Publisher’s version / Version de l'éditeur:
Vous avez des questions? Nous pouvons vous aider. Pour communiquer directement avec un auteur, consultez la première page de la revue dans laquelle son article a été publié afin de trouver ses coordonnées. Si vous n’arrivez pas à les repérer, communiquez avec nous à PublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca.
Questions? Contact the NRC Publications Archive team at
PublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca. If you wish to email the authors directly, please see the first page of the publication for their contact information.
https://publications-cnrc.canada.ca/fra/droits
L’accès à ce site Web et l’utilisation de son contenu sont assujettis aux conditions présentées dans le site LISEZ CES CONDITIONS ATTENTIVEMENT AVANT D’UTILISER CE SITE WEB.
Fire Study (National Research Council of Canada. Division of Building Research),
1961-02
READ THESE TERMS AND CONDITIONS CAREFULLY BEFORE USING THIS WEBSITE. https://nrc-publications.canada.ca/eng/copyright
NRC Publications Archive Record / Notice des Archives des publications du CNRC :
https://nrc-publications.canada.ca/eng/view/object/?id=3728b090-db21-4f69-8ac3-929e788770e3 https://publications-cnrc.canada.ca/fra/voir/objet/?id=3728b090-db21-4f69-8ac3-929e788770e3
NRC Publications Archive
Archives des publications du CNRC
For the publisher’s version, please access the DOI link below./ Pour consulter la version de l’éditeur, utilisez le lien DOI ci-dessous.
https://doi.org/10.4224/40001339
Access and use of this website and the material on it are subject to the Terms and Conditions set forth at
Fire research at the National Research Council 1960
N27f5
1
no.
4
NATIONAL RESEARCH COUNCIL CANADA
DIVISION OF BUILDING RESEARCH
FIRE RESEARCH AT THE NATIONAL RESEARCH COUNCIL 1960
by
G. W. Shorter
P r e s e n t e d to the Association of Canadian F i r e Marshals on 5 July, 1960, Banff, Alberta
F i r e Study No. 4 of the
Division of Building R e s e a r c h
OTTAWA February 1961
FIRE RESEARCH AT THE NATIONAL RESEARCH COUNCIL 1960
by
G . W. Shorter
The F i r e Section of the Division of Building R e s e a r c h was established approximately ten y e a r s ago with the object of conducting r e s e a r c h aimed at a reduction in the life and property 10s s e s by f i r e in Canada. In o r d e r to achieve a r e a l over-all reduction i n property l o s s e s i t was realized that any remedial m e a s u r e s suggested m u s t not involve undue expenditure nor introduce problems of subsequent operational efficiency.
Much of the work undertaken in the F i r e Section i s formulated within the Division itself a s a r e s u l t of general considerations of the
f i r e situation in Canada. Many problems continue to be brought to the attention of the Section f r o m s o u r c e s such as the Associate Committee on the National Building Code, f i r e officials, government departments, industrial companies and private individuals. Inquiries have also been received recently both f r o m the United States and over s e a s countries.
PROGRAMMING O F WORK
In establishing a p r o g r a m of r e s e a r c h , priority i s given to Canadian problems that a r e of most importance f r o m the national standpoint, although not necessarily unique to Canada. Thus high priority i s usually given to problems associated with building code requirements a s i t i s through building regulations that the g r e a t e s t p r o g r e s s can be made in effecting better protection f r o m f i r e to
buildings and their occupants. Accordingly one of the p r i m e functions of the F i r e Section i s to provide factual information upon which decisions concerning building code requirements may be based.
The solution of many of the problems submitted by outside agencies often r e q u i r e s only a l i t e r a t u r e survey. The F i r e Section has been able to provide such an advisory service without seriously interfering with i t s m a j o r laboratory activities. It i s c l e a r that a good l i b r a r y facility i s n e c e s s a r y for providing this type of s e r v i c e in addition to providing essential background m a t e r i a l for laboratory r e s e a r c h p r o - jects. The F i r e Section i s now receiving l i b r a r y m a t e r i a l f r o m almost every organization working in the field of f i r e r e s e a r c h throughout the world and already a fairly extensive collection of l i t e r a t u r e has been assembled.
It i s not always possible to undertake immediately the experiments which a r e n e c e s s a r y to provide solutions to the remainder of the problems received. In these c a s e s priority is established after consideration of the importance of the problem in i t s own right and of the possibility that the solution might have a m o r e general application. The choice of work i s in no way governed by i t s academic interest. Thus emphasis may often be given to those problems for which the solution i s theoretically simple and yet will provide a valuable contri- bution to the field of f i r e protection.
STAFF
AND
FACILITIESIn o r d e r to c a r r y out comprehensive r e s e a r c h studies i t
is n e c e s s a r y to have a number of different academic disciplines r e p - resented on the staff. Even at this e a r l y stage in i t s development, the F i r e Section has m e m b e r s of staff who a r e proficient in the fields of physics, chemistry, chemical engineering and mechanical engineering, a s well a s i n the actual practice of fire-fighting. A g r e a t advantage
enjoyed by the F i r e Section i s that i t constitutes p a r t of a l a r g e r e s e a r c h organization wherein assistance may be obtained on special problems
f r o m experts not only in the Division of Building R e s e a r c h but in other divisions of the Council. The co-operation of the Divisions of Mechanical Engineering, Radio and E l e c t r i c a l Engineering and Applied
Chemistry has often proved m o s t valuable. The computing facilities of the National R e s e a r c h Council a r e also available for handling problems involving cumbersome mathematical solutions.
Although a competent staff i s the essential feature of any r e s e a r c h organization, i t m u s t be provided with suitable facilities in o r d e r to pursue experimental investigations. The F i r e Section i s
privileged to have available to it a l a r g e new laboratory building devoted exclusively to f i r e r e s e a r c h (1). The F i r e Section i s gradually acquiring special apparatus if commercially available o r constructing such equip- ment when necessary. It has often been n e c e s s a r y to adopt this l a t t e r procedure, particularly for t h e r m a l radiation m e a s u r e m e n t s and the determination of the physical properties of m a t e r i a l s at high tempera- tures. Thus a great deal of staff time i s of necessity spent on the development of special instrunlentation and apparatus.
Last but not l e a s t , i t should be emphasized that information obtained at actual f i r e s i s used wherever i t i s applicable. Included
among these field studies was the St. Lawrence burns operation f r o m which most valuable r e s u l t s w e r e obtained.
TYPICAL STUDIES F i r e Fatalities
One of the major investigations has been a study on a s t a t i s t i c a l basis of f i r e deaths in Ontario. In carrying out this work, which was begun i n
19
54, the F i r e Section has enjoyed the full co- operation of many agencies such as the Ontario F i r e Marshal's Office and that of the Registrar-General of Ontario. What has been equally gratifying i s the co-operation received f r o m hundreds of individuals,particularly f i r e chiefs, who have conscientiously completed the
n e c e s s a r y report forms. In this survey each c a s e is classified in one of four p r i m a r y categories, depending on whether the victim was a child o r an adult, and whether the f i r e was a building f i r e o r a clothing fire. Inquiry has been made into every aspect of death due to f i r e that can possibly be treated statistically. To date this study has been reported on mainly in internal r e p o r t s of the Division, copies of which a r e sent to all f i r e m a r s h a l s with the exception of the short paper, F i r e Deaths i n Ontario by G. Williams-Leir, presented a t the F i r e R e s e a r c h and
F i r e Prevention Conference held p r i o r to the opening of the F i r e Research Building i n October
19
58 and since published in the proceedings of the conference (2). Although reporting has been on a consistent basis for only four y e a r s , consideration is being given to the publication of a paper l a t e r this year in the belief that reliance can be placed on certain trends indicated to date.St. Lawrence Burns
The l a r g e s t study s o f a r undertaken by the F i r e Section was the St. Lawrence Burns Operation. A complete s e t of r e p o r t s on this operation has been sent to a l l f i r e m a r s h a l s , with r e p r i n t s
of the paper which appeared i n the April i s s u e of the NFPA Quarterly ( 3 ) . This study furnished factual results which would have been difficult
to obtain i n any other way. The radiation r e c o r d s i n particular have provided a f i r m basis for establishing requirements for the spatial separation of buildings.
The results of smoke measurements emphasized the hazard of smoke with reference to the escape of occupants from a building. It was shown that smoke can seriously reduce visibility in an extremely
s h o r t time. For example, an open u p s t a i r s bedroom in a dwelling can become "smoke-logged" in two minutes. It would therefore appear that
f r o m the standpoint of life hazard, an effective f i r e detection system should be based on the e a r l y detection of smoke. In spite of a l l p r e - cautions, however, i t is probable that smoke in stairwells and c o r r i d o r s will s t i l l be a problem in l a r g e s t r u c t u r e s with high occupant loads, such a s schools and office buildings. Studies a r e being undertaken into means of keeping smoke out of escape routes in this type of building, The F i r e Section i s interested in this problem and will be studying the u s e of slightly increased p r e s s u r e s in such a r e a s while at the s a m e time having the f i r e a r e a vented.
Other r e s u l t s f r o m temperature m e a s u r e m e n t s provided confirmation of the validity of the standard time-temperature curve used in f i r e endurance t e s t s of walls, floors and ceilings. The r e s u l t s in- dicated that the temperatures a r e generally higher than those given by the ASTM curve where t h e r e i s a high f i r e load o r where flammable interior finishes a r e used. Other factors studied included the effect of wind in producing higher radiation intensities on the leeward side of a building than on the windward side. This effect i s vividly shown i n the coloured films which w e r e taken at each of the burns. The careful planning of these experiments grovided r e s u d s which have wide application.
Under r a r e circumstances, observations at f i r e s p e r m i t spot checks to be made which a r e valid for the particular circumstances prevailing. Of the many f i r e s investigated over the y e a r s by the F i r e Section, two have given r e s u l t s which a r e relevant to the ignition of m a t e r i a l s by radiation. It i s interesting to note that these r e s u l t s and those of other f i r e s reported by the British Joint F i r e R e s e a r c h Organi- zation have agreed with the general radiation theory derived from the St. Lawrence results.
F i r e Endurance
The l a r g e s t facilities in the F i r e Research Building a r e those associated with the f i r e endurance testing of building elements.
The two large furnaces serve a dual role in that they a r e used not only for carrying out standard tests but also for research. A study has
been carried out for example on the effect of restraint on the fire endur- ance of walls. These experiments a r e important when considering whether a wall tested as load-bearing should be assumed to have the same fire endurance a s the same wall tested while fully restrained on all sides, a s i s necessary if it i s to be employed as a non-load-bearing wall. Results from tests on the floor furnace have given useful information on the load at failure of floors and beams. Experiments have been carried out to determine the most appropriate method of measuring temperatures on the unexposed surface of a specimen during a test.
Extensometers have been designed and installed to measure the expansion of walls during fire tests, as well as instrumentation for measuring the deflection of floor slabs. A conditioning chamber has been designed and installed to facilitate the curing of specimens prior to test.
In order to reduce the number of these cumbersome and expensive tests in the future, one r e s e a r c h study i s concerned-with the prediction of f i r e endurance. Such a procedure would greatly facilitate the development of new constructions by industry. Similar studies have been going on in various countries for a number of years but all of the methods so far proposed have definite limitations to their use.
In some cases, their use would result in inaccurate predictions. Various analytical and numerical methods a r e being studied by the F i r e Section, in order to predict the time of both the thermal and load failure of
building elements during the f i r e test; the results a r e promising. When applying these methods one has to know the physical properties of the materials used in the construction being studied. Unfortunately very little information i s available on the physical properties of materials at elevated temperatures. It has therefore been necessary to design and construct apparatus to obtain this information. These properties include
the strength, specific heat and thermal conductivity. When this pro- cedure for prediction i s fully developed it should be possible, following a large-scale test, to predict the fire endurance of a similar construc- tion for different thicknesses of materials and possibly for different materials.
F i r e s in Corridors
The importance of the spread of flame characteristics of a building material has been appreciated for a number of years. Little information i s available, however, as to how the results of the various flame-spread tests should be applied. A modest approach to this problem has been made by the F i r e Section by considering corridors as a start. The main reason for this choice of building element was the fact
that corridors differ from almost all other compartments in a building in that they a r e characterized by a lack of furnishings or other combus- tible contents. A small-scale test model has been constructed for examining the spread of f i r e characteristics for combinations of wall, floor and ceiling lining materials in corridors. The test fires originate in a model room opening on to one end of the corridor. Ventilation conditions have been arranged to be close to the optimum for the pro- pagation of the f i r e to the end of the corridor. The criterion which has been adopted i s that an assembly shall be considered unsafe if a fully developed f i r e propagates to the end or to a point near to the end of the corridor.
Approximately thirty such tests have been carried out. Based on these studies it i s recommended that a composite index be used for determining the over
-
all requirements for flame-spread ratings for wall, ceiling and floor finishes. One interesting aspect of this study has proved to be the influence of floor coverings on the propagation of a fully developed fire along a corridor. Recent Danish full- scalet e s t s i n the s a m e field confirm the idea that the picture so f a r obtained will be applicable to full- scale c a s e s ( 4 ) .
It is possible that the F i r e Section may c a r r y out full-scale t e s t s a t a l a t e r date in o r d e r to substantiate the r e s u l t s of the small-scale t e s t s , although there is no reason to doubt their validity. Such full-scale t e s t s would be used in addition to study the effectiveness of sprinklers in stopping o r retarding the spread of a fully developed f i r e almg a corridor. The Section has been concerned to date with c o r r i d o r s be- cause they tend to present a relatively simple problem. It is probable that l a r g e a r e a s such a s auditoria may be studied i n the future to determine i f a somewhat s i m i l a r approach might be practicable.
Combus tion
A number of experiments have been c a r r i e d out on problems of combus tion including some on the ignition of combustible m a t e r i a l adjacent to s t e a m lines, and on the self-heating of lime- treated wood shavings. Much time has been devoted to the design and construction of a s m a l l furnace to be used i n the application of a t e s t method for d e t e r - mining whether or not a m a t e r i a l meets the requirements of incombusti- bility s e t forth by the Associate Committee on the National Building Code. The Section has participated i n a round robin s e r i e s of t e s t s on behalf of ASTM Committee D20 concerned with determining the ignition p r o - p e r t i e s of plastics.
A long-term project recently initiated i s designed to develop general knowledge on various aspects of the combustion process a s
applied to building materials. The properties of m a t e r i a l s to be studied include e a s e of ignition, evolution of gases a s affected by r a t e and
method of heat application, composition and flammability of the gaseous products.
F i r e Extinguishment
One study in this field i s concerned with the development of a s m a l l - s c a l e f i r e t e s t for mechanical foam. This study has been undertaken i n o r d e r to obtain a m o r e reproducible f i r e test. Due to the nature of this experiment, i t has to be c a r r i e d on out of doors at present, thus permitting wind to e x e r t a considerable influence on the results. If a s m a l l - s c a l e t e s t can be developed, i t will not only be much e a s i e r to c a r r y out standard f i r e t e s t s , but i t will lend itself to carrying out
r e s e a r c h studies on foam. A laboratory foam generator has been construc- ted for this study. The variables being investigated a r e r a t e of appli-
cation of foam, expansion ratio, concentration of foam liquid, 25 p e r cent drainage time and c r i t i c a l s h e a r s t r e s s . A new approach has been taken in that a control time i s determined which is defined a s the time a t which radiation f r o m the f i r e i s reduced to 10 p e r cent of the maximum value before application of foam.
Another long-term project i s concerned with the u s e of f i r e r e t a r d a n t s in f o r e s t f i r e control. Some laboratory studies have
already been c a r r i e d out and m o r e a r e yet to be undertaken. It is obvious, however, that due to variation in the fuel found on the f o r e s t floor it
will be n e c e s s a r y to p e r f o r m a number of field t r i a l s before any conclusive r e s u l t s m a y be obtained.
APPLICATION O F RESULTS
Probably the m o s t important medium through which r e s u l t s of the F i r e Section's work find application i s in various codes and
specifications, a notable example of which i s the National Building Code of Canada. Although the gection i s not directly responsible for the writing of any code o r specification, i t frequently provides essential
information upon which code requirements a r e formulated. A description of the relevant work i s either published o r p r e p a r e d in r e p o r t f o r m and
circulated to others interested both in Canada and elsewhere. Where work has been originated within the Section, s i m i l a r r e p o r t s or publi-
cations a r e prepared, and these a r e also sent out to interested authorities.
The r e s u l t s of work initiated in response to an inquiry received from an outside organization o r individual a r e immediately made available to the p a r t i e s concerned. Where the r e s u l t s a r e thought to have a wider application, appropriate publications may also be prepared.
CONCLUSION
It i s hoped that this s u m m a r y shows that the work undertaken by the F i r e Section provides a rational approach to f i r e problems. It i s the Section's d e s i r e to a s s i s t wherever possible in the solution of f i r e problems, with the hope that definite improvements will be made in the fields of f i r e protection and f i r e prevention. One of the p r i m a r y a i m s of f i r e r e s e a r c h is to enable m o r e effective use to be made of building m a t e r i a l s and construction techniques through increased knowledge of their c h a r a c t e r i s tics i n relation to fire.
REFERENCES
1. R. F. Legget. New Canadian f i r e r e s e a r c h laboratory. Nature, v. 183, March 7, 1959, p. 653-655 (reprinted a s NRC 5101, available from the National R e s e a r c h Council, March- 19 59,
6 ~ .
).2. G. Williams-Leir. F i r e deaths in Ontario. In F i r e r e s e a r c h and
-
f i r e prevention. Proceedings of a conference held October1 to 3, 1958 in Ottawa, p. 64-67. National R e s e a r c h Council, Division of Building Research, NRC 501 1, December 1958, 88p. 3. G. W. S h o r t e r , J. H. McGuire, N. B. Hutcheon and R. F . Legget.
The St. Lawrence burns. Quarterly of the National F i r e Protection Association, v. 53, n. 4, April 1960, p. 300-316 (reprinted a s NRC 5730, available from the National R e s e a r c h
4. Report on t e s t s concerning f i r e s in ships' c o r r i d o r s . Directorate of the Government Ships Inspection Service. Pindstrup,
