Fire behaviour of gypsum plasterboard wall assemblies: CFD simulation of a full-scale residential building

New trends in building energy efficiency include thermal storage in building elements that can be achieved via the incorporation of Phase Change Materials (PCM). Gypsum plasterboards enhanced with micro-encapsulated paraffin-based PCM have recently become commercially available. This work aims to shed light on the fire safety aspects of using such innovative building materials, by means of an extensive experimental and numerical simulation study. The main thermo-physical properties and the fire behaviour of PCM-enhanced plasterboards are investigated, using a variety of methods (i.e. thermo-gravimetric analysis, differential scanning calorimetry, cone calorimeter, scanning electron microscopy). It is demonstrated that in the high temperature environment developing during a fire, the PCM paraffins evaporate and escape through the failed encapsulation shells and the gypsum plasterboard's porous structure, emerging in the fire region, where they ignite increasing the effective fire load. The experimental data are used to develop a numerical model that accurately describes the fire behaviour of PCM-enhanced gypsum plasterboards. The model is implemented in a Computational Fluid Dynamics (CFD) code and is validated against cone calorimeter test results. CFD simulations are used to demonstrate that the use of paraffin-based PCM-enhanced construction materials may, in case the micro-encapsulation shells fail, adversely affect the fire safety characteristics of a building. © 2015 Elsevier Ltd. All rights reserved

Fire performance of sandwich panels in a modified ISO 13784-1 small room test: the influence of increased fire load for different insulation materials

Four sandwich panel rooms were constructed as prescribed in the ISO 13784-1 test. However, the construction followed normal industry practice, and the panels were also subjected to the kinds of damage typically found in commercial premises, although such damage may not typically be concentrated in such a small room. The fire load was increased to simulate fires actually occurring in commercial premises by stepping up the propane burner output from the usual maximum of 300–600 kW, and by placing a substantial wooden crib in two of the rooms. The results showed significant differences in fire growth rate and burning behaviour between those panels filled with polyisocyanurate (PIR) and those filled with stone wool in both the experiments without and with the wooden crib. Most significantly, the PIR pyrolysis products caused earlier ignition (by radiation from above) of the wooden crib 11 min into the experiment (1 min after the burner was stepped up to 300 kW), whereas the crib ignited 22 min into the test (2 min after the burner had been stepped up to 600 kW, which is beyond the test standard both in time and heat input) for the stone wool panels. This interaction between building and contents is most often ignored in fire safety assessments. After a few minutes, the PIR pyrolysis products that escaped outside the room, from between the panels, ignited. The extra thermal exposure from the PIR-fuelled flames distorted the panels, which in turn exposed more PIR, resulting in large flames on both the inside and outside of the enclosure. From a fire safety perspective this is most important as it shows that with the large fire loads that are commonly found in commercial premises, steel-faced PIR filled panels are not capable of acting as fire barriers, and may support flame spread through compartment walls and ceilings. In addition, the PIR panelled rooms produced very large quantities of dense smoke and toxic effluents, whereas the stone wool panelled rooms produced small amounts of light smoke of lower toxicity. Furthermore, the experiments showed that modifications to the standard test can lead to extremely different outcomes for some of the products. As the modifications simulated real-life situations, it seems important to discuss whether the standard is robust enough for property safety scenarios encountered in industrial premises

Assessment of fuel load survey methodologies and its impact on fire load data

Fuel load survey methodology has been recognized to have a significant impact on survey results; however, this impact has not been explicitly quantified. This study seeks to establish a structured approach to validate different fuel load survey methodologies and to enhance and develop guidance on means to correlate the fire load developed using those methodologies. A total floor area of 935 m2 in five office buildings was surveyed. The percentage difference in fire load densities obtained from different survey methods ranged between 1% and 50%. This difference has been attributed to the uncertainties associated with the use of each survey method. Statistically, the fire load density was found to be an extreme value (Gumbel) distributed using Kolmogorov-Smirnov test

Development of a Sensing Device to Reduce the Risk from Kitchen Fires

Fires originating from cooking areas are the second leading cause of fatalities and loss related to residential fires. The predominant root cause of residential stovetop cooking fires has been found to result from unattended cooking. The installation of smoke detectors can only detect and at best alert residents to a fire hazard. Control technologies for cutting gas supply to cooking devices upon receiving signals from detectors is not new. Many of stovetop mitigation technologies are currently in existence as consumer products or patents, however little evaluation has been conducted on these products in order to develop a more efficient and effective device to help reduce the frequency of cooking related fires. The paper presents a short review of literature and goes on to discuss a fire sensing device developed to act as a pre-ignition sensor that will cut off power supply to cooking devices upon receiving inputs from a detection device. The device proved to be effective when it was tested both in the laboratory and a real kitchen environment. The installation of this device, in addition to an installed detection device will play a major role in reducing the risk of most kitchen fires

Experiments fot the characterization of design fires for commercial buildings

This paper presents a study to characterize design fires for commercial buildings. The study includes a survey of different stores, which was conducted to determine fire load and type of combustibles and to design representative fuel packages, medium- and full-scale testing using the fuel packages, and computer modeling. The experiments were conducted in collaboration with the Fire Research Program of the National Research Council of Canada (NRC) using NRC's full-scale facilities. In total, 168 different stores were surveyed and the data collected were analyzed to determine the total fire load in each of the stores, the fire load density, and the contribution of different combustible materials to the total fire load. The survey was conducted in 2003 in the Canadian cities of Ottawa and Gatineau. The data from the conducted survey show that clothing stores occupy 30% of the total floor area of all surveyed stores, restaurants 13%, storage areas 9%, arts and crafts supplies 5%, and fast food outlets 4%. The data also show that the fire load in stores consists of a vast variation of combustibles with different contributions depending on thetype of store. Analysis of the data found a clear correlation between the floor area of stores and fire load densities. The fire load density decreases as the floor area increases. Based on the survey data, a number of fuel packages were designed repres

Structural fire performance of innovative moment-resisting connection joining steel beams to HSS columns

In this paper, experimental results of the structural fire behaviour of four large-scale steel frame test assemblies are presented. Test assemblies were made of HSS beams and columns connected together using an innovative extended end-plate moment connection configuration. Two different parameters were investigated, the connection end plate thickness and the degree of beam axial restraint. The fire performance of this beam-to-column configuration was compared to the behaviour of a commonly-used connection configuration with similar parameters and fire testing conditions. The newly-developed connection configuration behaved in a more flexible manner at elevated temperature than the regular configuration. In addition to improved constructability and pleasant appearance, the new connection configuration exhibits greater moment-carrying capacity and enhanced fire resistance characteristics

Design Fires for Commercial Premises - Results of Phase I

This report presents the results of nine medium-scale fire experiments from the first phase of a joint research project between Carleton University and IRC's Fire Research Program, which were conducted to determine the burning characteristics of combustibles in commercial premises. The test facility used was a test room with ISO 9705 compatible dimensions and the fire load density used in the experiments ranged from 661 MJ/m2 to 4,900 MJ/m2. The fire load density and composition of combustibles were determined from a survey of commercial buildings that was conducted by Carleton University in the Canadian cities of Ottawa and Gatineau.Ce rapport pr\ue9sente les r\ue9sultats de neuf exp\ue9riences sur des incendies de moyenne envergure r\ue9alis\ue9es dans le cadre de la premi\ue8re phase d'un projet de recherche men\ue9 par les responsables du programme Recherche en incendie de l'IRC de concert avec l'Universit\ue9 Carleton. Ces exp\ue9riences visaient \ue0 d\ue9terminer les caract\ue9ristiques de combustion des mati\ue8res combustibles situ\ue9es dans les locaux commerciaux. Pour les essais, on a utilis\ue9 une salle compatible avec les dimensions de la norme ISO 9705 et des densit\ue9s de charge calorifique variant entre 661 MJ/m2 et 4900 MJ/m2. La densit\ue9 de charge calorifique et la composition des combustibles ont \ue9t\ue9 \ue9tablies au moyen d'une enqu\ueate sur les b\ue2timents commerciaux r\ue9alis\ue9e par l'Universit\ue9 Carleton dans deux villes canadiennes, soit Ottawa et Gatineau.Peer reviewed: NoNRC publication: Ye