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Fire and Materials

Wiley Online Library : Fire and Materials

Published: 2017-08-01T00:00:00-05:00


On a planar thermal analysis of intumescent coatings


The paper discusses a complex model for a nonstationary planar thermal analysis of expandable intumescent coatings. Following the existing one-dimensional models, we develop novel and improved equations for the two-dimensional thermal analysis of intumescent coatings. A progressive expansion due to chemical reactions, phase changes, and the time and temperature-dependent thermal properties of the coating are considered. In the heating process, the coating may locally experience virgin, intumesced, or charred phases, and their transition with time. The rate of the density loss due to the pyrolysis reaction is described with the Arrhenius equation. The thickness of the coating is assumed to increase enormously during the pyrolysis. Consequently, the energy and mass equilibrium equations are formulated with respect to both the deformed and undeformed configuration. Since most of material properties of commercial products are not given by manufacturers, an innovative procedure is proposed to determine the time-dependent thermal conductivities and remaining fundamental properties of the coating from the set of measured temperatures. This, together with the two-dimensional formulation of the thermal equations with respect to the undeformed configuration, makes the present model unique and appropriate for the thermal analyses of an arbitrary steel cross section protected with intumescent coatings.

Fire performance of brominated and halogen-free flame retardants in glass-fiber reinforced poly(butylene terephthalate)


This paper investigates the effects of brominated and halogen-free fire retardants on the fire performance of glass-fiber (GF) reinforced poly(butylene terephthalate) (PBT). Brominated polystyrene was used as the brominated fire retardant, whereas aluminum diethylphosphinate with/without nanoclay as halogen-free fire retardants (HFFRs). Tests were conducted by using thermogravimetric analysis, limiting oxygen index (LOI), UL94, and the cone calorimeter. Thermogravimetric analysis results show that decomposition of GF plus PBT (PBT + GF) starts earlier in the presence of all fire retardants (FRs). In the cone calorimeter, all FRs reduce significantly the heat release rate (HRR) compared with PBT + GF, with brominated polystyrene achieving lowest HRR primarily because bromine released in the pyrolysis gases inhibits combustion. Brominate polystyrene does not, however, affect the mass loss rate. Aluminum diethylphosphinate alone has significant effects on reduction of both HRR and mass loss rate, which become considerably more when combined with nanoclay. It was also found that the combustion efficiency of the brominated polystyrene compound is much lower than that of HFFRs, indicating that brominated polystyrene has higher gas phase flame retardant efficiency compared with HFFRs because the bromine radicals released during degradation of brominated polystyrene effectively quench the chemical reactions of the pyrolysis gases due to degradation of PBT.

The ammonium nitrate explosion at West, Texas: A disaster that could have been avoided


On April 17, 2013, an explosion of ammonium nitrate (AN) fertilizer stored at the West Fertilizer Company resulted in 15 deaths, 260 injuries, and the destruction of a sizable portion of the town. AN fertilizer is classified as an oxidizer, not as an explosive; nonetheless, it is a chemical which can detonate, and there is a century's worth of history of such explosions, some of them in manufacturing operations, but many in storage or transport. A review of incidents showed that 100% of AN fertilizer explosions in storage or transport had a single cause—an uncontrolled fire. Thus, AN fertilizer explosions in storage are preventable accidents, because technology to preclude uncontrollable fires also has been available for a century. In the case of transport accidents, uncontrolled fires may not be avoidable. However, technologies exist that can make AN less likely to explode, and to show greatly reduced explosion intensity, if driven to explosion. None of these safety measures were in place for this disaster. Details of necessary fire safety measures and the effectiveness and utility of existing regulations for AN are examined. This is important because most AN storage facilities in the United States are similarly inadequate in their fire safety.

Experimental research on the burning behavior of dragon juniper tree


Tree crown fire is one of the extreme fire behaviors in the wildland-urban interface. This paper presents an experimental study on the burning behaviors of single and triple dragon juniper trees. The mass loss, flame height, plume temperature, radiation, and fire interaction are measured. It is found that the foliage moisture content and flame mergence dominate the mass consumed percentage (defined as the ratio of the total mass loss to initially total mass), while the tree crown height and flame mergence determine the flame height. The peak mass loss rate is mainly affected by the moisture content and tree species. For triple tree fires, the peak mass loss rate is also affected by the spacing due to the coupled effects of heat feedback enhancement and air entrainment restriction. Results also show that the flame height significantly increases as the spacing decreases. The spacing holds a significant effect on the fire plume temperature distribution and thermal radiation field. Empirical correlations are also developed for the flame height, radial temperature, and radiant heat flux distribution based on physical interpretation of the tree burning behaviors.

Oxidation behavior of carbon steel in simulated kerosene combustion atmosphere: A valuable tool for fire investigations


Fire investigations aim to establish the origin and cause of fires by collecting and analyzing the comprehensive fire-related evidences. Metallic materials exposed to the fire scene environments are usually subjected to melting and/or high-temperature oxidation, and they have been considered vital parameters for temperature determination, as recommended in NFPA 921. The oxide characteristics obtained from the conventional fire investigations primarily rely on simple visual observations such as the variations in oxide color, the so-called “oxidation patterns.” However, such information is not sufficiently convincing due to the complex nature of oxides formed in the fire scene. The oxide color is strongly affected by the type of oxide, the oxide thickness, the concentration of contaminant, and the interactions among different oxides. In this study, Q235 structural steel samples have been exposed to high-temperature air and simulated kerosene combustion conditions at certain temperatures and for indicated periods. The oxidation rate was examined by thermogravimetric analysis. The morphologies and microstructures of the oxide scales were investigated by scanning electron microscopy, energy dispersive spectroscopy, and X-ray diffractions. The results show that the oxide properties are strongly dependent on the oxidation temperature and oxidation atmospheres. These oxidation behaviors are expected to provide useful information on identifying fire characteristics.

The effect of the trimerization catalyst on the thermal stability and the fire performance of the polyisocyanurate-polyurethane foam


In this work, 3 currently used trimerization catalysts, TMR-2 (quaternary ammonium), K-15 (potassium octoate), and PU-1792 (potassium acetate) were used to produce rigid polyisocyanurate (PIR) foams with certain amounts of isocyanurate contents. The results from Fourier transform infrared (FTIR) quantitative analysis showed that PU-1792 had the highest catalytic efficiency in isocyanurate formation. Then, the effect of different amounts of PU-1792 catalyst on isocyanurate ring output was further investigated, and the result showed that the highest amount of isocyanurate ring formation could be attained by the 5 pphp of PU-1792 catalyst. It was also found that the increased amount of isocyanurate ring could result in reduced cell size, improved compressive strength, and lowered thermal conductivity of PIR foam. The results from thermogravimetric analysis (TGA) and cone calorimeter (CONE) test revealed that the thermal stability and fire performance of PIR foam could be improved with the increased amount of isocyanurate ring. Furthermore, the CONE test indicated that the smoke production of PIR foam decreased approximately 51.7% in comparison to the reference polyurethane (PU) foam, and the SEM image of char morphology showed that the char of PIR foam was more compact than PU foam.

Synthesis of microencapsulated zinc stannate and its application in flame-retardant poly(vinyl chloride) membrane material


The novel core-shell magnesium dihydroxide (MDH)/zinc stannate (ZS) and melamine-formaldehyde (MF) resin/MDH/ZS microcapsules were prepared. Their structures were characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, transmission electron microscopy, and X-ray photoelectron spectroscopy analysis techniques, then its flame-retardant application in poly(vinyl chloride) (PVC) composites. The PVC composites were investigated by the limited oxygen index, smoke density, vertical burning test (UL-94), cone calorimeter test, scanning electron microscopy, and thermogravimetric analysis. When directly exposed to flame, PVC generated a high-density char layer, giving PVC a self-extinguishing property. Furthermore, when the mass ratio of MDH/ZS and MF/MDH/ZS microcapsules were 2/8 and 10/2/8 with 16 wt% loading, the results showed that the limited oxygen index value reached 29% and 33%, and the smoke density value reached 51% and 41%. Thus, the microencapsulated ZS could greatly suppress the generation of the flame and smoke during combustion, showing potential applications as multifunctional advanced composites. Two aspects of this manuscript will make it interesting to general readers of Fire and Materials. The magnesium dihydroxide (MDH)/zinc stannate (ZS) microcapsule was firstly prepared via chemical deposition method, and then melamine-formaldehyde (MF) resin/MDH/ZS microcapsule was secondly prepared. The smoke density of poly(vinyl chloride) (PVC)/MDH/ZS microcapsule and PVC/MF/MDH/ZS microcapsule composites were less than half of the neat PVC. With the addition of the 16 wt% of MDH/ZS or MF/MDH/ZS microcapsules into PVC, the limited oxygen index value of PVC composites achieved a significantly high limited oxygen index value at 29%, 33%, and the smoke density value of PVC reached 51%, 41%, respectively. They are V-0 rating in UL-94 test. The results indicated that MDH/ZS and MF/MDH/ZS microcapsules behaved as an environmental friendly flame retardant and smoke suppressant. Thus, this study demonstrated the great potentials of the intrinsically flame-retardant MDH/ZS and MF/MDH/ZS microcapsules in the application of high performance matrix resin and composite material.

Development of water content sensor composed of small copper electrodes for use during fire resistance tests of concrete and cement mortar elements


The purpose of this study is to develop a sensor for measuring the water content in concrete and cement mortar elements usable in fire tests. Annealed copper wires were used as electrodes of the water content sensor. Each electrode is 20 mm in length and 0.8 mm in diameter. The separation distance between the electrodes is 2 mm. By measuring the electric resistance, water content can be monitored continuously. Mortar bar specimens were used to calibrate the sensor by measuring electric resistance as a function of water content at a constant temperature of 26°C. The temperature dependence of the electrical resistance was approximated by a functional relationship developed by Ichinose for a similar type of sensor. As a result, a calibration formula was derived for electrical resistances in the range of 1.51 to 2330 kΩ, temperatures in the range of 10 to 175°C, and volumetric water content in the range of 0.084 to 0.201 m3/m3. To verify the applicability, the sensors were embedded in a wall specimen heated by ISO 834 fire for 30 minutes. As a result, it was possible to measure the water contents continuously.

Thermal and residual mechanical profile of recycled aggregate concrete prepared with carbonated concrete aggregates after exposure to elevated temperatures


Thermal and residual mechanical performance of recycled aggregate concrete (RAC) prepared with recycled concrete aggregates (RCAs) after exposure to high temperatures has so far received less attention than that of conventional concrete prepared with natural aggregates (NAs). This study experimentally investigated thermal and residual mechanical performance of RAC prepared with different replacement percentages of non-carbonated and carbonated RCAs after exposure to high temperatures. The residual mechanical properties, including compressive strength, modulus of elasticity, and peak strain at the maximum strength, were measured for evaluating the fire resistance of RAC. The experimental results showed that although the fire-resistant ability of natural granite aggregates was high, thermal deterioration of the conventional concrete after exposure to 600°C, presented by thermal induced mesocracks, was more serious than that of RAC due to thermal incompatibility between NAs and mortar. Using the carbonated RCAs can reduce the width of thermal mesocrack in RAC. The residual mechanical properties of RAC after exposure to 600°C can be obviously improved by incorporating 20% to 40% of the carbonated RCAs. For the RAC made with the 100% carbonated RCAs, the ratio of residual to initial compressive strength after exposure to above 500°C was even higher than that of the conventional concrete.

An experimental setup for observation of smoldering-to-flaming transition on flexible foam/fabric assemblies


Fires that involve upholstered furniture frequently begin as a smoldering combustion and, with time, transition to a flaming combustion, which sharply increases the level of hazard. Therefore, understanding how the compositions of the primary flammable components of the furniture, ie, flexible foam and upholstery fabric, affect this transition is important for fire safety considerations. In the current study, an experiment was designed to observe this transition using a sample consisting of 30 × 15 × 6 cm3 rectangular foam block covered with 30 × 15 cm2 piece of fabric. For a representative system of 1.8 lb/ft3 (29 kg/m3) flexible polyurethane foam and 11 oz (0.37 kg/m2) cotton fabric, 0.69 transition probability was measured. This probability decreased by a factor of 4 when a small amount of phosphorus-based flame retardant, Fyrol® HF-9, was added to the foam. The transition to flaming was speculated to be associated with the formation of adjacent pyrolysis and smoldering regions within the foam. The pyrolysis region, dominated by anaerobic decomposition, provided gaseous fuel, the ignition of which resulted in the transition. The smoldering region, dominated by oxidation reactions at the solid-gas interface, generated the heat necessary to maintain the pyrolysis process and ignite the gaseous fuel.

Flexible transparent flame-retardant membrane based on a novel UV-curable phosphorus-containing acrylate


A novel phosphorus-containing acrylate monomer (AOPA) was synthesized starting from 2-methy-2,5-dioxo-1,2-oxaphospholane and hydroxyethyl acrylate. The structure of AOPA was characterized with FTIR and 1H NMR. AOPA shows good compatibility with polyethylene glycol diacrylate (PEGDA) and can polymerize with PEGDA under UV light irradiation at different mass ratios to form membranes with high transparency (above 88.9% of light transmittance in the range of 400-800 nm) and flexibility. Incorporating 20 wt% of AOPA in PEGDA reduced the total heat release and peak rate by 50.3% and 38.4%, respectively, as measured by micro combustion calorimeter. The membrane containing 40 wt% of AOPA with 0.4 mm thickness can pass the UL94 V0 rating, and limiting oxygen index reaches 33.4%. TG-FTIR and SEM-EDX analysis show that the presence of AOPA depresses the thermal degradation and promotes the char formation.

Study of the relationship between thermal insulation behavior and microstructure of a fire-resistant gel containing silica during heating


Adding a transparent gel containing silica between 2 sheets of glass could improve the fire resistance of laminated glazing by its thermal intumescent behavior at high temperature. In this study, a custom fire test shows that the glazing reaches the highest thermal insulation rating of 40 minutes when the molar ratio of SiO2 and Na2O in the gel is 4.0, but above this ratio, the thermal insulation rating of the glazing decreases with the increasing silica content. Thermal and scanning electron microscopic analyses have been used to investigate the thermal behavior and microstructure of the residual layer, respectively. The results indicate that, although the high silica content is responsible for the high amount of residue that is essential in the formation of a protection barrier between fire-exposed and unexposed sides of the glass, it is not the only factor that resulted in the improved thermal insulation of the glazing.

Specimens size, aggregate size, and aggregate type effect on spalling of concrete in fire


This paper attempted to isolate variables that govern concrete spalling when exposed to a hydrocarbon fire. The influence of specimen size was investigated by studying 4 specimen sizes consisting of cylinders, columns, and panels. Three aggregate sizes, 7 mm, 14 mm, and 20 mm were used in the concrete mixes to determine their effect on concrete spalling. Influence of aggregate type on concrete spalling was also investigated. Forty-two different specimens were considered in this investigation. Concrete spalling was quantified as nominal spalling depth, which has been presented as a new way of quantifying the degree of concrete spalling. The results indicated that specimen size did have an effect on the spalling of concrete under hydrocarbon fire exposure and that nominal spalling depth of concrete increases as the specimen size increases. Aggregate size effect was evident when the maximum aggregate size increased from 7 mm to 20 mm, and explosive spalling was more severe for specimens with small size aggregates. Specimens with 14-mm aggregate size showed inconsistent results and the spalling behavior witnessed was more random and sporadic. The type of aggregate used has no clear bearing on concrete spalling given both aggregates had similar linear expansion profiles.

Experimental studies on the thickness of upward flame over poly(methyl methacrylate) slabs


Experiments were performed to investigate the flame thickness of the upward flame on the poly(methyl methacrylate) slabs with width of 100-400 mm. The results indicated that the flame thickness exhibited an increase first and then decrease trend in the upright orientation, and the maximum thickness location was approximately equal to the pyrolysis front location. The thickness of the flame along the lateral side of slab was less than that of the interior flame. The flame maximum thickness as a function of pyrolysis height and width was obtained, which showed the maximum thickness provided a power law increase with the pyrolysis height and width. Furthermore, the maximum thickness exhibited a power law increase with the total heat release rate as well. Based on the obtained flame thickness, the radiation heat flux at the pyrolysis height was estimated by using a simplified model. Comparison with the calculated convective heat flux revealed approximated pyrolysis heights for upward flame transition from convective heat flux controlled to radiation heat flux controlled.

Prediction of time to ignition in multiple vehicle fire spread experiments


This paper describes the application of the flux-time product ignition criterion and the point source flame radiation model to predict the time to ignition in multiple vehicle spread scenarios. Ten experiments from the literature have been selected due to sufficiency of information required to apply the methods. The outcome of this work is to be applied to a risk-based model for the design of car parking buildings to determine when and if a fire spreads between vehicles; therefore, the analysis suggests properties of a representative material that can reasonably account for those external vehicle components that are most likely to ignite first. The application of both methods to the complex problem of multiple vehicle ignition requires several assumptions and simplifications which are discussed in the paper.

Cable tray fire tests in a confined and mechanically ventilated facility


Cable fires are one of the main fire hazards in nuclear power plants. As part of the cable fire spreading (CFS) campaign of the OECD PRISME-2 programme, 3 real-scale cable tray fire tests were performed in open atmosphere (1 CFS support test, named CFSS-2) and in a confined and mechanically ventilated facility (2 CFS tests, named CFS-3 and CFS-4). This study aims at investigating the effects of confined and ventilated conditions on cable tray fires that used a halogen-free flame retardant cable-type. The CFS-3 and CFS-4 tests involved 2 ventilation renewal rates of 4 and 15 h−1, respectively. The confined conditions lead to decrease the fire growth rate and the peaks of mass loss rate and heat release rate, compared with open atmosphere. The reductions are larger for the lower ventilation renewal rate. Furthermore, it is shown that the CFS-4 test may be classified as a well-ventilated fire and the CFS-3 test as an under-ventilated fire. For this last one, its fire characteristics and its consequences in the fire room highlight an oscillatory behaviour, with the same low frequency, for about 30 minutes. These oscillations arise from successive combustions of unburnt gases.

Flame retardant treated flax fibre reinforced phenolic composites: Ageing and thermal characteristics


In this study, flax composites were prepared from flax fabric and phenolic resin. Chemical treatments were imparted to the fabric to improve adhesion between the fabric and the phenolic matrix. Diammonium phosphate was applied to improve the flammability of the composites. The thermal and flammability properties of the untreated, chemically treated, and flame retardant (FR) treated flax fabric reinforced phenolic composites were studied. Ageing studies were carried out by subjecting the composites to varying conditions of temperature and humidity in an environmental chamber for 2 weeks. FR treatment of flax fabric was shown to be very effective in improving flame retardancy of the composites due to decreased peak heat release rate (PHRR) and smoke production rate (SPR). Thermogravimetric analysis (TGA) of composites showed that after FR treatment, the decomposition temperatures shifted to lower temperatures. Ageing studies revealed that the mechanical properties of untreated, chemically treated and FR treated composites decreased with an increase in ageing temperature.

New polyether diols as flame retardants for polyurethane: Derivatives of epoxy-functionalized phosphonates and phosphates


Phosphorus-containing epoxides were used to generate several oligomeric polyether diols, which were in turn utilized in the preparation of model polyurethane (PU) samples, either as comonomers in the polymerization (Prep samples) or solvent blended into a priori prepared PU (Blend samples). The resultant samples were evaluated for heat release reduction potential using microcombustion calorimetry. Several variables were investigated in the oligomerization of the original epoxides, such as presence of initiator, epoxide comonomer, and solvent. The oligomer mixtures were thoroughly characterized, using NMR, mass spectrometry (MS), elemental analysis, and viscosity measurements. The final PU Prep samples were carefully analyzed to demonstrate and evaluate the degree of chemical incorporation of the polyether diols into the PU main chain. Results from the heat release studies demonstrated that incorporation of the phosphorus-containing diol did lower flammability, but the structure of the original epoxide, as well as the oligoimerization conditions, had an effect on heat release reduction. The results are complex and require further study, but the phosphonate-based materials showed greater heat release reduction potential, both in the form of Prep and Blend samples, especially in one case of a Blend sample, where a notable amount of intumescent char was formed.

Characterization of arc beads on energized conductors exposed to radiant heat


It has been discovered through experimentation the mechanism of how and when an arcing short or a physical short occurs on a cable when exposed to a radiant heat flux. It is then considered how this mechanism acts on the size of the resulting arc beads. Another discovery was that a leakage current precedes a short circuit. Subsequently, it was found that arcing shorts and physical shorts can be distinguished based on the amount of leakage current that precedes the short circuit. In the case of an arcing short, the leakage current is large and the arc bead is small. The opposite is true for a physical short. In the case of a physical short, the leakage current is small and the arc beads are large. Tests were conducted with a Japanese polyvinyl chloride (PVC)–insulated sheathed cable, an American PVC–sheathed non-metallic (NM) cable, and an American cloth–sheathed NM cable. The following were found: A Japanese PVC–insulated sheathed cable tends to cause a physical short and to form larger arc beads than other cables. American NM cables tend to cause an arcing short. Especially, an American cloth–insulated cable tends to be preceded by a larger leakage current and to form smaller arc beads than other cables. This result corresponds to the experimental description in NFPA 921 concerning arc beads on a cloth-sheathed NM cable.

Enhancing egress drills: Preparation and assessment of evacuee performance


This article explores how egress drills—specifically those related to fire incidents—are currently used, their impact on safety levels, and the insights gained from them. It is suggested that neither the merits of egress drills are well understood, nor the impact on egress performance well characterized. In addition, the manner in which they are conducted varies both between and within regulatory jurisdictions. By investigating their strengths and limitations, this article suggests opportunities for their enhancement possibly through the use of other egress models to support and expand upon the benefits provided. It is by no means suggested that drills are not important to evacuation safety—only that their inconsistent use and the interpretation of the results produced may mean we (as researchers, practitioners, regulators, and stakeholders) are not getting the maximum benefit out of this important tool. © 2017 Her Majesty the Queen in Right of Canada. Fire and Materials StartCopText© 2017 John Wiley & Sons, Ltd.

Procedures for development and revision of codes and standards associated with fire safety in the USA


The process of codes and standards development, and subsequent regulation, in the USA is very different from that in most other countries: it is managed by private (not-for-profit) companies and is via a consensus process. With regards to codes, primary code development occurs through International Code Council (ICC), for building, fire, and mechanical codes, and National Fire Protection Association (NFPA), for electrical and life safety codes. With regards to standards, the key fire test standards used in codes are also developed by companies, primarily American Society for Testing and Materials (ASTM) International and NFPA. All meetings at which codes and standards are developed are open to interested parties and/or observers. This study describes the way the major codes and standards are developed and amended, by the organizations referenced. Participation by all stakeholders is strongly encouraged, and the opinions of any interested parties are an essential component of the process. However, producers (or manufacturers) cannot represent more than a fraction of voting members in the committees and, in fact, in the case of ICC, only public officials are permitted to vote on the final action. At ASTM, technical committees are created by the organization and anyone can become a member. However, voting is restricted and balanced to ensure that producers cannot be a majority. No codes are developed by ASTM. Each committee chooses its projects to develop standards, within an overall scope; committee membership is not limited. The technical committee handling fire issues is ASTM E05, but other committees also develop fire test standards and specifications, including fire tests. At NFPA, technical committees are formed, and its members appointed, by the NFPA Standards Council, and committees are kept small. Appointments are made based on technical expertise and interest categories (one of which is manufacturers). Members in none of the interest categories can exceed one third of the committee membership. Every committee decision can be appealed (commented on), and the committee must consider the comments. The committee decisions can be appealed again, and the issues are debated in front of the general membership at meetings. Fire tests are issued by the technical committee on fire tests, while other committees deal with various codes and standards that can be adopted for regulation, including the National Electrical Code (NEC) (NFPA 70) and the Life Safety Code (NFPA 101). Most technical committees deal with a single document, but the technical committee on fire tests deals with all the fire test methods. In contrast, multiple committees handle separate sections of the major codes. Virtually, the entire country adopts the NEC and many states (as well as the healthcare industry) adopt NFPA 101. Almost all of the major codes with fire implications are developed at ICC. This includes the International Building Code, International Fire Code, International Mechanical Code, International Residential Code, International Existing Building Code, and International Wildland Urban Interface Code. Codes are revised on a 3-year basis, with code development committees appointed for each cycle, on the basis of expertise, interest category, and geographical location, to ensure full balance. Stakeholders are invited to argue for or against code proposals in front of the committees. Committee decisions can be appealed (commented on) by the public, and the comments are argued in front of code officials who[...]

Thermal degradation and fire performance of wood treated with PMUF resin and boron compounds


Plantation Chinese fir wood was modified by low molecular weight phenol melamine urea formaldehyde (PMUF) resin, boron compounds (BB), and the mixture of PMUF/BB (PMUF-BB), followed by a curing step. The fire performance and thermal degradation of wood was measured by limiting oxygen index instrument, cone calorimeter, and simultaneous thermal analysis. The results showed that the limiting oxygen index increased to 50.7%, 43.5%, and 55.0% for BB, PMUF, and PMUF-BB samples, respectively. The PMUF resin decreased the heat release rate of wood but increased the total heat release compared with the control samples. The thermal analysis results demonstrated that PMUF resin enhanced the thermal stability of wood, however, had little impact on the residual chars. Combinative treatment with boron compounds could substantially reduce the fire risk for PMUF-modified wood, making them especially useful for application in public settings.

Tensile properties of plant fibre-polymer composites in fire


The structural performance of polymer composites reinforced with plant fibres when exposed to fire was experimentally evaluated and compared against an E-glass fibre laminate. Fire testing under combined one-sided radiant heating and static tensile loading revealed that flax, jute, or hemp fibre composites experience more rapid thermal softening and fail within much shorter times than the fibreglass laminate, which is indicative of vastly inferior structural performance in fire. The plant fibre composites soften and fail before the onset of thermal decomposition of the plant fibres and polymer matrix, whereas the E-glass fibres provide the composite with superior tensile properties to higher temperatures and higher applied tensile stresses. The tensile performance of the three types of plant fibre composites in fire was not identical. When exposed to the same radiant heat flux, the flax fibre composite could withstand higher tensile stresses for longer times than the hemp and jute laminates, which showed similar performance.

Study on different finite difference methods at skin interface for burn prediction in protective clothing evaluation


For protective clothing evaluation by using the flame engulfment method, a skin burn injury model is required to predict burn degree of the covered skin. By applying finite difference methods, 2 numerical methods are compared. One is based on equivalent heat intensity; the other is based on the law of conservation of energy. In this study, skin temperature rise is compared between these 2 methods by using homogeneous skin properties as well as the analytical solutions. Differences between these 2 methods in application of measured heat exposure tests data are also explored. The results show that assuming equivalent heat intensity at the skin layer interfaces overestimates severity of burn injury. Burn injury time is sensitive to the investigated numerical methods, especially for third-degree burns. The differences of the 2 methods can be reduced by optimization of the grid size using the test cases described in ASTM F1930. A detailed description of requirements regarding applicable numerical methods in future revisions of the relevant standards is recommended. The finite difference model applied in this paper can act as an effective tool to predict temperature distribution in the skin as well as predict burn injury for evaluation of thermal protective clothing.

Crack evolution process of window glass under radiant heating


Window glass breakage has a significant impact on the compartment fire development being sometimes a weak link for fire safety design. This work focuses on the process of crack evolution of window glass in a fire environment. A total of 11 experiments were conducted in a box apparatus by changing heating rate of a heat source. The box apparatus is an enclosed compartment, which includes the heat source, assembled boxes, and glass pane. Crack time, temperature field, breaking stress, crack evolution, and fall-out of the glass panes are presented. Main and secondary fractures are defined and illustrated in the process of crack evolution. Average time to the first, second, and third main fractures decreased as the heating rate of heat source increased. The average breaking stress was 71.14 MPa for float glass at the time of first main fracture. The crack evolution process was very complicated. Cracks initiated at an edge and propagated towards other edges for main fractures. Multiple cracks were joined together to form cracked glass islands. The fall-out of cracked glass islands under radiant heating was more difficult than that under real fire scenarios.

Measurement of self-heating potential of biomass pellets with isothermal calorimetry


To assess the risk for spontaneous combustion of biomass pellets during storage, it is important to know how prone the fuel is to self-heating, ie, to determine the reactivity. This article presents the results from isothermal calorimetry tests performed on 31 different biomass pellet batches. The purpose of the tests has been to characterize pellets by measuring the reactivity and investigate how the pellet composition influences the heat release rate (HRR) and thereby the self-heating potential of pellets. The results from the tests clearly indicate that there is a significant difference in reactivity between different types of pellets. The tested high reactive pellet batches reached maximum specific HRRs (HRRmax) of 0.61 to 1.06 mW/g while pellet batches with low reactivity showed HRRmax of 0.05 to 0.18 mW/g. The tested batches were primarily ranked on the basis of HRRmax, but an alternative ranking based on specific total heat release rate (THR) during the test period was also used for comparison. The test results also indicate that pine/spruce mix pellets are significantly more reactive than all other types of pellets tested and that pellets consisting of 100% pine are more reactive than pellets consisting of 100% spruce. Pellets produced from wine pruning/grape pomace (winery wastes), straw, or eucalyptus are not very reactive compared to pellets consisting of pine/spruce. The results also show that the reactivity of the pellets can be reduced either by introducing certain kinds of antioxidants into the pellets or by extracting lipids from the raw material of pellets.

Poly(vinyl chloride) and its fire properties


This work provides an up-to-date review of the fire properties of poly(vinyl chloride) (PVC) materials, both rigid (unplasticized) and flexible (plasticized). The fire properties addressed include ignitability, ease of extinction (oxygen index), flame spread (small scale and intermediate scale), heat release, smoke obscuration, smoke toxicity, hydrogen chloride emission and decay, and performance in real-scale fires. This comprehensive review includes a wide selection of references and tables illustrating the properties of PVC materials in comparison with those of other polymeric materials, including, in many instances, wood materials. The work puts these fire properties in perspective, showing that the heat release rate (the key fire property) of rigid PVC (and that of properly flame-retarded flexible PVC) are among the lower values found for combustible materials. This work also shows that the smoke toxicity and smoke obscuration resulting from burning PVC materials in real-scale fires is in the same range as those of other materials.

Study of using aluminum hypophosphite as a flame retardant for low-density polyethylene


Aluminum hypophosphite (AHP) was first used to improve the flame retardance of low-density polyethylene (LDPE). The flame-retardant properties of LDPE composites were investigated by the limiting oxygen index, vertical burning test (UL-94), microscale combustion calorimetry, and cone calorimeter tests. The results showed that the incorporation of AHP could improve the flame retardancy of LDPE dramatically, the limiting oxygen index of LDPE containing 50 phr AHP reached 27.5%, and the UL-94 could pass V-0 rating. The cone calorimeter test results indicated that PP/AHP composite exhibited superior performance, and the heat release rate and the total heat release of composites were significantly reduced. In addition, the strength of the char was improved with the load of AHP increased. The structure of the char was researched by Fourier transform infrared spectrometry (FTIR) and scanning electron microscope-energy dispersive spectrometer, and the results revealed that AHP promoted the formation of compact char layer. The TG-FTIR analyses proved that AHP could react with LDPE to reduce the production of olefin in gas phase. Moreover, the structure of P–O–C was found, and the effective mechanism of AHP in LDPE composites was also hypothesized in this work.

Preparation and studies of new phosphorus-containing diols as potential flame retardants


Several new phosphorus-containing potential flame retardants (FRs) were prepared and evaluated for heat release reduction potential, by incorporation of the molecules into polyurethane samples, generated from methylene diphenyl diisocyanate and 1,3-propane diol. The potential FRs were all prepared from commercial diisocyanates, with the phosphorus-containing substructure introduced as a semicarbazone. All of the target structures were diols, to facilitate their incorporation into a polyurethane main chain. The polyurethane samples were prepared via copolymerization, and analysis clearly demonstrated that the potential FRs were chemically incorporated, prior to heat release testing. The heat-release reduction potential of these substances was evaluated using the microcombustion calorimeter. Results demonstrated that both heat release reduction potential and char formation were structure dependent. Some of the compounds containing an aromatic core had more effect on char formation (higher char yields) and peak heat-release rate (lowered heat release) than just phosphorus content alone.

Revealing the inner secrets of intumescence: Advanced standard time temperature oven (STT Mufu+)—μ-computed tomography approach


Intumescent coatings have been used for fire protection of steel for decades, but there is still a need for improvement and adaptation. The key parameters of such coatings in a fire scenario are thermal insulation, foaming dynamics, and cohesion. The fire resistance tests, large furnaces applying the standard time temperature (STT) curve, demand coated full-scale components or intermediate-scale specimen. The STT Mufu+ (standard time temperature muffle furnace+) approach is presented. It is a recently developed bench-scale testing method to analyze the performance of intumescent coatings. The STT Mufu+ provides vertical testing of specimens with reduced specimen size according to the STT curve. During the experiment, the foaming process is observed with a high-temperature endoscope. Characteristics of this technique like reproducibility and resolution are presented and discussed. The STT Mufu+ test is highly efficient in comparison to common tests because of the reduced sample size. Its potential is extended to a superior research tool by combining it with advanced residue analysis (μ-computed tomography and scanning electron microscopy) and mechanical testing. The benefits of this combination are demonstrated by a case study on 4 intumescent coatings. The evaluation of all collected data is used to create performance-based rankings of the tested coatings.

Improvement of the flame retardancy of plasticized poly(lactic acid) by means of phosphorus-based flame retardant fillers


The aim of this study is to improve the flame resistance and toughness of poly(lactic acid) (PLA) with the addition of low amount of flame retardant fillers and plasticizer simultaneously. Poly(ethylene glycol) (PEG) was used as plasticizer for PLA. Ammonium polyphosphate, boron phosphate, and tri-phenyl phosphate (TPP) were used as flame retardant additives. Among these flame retardant additives, boron phosphate was synthesized from its raw materials by using microwave heating technique. Characterization of PLA/PEG-based flame retardant composites was performed by conducting tensile, impact, differential scanning calorimeter, thermal gravimetric analysis, scanning electron microscope, limiting oxygen index, and UL-94 vertical burning tests. Mechanical tests showed that the highest tensile strength, impact strength, and elongation at break values were obtained with the addition of ammonium polyphosphate and TPP into PLA/PEG matrix, respectively. Scanning electron microscopy analysis of the composites exhibited that the more homogeneous filler distribution in the matrix was observed for TPP containing composite. The best flame retardancy performance was also provided by TPP when compared with the other flame retardant additives in the plasticized PLA-based composites.

Development of a screening test based on isothermal calorimetry for determination of self-heating potential of biomass pellets


For the risk for spontaneous combustion in storage of biomass pellets to be assessed, it is important to know how prone the fuel is to self-heating. There are traditional methods that are used to determine self-heating characteristics of fuels, eg, basket heating tests. The results from basket heating tests indirectly give the reactivity from a series of tests at high temperatures. This paper presents a sensitive screening test procedure for biomass pellets using isothermal calorimetry for direct measurement of the heat production rate at typical bulk storage temperatures. This method can be used to directly compare the reactivity of different batches of biomass pellets. The results could be used, eg, by storage security managers to gain better knowledge of their fuels propensity for self-heating and thereby for safer storage. A large number of tests have been performed to develop the test procedure presented. Different parameters, such as temperature, type of the test sample (powder/crushed or pellets), mass of test sample, and preheating time, have been varied. Furthermore, gas concentrations in the sample ampoule have been measured before and after some tests to study the oxygen consumption and the formation of CO and CO2. Three different types of pellets with different characteristics were tested to assess the variation in behaviour. Based on these tests, a screening test procedure is presented with a test temperature of 60°C, a sample size of 4 g, a 15-minute preheating period at the test temperature, and 24-hour test duration.

An exploration of enhancing thermal protective clothing performance by incorporating aerogel and phase change materials


Thermal liners play a critical role in thermal protective performance for firefighter gear. Effective engineering of textile material is necessary to enhance this protective performance. A modified thermal protective erformance (TPP) tester was used to study the influence of incorporating aerogel and microencapsulated phase change materials (MPCMs) in thermal liners (including a traditional thermal liner, phase-change layer, and aerogel layer) and the relevant parameters associated with enhanced thermal liner performance. Two different phase-transition temperature (45°C and 50°C) of MPCM were selected. The samples were exposed to a medium intensity radiation of 15 kW/m2 for 240 seconds, and a skin burn model was applied for second-degree burn prediction. Given the selected, results showed that the best TPP in this study was achieved when the phase-transition temperature of MPCM was 45°C and the layering order consisted of the traditional thermal layer (closest to heat source), followed by an aerogel layer, and a final MPCM layer. The predicted second-degree burn time was 218.3 seconds and increased by 90% compared with only containing traditional thermal liner with a thickness of 5 mm. For all 3 materials contained in the thermal liner, the relationship between absorbed energy and predicted second-degree skin burn time indicated that they had a remarkable negative linear correlation (R2 was 0.9792). The experimental data and predicted results were in good agreement, with a correlation coefficient (R2) of 0.9911. The findings provide a scientific basis for future textile engineering and a novel approach to improve TPP.

The effects of coal dust concentrations and particle sizes on the minimum auto-ignition temperature of a coal dust cloud


Flash fires and explosions in areas containing an enriched combustible dust atmosphere are a major safety concern in industrial processing. An experimental study was conducted to analyse the effects of atmospheric coal dust particle sizes and concentrations on the minimum auto-ignition temperature (MAIT) of a dust cloud. Two different coal samples from Australian coal mines were used. The coal dust particles were prepared and sized in 3 ranges, of below 74 μm, 74 to 125 μm and 125 to 212 μm, by using a series of sieves and a sieve shaker. A humidifier was used to increase the moisture content of the particles to the required level. All the experiments were conducted in accordance with the ASTM E1491-06 method in a calibrated Goldbert-Greenwald furnace. The results from this study indicate that coal dust properties, such as the chemical nature (H/C), concentration, particle size (D50), and moisture content, impact on the MAIT. For coal dust concentrations less than 1000 g.m−3, the MAIT decreases with increasing coal dust concentrations. On the other hand, for low concentrations of 100 to 15 g.m−3, the MAIT becomes more reliable for particle size D50 rather than for volatile matters.

The flame retardant and smoke suppression effect of fullerene by trapping radicals in decabromodiphenyl oxide/Sb2O3 flame-retarded high density polyethylene


To improve the large release of smoke and heat for brominated flame retardants (BFRs) in fire hazard, fullerene (C60) had been introduced in high density polyethylene (HDPE)/bromine flame retardant (Deca/Sb2O3, BFR in short) system in this study. The effects of C60 on the thermal properties, flame retardant properties, rheological behaviors, and smoke release behaviors in HDPE/BFR blends were researched. During polymer thermal degradation, C60 and BFR exhibited the trapping radical ability in condensed phase and gaseous phase, respectively. The intergrated effects of C60 and BFR on the thermal stability and flammability of HDPE were studied by thermo-gravimetry and cone calorimeter. It was indicated that the introduction of C60 improved the thermal and thermo-oxidative stability of HDPE/BFR blends. A remarkable advantage of adding C60 was to reduce the peak heat release rate and the average specific extinction area, especially at higher concentration of C60. The analysis of rheological behaviors and pyrolysis products revealed that C60 can capture alkyl radicals, chain radicals, and bromine radicals in the condensed phase, which was in favor of terminating the thermo-oxidative decomposition and inhibiting the heat and smoke release of HDPE/BFR blends during combustion.

Experimental study of the burner for FAA fire test: NexGen burner


The NexGen (Sonic) burner is the new burner developed by the Federal Aviation Administration, FAA, to replace old oil burners used for the required fire certification tests on power plant-related materials, as it provides the capability to control both air and fuel flow rates. During a fire test, the burner is supposed to simulate a certain fire condition, so the flame properties should be robust and repeatable. The NexGen burner can achieve this due to the precise fuel and air controls. However, the current calibration criterion (ISO2685:1998 and AC20-135) may not be good enough to ensure consistent flame properties. In the presented work, the sensitivity of the burner performance to air and fuel flow rate, as measured by the temperature and heat flux for calibration purposes, was studied. Additionally, the influence of the turbulator and the thermocouple size used for flame calibration was also studied. The impact of varying fuel/air ratio and thermocouple sizes was studied by conducting fire tests on aluminum samples, to show the inadequacies in the current calibration standards.

Influence of zinc borate on flame retardant and thermal properties of polyurethane elastomer composites containing huntite-hydromagnesite mineral


The effect of zinc borate (ZnB) was studied on the flame retardant and thermal properties of thermoplastic polyurethane containing huntite-hydromagnesite. The flame retardant properties of thermoplastic polyurethane–based composites were investigated using limiting oxygen index, vertical burning test (UL 94), thermogravimetric analysis, and mass loss calorimeter. No remarkable effect of ZnB was observed on the flammability properties of composites. UL 94 rating did not change regardless of the added amount of ZnB, and the slight increase in limiting oxygen index value was observed at ratio of 1:1. The adjuvant effect of ZnB was observed during the mass loss calorimeter studies by increasing the barrier effect of the residue in the condensed phase and by increasing the formation of incombustible gasses in the gas phase. The highest fire performance was achieved at ratio of 1:1.

Designing an experimental rig for developing a fire severity model using numerical simulation


In this study, an experimental rig representing a deep enclosure was designed to be used to validate a CFD-based fire model in predicting the outcome. The model then can be used for further study to investigate physical phenomenon within a deep enclosure and to develop an engineering fire severity (heat release rate, HRR, vs time vs position [1]) model. Two empirical models (the VU model [1] and Kawagoe model [2]) were used along with Fire Dynamics Simulator (FDS) in designing the experimental rig. For a specific-sized enclosure, when the HRR was prescribed to the FDS as input from the VU model, it was accurately reproduced, while the HRR from the Kawagoe was used as the input, the FDS calculated much lower value. The experimental rig of that specific size was then built, and various parameters were measured from the tests with liquid fuel fire within this experimental rig. The measured HRR was prescribed into the FDS, and the FDS could reproduce HRR values well. However, the predicted temperature and radiation flux was not as good, especially when the flames were near the opening. This may be due to the tendency of flames over-projecting outside the opening in FDS simulations.

Curing kinetics of a novolac resin modified with oxidized multi-walled carbon nanotubes


The influence of oxidized multi-walled carbon nanotubes (o-MWCNTs) on the curing kinetics of a novolac resin was studied by means of non-isothermal differential scanning calorimetry. Regarding the kinetics issues, the high concentration of hydroxyl groups on the o-MWCNTs slightly modified the curing reaction of the novolac resin, shifting the differential scanning calorimetry exothermic peak to higher temperatures. The effective activation energy of the curing reaction was calculated by the isoconversional Kissinger-Akahira-Sunose method and increased by the presence of o-MWCNTs with respect to neat novolac. This change was attributed to the increase of the material viscosity. In addition, thermogravimetric analysis revealed that nanocomposites samples containing 0.4 and 1.0 wt% o-MWCNTs presented increased char yield values, indicating an improvement of flame retardancy.

Using the microstructure and mechanical behavior of steel materials to develop a new fire investigation technology


In the study, an A36 steel board, a frequently used building construction material, was heated to a high temperature, and then a metallographic replication experiment and tensile experiment were performed to obtain the composition and proportion of the microstructure and the mechanical behavior of fire-damaged steel boards. When the steel board was heated to 800°C or higher and then rapidly water cooled, significant changes were found in its composition and proportion. More specifically, pearlite was completely lost, ferrite was reduced from 80% to 30%, bainite was increased to 30%, and martensite was also increased to 40%. The significant increase in the martensite phase altered the structure of the fire-damaged steel board by making its structure more delicate and loose. Even though the yielding strength and tensile strength showed a tendency to increase, element ductility dropped from 32.5% to 15%. Reducing the extensibility substantially can make the steel board more likely to crack suddenly. The aim of the study is using changes in the structure and mechanical behavior of these steel components because of high-temperature burning to reconstruct fire spread in fire investigation technology.

Effect of intumescent compositions on flammable properties of ethylene vinyl acetate and polypropylene


An intumescent flame retardant (IFR) system was prepared by 2 ways. Firstly, bis(2,6,7-trioxa-1-phosphabicyclo[2,2,2]octane-1-oxa-4-hydroxymethyl) phosphonate methyl (bis-PM) was synthesized and characterized by 1H nuclear magnetic resonance (NMR), 31P NMR, and Fourier transform infrared spectroscopies. This carbonization agent was mixed with melamine (ME), ammonium polyphosphate (APP), and pentaerythritol (PER) to constitute an IFR system. Secondly, an IFR system by reaction was prepared by reaction, and the presence of compositions in product was confirmed by 1H NMR and Fourier transform infrared. Both of systems enhanced the flammable retardation of ethylene vinyl acetate (EVA) and polypropylene (PP). Flammability and thermal behaviors of IFR-EVA and IFR-PP were investigated by vertical burning test (UL-94 V) and thermogravimetric analysis. Results indicated that the IFR systems performed excellent flame retardancy and antidripping ability for PP. At 30 wt% loading, the optimum flame retardant formulations that are bis-PM/ME: 4/1, bis-PM/ME/PER: 3/1/1, APP/ME/PER: 3/1/1, and bis-PM/ME/PER/APP: 1.5/1.5/1/1 give UL-94 V-0 rating. However, V-0 rating results were only obtained for EVA when systems contain bis-PM/ME: 4/1 and bis-PM/ME/PER: 3/1/1. The char yield from decomposition of the IFR-EVA and IFR-PP has effects on the flame retardancy and antidripping behaviors of EVA and PP.

An empirical model for confined concrete after exposure to high temperature


In this study, constitutive relationships have been developed for confined concrete subjected to elevated temperature to specify the fire-performance criteria for concrete structures after exposé to fire. This study extends over a total of 63 circular hoop confined concrete specimens that were casted and tested under concentric compression loading after exposure to high temperature. The test variables studied are the yield strength of transverse reinforcement, spacing of the hoop, and exposure to temperatures from ambient to 800°C. It is shown that all of these variables have significant influence on concrete behavior at different temperatures and further an improvement in the thermal resistance of concrete when confined using transverse steel reinforcement. On the basis of experimental results, a model for confined concrete after exposed to high temperature is proposed to predict the results of residual behavior after thermal cycles. The proposed empirical stress-strain equations are suitable to predict the postfire behavior of confined normal strength concrete in compression. The predictions were found to be in good agreement and well fit with experimental results.

The rapid mass calorimeter: A route to high throughput fire testing


The rapid mass calorimeter based on reduced-size specimens is proposed for accelerated fire testing and put up for discussion, particularly for flame retarded polymeric materials. A mass loss calorimeter is combined with a semiautomatic sample changer. Experiments on specimens of reduced size were conducted on poly(methyl methacrylate), poly(propylene), polyamide 66, poly(ether ether ketone), and pine sapwood square samples with edge lengths of 100, 75, 50, 25, 20, and 10 mm. Specimens of 20 × 20 mm2 were selected to achieve a crucial reduction in specimen size and a measuring protocol developed. A total of 71 different polymeric materials were investigated in the rapid mass calorimeter and cone calorimeter for comparison and several materials with different heat release rate characteristics in the pyrolysis combustion flow calorimeter to test this additional screening method as well. The important fire properties obtained in the rapid mass calorimeter show reasonable correlation with the cone calorimeter results but also with the oxygen index. All in all, the rapid mass calorimeter produces reliable and meaningful results and, despite acceleration and size reduction, still allows for a certain degree of burning behavior interpretation. Material savings of 96% and time savings of around 60%-70% are achieved compared to measure cone calorimeter.

Experimental study on fire behaviors of external thermal insulation composite system under vertical radiation


Using a vertical thermal radiator, we perform a set of experiments on the external thermal insulation composite system (ETICS) and pure extruded polystyrene (XPS). Several important parameters, including time to ignition, mass loss, and sample temperature, were measured. The combustion degree of XPS used during the experiments was B1 and B2. Results show that the whole burning process can be divided into 3 typical stages. Because of the protection effect of the outer layer of ETICS, the burning process of ETICS was noticeably different from that of pure XPS. The experimental results indicated that the protection effect of the outer layer weakened the difference between B1 and B2 flame-retardant XPS. The time to ignition was increased under the effect of outer layer, while the core material (XPS) was easier to be ignited when the outer layer falls out. The research results are useful to the theoretical and numerical study on the fire characteristics of foamed polymer under vertical thermal radiation condition.

Nanostructured phenolic matrices: Effect of different nanofillers on the thermal degradation properties and reaction to fire of a resol


In this work, the effect of 6 different fillers as a nanomodifier of phenolic matrix was evaluated in thermal stability and reaction to fire. The chosen nanoparticles were montmorillonite, silica, carbon black, and 3 carbides—boron, silicon, and zirconium carbides. The nanofillers were mechanically dispersed in the matrix, and the dispersion and distribution of the nanosized particles in the matrix was evaluated by transmission electron microscopy. The thermal stability of nanocomposites was investigated by thermogravimetric analysis both in nitrogen and in air while the thermal combustion properties were measured using a microscale combustion calorimeter. The experimental data highlighted the remarkable effects of nanoboron carbide on the thermal properties it can confer to the phenolic matrix. Rheological behavior of the blends was also investigated to evaluate the effect of the different fillers on the viscosity of the nanostructured matrices.

Potential for the formation of respirable fibers in carbon fiber reinforced plastic materials after combustion


Fundamental aspects for the thermal decomposition and formation of respirable fragments of carbon fibers are investigated to assess the health hazard of carbon fiber reinforced plastic material after a fire. The influence of temperature (600°C-900°C)/heat flux (30-80 kW/m2), time of thermal load (up to 20 minutes), and oxygen exposure is analyzed by means of mass loss and fiber diameter of intermediate modulus and high tenacity fibers with initial diameters of 5 to 7 μm. Various types and concentrations of flame retardants were tested with respect to fiber protection. Epoxy-based composite specimens (RTM6/G0939) additionally containing aluminum or magnesium hydroxide and/or zinc borate (1-25 wt% per resin) were analyzed by cone calorimetry. Carbon fiber decomposition increases with combustion/irradiation time and temperature/heat flux, after a threshold temperature (ca 600°C) is exceeded. Critical fiber diameters below 3 μm are reached within minutes and are predominantly observed close to the panel surface in contact with air. Effective fiber protection is achieved by flame retardants acting beyond 600°C, forming thermally resistant layers such as zinc borate. A new field of research is opened identifying flame retardants, which protect carbon fibers in carbon fiber reinforced plastic.

Mass loss and flammability of insulation materials used in sandwich panels during the pre-flashover phase of fire


Nowadays, buildings contain more and more synthetic insulation materials in order to meet the increasing energy-performance demands. These synthetic insulation materials have a different response to fire. In this study, the mass loss and flammability limits of different sandwich panels and their cores (polyurethane (PUR), polyisocyanurate (PIR) and stone wool) are studied separately by using a specially designed furnace. Expanded polystyrene and extruded polystyrene are tested on their cores only. The research has shown that the actual mass loss of synthetic and stone wool-based cores is comparable up to 300 °C. From 300 °C onwards, the mass loss of PUR panels is significant higher. The mass losses up to 350 °C are 7%, 29% and 83% for stone wool, PIR and PUR respectively, for the influenced area. Furthermore, delamination can be observed at exposure to temperatures above 250 °C for the synthetic and 350 °C for the mineral wool panels. Delamination occurs due to the degradation of the resin between core and metal panels and the gasification of the (PUR) core. The lower flammability limits have been established experimentally at 9.2% m/m (PUR) and 3.1% m/m (PS). For PUR, an upper limit of 74% was found. For PIR and mineral wool, no flammability limits could be established. Copyright © 2017 John Wiley & Sons, Ltd.

Uncertainties in modelling heat transfer in fire resistance tests: A case study of stone wool sandwich panels


Modelling fire performance of building fire barriers would allow optimising the design solutions before performing costly fire resistance tests and promote performance-based fire safety engineering. Numerical heat conduction analysis is widely used for predicting the insulation capability of fire barriers. Heat conduction analysis uses material properties and boundary condition parameters as the input. The uncertainties in these input parameters result in a wide range of possible model outcomes. In this study, the output sensitivity of a heat conduction model to the uncertainties in the input parameters was investigated. The methodology was applied to stone wool core sandwich panels subjected to the ISO 834 standard fire resistance temperature/time curve. Realistic input parameter value distributions were applied based on material property measurements at site and data available in literature. A Monte Carlo approach and a functional analysis were used to analyse the results. Overall, the model is more sensitive to the boundary conditions than to the material thermal properties. Nevertheless, thermal conductivity can be identified as the most important individual input parameter.

Test method for characterising the thermal protective performance of fabrics exposed to flammable liquid fires


People, such as emergency service and military personnel, require protection from fires involving flammable liquids and liquefiable solids (Class B fires) in a number of situations. Fires involving flammable liquids typically reach higher temperatures sooner when compared to other types of fuel, yet there appears to be little literature that specifically investigates the protective performance of fabrics against such fires. Therefore, a new method was developed to enable the characterisation of the protective performance of fabrics when exposed to flammable liquid fires. Fabric samples were mounted on a sample plate inclined to three different angles of incidence. Known volumes of hydrocarbon fuel were pipetted into a fuel reservoir, ignited, then tipped onto fabric samples. Ten thermocouples embedded in the sample plate measured the resultant change in temperature at the technical rear of the fabric samples throughout the exposure. Significant differences were observed between fabrics for maximum temperature, time to maximum temperature, maximum heat flux, transferred energy and estimated burn risk. Therefore, this new methodology enabled discrimination among fabrics based on the protection they provide. Differences were also observed when the volume of fuel and the angle of incidence varied and, therefore, these device settings must be controlled for repeatable results. Copyright © 2016 John Wiley & Sons, Ltd.

Assessing the reaction to fire of cables by a new bench-scale method


The recently approved EU Construction Products Regulation (CPR) applies to cables as construction products. The difficulty of predicting the fire performance of cables with respect to propagation of flame and contribution to fire hazards is well known. The new standard EN 50399 describes a full-scale test method for the classification of vertically mounted bunched cables according to CPR. Consideration of the material, time, and thus cost requires an alternative bench-scale fire test, which finds strong demand for screening and development purposes. The development of such a bench-scale fire test to assess the fire performance of multiple vertically mounted cables is described. A practical module for the cone calorimeter is proposed, simulating the fire scenario of the EN 50399 on the bench scale. The efficacy of this module in predicting full-scale CPR test results is shown for a set of 20 different optical cables. Key properties such as peak heat release rate (PHRR), fire growth rate (FIGRA), and flame spread are linked to each other by factors of around 5. In a case study, the bench-scale test designed was used to investigate the influence of the main components on the fire behaviour of a complex optical cable. Copyright © 2016 John Wiley & Sons, Ltd.

Fire safety assessment of Open Wide Gangway underground trains in tunnels using coupled fire and evacuation simulation


A new type of train configuration, known as Open Wide Gangway (OWG) is becoming popular, particularly in underground environments. Previous fire modelling analysis demonstrated that the OWG configuration was considered safe as or safer than conventional configurations as it reduced the likelihood of flashover. However, these studies have ignored the impact on evacuation of the spread of fire effluent to non-fire cars. Here we explore the fire safety offered by conventional and OWG configurations using coupled fire and evacuation modelling techniques. Two tunnel train situations are considered: one in which the car side doors are available for evacuation (train in a wide tunnel) and the other in which only the end cab doors are available (train in a narrow tunnel). Two population configurations are considered, fully and half loaded. Two ignition sources are also considered, one representing an accidental fire and the other an arson fire. The analysis demonstrates that while the OWG configuration may produce improved fire performance in the car of fire origin compared to the conventional configuration, if the interaction of the fire effluent with the evacuating passengers is considered, the OWG configuration results in a significantly greater number of casualties in virtually all the scenarios considered. Copyright © 2016 John Wiley & Sons, Ltd.

Experimental determination of the effective thermal conductivity of Vacuum Insulation Panels at fire temperatures


In this study, the effective thermal conductivity of a commercial Vacuum Insulation Panel (VIP) at temperatures up to 900 °C is experimentally determined. An experimental setup, based on the Heat Flow Meter Apparatus (HFMA) method, is designed and realized. Two commercially available VIPs (each 20 mm thick) are joined together to form a specimen, which is subjected to fire conditions from one side, while the other side is at ambient conditions. The temperatures on both sides of the specimen and the heat flux on the unexposed side are recorded. The experimental data are coupled with a numerical model, which takes into account the one dimensional steady state heat transfer through the thickness of the specimen and the detailed heat transfer mechanisms for the effective thermal conductivity of the VIP. Gas, solid and radiation conduction mechanisms are considered and their parameters are defined through an optimization technique. The defined optimized values are found to lie between the respective values reported in the literature. The contribution of each heat transfer mechanism to the overall effective thermal conductivity is also discussed. The paper provides a generalized methodology for the estimation of the effective thermal conductivity of VIPs from ambient to fire temperatures. Copyright © 2016 John Wiley & Sons, Ltd.

Effect of aluminum trihydrate as flame retardant on properties of a thermoplastic rubber nanocomposite


In this work, different concentrations, per hundred rubber (phr), of aluminum trihydrate (ATH) were added to thermoplastic rubber nanocomposite based on ethylene propylene diene monomer and linear low-density polyethylene. The effect of the added compound on the flammability, rheological, mechanical properties, and electrical conductivity of the composite was studied. The results of the cone calorimeter showed a significantly reduction in the flammability of the composites occurred when the composite was treated with ATH. The peak heat release rate was reduced by about 66% when the composite was loaded with 180 phr of ATH. Moreover, the time to ignition prolonged up to 160%. The total smoke released decreased significantly as the concentrations of the ATH were increased. A reduction of about 69% in the total smoke released was observed when the composite was treated with 180 phr. The thermogravimetric analysis showed a reduction in the overall weight loss as the concentrations of ATH were increased. A reduction of about 50% of the original weight was observed when 180 phr of ATH was used. An appreciable decrease in tensile stress and strain with increasing ATH contents had been observed. The addition of ATH markedly reduced the conductivity of the thermoplastic rubber nanocomposite. Copyright © 2016 John Wiley & Sons, Ltd.

Flame retardancy, antifungal efficacies, and physical–mechanical properties for wood/polymer composites containing zinc borate


This work aimed to examine flame retardancy, antifungal performance and physical–mechanical properties for silane-treated wood–polymer composites (WPCs) containing zinc borate (ZnB). ZnB with content from 0.0 to 7.0 wt% was added to WPCs, and silane-treated wood contents were varied. The polymers used were poly(vinyl chloride) (PVC) and high-density polyethylene (HDPE). The decay test was performed according to the European standard EN 113. Loweporus sp., a white-rot fungus, was used for antifungal performance evaluation. Antifungal performance was observed to decrease with wood content. Incorporation of ZnB at 1.0 wt% significantly increased the antifungal performance of WPCs. ZnB content of greater than 1.0 wt% lowered the antifungal properties of WPCs. The results suggested that the wood/PVC composite exhibited better antifungal performance than the wood/HDPE composite. The addition of wood flour to PVC and HDPE decreased flame retardancy, whereas the incorporation of ZnB retained the flame retardancy. ZnB was found to be more appropriate for wood/PVC than wood/HDPE as a result of hydrogen chloride generated from the dehydrochlorination reaction of PVC. The results indicated that the addition of ZnB did not affect the physical-mechanical properties of neat polymers and the composites. Copyright © 2016 John Wiley & Sons, Ltd.

Consolidation grouting technology for fire prevention in mined-out areas of working face with large inclined angle and its application


The phenomenon of linear flow of slurry in mined-out areas of working face with large inclined angle is a crucial issue that hinders grouting for fire prevention. The traditional way of grouting exerts a poor effect on inhibiting coal spontaneous combustion, so it is in urgent need of a suitable grouting technology for fire prevention in mined-out areas with large inclined angle working face. This paper brings up the consolidation grouting method for fire prevention for the first time and conducts a systematic study on the flow characteristics of slurry and sedimentation characteristics of slurry in mined-out areas with large inclined angle working face. Consolidation slurry materials and their ratio are optimized by experiments. Test platform has been established, and effectiveness of the consolidation grouting for fire prevention has been simulated. The results show that settling velocity of yellow mud increases at first and then decreases as the concentration of consolidation slurry materials ascends. The optimum mass concentration is 0.2%–0.8%. The flow speed of mud is greatly reduced by laying consolidation slurry materials (The decreasing range is approaching 50%). The retention of yellow mud in mined-out areas has significantly increased. Finally, technology in working site has been developed; meanwhile, compressed air and spray between frames have been used during the period of working face, and the consolidated way of expansion bags in wood crib to lay consolidation slurry materials has been adopted during the period of stopping work. Field application shows that CO concentration at upper corner decreases significantly and eliminates signs of spontaneous combustion. Besides, the flowing water becomes clearer, and effectiveness of the consolidation grouting is remarkable after laying consolidation slurry material band. Research results can provide theoretical guidance to technology for fire hazard prevention in mined-out areas with large inclined angle. Copyright © 2016 John Wiley & Sons, Ltd.

Multi-scale experimental investigations of the thermal degradation of pine needles


In this work, the thermal degradation of pine needles (from a Mediterranean species) was studied using a thermogravimetric analysis and cone calorimeter that were coupled to Fourier transform infrared spectrometer. The thermogravimetric analyses were carried out at four heating rates, in both air and nitrogen atmospheres. The evolution of gaseous components, mass loss and mass loss rate were recorded as a function of time and temperature. In order to account for the observed behaviours of the materials, we have also proposed a mechanism for the thermal degradation of pine needles, by primarily analysing the evolutions of both mass loss rate and gaseous components under nitrogen and air atmospheres. The kinetic parameters were subsequently estimated by using a genetic algorithm method. The cone calorimetric measurements were mainly conducted with a view to investigating the influence of thermal transfer processes, occurring in a porous bed of pine needles with regard to its thermal degradation. The experiments were conducted at five external heat fluxes under a well-ventilated atmosphere. Measurements consisted of the mass loss, mass loss rate and the amount of gaseous emissions. The main gases emitted during the thermal degradation and the combustion of the pine needles were found to be CH4, CO, CO2, NO and water vapour. In addition, the evolution of the temperature was measured by using a set of five thermocouples, placed in a vertical position at the centreline of the sample. The results obtained showed that the bed of pine needles behaved as a thermally thick fuel. On the contrary, at higher external heat fluxes, the sample behaved as a thermally thin sample. Copyright © 2016 John Wiley & Sons, Ltd.

Continuous fiber-reinforced thermoplastic composites: influence of processing on fire retardant properties


Fiber-reinforced thermoplastic composite materials can find numerous applications in the transportation sector and replace thermoset composites. However, they have to comply with strict standards, particularly with those concerning their fire behavior. In this frame, composites based on an acrylic resin Elium® (Arkema), a woven fiberglass, (taffetas tissue Chomarat G-Weave 600 P/A) and Exolit OP930 (Clariant) as fire retardant were prepared by using three processes. The thermal stability and fire behavior were studied by means of thermogravimetric analysis and cone calorimetry. The obtained results allowed to highlight the drawbacks of each processing method and to select the most appropriate. The improvement of the fire behavior by combining post-curing of the composites, addition of a cross-linking agent, and addition of aluminum trihydroxide was also investigated. Copyright © 2016 John Wiley & Sons, Ltd.

Evaluating methods for preventing smoke spread through ventilation systems using fire dynamics simulator


Fires in enclosures equipped with mechanical ventilation remain one of the key issues for fire safety assessment in multifamily homes and industries. Therefore, a wide variation of methods for preventing smoke spread through the ventilation system exist and are applied, in performance-based designs. Through the use of the heating, ventilation and air conditioning (HVAC) model in the fire dynamics simulator, several different common and less common methods for preventing smoke spread in the ventilation system were tested. The effects on smoke spread with changing building leakage and fire growth rates were also investigated. The results were evaluated by determining the total soot spread from the fire room to other compartments connected to the ventilation system, as well as soot/thermal load on the fans and system in general. The maximum and average heat release rate was also of interest and hence compared between systems. It was found that, while many methods perform similar, a few proven methods, such as fire and smoke dampers, performed very well with very little smoke spread to the rest of the system. The study should be considered as an introduction to implementing a similar methodology in specific cases because different ventilations systems will present very different challenges and weaknesses. Copyright © 2016 John Wiley & Sons, Ltd.

Investigations on oxidation and microstructure evolution of pure Cu in simulated air–kerosene combustion atmospheres


Copper is among the most frequently found metallic residues in fire scene environment. Investigations on the thermal patterns produced on copper after fire scene exposure can provide important physical evidence for fire cause/origin determination. In this paper, the high temperature oxidation behaviors and the accompanying micro-structural changes of pure copper have been studied in air and laboratory simulated kerosene-combustion atmospheres at 600–800 °C. The oxidation kinetics, morphologies and microstructures of the oxide scales-substrate were characterized by thermogravimetric analysis, scanning electron microscopy, energy-dispersive spectroscopy and X-ray diffractions. The results reveal that the increasing temperature can significantly affect the oxide properties and modify the substrate metallurgical microstructure. Especially, the presence of kerosene in the environmental atmosphere has caused accelerated oxidation and produced oxide scales different from those formed in air alone. These feature evolutions in surface oxides and substrate are expected to offer complementary insight on determining the fire characteristics, such as the exposure temperature, time period and whether liquid accelerant is involved.Copyright © 2016 John Wiley & Sons, Ltd.

CFD analysis of smoke backlayering dispersion in tunnel fires with longitudinal ventilation


In a longitudinally ventilated tunnel fire, the backlayering flow propagated in the opposite direction to the air current is the most fatal contaminations to users which are blocked upstream of the fire. In the present paper, numerical simulations were conducted using Fire Dynamic Simulator, which is based on large eddy simulations to estimate the backlayering arrival time in a longitudinally ventilated tunnel fire. The effect of a vehicle obstruction on the backlayering arrival time will be also investigated. For this, a vehicle model occupying about 31% of the tunnel cross section is simulated upstream of the fire source with its location relative to the tunnel floor is varied. The numerical investigation shows that the inertia and the buoyancy forces produced by ventilation and fire, respectively, affect the backlayering spread. The backlayering arrival time increases with the longitudinal ventilation velocity while it decreases with the fire heat release rate. When a vehicle obstruction existed within the tunnel, the numerical results show an increase of backlayering arrival time. This increase is significantly more important with the fire distance when the vehicle obstruction approaches the tunnel floor. Two correlations are developed, with and without obstruction in the tunnel, to predict the backlayering arrival time against the distance to fire. Copyright © 2016 John Wiley & Sons, Ltd.

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Burning down the silos: integrating new perspectives from the social sciences into human behavior in fire research


The traditional social science disciplines can provide many benefits to the field of human behavior in fire (HBiF). First, the social sciences delve further into insights only marginally examined by HBiF researchers, in turn, expanding the depth of HBiF research. In this paper, I present examples of studies from the fields of social psychology and sociology that would expand HBiF research into non-engineering or ‘unobservable’ aspects of behavior during a fire event. Second, the social sciences can provide insight into new areas of research; in turn, expanding the scope of HBiF research. In this section, I introduce pre and post-fire studies and explore potential research questions that fall outside of the response period of a fire, the phase upon which, most focus is currently placed. Third, the social sciences elucidate the value of research methods available to study human behavior. Qualitative research methods are specifically highlighted. These three benefits will allow HBiF researchers to collect a wider range of data, further develop and expand current behavioral knowledge, and increase the impact of this research for both social and engineering applications. Finally, I end with a discussion on possible ways to better integrate the social sciences within human behavior in fire. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

Modelling and influencing human behaviour in fire


The purpose of this article is to present a conceptual model of human behaviour in fire and its impact on egress modelling, life safety analyses and evacuation procedures. This model is based on a theoretical framework of individual decision-making and response to emergencies. From this foundation, the conceptual model is populated with behavioural statements or mini-theories distilled from articles and authoritative reports describing emergency incidents, observations from within the field of evacuation analysis and studies of human behaviour in fire and other emergencies. The conceptual model is intended to guide the egress tool developer, user and practitioner to better account for human behaviour in their respective roles. It is contended that a more credible representation of the evacuee response, that incorporates the behavioural statements described, provides both theoretical and practical advantages. Copyright © 2016 Her Majesty the Queen in Right of Canada. Fire and Materials © 2016 John Wiley & Sons, Ltd.

Human response to non-injury accidental house fires


Research on fatal fires and evacuation exercises yield little or no information about how fire victims respond to a real house fire incident where occupants' mental stress levels differ greatly. Drawing upon daily records of fire incidents from the Victorian Metropolitan Fire Brigade and Country Fire Authority, Australia, 182 individuals who had survived accidental residential fires without serious injuries were interviewed. Similar to most literature, this paper found that electrical failure and cooking-related activities were the main causes of non-injury house fires. The smell of smoke was the top listed cue that first alerted an individual (‘host’ or person in the vicinity). The majority of hosts took proactive actions when facing the threat of a fire, while in only one third of survived fires no attempt to extinguish the fire was made at the time of ignition. This study did not reveal any significant relationships between main activities during a fire and occupant characteristics; however, people with no or only basic fire safety knowledge were more likely to engage in activities such as attempting to extinguish a fire/collect personal belongings/rescue pets/disconnect power source than those who had some level of fire training. Copyright © 2016 John Wiley & Sons, Ltd.

Analysis of response behavior of people in fire incidents where residential fire alarms successfully worked


All residential homes in Japan have been required to install residential fire alarms since 2006. According to a survey by Tokyo Fire Department in 2011, the installation rate of residential fire alarms per household within the jurisdiction of the Tokyo Fire Department is 80.6%. The authors carried out an analysis of reports of cases, where residential fire alarms successfully worked. The information in these real fire incident reports is very useful for us to understand the actual circumstances as well as the behavior of the people involved in and nearby a fire incident. In many cases of successful activation of fire alarms for fires originating in a living room and bedroom, the occupants were likely to be in sleeping in the room of fire origin and did not become aware of the fire alarm, even if it sounded. By contrast, other family members and/or neighbors outside the room of fire origin were more likely to hear the sound and initiated the response activity to the fire incident. This indicates the potential for persons in the room of fire origin at the time of fire to be saved by others nearby because of the activation of residential fire alarms, even if they are sleeping and do not respond by themselves to the alarm sound. Copyright © 2017 John Wiley & Sons, Ltd.

Evacuation response behaviour in unannounced evacuation of licensed premises


An understanding of the behaviour of individuals and groups during evacuation is key to the development of evacuation scenarios as part of an engineering design solution. Furthermore, it is important that engineers have reliable and accurate data on pre-evacuation times and movement for use in time-based evacuation analysis. This paper presents, for the first time in the published literature, a detailed analysis of an unannounced evacuation of licensed premises and provides important data and understanding regarding behaviour for use in fire safety engineering design and evacuation modelling. Findings on recognition times, response behaviours, pre-evacuation times and final exit flows for a function room and lounge bar in the licensed property are provided. The results suggest that the evacuation time in the lounge bar was characterised by generally longer pre-evacuation times and relatively shorter movement times, whereas the evacuation time in the more densely populated function room was characterised by shorter pre-evacuation times but extended flow times. The paper highlights important design and management issues with respect to the evacuation of persons under the influence of alcohol and considers the impact of staff intervention through directed voice communications. The variation in response behaviours between the two separate areas of the premises are highlighted and discussed. Copyright © 2017 John Wiley & Sons, Ltd.

Evacuation response behaviour of occupants in a large theatre during a live performance


This paper presents the results of an unannounced theatre evacuation involving 1200 occupants. The evacuation took place towards the end of a live theatre performance in the Marlowe Theatre in Kent, UK. In particular, Response Phase behaviours are discussed, and response time data is presented. A significant finding of this work which is different to other reported work is that the occupant response time distribution, while following the typical log-normal distribution is related to the geometrical positioning of the occupants relative to proximity to exit aisles and exits. Response time is found to increase relative to seat distance from the exit aisles and distance of the seat row to an exit. The identified trends in response time distribution will have a profound impact on the analysis of evacuation times and congestion levels determined using agent based evacuation models and so should be represented within these models. Based on these findings, a generalised methodology is proposed to distribute response time within a theatre for use in evacuation simulation applications. Further experimental analysis is required to determine whether these observations can be generalised and applied to other seated venues such as cinemas, music venues and sports arenas. Copyright © 2017 John Wiley & Sons, Ltd.

An international survey and full-scale evacuation trial demonstrating the effectiveness of the active dynamic signage system concept


Rapid evacuation from large buildings is challenging because of their complex layout making wayfinding difficult. While emergency signage is widely used to aid wayfinding, recent research demonstrates that only 38% of people perceive conventional exit signs. Furthermore, conventional signage only conveys single and passive information and so cannot adapt to changing conditions. The EU FP7 GETAWAY project addresses this problem through the development of a unique and innovative Intelligent Active Dynamic Signage System (IADSS), which routes occupants to their optimal exits during an evolving incident. This paper presents two key steps in the development of the IADSS concept. First, a novel negated signage concept identifying that an exit route is no longer viable was devised and tested using an international survey. The results demonstrate that the negation concept can be clearly understood by over 90% of the sample. The second step involved two full-scale evacuation trials in a rail station that demonstrated that it was possible to direct over 60% of the participants to the targeted exit through the use of the Active Dynamic Signage System (ADSS). The ADSS makes use of the negated signage concept and a development involving a green flashing arrow within the standard emergency exit sign. Copyright © 2016 John Wiley & Sons, Ltd.

Ascending stair evacuation: walking speed as a function of height


There is reason to believe that factors such as physical exertion and behavioural changes will influence the ascending walking speed and ultimately the possibility of satisfactory evacuation. To study these effects, a 2-year research project was initiated with the focus on effects of physical exertion on walking speeds, physiological performance and behaviours during long ascending evacuations. Two sets of experiments on human performance during ascending long stairs, with a height of 48 and 109 m, were performed. The results include aspects such as walking speeds, physical exertion (oxygen consumption, heart rates and electromyography data), perceived exertion and behavioural changes, showing that physical work capacity affects walking speeds in case of long ascending evacuation and should be considered while using long ascending evacuation. Analysis of both walking and vertical speeds is recommended because it provides additional insights on the impact of stair configuration on vertical displacement and the importance of not using the same value for walking speed for different stairs because the design of the stairs has an impact. The novel datasets presented in this paper are deemed to provide useful information for fire safety engineers both for assisting fire safety design as well as the calibration of evacuation modelling tools. Copyright © 2016 John Wiley & Sons, Ltd.

School egress data: comparing the configuration and validation of five egress modelling tools


Data were collected between 2011 and 2014 from five evacuations involving the same school buildings located in Spain. Children from 6 to 16 years of age were observed during the evacuation exercises. Background information was collected on key factors deemed to influence evacuation performance: a description of the geometry, the population involved, the procedures employed and the organization of the drills conducted. Using live observations and video footage of these drills, evacuation data were collected, focusing on the pre-evacuation times, the routes employed, the travel speeds adopted and the arrival times. These data informed a range of a posteriori simulations, conducted by using four computer models (buildingEXODUS, MassMotion, Pathfinder and STEPS) and the Society of Fire Protection Engineering hydraulic model (i.e. Society of Fire Protection Engineering hand calculations). Comparisons were drawn between the models' output and against the observed outcome for one of the trials to determine the accuracy of the model predictions given that they were configured by using the initial conditions for a specific evacuation. The purpose of this work is to (1) provide insight into the configuration of these models for equivalent scenarios, (2) examine any variation in the simulated conditions given equivalent initial conditions, and (3) provide suggestions on how to perform validation studies for multiple evacuation models. Copyright © 2016 John Wiley & Sons, Ltd.

Effects of pre-fire age and health status on vulnerability to incapacitation and death from exposure to carbon monoxide and smoke irritants in Rosepark fire incident victims


Age-related decline and illness increase susceptibility to smoke and toxic fire gases, with incapacitation and death likely for lower exposures. Carbon monoxide (CO) in non-burned fire fatalities as %COHb indicates the fatal ‘dose’ of toxic effluents (including CO and other toxic species). The elderly and infirm should be overcome earlier during a fire, with lower post-mortem blood %COHb levels than younger fatalities. The Rosepark care home incident involved 18 elderly casualties (average age 85 years, range 61–99) with a variety of illnesses. Post-mortem reports and health records provided %COHb concentrations at death or time of rescue, age and pre-fire health status. To examine effects of health status on susceptibility, heart, circulation, lungs and general health conditions were classified on a 0–5 severity scale for each condition. Scores for each subject were plotted against age or %COHb and examined for trends. No increase in susceptibility to incapacitation was found for survivors. %COHb in fatalities (range 48–82% average 63% COHb) was similar to published levels for young adults (average 61% COHb). There was no increasing susceptibility with age or severity of lung or ‘other health’ conditions, but some trend with severity of cardiovascular disease, especially heart disease (statistically significant 5% level). Copyright © 2016 John Wiley & Sons, Ltd.