摘要:

AbstractMeasurement of the rate of oxygen consumption provides a simple, versatile and powerful tool for estimating the rate of heat release in fire experiments and fire tests. The method is based on the generalization that the heats of combustion per unit of oxygen consumed are approximately the same for most fuels commonly encountered in fires. A measurement of the rate of oxygen consumption can then be converted to a measure of rate of heat release. Data on heats of combustion are presented to support this generalization. The applicability of the technique to combustion under fire conditions is examined, possible sources of error in the measurements are discussed, and applications of the method are reviewed. It is concluded that the accuracy of oxygen consumption based rate of heat release measurements should compare favorably with those derived from conventional calorimetric measurements.

ISSN:0308-0501    

DOI:10.1002/fam.810040202

出版商:Heyden&Son Ltd.    

年代:1980

数据来源: WILEY

摘要:

AbstractResults of measurements of thermal expansion of Portland cement paste, mortar, concrete and a dolomitic rock aggregate are presented. Test temperatures ranged from 27 to 871°C. Cement paste contracted when subjected to temperatures from 204 to 871°C. Thermal expansion of mortar and concrete was dominated by thermal expansion characteristics of the mineral aggregate. However, expansion was moderated by contraction of the cement paste matrix at elevated temperatures. Average coefficients of expansion, over specific temperature ranges, are given for the materials tested. Equipment developed to control automatically the rate of heating and record strain vs. temperature relationships is describe

ISSN:0308-0501    

DOI:10.1002/fam.810040203

出版商:Heyden&Son Ltd.    

年代:1980

数据来源: WILEY

摘要:

AbstractBecause language conveys the idea of fire severity by a single expression, it has always seemed desirable to find a single variable for its quantification. The earlier suggestion by the author that the total heat absorption per unit surface area of the compartment boundaries during the period of full fire development, to be referred to as overall heat load, be used as a measure of destructive potential of fires, has been critically examined. It has been found that for many reinforced and prestressed concrete building elements, the overall heat load is indeed an approximate descriptor of the severity of compartment fires, irrespective of their temperature histories.

ISSN:0308-0501    

DOI:10.1002/fam.810040204

出版商:Heyden&Son Ltd.    

年代:1980

数据来源: WILEY

摘要:

AbstractExperiments using a thermobalance, a hot‐plate and a moving furnace have all shown that polymers can evolve oxidation products in air even at moderate temperatures. These gases can include carbon monoxide, formaldehyde and acrolein. The amounts are generally low except near the very top of the temperature range used in some processes. Tests in the vicinity of three different extruders have confirmed some of these small‐scale findings but also showed that the evolved gases were adequately handled by the ventilation installed. The evolution of other gases in certain cases has also been briefly studied. Some measure of the heat evolved in oxidative pyrolysis has also been obtained for polyethylene. The polymers investigated were low density and high density polyethylene, poly(ethylene vinylacetate), polypropylene, poly(vinylonitrille) polypropylene, poly(vinylchloride), polystyrene, poly(methylmethacrylate), polycarbonate, poly(ethylene terephthalate), nylon 6‐6, acrylonitrile/butadiene/styrene and one nature material (

ISSN:0308-0501    

DOI:10.1002/fam.810040205

出版商:Heyden&Son Ltd.    

年代:1980

数据来源: WILEY

摘要:

AbstractAn important observation during full‐scale fires was that burning behaviour is often determined by softening characteristics as well as ignitability, flame spread, etc. Examples include stacking chairs where thermoplastics give a rapid rate of fire growth and suspended ceilings where thermoplastics reduce fire hazard. A test rig has been progressively developed at RAPRA to reproduce the mechanisms and fire growth rates of stacked chairs and to evaluate the role of softening in fire growth. Although the ignitability of fire‐retarded materials is less than that of non‐fire‐retarded grades, the fire growth rate in stacks is similar and may be related to the softening behaviour determined by exposing sheets of material to radiant heat. The rate of fire growth in stacks may be significantly reduced by modifying the softening behaviour of materials, e.g. by using asbestos‐reinforced thermoplastics which can form an integral, non‐melting felt or by using non‐melting materials such a

ISSN:0308-0501    

DOI:10.1002/fam.810040206

出版商:Heyden&Son Ltd.    

年代:1980

数据来源: WILEY

摘要:

AbstractThis paper describes work carried out on flame‐retarded polypropylene comparing results on selected small‐scale laboratory fire tests with those obtained on a larger‐scale test designed to simulate the typical real life hazard situation. In the latter test a number of important parameters such as heat build‐up, Hame spread, smoke development and gas evolution were assessed. The results indicate that there is need to use both types of tests to gain a fuller understanding prior to using new materials. An assessment based on small‐scale tests alone could be misleading and allow the use of potentially hazardous material in the particular application

ISSN:0308-0501    

DOI:10.1002/fam.810040207

出版商:Heyden&Son Ltd.    

年代:1980

数据来源: WILEY

摘要:

AbstractConsiderable concern has been expressed about the increasing number and changing pattern of fires and the fact that modern upholstered furniture is relatively easy to ignite and, once ignited, burns rapidly to produce large quantities of smoke and toxic gas. This led to a number of major research programmes and to the evolution of a number of test procedures in the UK. The first major test procedure was published in 1976 by the BPF in conjunction with RAPRA, BRMA and FIRA. An important aspect of this approach was the linking of ignition and rate of initial burning data with the application of the product and the environmental hazard. It was evolved within a short period of time to proved furniture designers and specifies with a means of avoiding products of high risk. The DOE/PSA are using a comprehensive series of Fire Retardant Specifications to control and specify their upholstered furniture and bedding. Specifications have been developed which enable individual components and sub‐assemblies as well as the final product to be characterized in terms of ignitability and burning characteristics, i.e. temperatures, smoke, and carbon monoxide production. BS DD58 and BS 5852 Part1, ignitability tests for upholstered seating are essentially a combination of BPR and DOE/PSA test procedures. Cigarettes, gas flames and wooden cribs are used for the ignition sources and are positioned on a composite seat/back test ri

ISSN:0308-0501    

DOI:10.1002/fam.810040208

出版商:Heyden&Son Ltd.    

年代:1980

数据来源: WILEY

摘要:

AbstractThe standard NBS/Aminco smoke test chamber is critically examined from the point of view of repeatability and reproducibility of the apparatus itself. Individual components contributing to the overall determination are examined and suggested lines for improvement are made which should result in more consistent results. Problems associated with the presentation of results are discussed and a new approach which includes time‐weighted data is proposed. This attempts to consider the rate dependence of smoke production in one calculated figure rather than isolated observations such as maximum optical density. Utilizing the NBS/Aminco chamber, a novel procedure for determining the smoke evolution characteristics of materials has been developed which can be considered to simulate more closely the progress of thermal degradation that a material undergoes in a real fir

ISSN:0308-0501    

DOI:10.1002/fam.810040209

出版商:Heyden&Son Ltd.    

年代:1980

数据来源: WILEY

摘要:

AbstractThe heat flux in the NBS smoke chamber has been varied from 1.0 to 5.0 W cm−2in 0.5 W cm−2steps for some fifteen natural and synthetic materials. These experiments confirm the results given in previous papers for a smaller heat flux range, namely that smoke density varies ove4r the temperature/heat flux range. The extended range studied ensured that a much higher proportion of the materials reached a heat flux at which ignition occurred. As before at this and higher heat fluxes, the experiments were repeated in the flaming mode to ensure better reproducibility. With a few exceptions the general shape of the specific optical density/heat flux plot was similar, with a steep rise to a peak and then a corresponding drop to a low value at high fluxes. At 5 W cm−2the drop had not been reached in some cases, but it is assumed to occur later by inference from earlier work on a smaller‐scale apparatus at high temperatures. Complex materials can give unusual plots during the transition from pyrolysis to combustion. This is true of certain polymers containing fire retardant when the pyrolysis of the additive can have a separate

ISSN:0308-0501    

DOI:10.1002/fam.810040210

出版商:Heyden&Son Ltd.    

年代:1980

数据来源: WILEY

ISSN:0308-0501    

DOI:10.1002/fam.810040201

出版商:Heyden&Son Ltd.    

年代:1980

数据来源: WILEY