The study aimed to test the hypothesis that biochar's unique properties, such as its microporous structure, can enhance concrete's resilience to high temperatures. Despite expectations of reduced crack formation and enhanced fire resistance, the experimental results revealed a limited impact on concrete's fire behaviour. The investigation involved the use of two biochar types, fine and coarse biochar as replacements for cement and aggregates, respectively. Fine biochar exhibited higher water absorption and Young's modulus than coarse biochar, but both resisted ignition at 35 kW/m2 radiative heat flux and had peak heat release rates below 40 kW/m2. Incorporating these biochars at varying weight percentages (10, 15, and 20 wt.%) into concrete led to a gradual decline in compressive and tensile strength due to reduced binding ability with increased biochar content. Exposure to 1000 °C compromised mechanical properties across all the samples. However, the biochar concrete maintained compressive strength (compared to the control) with up to 20 wt.% biochar as a fine aggregate substitute after exposure to 600 °C, and as a cement replacement after exposure to 200 °C. This substitution also yielded a significant reduction in CO2 emissions (50 % reduction as the biochar loading amount doubled) from concrete manufacturing, showcasing biochar's potential for sustainable construction practices. Despite not fully supporting the initial hypothesis, the study demonstrated biochar's viability in reducing carbon footprint while maintaining concrete strength under certain fire conditions.

This paper examines the reaction-to-fire behaviour of building materials containing phase change materials by predicting their fire classification according to the European reaction-to-fire classification system (Euroclasses). While various building materials containing PCMs exist today, their application in buildings has been somewhat limited due to the fire behaviour of these building materials. Existing research has focused on small scale testing which does not allow determination of the Euroclass of the material. In this application, large scale performance is predicted based on previously published small scale data to provide some valuable insights into the expected fire performance of these materials. As a starting point, a systematic literature review on phase change materials (PCM) and fire behaviour was conducted, with the purpose of identifying all existing literature concerning experimental investigation of the fire behaviour of building materials containing PCMs. In total, 816 articles were selected from the literature search. After screening of these papers, 51 articles were fully reviewed and included in the next step of the study. In the next step, the reaction-to-fire behaviour of the building materials with PCMs that were identified from the literature was predicted using the ConeTools simulation program. The input data required for ConeTools was obtained from the identified literature. Initially, 27 of the 51 studies used cone calorimetry as a fire testing method and could therefore be considered for the Euroclass assessment. However, of the 27 studies, only 17 studies provided information on both the heat release rates (HRR) and time to ignition (TTI) and were selected for use in the ConeTools program. The ConeTools program predicted Euroclasses for all the building materials containing PCMs from the selected 17 studies. The predicted Euroclasses for most materials was low (i.e. fire classes ‘D' or ‘E or worse') which confirms that materials containing PCMs generally have a low react-to-fire behaviour even with addition of flame retardants (FR). Our findings indicate that the fire behaviour, typically Euroclass ‘D' or ‘E or worse', of the building materials containing PCMs is indeed a barrier to their implementation in the building applications where Euroclass C or higher is required, e.g. in evacuation pathways or certain public spaces. The predictions of the Euroclasses based on ConeTools need to be confirmed using Single Burning Item tests (EN 13823) and/or Room Corner tests (ISO 9705) in the future, to enable a better understanding of fire behaviour of these building materials.

Low pressure, medium pressure and high pressure water-based fire suppression systems were tested in a medium scale tunnel (scale 1:3). The primary objective was to investigate which of these systems are most effective in the suppression or control of different types of tunnel fires. The default low, medium and high pressure systems refer to full scale water flow rates of 10 mm/min, 6.8 mm/min and 3.7 mm/min, respectively. Some other water densities were also tested to investigate the effects, as well as different ventilation velocities and activation criteria. Several series of fire tests were conducted for different fire scenarios. The fire scenarios considered included idle wood pallet fires, loosely packed wood crib fires, loosely packed wood and plastic crib fires, and pool fires, with or without a top cover on the fuel load. Comparisons of the three default systems based on the three parameters: heat release rate, energy released and possibility of fire spread, show that the performance of the default low pressure system is usually the most effective based on the parameters studied. The default high pressure system usually yields results less effective in comparison to the default low pressure system. The performance of the default medium pressure system usually lies in between them. The high pressure system behaves very differently in comparison to the others, in terms of tunnel ventilation velocity, water density, operating pressure, and the presence of the top cover.

In this study, Kraft lignin was modified by ammonium dihydrogen phosphate (ADP) and urea for achieving phosphorylation and carbamylation, aiming to protect wood against biological and fire attack. Scots pine (Pinus sylvestris L.) sapwood was impregnated with a water solution containing Kraft lignin, ADP, and urea, followed by heat treatment at 150 °C, resulting in changes in the properties of the Kraft lignin as well as the wood matrix. Infrared spectroscopy, 13C cross-polarisation magic-angle-spinning (MAS) nuclear magnetic resonance (NMR), and direct excitation single-pulse 31P MAS NMR analyses suggested the grafting reaction of phosphate and carbamylate groups onto the hydroxyl groups of Kraft lignin. Scanning electron microscopy with energy dispersive X-ray spectroscopy indicated that the condensed Kraft lignin filled the lumen as well as partially penetrating the wood cell wall. The modified Kraft lignin imparted fire-retardancy and increased char residue to the wood at elevated temperature, as confirmed by limiting oxygen index, microscale combustion calorimetry, and thermogravimetric analysis. The modified wood exhibited superior resistance against mold and decay fungi attack under laboratory conditions. The modified wood had a similar modulus of elasticity to the unmodified wood, while experiencing a reduction in the modulus of rupture.

Scheimpflug lidar is a compact alternative to traditional lidar setups. With Scheimpflug lidar it is possible to make continuous range-resolved measurements. In this study we investigate the feasibility of a Scheimpflug lidar instrument for remote sensing in pool flames, which are characterized by strong particle scattering, large temperature gradients, and substantial fluctuations in particle distribution due to turbulence. An extinction coefficient can be extracted using the information about the transmitted laser power and the spatial extent of the flame. The transmitted laser power is manifested by the intensity of the 'echo' from a hard-target termination of the beam located behind the flame, while the information of the spatial extent of the flame along the laser beam is provided by the range-resolved scattering signal. Measurements were performed in heptane and diesel flames, respectively.

This study provides an analysis on the fire safety of passengers and the fire protection of coaches and buses. A brief review of major bus fire incidents, an overview of current regulations in Europe, and their limitations are presented. The study finds that the current small-scale fire test methods described in UN ECE Reg No. 118 need to be replaced by test methods that can assess the reaction to fire of materials when exposed to ignition sources of varying sizes. To address these shortcomings, the study proposed an expert recommendation to update the material fire safety requirements and testing for buses. Additional measures are proposed, derived from objectives and strategies applied in other transport sectors, and can be tested through existing European and international standards, which are widely used by several industries. These measures aim to extend the time with tenable conditions for a safe evacuation in case of fire, reduce the degree of damage to buses, reduce the risk for fast and excessive thermal exposure on modern energy carriers needed for a more sustainable transport sector.

Fire retardants, although can impart fire-safety in polymeric composites, are detrimental to the mechanical properties. Biochar can be used, in conjunction with fire retardants, to create a balance between fire-safety and mechanical performance. It is possible to thermally dope fire retardants into the pores of biochar to make it functionalised. Thus, the current work is intended in identifying a composite having the combination of the most desirable fire retardant, bioplastic, and a suitable processing method. A comparison was made between two fire retardants (lanosol and ammonium polyphosphate), bioplastics (wheat gluten and polyamide 11), and composite processing methods (compression and injection moulding). It was found that wheat gluten containing ammonium polyphosphate-doped biochar made by compression moulding had the best fire-safety properties with the lowest peak heat release rate (186 kW/m2), the highest fire performance index (0.6 m2s/kW), and the lowest fire growth index (1.6 kW/ms) with acceptable mechanical properties compared to the corresponding neat bioplastic. Thus, for gluten-based polymers, the use of ammonium polyphosphate thermally doped into biochar processed by compression moulding is recommended to both simultaneously improve fire-safety and conserve the mechanical strength of the resulting biocomposites.

The exterior application of fire-retardant (FR) timber necessitates it to have high durability because of the possibility to be exposed to rainfall. In this study, water-leaching resistance of FR wood has been imparted by grafting phosphate and carbamate groups of the water-soluble FR additives ammonium dihydrogen phosphate (ADP)/urea onto the hydroxyl groups of wood polymers via vacuum-pressure impregnation, followed by drying/heating in hot air. A darker and more reddish wood surface was observed after the modification. Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, solid-state 13C cross-polarization magic-angle-spinning nuclear magnetic resonance (13C CP-MAS NMR), and direct-excitation 31P MAS NMR suggested the formation of C–O–P covalent bonds and urethane chemical bridges. Scanning electron microscopy/energy-dispersive X-ray spectrometry suggested the diffusion of ADP/urea into the cell wall. The gas evolution analyzed by thermogravimetric analysis coupled with quadrupole mass spectrometry revealed a potential grafting reaction mechanism starting with the thermal decomposition of urea. Thermal behavior showed that the FR-modified wood lowered the main decomposition temperature and promoted the formation of char residues at elevated temperatures. The FR activity was preserved even after an extensive water-leaching test, confirmed by the limiting oxygen index (LOI) and cone calorimetry. The reduction of fire hazards was achieved through the increase of the LOI to above 80%, reduction of 30% of the peak heat release rate (pHRR2), reduction of smoke production, and a longer ignition time. The modulus of elasticity of FR-modified wood increased by 40% without significantly decreasing the modulus of rupture.

The mutual inhibition effect of transport of sulphate and chloride in concrete specimen was determined in a macroscopic experiment. Higher concentration of sulphate has a better inhibition effect on chloride transport and the opposite is also true. In this paper, molecular dynamics (MD) simulation was performed to explore the effect of concentration (0, 0.5, 1.0 mol/L) on the transport of mixed solutions (NaCl and Na2SO4) in the main hydration products of aluminium-doped cement-based materials (i.e., calcium-aluminium-silicate-hydrate (C-A-S-H) gel). Sulphate was found to promote the aggregation of other ions to form ion clusters, which can reduce the effective width of the channel entrance and create a “necking” effect, thus reducing the overall transport rate of the solution. With the increase of NaCl concentration, sulphate ions in the mixed solution can adsorb more Na+ and Cl+ ions, and then form larger ion clusters to block the nanopores. Moreover, with increasing Na2SO4 concentration, higher amount of sulphate ions existing in the solution makes it possible to form more ion clusters. The results can provide a reasonable nanoscale explanation for macroscopic experiment.