way. In addition it gives a framework for understanding where we should put our research effort.

Mr. Harmathy commented that in the desclsslon tree approach the designer

must rely on the state-of-the-art at the time he or she makes the final

design choices. The continuing research effort will refine our understanding

and the code of practice must be geared to a char»glng set of choices at specific locations in the desclsslon tree.
- 4 -

Document 44/74 (S) "The Connection between a Real Fire Exposure and the

Heating Conditions According to Standard Fire Resistance Tests, With Special Ref.

to Steel Structures" by 0. Pettersson. The author described the whole

document of which this contribution Is the second chapter. He then

described the content of the paper and there was considerable discussion on

the topic.

Document 47/74 "Principles of Fire Engineering Design" was discussed In the

complete Commission W14 meeting on Monday and may be discussed again on Thursday

Documents 22/74 (USA) "Fire Safety Criteria and Tests for DwelllngsPreflashover" by R.B. Williamson describes a restatement of existing fire

safety requirements and some criteria and tests In a new form. The author

noted that It was an early draft and he welcomed an suggestions or comments.

Mr. Thomas indicated that the Inclusion of feedback and research Into the

traditional scheme of contrxjl requirements and criteria assumed a dynamic

system.

Document 2V74 (USA) "Fire Safety Criteria and Tests for Dwellings - Post

Flashover" . A special report by Mr. Vytenls Babranskas on the general topic

of compartment fires was submitted In the place of the above named document.

This report discusses the bases of our understanding ef fully developed fires

in compartments.

Document 24/74 (USA) " Impact of Contacts on Building Fires by P.S.Klltgaard

and R.B. Williamson. This paper describes some of the new hazards represented

by the large growth of plastics in buildings for furniture and other large

content Items. Mr. Williamson noted that the criteria for fire propagation

in 22/74 could be used to control these hazards to some extent. The role of

plastics in the fully developed fire were discussed earlier.

^3
- 5 -

3. C.I.B. Contribution on Prin ciples _ol_F lre Safety

The group 2 discussion centered on the design and control of building

fires in a changing society. It was noted that there are a number

of organizations engaged in trade-off schemes and it was decided to make the recommendation to the entire Connnlssion W14 that a draft

document be prepared prior to our next meeting which Identifies the

general concepts of fire safety. This might include a methodology

of approaching trade-off as well as other topics.
Report of Group m CIB WG 14, 1974

Chairman ; Mr. Robertson

Participants:

Mr, Maroni

Mr, Bengtson

USA

Sweden

Sweden

Finland

Sweden

Japan

Hungary

France

Gernaan\'

Germany

German;^'

U, K

Denmark

USA

Netherlands

Germany

Mr, Tolstov

Mr, Oksanen

Mr. Sjolin

Mr, Kawagoe

Mr. Kovacs

M. Cabret

Mr. Westhoff

Mr, Becker

Mr. Gliislng

Mr. Nice

Mr. Aegidius

Mr. Berl

Mr, Stolp

Mr, Klingelhofer

Mr, Gross

Mr. Keough

USA

Australia

This group was concerned with problems of smoke and reaction to fire phenomena,

Mr, Westhoff opened the session and proposed that Mr, Robertson serve as chairman. This was unanimouslv agreed to. The members of this group are listed above.

Mr. Robertson proposed a subdivision of the papers Into four groups;

1, Fire Behaviour of Plastics and Textiles. 27/74 31/74 12/74 and 12/14

2, Measuring the Fire Hazard, 72/56 13/74 14/74 and 6/74

3. Movement of fire gases and smoke in buildings, 5/74 17/74 72/70 18/73 16/74

4. Growth and Spread of Fires, 15/74 18/74 19/74

A, Fire Behaviour of Plastics and Textiles

Mr. Nice discussed paper 27/74 Fire Hazards of Plastics in Furniture and

Furnishings; Ignition Studies

This report of the tirsi ^'cars work on a three \'ear study describes a systenatic

studv of ignition and burning of textiles and foamed polymers used in furniture. The

study involves application of the following standard and special tests;

1. BS 4735:71 horizontal burning

2. ASTM D 2H43-70 Smoke production

3. Several ad hoc ignition tests

a. Cigarettes

b. Matches

c. Hot wire

d. Candle

e. Radiant heating

^5
-2-

The results showed that uncovered foamed polymers give var\'iiig fire propagation

with ignition more likely for larger sources and lower density foams. With a cellulosic cover between a cigarette and the foam, smouldering of the foam was

usually observed. The cushimlng on a chair could ignite and burn out up to 70 minutes after a burning cigerette had been placed on it.

Mr. Berl brieflv reviewed the complementary Australian paper 31/74

Fire Properties of some Commonly used Upholstery Materials .This paper

reports studies ol the ignition of the materials with radiant energy' of various

levels. Again the covering material, when of cellulosic nature, seemed to encourage

the ignition and smouldering propiagation of foamed materials.

In England and most other countries there is little if any control over furnishings

of residential occupancies. UK considers this an important fire hazard problem

and Is investing about ten percent of the time of the Fire Research Station on it,

Jn the USA the Consumer Product Safety Commission is charged through the Flammable Fabrics A:t with Insuring public safety from such fire probleii>s.

It nas already set some standards for carpets and mattresses.

Mr. Nice reported that studies in UK had shown that the toxic effect of CO

in the presence of HCl or HCN is greatly enhanced. A report on this work will be available shortly, , r : , .

Mr. Robertson suggested the possibility of animal experiments in the sleeping

mode to determine if an alarm mechanism could be provided by an irritating gas. Mr. Nice mentioned work currently in progress on toxic hazards of "jases and

said that they too had considered work of the type suggested bv Robertson.

Mr. Kawagoe reported studies which had been made in Japan of the time required

for smoke to complete various stages of filling a compartment. He reported

modification of the relationship for pOInt source^. ^1/Q proposed bv Mr. Thomas.

Dr. YOkoi proposed the relationship t 1/Q r which recognizes the effect of

fire radius in modifying the behaviour.

t is time,

Q is burning rate and

r is the fire radius.

Mr. Maroni's paper was 12/74 Large Scale Fire Tests of Kigid Cellulai- Plastic

Wall and Roof Insulations , but this was not discussed turlher. It was t;enerall\'

recognized that the behaviour of the materials presented an important froblem.

There was some discussion on the relative hazard of the different polvraer foams.

In Summary —TM—

\ The group agreed that

1. Fires involving building furnishing items present a serious hazard problem.

2. Legislative action in several countries places increasing emphasis on this subject.

3. Further studies on various methods for alerting people during earlv stages of a fire are needed.

^6
-3-

4. Although CO has been shown to be one of the most important of the toxic fire gases a lot remains to be learned on the toxic hazard of other combustion

products (HCN, HCI etc. ) Attention should be directed to the importance of time as a measure of fire safety*.

5. .The group recommended that Commission W14 give continued consideration

to a rapid resolution of the fire gas hazard, to help in the coordination of the

effort and assist in rapid interchange of information on this subject.

B. Measuring the Fire Hazard

Mr. Kawagoe discussed paper 72/56 Visibility through Fire Smoke. A previous

paper bv the same author. Dr. Jin, had discussed visibility through smokfes from

cellulosic materials. The present paper is primarilv concerned with smokes from

polymeric materials. R includes statistical information on the particle size

distribution as well as range of visibility of both front and back lighted signs

both in the presence and absence of scattered light. R was concluded that

1. The product of the attenuation coefficient and the visual range is proportional

to the brightness of the sign divided b\- the intensity of the illumination

causing scattered light.

2. The visibility of signs through smoke is reduced when the smoke particulate

is black and illumination favours light scatter.

3. In these experiments the effect of e\« irritants was not investigated although

it was stated that such effects would greatly reduce visual range.

4. It was also stated that the color of the sign was unimportant comjiaxed to

its brightness.

Mr. Nice suggested that emphasis should be placed on elimination of smoke

production as far as possible and on controlling smoke movement.

Col. Cabret suggested the importance of contrast measurements. Mr. Berl suggested

the need for floor level indication of the direction for movement to exits or refuge centers.

Mr. Robertson summarized the papers 13/74 and 14/74 Development of a Heat Release Rate Calorimeter and An Experimental Method for Kvaluating

Fire Hazard . These both involve heat release rate measurement methods.

They both depend on the radiant exposure of a specimen in a flowing air stream

and provide for a measurement of the resulting heal release of the specimen

as a function of time. There are significant differences in the mass and complexity

of the experimental apparatus. One apjiarat us, NBS, measures heat release only

whereas the Smith calorimeter furnace is claimed to provide inlormation on

^7
-4-

f latranabllltv . time related heat and smoUp release, and flame soread behavior

at various irradiance levels. Provision is made for testing the specimen in both

vertical and horizontal positions.

Mr. Becker described a full scale Dortmund room calorimeter device designed

to measure the heat flux to room walls. The purpose is to compare this heat

flux from a variety of materials with the heat flux measured during development

of ISOR/834 fire temperature time curve in the same room. The results are reported as

the M factor of the specimen. This factor is found to be dependent on geometry and

subdivision of the specimen and product under study.

Col. Cabret questioned the merit of the method since the measurements are Influenced

by the surface to volume ratio of the specimen. He emphasized the large number of measurements which would have to be made for a given material for all possible

products.

Several participants emphasized the need to make heat release rate measurements

under a range of irradiance levels including the maximum values to be expected

under full scale fire conditions (Maroni, Stolp and Berl),

Mr. Berl introduced paper 6/74 Survey of Toxic Species Evolved

in the P\Toh'Sis and Combustion of Polvmers . This was ver\ briell>' reviewed . Mr. Berl seriously questioned the possibility that phosgene could be present

as a hazardous product of the combustion of an\' chlorinated pohoners because

of its instabijitv at high temperatures and unfavourable equilibrium concentration

at low temperatures. However he drew attention to the possibilitv of metal oxides

appearing in smokes. He encouraged further studv of them.

In Summary;

The group ag reed that;

1. The Japanese work on visual range of signs was of great value although the

importance of securing information on the reduction of visual range resulting

from e\'e irritation should not be overlooked.

2. The group recognized tlie fallacv of the belief thai smoke production during

building fires could be signilicantl\' reduced bv control of smoke production of building materials in tlie absence of Srailar controls on the occupancy fire load,

3. The importance of heat release measurements was recognized and the group

offered encoiu-agemcnts to ISO/TC 92 towards their planned development

of a heat release calorimeter. Such a device should provide flexibililv in the heat flux levels during specimen test.
-5-

4. Metal oxides appear to warrant further study as a possible hazard in fire. This may pose a special occupational hazard for fire fighters.

C. Fire Gas Movement in Buildings

Mr. Berl presented paper 5/74 The Accumulation of Gases on an Upper Floor

During Fire Buildup. This paper describes experiments in which tires were

started in a first floor room of a building and measurements were made of temperatures in the fire room and oxvgen depletion, CO and CO accumulation in an upstairs room. These measurements were made at three different heists

above the floor level roughly 15 cm, 60 cm and 160 cm. Both a large wooden

crib and a chair were burned individuallv. The development of toxic concentrations

occurred verv rapidlv with little difference in the time of their occurance

at different levels above the floor, bx the case of the crib burn verv little smoke was produced but the CO concentration rose to lethal levels in less than eight

minutes. The burning chair on the other hand produced large quantities of smoke.

It was concluded that the danger from CO was dominant over oxvgen depletion

and COg generation.

Mr. Stolp suggested that it might be possible to incorporate an olfactory material

in the furniture or building finish Item which in the event of fire could serve as an alarm mechanism to alert building occupants.

Mr. Robertson very briefly discussed paper 17/74 Report on Fire Tests Flexible

Connectors on HTVAC (Heating Ventilating and Air Conditioning) Svstems . Briefly

this paper is concerned with design of duct systems which will limit the movement of gas between floors during a building fire. It also reconsnends

precautions for limiting smoke production from materials used in duel connections.

This paper stimulated discussion by Mr. Klingcl'-bfer of work under way at Dortmund on fire performance of ventilating s\-stems and the testing of dampers.

Mr. Keough presented paper 72/70 Venting Fires Through Roofs ( Fires in an

aircraft hangair). The object'xre was to study the roof venting conditions required

to permit disposal of fire gases. The following variables were considered;

1. Fire burn area

2. Roof vent area

3. Wall inlet area

4. Depth of roof curtain

A9
-6-

He emphasized the importance of recognizing the gas discharge coefficient of various t^Tjes of roof vents. B was concluded that an effective roof vent area

of about 3,5 percent of the floor area covered. For large hangers air leakage

of the building was adequate tp replace the gas outflow, Howeverfor :i mailer

buildings special provision should be made for such openings. During the study

fire whirls were sometimes observed and it was suggested that building design

might be arranged to dispose of gases where they could burn outside the building.

Mr. Becker asked about the possibilitv that PVC might be used as a vent closure,

Mr, Keough did not consider that this would be feasible. The UV degradation is a serious problem at the Australian latitudes.

Mr, Nice presented paper 18/73 Problems of Pedestrian Precincts Part B

Smoke Production of Sprinl^elerd Fires . This is a part of an extending study

of smoke behaviour and control in a shopping arcade during a fire. Four noints were emphasized;

1. Automatlc^inklers must be properh' located to cool the products of combustion

2. Reservoirs shoidd be provided as part of the building design to collect the smoke

3. Venting devices must be available to exhaust the smoke to the outside

4. Adequate air inlets must be present

The sprinkler tests indicated that gas temperatures were substantialh' lowered even in circumstances where direct impingement on the burning

materials did not occur. The smoke densitv was not affected b\' the sprinkler

action.

Mr. Stolp reported on similar experiences in Holland where venting dev.ces

proved adequate to remove accumulated smoke. Mr. Nice responded tliat English building regulations do not as '«t permit the use of venting devices

that relv on the building electric power supply.

Kawagoe outlined Japanese practice regarding means to establish

pressure fields that could inhibit the flow of smokes through corridors.

Cabret agreed with Kawagoe that air curtains did not provide an effective means

to modify smoke flow patterns.

Mr. Gross presented paper 16/74 Evaluation of a pressurized stairwell

smoke control svstem for a 12 store\ apartment building . As part of the US Department ot Housing and Urban Development Project Break - through an apartment building was designed with a stairwell having an independent

air supplv and exhaust in conformity with Canadian building design. The tests were run under climatic conditions where the temperature difference between

Inside and outside were 10-18 F. Sulfur h exaflutridewas used as a tracer substance.

50
-7-

The "ignition source" was located either on the second or ninth floor.

E was found that the fan capacit>' was adequate to frevent intrusion of the tracer

gas- into the stairw^l with as manv as five doors open to the building,

Kawagoe described Japanese Fire Service techniques by which escape corridors

could be sealed off from the building bv the use of inflatable barriers equipped

with escape hatches for occupants.

In Summary

The group emphasized that;

1. The speed of movement and the concentration of smoke and toxic gases 'observed

during experimental fires place emphasis on the associated life liazard.

2. The quantitv of smoke which can result from the burning of even small amounts

of building finish or furnishing items is so large that it seem unlikelv that control of these items on a national basis will be effecting in eliminating the hazard. Because of this great importance is attached to the need far incorporation

of special gas transport systems in buildings for movement and removal of gases

when fire occurs,

3. There continues to be a need for development of improved engineering design

methodolog\' for propjer control cf smoke to insure life safetv of building

occupants.

4. Consideration should be given to the desireablitv of a symposium which might

be sponsored by Commission W 14 of CIB on the subject building design methods

to assure smoke and gas movement during building fires.

5. A need exists for studies of methods suitable to encourage desireable and

life saving human response during building fires.

51
-8-

Mr, Gross described recent fire stiidles reported In dociiment 15/74

NBS Corridor Fire Tests; Enerp' and Radiation Models. A corridor test facility

has been used to study the importance of floor covering material in influencing

fire -spread along the corridor length, ge reported fire loads in the associated burn room were on the order of 13-14 kc/m . This comprised 4 wooden cribs which were

ignited simultaneously. During these studies all floor covering were found to ignite

with the result of rapid flame travel down the corridor length after 5-15 minutes of crib burning time. This behaviour has been attributed to heating of the floor covering

throu^ radiation from hot gases and the celling of the corridor.

Mr. Gross described plans for development of a test method to measure fire properties

of floor covering materials. This device involves use of a radiant panel heat'source

with a hor^ontally oriented specimen irradia^ with a flux level varving ffom

1-2 /cm at one end to about O, l-0, 2 /cm at the other end.

Mr. Stdp described recent studies of a similar nature in Delft, A varietv of floor covering material including wood and linoleum as well as carpeting had been tested

In a corridor of roughly 2 m width and 2, 5 m height. The walls and ceiling were

lined with light weight concrete block walls. All the combustion air entered the corridor from the end opposite to that at which the exposing fire was located. This

ftre as in the NBS tests was developed in a separate but connecting room. It made

use of four wooden cribs representing a fire load of about lO kg/m . Only one of these cribs was ignited and it took about 20 minutes before all were completely

Involved.

Mr. Stolp indicated that none of their ten or more tests exhibited complete involvement

of the floor covering. Fire spread on the carpet extended but &ho\A one fourth

of the corridor length and they have concluded that floor covering materials which

do not spread fires from a small ignition source do not is'esent a prominent fire hazard.

Paper 19/74 on Extinguishment a.' Radiation Augmented Plastic Fires by Water Sprav

by R. S. Wagee and R . D. Reitz deals with the turbulent burning of several plastics

(Plexiglass, polystyrene, polvethvlene and Delrin 500) with and without added

radiation enhancement and determining the effect of varying amounts of water spray on burning rates and complete extinction of combustion. Water was applied by a

single spray nuzzle.

Results have been obtained for a varietv of energy fluxes superimposed on the "normal" burning of plastic sheets, mounted both vertically or horizontally. All data

indicated a linear dependence of burning rate on external radiant flux. Water spray

produced a lower burning rate, still linearly dependent on external radiant flux. At

a critical radiant flux level and water flow rate, combustion stopped.

From the results it should be possible to obtain a clearer understanding of minimum

water requirements for sprinklers or other water suppression methods.

Col. Cabret emphasized the observed difficulties under realistic conditions to extinguish rubber fires with water.

52
-9-

Complementarv experiments on water extinguishment of wood cribs were described

by Mr. Stolp. Water was applied to the top of a rotating burning fuel crib. The

weight loss of the crib was obtained as a function of time and as a function of water

flow rate. By enclosing the rotating crib in housings in which the ventilation and combustion

gas exhaust flow can be varied the experimental technique lends itself to a variety

of investigations.

Toe paper bv G. Marltstein 14/18 on Radiative energy transfer from gaseous

diffusion flames deals with a studv of radiation from laminar gaseous diffusion

flames of nine saturated and unsaturated hydrocarbons burning in air. The objective

is to investigate the contribution of emitted radiation from the flame soot and from

the heated gaseous products of combustion. Since considerable temperature

gradients exist absorption of parts of the radiant energy in the cooler parts of the flame is lilcely, thereby reducing the radient heat output.

From the experimental results, in which the integrated radiation from up to ten parallel flames was observed it was concluded that their radiant output could

be described as being due to 6 combinations of radiation coming from the soot

at the hottest part of the flame and from the variatlng product gases, CO^ and H^O

at a lower effective temperature.

At a future date measurements in turbulent diffusion flames will be undertaken

under conditions that will be similar to those met in actual fires.

In Summary

The group decided that:

1. The apparent conflicting findings of two reported studies on the behaviour of floor covering materials emphasizes our lack of understanding of the phenomena involved.

They encourage further studies of the reason for the differences observed in the two investigations with the objective of clarifying the relationship between the

test method results to those observed in actual building fires.

2. Basic combustion studies of the l\'pe v-eported in two of the papers considered are likely to provide a portion of the basic technical information required for future engineering system design for fire safety.

53
-lOGeneral Summary and Recommendations

The definition of occupancy safety during building fires requires a more intensive

effort than has been given to it heretofore. The emphasis on building structural

safetyneeds to be accompanied bv a oarallel pffort o" l<f«. sn^etv an<* 'Ire prevention.

1. The group noted increasing evidence of the importance of fire gas properties

and behaviour as serious life hazard.

2. The group agreed that smoke and toxic gas production from the occupancy

fire load presents a grave hazard and must be recognized in any attempts

to minimize smoke and fire gas production. '

3. Several countries have alreadv established minimum performance standards

for b uilding furnishings and clothing items to minimize fire caBialtie&

4. There is need for increased emphasis on:

a) Earlv detection and warning of occupants to permit effective evasive

action.

Study of human behaviour during presence of fires.

c) Characteristic times of fire phenomena as a determinant of fire safety,

d) Investigation of the relative hazxirds associated with toxic gases and smokes

from both construction and building occupancy materials.

5. Because of the quantities of smoke and toxic gases resulting from the burning

of even small quantities of building finish or furnishing items a great need

exists for the development and utilization of special means for the control of

and removal of smoke and toxic gases during building fires.

C. The importance of reaction to fire measurements including heat release, gas and smoke evolution and nammabilitv under a wide range of thermal exposure

conditions call for the rapid development of suitable testing methods.

7. n is recommended that Commission W 14 of CIB sponsor a s^'mpo8ium on the subject of building design methods to control gas and smoke movement during

building fires.

8, R has been brought to the attention of the group that a substantial number of

investigations are planned and are being carried out on tne influence of fire gases

and smokes on animals and humans. An effort should be made to survey and

document this work in time for a report at the next meeting of W 14.

US( ( IMM-NHS U( 5^
NBS-lUA IREV. 7-73)

U.S. DEPT. OF COMM.

BIBLIOGRAPHIC DATA

SHEET NBSIR 75-67^

V H) V I A t t { S S 1 Oil No.

3. Kecipicnt^s Acccs.sion No.

Building Associated Fire Problems — Report of Meeting CIB,

Wlii, Apri 1 1-5, 197A

5. Publication Date March 1975

6W> fI rIVJIIIIIllK I r\r m i r\ o l)r vy Ik£IIII<..uI oArtt7'Atii\rt Il/ll \V'WUd ciHf

7. AUrHOK(S)

A. F. Robertson, D. Gross, R. B. Williamson

8. P<-rfi)rniing Organ. Report No.

y. P h K r UK M i N ( I OK (. i A i\ 1 /- A 1 K JiN [\ A M 1 A N w A 1 ) U K i. NATIONAL BUREAU OF STANDARDS

DEPARTMENT OF COMMERCE

WASHINGTON, D.C. 20234

10. '''^'IIJ'^^J^^'^*^"'''

11. ( ontratt/Grant No.

1 y r» n <z r\r i f\ o (Ir o An \'7 'At % m* • .ir>il ( iirnrtw-ff- Aiiiir^'i^i., f\tr^**t l i t\j ^ t s* t £^ y 1 P \

same as No. 9

13. Type of Report & Period

( overed Final

14. Sponsoring Agency Code

15. SUPPI.KMI-NTARY NO I KS

16. ABSI RAC 1 (A 200-woTd or less {actual summary of most stgpiiicant mformation. If document includes a sidnificant bibliography or I iterature survey, mention it here.)

This report summarizes discussions which took place at the recent

meeting of Commission Wl^ of CIB. About k(> of the more than 100 documents

related to fire problems were considered at the meeting. It was agreed

that current trends in building construction and furnishing materials

present new forms of fire hazard which warrant increased attention. While

progress was evident in methods for analyzing fire endurance performance

of structural building elements it seems desirable to place greater emphasis

on the fire gas hazard as a cause of fire casualties. A symposium is planned

on methods for managing gas movement and disposal during building fires. A

state-of-the-art paper is also planned to review and document current work

on the influence of fire gases on animals and humans. It was noted that

the smoke production characteristics of furnishing items may present serious

problems and must be considered in any attempt to control smoke during

bu i Id i ng f i res

.

17. KEY WORDS (six to twelve enfrte.s, alphabetical order, capitalize only the first letter of the first key word unless a proper name; separated by semicolons) Qig. codes ; Commission Wl4; fire endurance; fire gases;

fires; fire tests; growth; models; smoke.

18. AVAILABILITY [ Unlimited

f-or Official Distribution. Do Not Release to N TLS

[

' Order 1- rotn Sup. of Doc, U..S. (jovernmcnt Printing Office Washington. D.( . 20402. SD ( at. No. C13

[ T Order I- rom National Technical Information Service (NT IS) Springfield, Virginia 221'il

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'THIS REPORT)

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21. NO. OF PAGES

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