Building Fire Research Articles

Research of the effect of compactness of fireproof mud plugging and proportion of backing material on fireproof performance

Building fire sealing technology is of great importance in preventing the spread of fire in buildings and reducing the damage caused by fire accidents. In order to investigate the influence of compactness, thickness and proportion of backing material on the fireproof performance of fireproof plugging material, this paper carries out experimental analysis on the pyrolysis process of fireproof plugging material to obtain the relevant parameters, and adopts a small-size fireproof mud-blocking combustion experimental platform to carry out combustion experiments. The experimental results prove that: with the increase of compactness, the thermal insulation and fireproofing performance of fireproof plugging material are enhanced; when the backing material is glass wool, the thermal insulation and fireproofing performance decreases with the increase of the proportion of glass wool; the expansion of fireproof plugging material caused by fire causes the hysteresis phase of thermal response in part of the cross section, and the time period of the hysteresis phase is delayed with the increase of compaction of fireproofing mud, and delayed with the decrease of the proportion of the thickness of backing material. The hysteresis phase is delayed with increasing compactness of fireproof plugging material and decreasing thickness of the backing material. The results of this paper can provide theoretical assistance for the expansion of fireproof plugging material by fire and for the process of installation.

Modeling smoldering ignition by an irradiation spot

Irradiation spots, such as lasers, lightning strikes, and concentrated sunlight, are common ignition sources in building and wildland fires, where smoldering is generally first ignited and then transitions to flaming. In this work, a physics-based 2-D computational model that integrates heat-and-mass transfer and heterogeneous chemistry is built to investigate the smoldering ignition of typical solid fuels using irradiation spots. Simulation results predict that, given the size of the irradiation spot, the ignition time decreases as the radiant heat flux increases. However, as the diameter of the irradiation spot decreases, the modeled minimum heat flux of smoldering ignition increases significantly, agreeing well with experiments and theoretical analysis. When the irradiation spot is smaller than 20-50 mm, assumptions of constant ignition temperature and fuel-burning flux become invalid. The commonly-used physical dimensions of thermally thin/thick fuels are not applicable for smoldering spotting ignition due to the significant radial conductive heat loss in the lateral direction. Further analyses show that the minimum irradiation of smoldering ignition increases as the fuel thickness increases, but it is insensitive to the fuel moisture content. This is the first time that a sophisticated 2-D model has been used to predict the smoldering ignition using irradiation spots, which deepens the understanding of the ignition by a remote heating source and large irradiation.

Application of travelling behaviour models for thermal responses in large compartment fires

Large open-plan compartment fires in modern buildings may exhibit a local burning region travelling across the floor plan as a ‘travelling fire’. This phenomenon has been found in the forensic investigations of fire accidents and in the large compartment fire tests. The fire impact in a large compartment is spatially non-uniform and time-variant, which can cause severe local damage to structural components. Advanced from the previous models assuming constant travelling, the natural fire model established in this paper comprises time-variant and test-based travelling behaviour models and localised fire models of various modes. It is demonstrated with the fast-spread Veselí fire test and the slow-spread Malveira fire test. A generic structural model is set up within OpenSees for fire to examine the thermal impact on structural members under various travelling fire scenarios of different travelling parameters, fire travelling directions, and beam sizes. Locally much higher thermal responses are represented after introducing behaviour models while adopting the same design fire load. Based on the work in this paper, a library of design fire models can be potentially enabled to examine the fire safety performance of structures regarding the realistic fire load and fire impact aiming for discovering unknown worse fire scenarios.

Mechanical and Thermal Properties Analysis of Recycled Concrete Aggregate on Its Fire Exposure

Concrete constructions can be badly damaged by fire, and the damage can be estimated using knowledge of material properties. The major focus on using green materials instead of traditional materials are promoted. Recycled concrete aggregates (RCA) are nominated and analyzed its mechanical and thermal properties with its fire exposure. Conclusions are when using RCA to mix natural aggregate in concrete, and it will help obtaining a better performance of concrete at high temperatures (more than 50 percent). Rich mixed RCA outperforms standard mixed RCA and natural concrete aggregate regarding fire resistance and remaining compressive strength. The effects of varying mixing percentages above 50% mixed concrete and different time effects on concrete performance are examined. It suggests the replacement of RCA is suitable for modern building construction and fire safety sector from its performance post fire residual.

Mechanical and Thermal Properties Analysis of Recycled Concrete Aggregate on Its Fire Exposure

Concrete constructions can be badly damaged by fire, and the damage can be estimated using knowledge of material properties. The major focus on using green materials instead of traditional materials are promoted. Recycled concrete aggregates (RCA) are nominated and analyzed its mechanical and thermal properties with its fire exposure. Conclusions are when using RCA to mix natural aggregate in concrete, and it will help obtaining a better performance of concrete at high temperatures (more than 50 percent). Rich mixed RCA outperforms standard mixed RCA and natural concrete aggregate regarding fire resistance and remaining compressive strength. The effects of varying mixing percentages above 50% mixed concrete and different time effects on concrete performance are examined. It suggests the replacement of RCA is suitable for modern building construction and fire safety sector from its performance post fire residual.

Estimation of Thermal Radiation in Bed Mattresses

The population density of cities has been increasing with time and the development of industry. Building fires in large cities with high population density cause extensive human and property damage. To prevent such damage, the characteristics of flames such as the thermal radiation and intensity of the fire source must be considered when designing building structures. However, the consideration of these factors is practically inadequate. Accordingly, in this study, when a mattress was ignited in an open environment at a different installation height (0–515 mm), the measurements from a heat flux meter and the calculated thermal radiation were compared, and a comparative analysis was conducted using the existing prediction formulas by researchers described in ISO 24678-7. We examined the fire risk of mattresses according to the mattress installation height. As a result, the fire risk of the mattress was confirmed according to the mattress installation height; upon comparing the experimental and calculated values for radiant heat, it was found to be necessary to estimate the radiant heat using a calculation method that applies the configuration factor differently depending on the change in the flame shape. In addition, as a result of substituting the experimental value into the calculation method of ISO 24678-7 (a method for estimating the radiant heat of liquid combustibles), the experimental value and the calculated value were found to be significantly different. Therefore, similar to ISO 24678-7 for the radiation heat estimation method for “liquid combustibles”, an international standard for establishing the radiation heat estimation method for “solid combustible materials” as a standard was also required for a reasonable analysis of the fire safety phenomenon of solid materials, such as bed mattresses.

A Fault Tolerant Surveillance System for Fire Detection and Prevention Using LoRaWAN in Smart Buildings.

In recent years, fire detection technologies have helped safeguard lives and property from hazards. Early fire warning methods, such as smoke or gas sensors, are ineffectual. Many fires have caused deaths and property damage. IoT is a fast-growing technology. It contains equipment, buildings, electrical systems, vehicles, and everyday things with computing and sensing capabilities. These objects can be managed and monitored remotely as they are connected to the Internet. In the Internet of Things concept, low-power devices like sensors and controllers are linked together using the concept of Low Power Wide Area Network (LPWAN). Long Range Wide Area Network (LoRaWAN) is an LPWAN product used on the Internet of Things (IoT). It is well suited for networks of things connected to the Internet, where terminals send a minute amount of sensor data over large distances, providing the end terminals with battery lifetimes of years. In this article, we design and implement a LoRaWAN-based system for smart building fire detection and prevention, not reliant upon Wireless Fidelity (Wi-Fi) connection. A LoRa node with a combination of sensors can detect smoke, gas, Liquefied Petroleum Gas (LPG), propane, methane, hydrogen, alcohol, temperature, and humidity. We developed the system in a real-world environment utilizing Wi-Fi Lora 32 boards. The performance is evaluated considering the response time and overall network delay. The tests are carried out in different lengths (0-600 m) and heights above the ground (0-2 m) in an open environment and indoor (1st Floor-3rd floor) environment. We observed that the proposed system outperformed in sensing and data transfer from sensing nodes to the controller boards.

Analytical Study on the Prediction of Fire Evacuation Time in Large Complex Buildings Using the Ensemble Learning Technique

With the recent increase in the risk of fire in buildings, the number of casualties that occur in the event of a fire have increased. This emphasizes the importance of performance-based design. However, simulating a performance-based design requires a lot of manpower and time, and re-simulation with minor changes is a difficult task. Therefore, in this study, we attempt to develop a prediction model that can easily predict the ASET for each fire distance as a fire factor and spatial factor by applying ensemble learning. The prediction model developed using machine learning based on FDS data showed a high coefficient of determination of 0.91, and we believe that ASET for each distance can be derived in real time by applying this prediction model.

Demonstration of the Effect of Evacuation Systems in Buildings

In the event of a fire in a building, casualties are likely to occur due to various causes. The most common causes of fatalities and injuries due to building fires are related to the inability to use evacuation routes smoothly. The casualties caused by fires could be greatly reduced if a systematic evacuation system is prepared by considering the characteristics of the target building. Accordingly, an appropriate evacuation route can be established based on the location of the fire. Therefore, in this study, an evacuation system that reflects the characteristics of the building was established to minimize casualties in the event of a building fire. Further, to facilitate quick and safe evacuation, an appropriate evacuation route was provided to the occupants in the event of a building fire. The usability of the proposed evacuation system and evacuation route guidance system was verified through empirical experiments involving occupants of various age groups and real buildings.

Assessment of the possibility of using various fire extinguishing means in high-rise buildings

Introduction. To date, fires in high-rise buildings are one of the significant problems faced by fire protection units. Unique objects require a special approach in terms of fire safety and fire extinguishing. The most important task is to ensure the supply of extinguishing agents to the height using modern fire-fighting equipment and installations.Materials and methods.In September 2021, to conduct experimental scientific and tactical exercises on the roof of the Neva Towers tower, a program and methodology for supplying fire extinguishing agents in various ways to the height were developed. The following methods of feeding to height were considered: deployment using the equipment of a container for high-altitude firefighting, feeding from an installation with compression foam technology, feeding using a waterjet cutting unit “Cobra”.Theoretical bases. A theoretical assessment of the possibility of supplying extinguishing agents to a height with the help of new fire-rescue equipment confirmed the need for experimental scientific and tactical exercises on the roof of the Neva Towers tower.Results and discussions. As a result of the scientific and tactical exercises, the effectiveness of the use of new fire extinguishing systems with compression foam supply, as well as installations with waterjet cutting technology “Cobra” was proved. It was possible to provide a feed to a height of 350 m.Conclusions. To date, with the help of new fire extinguishing technologies, it has been experimentally proven that their use is most effective compared to “traditional” methods of supplying extinguishing agents. In the future, it is necessary to conduct more detailed studies of the hydrodynamic parameters of pumping and bag systems in order to develop recommendations for preliminary planning of the actions of forces and means of fire and rescue units.

노후목조건축물 지구단위에서의 화재 시 임시집결지 지정을 위한 피난안전성 검증평가모델 개발

Areas densely populated with old wooden buildings are vulnerable to fire as there is a risk of combustion diffusion among various buildings, and there is a risk of secondary damage from the outside after evacuation inside the building. According to the current domestic system, only facilities that provide relief services to temporary evacuees such as ‘temporary housing facilities’ are designated, so specific preparations and countermeasures are required. Therefore, this study tried to devise a methodology and physical standards for the application of ‘Fire Assembly Point’ in a fire evacuation situation. For this purpose, assuming that a large-scale fire in an old wooden building, it was attempted to determine suitability by checking the heat effect and CO·CO₂ concentration of the relevant area in case of a fire and checking the required safe egress time(RSET) through Pathfinder evacuation program.

Two dimensional temperature distributions in a ceiling jet generated by a finite line-source fire: An experimental study

The temperature distributions of ceiling jets are fundamental characteristics in enclosure fire dynamics. It is also the basics in the designs of fire safety devices in buildings, like detection, sprinkler, smoke control and standard fire protection. However, the only exists equation is for the radial ceiling jet temperature profile induced by a point source. There are no studies on line source despite the fact that the non-axisymmetric sources are the more common fires in buildings. This paper, for the first time, investigates the temperature profiles in ceiling jet induced by a finite line-source fire plume impinging upon an unconfined ceiling. Experiments are carried out with a buoyant jet fire and a pool fire. The temperature profile under the ceiling was measured along with flow condition visualized by a laser sheet. It is found that the temperature profile is two-dimensional and decays slower in the y-direction (perpendicular to line source longer side) than that in the x-direction (parallel to line source longer side). The characteristic length scales for characterizing the temperature profiles in the two directions are then proposed on the basis of the dimensions of the plume impinging zone. An equation is derived to describe the two-dimensional temperature profile based on the characteristic length scales. The present study provides basic data and a new equation for temperature profiles of ceiling jet induced by finite line-sources for building fire science.

A Coproduced Traumatic Bereavement Therapeutic Group for Moroccan Adolescents Affected by the Grenfell Tower Fire

There have been increasing calls to coproduce psychological initiatives and services for children and young people to improve access to mental health services and service user experience. This paper outlines the development of an innovative therapeutic group for young people affected by collective trauma and loss who were reluctant to engage with mainstream services following the Grenfell Tower fire. The June 2017 apartment building fire was one of the largest and deadliest to occur in the United Kingdom (UK) in decades, with 72 deaths. The project’s central principle was partnership and coproduction with potential users and offering a culturally appropriate service. Its aim was to meet the mental health and other needs of young people, support them through their bereavement and trauma, and to improve access to mental health services by addressing the barriers they reported. The group approach used community psychology and systemic principles, narrative therapy concepts, creative arts, and collective memorialization. Semi-structured focus groups were conducted with 14 Moroccan-origin adolescents, 13 whom identify as Muslim. A thematic analysis was conducted. Findings indicated the benefits of collective memorialization and therapeutic groups, such as improved emotional expression, recognition of shared Grenfell-related experiences, strengthened social support networks and subjugated narratives, and reduced social isolation and stigma. The evaluation findings indicated that the group’s coproduction and collaboration between statutory services, potential/service users, and community organizations improved community engagement, access to mental health services, and service provision for children and young people from Moroccan and Muslim backgrounds. Note: Any views expressed in this service evaluation are of the authors and do not necessarily reflect the views of their employers.

Assessment of Maximum Possible Loss Caused by Fire in High-Rise Buildings Using the LOPA Method: A Case Study on Central Insurance Building of Iran

Background: Fire safety is one of the most important issues in high-rise buildings. The purpose of this study is to assess maximum possible loss in the fire in Central Insurance Building of Islamic Republic of Iran using the layer of protection analysis (LOPA) method.
 Method: In 2017, this analytical study was conducted on the 21-floor building of the Central Insurance in Iran. To identify the hazard sources and assess the maximum possible loss, the authors used the preliminary hazard list (PHL) and layer of protection analysis (LOPA) respectively. In addition, the analysis of the study data was performed based on the 10×10 risk assessment matrix.
 Results: The results of the PHL showed that 26 hazardous conditions and four major sources including structural engineering, fire alarm systems and fire extinguishers, design and maintenance of building safety, and behavioral habits were identified as main hazards of fire in the studied building. The application of the LOPA method showed that highest risk level was associated with the fire caused by the exhaust heat from the engine room (RL=48) and the emergency power generator diesel (RL=40), respectively.
 Conclusion: The findings of this study indicated that calculating the maximum possible loss in the fire of high-rise buildings can help to increase the safety factor. Moreover, the use of the two methods, PHL and LOPA, can be useful in these types of risk assessments.

Risk Assessment of Green Intelligent Building Based on Artificial Intelligence.

Green smart building is the development direction of future architecture. It is of great significance to carry out risk assessment. Fire risk is the key content of building risk, so this paper takes fire risk as the research object, with the help of artificial intelligence technology, to carry out the risk assessment research of green smart buildings. With the rapid development of the economy, urban fire risk factors are increasing, and the fire situation is becoming more and more serious. Building fire risk assessment is an important measure to effectively prevent and control urban building fires. This paper uses Internet of Things data to carry out fire risk assessment and realize Internet of Things data mining. Collect a large number of expert samples to build training samples, train the green intelligent building monomer fire risk assessment and prediction model based on deep neural network, constantly adjust the model parameters to optimize the model, and finally verify and modify the model.

Investigation of a novel insulation foam made from gypsum drywall waste

Foamed plastic rigid insulation panels are effective for reducing building heating and cooling loads, with consequent reductions in energy use and associated greenhouse gas (GHG) emissions. However, plastic foam manufacturing and in-service use result in significant GHG emissions. In addition, plastic foams are flammable, and have been implicated in recent building fires. This paper describes proprietary mixtures and methods for producing drywall waste foam (DWF) panels, a carbon-neutral, fire-protective insulation made from gypsum drywall waste and other construction and demolition (C&D) waste materials. Gypsum drywall waste is inherently fire-protective and has relatively low thermal conductivity, but is a low-value commodity with few current reuse and recycling applications. DWF panels address two pressing issues in the built environment: decarbonization of building materials, and diversion of problematic C&D waste from landfills. Investigation of DWF panel engineering properties, including density, hardness, friability, burn-through time, and thermal conductivity are reported, with results compared to analogous commercially-available materials. Potential applications and areas for future investigation are also discussed.

Numerical Simulation of Fire in Underground Commercial Street.

In this study, while aiming at the prevention of fire accidents in underground commercial streets, an underground commercial street is selected as a research object, and the building fire is numerically simulated using the PyroSim software. Fire simulation scenarios are divided according to different fire zones by analyzing the temperature, carbon monoxide (CO) concentration, and visibility in the smoke layer inside a building. The available safe evacuation time is calculated according to the critical fire hazard judgment conditions. We found that the time when the flue gas temperature and CO concentration reached the critical value in the fire site was longer than the time when the visibility reached the critical value reducing or even avoiding the spread of smoke from the fire area to the evacuation stairs can provide effective help for crowd evacuation. Finally, the safety of the building is evaluated, and fire prevention countermeasures are defined based on the actual situation and fire numerical simulation results to reduce fire incidence, casualties, and economic losses.

Analysis of Characteristics of Fire Incident on 24 July 2021 in Jilin Province, China

At 15:48 on 24 July 2021, a fire accident occurred in Changchun City, Jilin Province, China, resulting in 15 deaths and 25 injuries. After the accident happened, Jilin Province comprehensively organised an emergency rescue, saving more than 100 trapped people. Given the dangers posed by these events, it is recommended that we must strengthen our risk awareness. Combined with the general background and scene of the fire, in this study, we analysed the causes of the accident and described the on-site rescue actions. The direct cause of the accident was an arc fault, and the indirect cause was the dereliction of duty in the laying and installation of the circuit and the subsequent fire supervision. From our case analysis of electrical fires in public buildings, we found that electrical failure, human factors (illegal operation), ageing and short circuits of wires, poor contact of wires, and ignition of other combustibles by electrical appliances are the main factors causing electrical fire accidents in public buildings. To avoid serious fire accidents caused by arc faults, we proposed suggestions to reduce or prevent electric fire accidents caused by arc faults.

Numerical study on the smoke movement in office rooms with various exhaust vents settings

The ventilation system is essential to maintain a high level of the smoke layer to improve visibility during a building fire. The high level of the smoke layer allows the nearby exits can be easily located, and the fire sources can be identified during the building fire and rescue. Hence, the study of smoke movement in building fires with exhaust vent settings is essential to improve fire safety in the building. In this study, the smoke movement in real-scale offices is numerically investigated by utilising the Large Eddy Simulation (LES) computational model. Six scenarios with various exhaust vents settings are considered. The temperature distribution and the smoke layer height in the four office rooms and lobby area are analysed for all the cases. Results confirmed that the temperature distribution and the layer height have no significant difference by increasing exhaust vent size. However, the upper wall-mounted exhaust vents provide an effective smoke exhaust system, significantly increasing the smoke layer height in all office rooms.

Fire retardant performance, toxicity and combustion characteristics, and numerical evaluation of core materials for sandwich panels

According to fire accident statistics, fires in buildings are increasing. The flame-retardant performance of insulation materials is considered an important factor for preventing the spread of fire and ensuring evacuation. This study evaluated the flame-retardant performance and combustion characteristics of four types of organic thermal insulation used as core materials in sandwich panels. The flame-retardant performance evaluation based on total heat release and heat release rate revealed that phenolic foam (PF) satisfied the criteria for non-combustible grade insulation. An analysis of the hazardous gases released while combustion of the four insulation materials indicated that a significant amount of CO was released—an average of 19,000 ppm or higher—in the rigid urethan foam (PIR) and spray-type polyurethane foam (SPU). The fractional effective dose (FED) value was derived from the gas analysis results according to ISO 13344. PIR and SPU had an average FED value of 2.0 or higher and were identified as very dangerous in the case of fire accidents. Moreover, the evacuation time in the case of a fire in a warehouse-type building was comprehensively analyzed considering the material, size, and height for the four types of insulation. PIR was the most vulnerable to fire, and for PF, the danger limit was not reached until the end of the simulation.