Since Engineered Wood Products (EWPs) have entered the building industry as structural elements, several fire safety concerns have arisen, especially for high-rise structures.The combustible nature of timber suggests that the current knowledge on compartment fire dynamics might not apply to compartments with timber boundaries, due to the increased fuel load and its redistribution across the compartment.In order to fill this knowledge gap, 24 medium-scale timber compartments have been executed to characterise the fire dynamics when timber members are present.This experimental campaign provides data about the gas-phase temperatures, the flow fields at the opening, the burning behaviour of timber and its contribution to the total heat release rate. This data is then compared to current tools that predict the fire development in conventional compartments.This comparison dismantles the limitations of the current framework, and the subsequent analysis proposes several changes to include the effect of burning timber elements. It is concluded that gas flow velocities increase with the amount of more timber present in the compartment. Therefore the fire transitions to a new regime where the gases do not have enough time to mix and react inside the compartment, the temperatures decrease and the horizontal velocities at the opening increase.
A novel performance-based methodology for the quantitative fire safe design of building assemblies including insulation materials has recently been proposed. This approach is based on the definition of suitable thermal barriers in order to control the fire hazards imposed by the insulation. Under this framework, the concept of "critical temperature" has been used to define an initiating failure criterion for the insulation, so as to ensure there will be no significant contribution to the fire nor generation of hazardous gas effluents. This paper proposes a methodology to evaluate this "critical temperature" using as examples some of the most common insulation materials used for buildings in the EU market, i.e. rigid polyisocyanurate foam (PIR), rigid phenolic foam (PF), rigid expanded polystyrene foam (EPS) and low density flexible stone wool (SW). A characterisation of these materials, based on a series of ad-hoc Cone Calorimeter and thermo-gravimetric experiments, serves to establish the rationale behind the quantification of the critical temperature. The temperature of the main peak of pyrolysis, obtained from differential thermo-gravimetric analysis (DTG) under a nitrogen atmosphere at low heating rates, is proposed as the "critical temperature" for materials that do not significantly shrink and melt, i.e. charring insulation materials. For materials with shrinking and melting behaviour it is suggested that the melting point could be used as "critical temperature". Conservative values of "critical temperature" proposed are 300 °C for polyisocyanurate, 425 °C for phenolic foam and 240 °C for expanded polystyrene. The concept of a "critical temperature" for the low density stone wool is examined in the same manner and found to be non-applicable due to the inability to promote a flammable mixture. Additionally, thermal inertia values required for the performance-based methodology are obtained for PIR and PF using a novel approach, providing thermal inertia values within the range 4.5-6.5 •10 3 W 2 •s•K-2 •m-4 .
This paper aims to characterize dynamics of a fire in the Large-Scale Demonstrator Malveira Fire Test, a full-scale fire experiment carried out in a disused industrial building in Portugal. The Malveira Fire Test is the second stage in the series of full-scale experimental programmes developed for the Real Fires for the Safe Design of Tall Buildings project at the University of Edinburgh. This experiment is intended to act as a real-building demonstration of fire dynamics in large open-floor plan compartments and has as objective to provide a data set to contrast methodologies aiming at design fire inputs representative of real fire dynamics in compartments typical of tall buildings. The Malveira Fire Test showed three distinct fire behaviour modes characterised by the ratio between the velocities of the fire front (") and the burnout front (#$
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