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The thermal performance of a novel intumescent coating was investigated at a laboratory scale. A combination of small and large-scale tests was performed in order to fully understand the behavior of the coating. For small-scale testing, experiments were conducted using thermogravimetric analyses. These experiments were run at several heating rates in a nitrogen atmosphere. The results showed that the thermal degradation of the coating occurred in different stages, and, the main mass loss took place around 300 °C. Furthermore, the current work showed that oxygen doesn't exert any significant effect during the early stages of degradation of the materials; however, its interference can be noted past the attainment of the peak value for mass loss rate curve. For large-scale testing, the experiments were carried out in a cone calorimeter using a stainless steel plate as a platform to support the test specimen. The back surface temperature and expansion height of the intumescent coating were measured as a function of time. Several factors such as heat flux, distance to cone heater and coating thickness were also investigated. The results showed that the normalized expansion height of intumescent coating was consistent at different heat flux levels. Hence the expansion of the coating can be considered to be dependent only on the mass loss rates and not the value of the external heat flux. Also, results from the cone tests, permit the formulation of an experimental protocol for evaluating of the thermal shielding efficiency of the intumescent coatings. The results showed that the data obtained using a cone calorimeter with 2.5 cm of distance cannot be compared with other distances, such as 4 or 6 cm. The present work also showed that the values of the relevant parameters did not differ significantly at distances to the cone heater above 4 cm. In a second evaluation, the new intumescent coating was applied to polyurethane and Gypsum boards, for study using cone calorimetry. The use of the coating led to a decrease in the peak of heat release rate for combustion of polyurethane. The application of a coating layer can be used to decrease the overall requirement of thickness of the Gypsum board without compromising its thermal insulation performance. [ABSTRACT FROM AUTHOR]

Modelling of spread of fires and their extinguishment in solid materials still present a significant challenge. In order to reliably predict the behaviour of a material in a fire scenario, an adequate description of the processes occurring at the gas/solid interface is highly crucial. In this context, those fire scenarios involving polymeric materials are of primary importance because of their increasing use as components in buildings and in transportation. The purpose of this study is to propose an accurate model for the thermal degradation of polymethyl methacrylate (PMMA) by primarily using thermogravimetric analysis (TGA). TGA in non-isothermal conditions, together with Fourier-transform infrared spectroscopy (FT-IR), was applied to investigate the thermal degradation of black PMMA in inert (nitrogen) and oxidizing (air) atmospheres, at different heating rates. The volatile degradation products as well as mass loss history provided sufficient information regarding the kinetics and possible degradation mechanisms of PMMA. A genetic algorithm (GA) was applied to estimate the kinetic parameters, which showed an excellent agreement with corresponding experimental observations for several heating rates and at different atmospheres (0, 10.5, 15 and 21 vol.% O 2 ). [ABSTRACT FROM AUTHOR]

The paper presents flammability studies related with the combustion of Maritime pine needles (pinus pinaster, representative of Mediterranean vegetation) in a cone calorimeter (CC) under air atmosphere with piloted ignition and self-ignition for different heat fluxes, from 10 to 50 kW m −2 . The Main objective is to measure the yields of the gaseous emissions released during the experiments because one of the major risks during the fire is from the smoke and products of combustion. Identification of exhaust gaseous compounds and concentration measurements have been done by FTIR, NDIR, chemiluminescence and paramagnetism gas analyzers for assessing the fire behavior and identifying the decomposition chemistry. Among the 15 different compounds simultaneously analyzed, the yields of CH 4 , CO 2 , CO, H 2 O, NO and O 2 have been quantified. HCN and light-weight hydrocarbons (C 2 H 2 , C 2 H 4 , C 3 H 6 and C 3 H 8 ) have been observed at low concentrations. The results show that carbon dioxide and water are the main emissions during the experiments. Also, the carbon balance shows that about 5% of the carbon released as carbon monoxide and hydrocarbon whatever the external heat flux chosen. Moreover, flammability parameters such as Mass Loss, Mass Loss Rate (MLR) and Time to Ignition (t ig ) have been determined for each condition during the experiments. Pine needles is considered often as a thermally thin material. However, the bed of pine needles behaves as a thermally thick material in the conditions tested. [ABSTRACT FROM AUTHOR]

Highlights: [•] Cone calorimeter was used to study the thermal decomposition of two kinds of plywood. [•] Flammability parameters calculated. [•] Analysis of the gaseous emissions by using FTIR. [•] Calculation of emission yields and carbon atomic balance. [•] Analysis of the smoke evolution. [ABSTRACT FROM AUTHOR]

Thermal degradation plays a very important role in the understanding of pyrolysis and oxidation. Parameters of ignition, flammability and flame propagation depend on it. In this context, the aim of this study is to study experimentally thermal degradation of two terpene-derived biofuels: α-pinene and β-pinene. Thermogravimetric analyses are performed for four heating rates (3, 5, 10, 20 K/min) under two atmospheres: air and nitrogen. Kinetic parameters are extracted using three different methods. Activation energies for these two biodiesels are given for the first time. In addition, GC–MS analyses are performed to study gaseous emissions of these two compounds. Results show that α-pinene is slightly more reactive than β-pinene. Comparisons with literature show that activation energies of these two biofuels are close to diesel and sunflower biofuel ones. Obtained results will be useful for numerical simulations of biodiesel combustion, as an alternative to fossil fuels. [ABSTRACT FROM AUTHOR]

The use of fire models to support fire protection engineering decisions requires an understanding of model shortcomings and assurance in their predictive robustness. This note is a summary of the online 'compartment fire' workshop that was organized prior to the International Association of Fire Safety Science (IAFSS) symposium, hosted online by the University of Waterloo (Canada) in April 2021. The objectives of the Workshop were to identify, discuss and prioritize key compartment fire modeling challenges. It is recognized that the substantial changes in the built environment and the variety of subsequent fire dynamics problems necessitate significant advances in modelling, particularly with respect to (amongst other aspects) (i) under-ventilated fires (the prediction of soot and CO concentrations, extinction and reignition), (ii) heat transfer and the interaction with structural and non-structural elements, and (iii) the interaction with water-based fire suppression systems. High-quality and well-documented experimental tests play an essential role in fostering model development and validation; a good synergy between experimentalists and modellers is of utmost importance. • Key compartment fire modeling challenges are discussed. • Significant advances in modelling are necessary. • High-quality and well-documented experimental tests are of utmost importance. • A strong collaboration between modelers and experimentalists fosters progress. [ABSTRACT FROM AUTHOR]

Evaluation of a specific facade system's fire performance can be undertaken using large-scale testing, following the local regulations. The fire test protocol detailed in BS 8414 series is representative of an external fire source, or a fully developed (post-flashover) fire in a room, venting through an opening such as a window that exposes the façade to the effects of external flames. This test can be performed indoors or outdoors, with a wind or air velocity of less than 2 m/s. However, wind can have significant effects on the external flame shape, and thus on the thermal exposure of the tested façade. According to the testing conditions given in BS 8414 series, the test uses a wood crib as a fire source with Heat Release Rate between 2.5 MW and 3.5 MW (3.0 ± 0.5 MW). In this paper, a numerical model of the BS 8414 facility is validated based on experiments for an incombustible façade system. Then, the influence of the wood crib contribution on the heat exposure is investigated numerically, using three different values of the wood crib HRR. It was thus shown that the uncertainty allowed for wood crib HRR in BS 8414 with a peak rate of (3.0 ± 0.5) MW and up to 4 MW had no significant influence on the temperature results achieved for the calibration system, but had an impact on the heat flux imparted to the walls for the lower HRR value. The effect of an external wind with three different directions is addressed in terms of variation of the thermal exposure on the façade. A strong impact was observed in terms of patterns of fire exposure and flame height. [ABSTRACT FROM AUTHOR]

Observations and numerical studies have allowed an understanding the fire development inside apartments and over the façade during the Grenfell Tower fire. During these analyses, the highlighted need was for a deeper investigation into the failure of windows during the fire. This detailed and complex model for window failure validates the thermal breakage criteria used in fire simulations of the whole Grenfell Tower fire. However, the present investigation is dedicated to a single pathway for the influx of fire and toxic smoke. Other pathways from the façade to the apartments, such as the melting of elements surrounding the window frame, are not addressed here. To analyse window behaviour during fire, Finite Element Method thermomechanical modelling is used. First, a heat transfer analysis is performed for windows subjected to the external flames from the identified façade fire scenario. The thermal loads evaluated from the fire are applied to the window structures to estimate their failure times. Two window casement configurations, closed and tilted-in, are investigated numerically. Then, a thermomechanical analysis of the window is addressed for each casement configuration. The modelled failure times are compared with those used in the general fire development model and from the observations. The good correlation that is observed, regardless of casement configuration, justifies the use of a simplified criterion for window failure in CFD fire models. [ABSTRACT FROM AUTHOR]

Flammability and combustion of softwood treated with intumescent coatings were studied in the present work. The formulations applied onto wood surfaces contained different ratios of industrial fillers, titanium dioxide TiO2 and aluminium trihydroxide Al(OH)3, and/or bio-fillers, eggshell and rice husk ash. Combustion behaviours of unprotected and protected wood samples have been examined with the aid of cone calorimetry performed under the varied levels of thermal flux ranging from 30 to 50 kW/m². The char residues obtained after the completion of cone calorimetry test at 40 kW/m² were analysed by the Raman spectroscopy. The fire protective properties of the studied coatings were strongly influenced by the nature of the fillers as well as by the intensity of thermal irradiance. The incorporation of bio-based fillers into the water-based intumescent formulations significantly improved fire resistance of wood substrates. For example, at 30 kW/m², the Effective Heat of Combustion was reduced by more than 40%, whilst the average Peak to Heat Release Rate had dropped from 193.2 to 150.3 kW/m² for the wood sample protected with the formulation incorporating two industrial and two bio-fillers. Moreover, an application of the studied coatings resulted in a notable reduction of the back surface temperature of the wood specimens. [ABSTRACT FROM AUTHOR]

The article Reconstruction of the Grenfell Tower Fire—Thermomechanical Analysis of Window Failure During the Grenfell Tower Disaster. [ABSTRACT FROM AUTHOR]