Structural Fire Research Articles

Forest Fire Risk Zone Mapping in Mizoram Using RS and GIS

In recent years, India’s Northeastern territory has been plagued by wildfires. Mizoram, as per FSI, has been among the most affected regions, with approximately 20,744-recorded wildfires. Forest fire directly or indirectly affects human health, climate change, and the environment. The forest fire risk zonation is generated utilizing remote sensing data, and Geographic Information System based on specified physical and socioeconomic factors. As part of the current study, a Geographical Information System is employed to determine forest fire risk based on predetermined physical and socioeconomic parameters. This study used three distinct models of fire risk zonation index namely FRI (Fire Risk Index), HFI (Hybrid Fire Index), and SFI (Structural Fire Index) to identify the zones in the study area under the risk of forest fires. The Indian state of Mizoram is categorized into five distinct hazard zones based on the probability of wildfire incidents. Fire alerts generated using risk models, and real-time hotspot datasets (forest fire spots) received from MODIS and USGS have been validated. According to the study’s findings, 18.84 km2 of the study area is at low risk of forest fire, 11.072 km2 is at moderate risk, and 5.38 km2 is at high risk. The probability from each metric varies since the input and weightage of the different parameters vary from one another. SFI, therefore, therefore predicts a lower frequency of high-risk wildfire-prone zones than HFI and FRI. In this research, the coefficient of discrimination (R2) is employed to assess the reliability of the projected fire indices being compared with real-time hot spots. Here, FRI possesses the highest accuracy (R2=0.892), HFI has moderate accuracy (R2=0.676), and FRI has the lowest accuracy (R2=0.629).

Review of Structural Fire Hazards, Challenges, and Prevention Strategies

Reducing the occurrence of structural fires is the common goal of all countries. However, the development level of different countries determines the degree of perfection of local fire management regulations. Developed countries have a more rational urban layout, sufficient firefighting resources, and the ability to guarantee fire safety. In contrast, haphazardly built residential areas in developing and underdeveloped countries have more safety hazards, which increases the challenges of local fire management. This study provides an overview of the causes and impacts of fires in different countries and identifies gaps in fire safety between developed and developing countries, as well as corresponding strategies to deal with fires. It is worth mentioning that the development and evolution of artificial intelligence (AI) has made it possible to predict fires, thereby greatly reducing damage and losses caused by fires. In addition, the development of new fire-resistant building materials, etc., provides more means to reduce the possibility of fire.

Effect of thermal expansion on three-dimensional reinforced concrete frames under high temperature

When exposed to high temperatures, reinforced concrete members undergo major changes in their properties which in turn affects their structural performance. Fire accidents in frame structures at local or global level may lead to collapse of structures. Structural fire has dire consequences like collapse of structures, colour changes, spalling of concrete and failure of essential elements. It is essential to study the conduct of reinforced concrete frame under thermal expansion in order to understand fire-induced collapse of concrete structures. This study observes how a three dimensional single-bay single-storey reinforced concrete frame is performed under thermo-mechanical analysis in ABAQUS (FEA). The paper aims to note the effect of slab and infill wall with respect to thermal expansion. The paper also discusses the main findings regarding the structural performance, structural leading conditions and structural stiffness of the reinforced concrete frame with slab and infill wall under thermal expansion. The results found that the infill frame has better stiffness and performs well under fire conditions.

Association of Structural Fires in New York City With Inequities in Safe Heating for Immigrant Communities

This cross-sectional study assesses the association of heating complaints with structural fires in New York, New York.

Excretion of polybrominated diphenyl ethers and AhR activation in breastmilk among firefighters.

Excretion of toxicants accumulated from firefighter exposures through breastmilk represents a potential hazard. We investigated if firefighting exposures could increase the concentration of polybrominated diphenyl ethers (PBDEs) and aryl hydrocarbon receptor (AhR) activation in excreted breastmilk. Firefighters and non-firefighters collected breastmilk samples prior to any firefighting responses (baseline) and at 2, 8, 24, 48, and 72 hours after a structural fire (firefighters only). Five PBDE analytes (BDEs 15, 28, 47, 99, and 153) detected in at least 90% of samples were summed for analyses. The AhR in vitro DR CALUX® bioassay assessed the mixture of dioxin-like compounds and toxicity from breastmilk extracts. Baseline PBDEs and AhR response were compared between firefighters and non-firefighters. Separate linear mixed models assessed changes in sum of PBDEs and AhR response among firefighters over time and effect modification by interior or exterior response was assessed. Baseline PBDE concentrations and AhR responses did not differ between the 21 firefighters and 10 non-firefighters. There were no significant changes in sum of PBDEs or AhR response among firefighters over time post-fire, and no variation by interior or exterior response. Plots of sum of PBDEs and AhR response over time demonstrated individual variation but no consistent pattern. Currently, our novel study results do not support forgoing breastfeeding after a fire exposure. However, given study limitations and the potential hazard of accumulated toxicants from firefighter exposures excreted via breastfeeding, future studies should consider additional contaminants and measures of toxicity by which firefighting may impact maternal and child health.

Atypical Case of Fractal Wood Burning: Two Burned Bodies.

Fractal wood burning is a form of pyrography that uses high-voltage electricity to burn branching, Lichtenberg-type patterns into a wooden canvas. This process often uses electrical transformers salvaged from household appliances, such as microwave ovens, to amplify available voltage to potentially lethal levels. In this case, 2 individuals were found dead inside their burned residential garage. Initially, law enforcement was suspicious of a double homicide with subsequent arson. However, postmortem examination showed the decedents had neither fatal antemortem trauma nor significant natural disease. Findings consistent with smoke inhalation were absent, suggesting that the victims were deceased before the fire. Interestingly, one decedent had jumper cables in their hand, and their recent computer activity included fractal wood burning-related content. Upon further scene investigation, 2 microwave ovens were identified in the garage, one of which had been disassembled with its transformer found adjacent to the bodies. The decedents likely died from high-voltage electrocution with ignition of the wooden canvas starting the structural fire. Since the first reported case in 2016, there have been 33 reported deaths attributed to fractal wood burning. The current study would be the first to report multiple fatalities due to a single fractal wood burning event.

The effect of thermal creep on the fire resistance of steel columns

An appropriate assessment of the structural fire resistance of steel columns necessitates an accurate mechanical material modeling considering thermal creep in the stress-strain response of steel at elevated temperatures. This paper presents a novel thermal creep model achieved from available experimental results in the literature and its application to structural members in fire within a numerical study on the proposed creep model. Based on this model, a comparative set of numerical studies is performed for a specific benchmark structure in fire conditions, considering protected and unprotected structural steel columns, different stress ratios, different severity of fire exposure and the role of creep buckling. The effect of thickness of the protection material and associated heating rate of the structure on the fire resistance with regard to creep buckling is also investigated. In addition, the structural buckling behavior in fire conditions with explicit consideration of thermal creep in the aforementioned model is studied in comparison to the existent simplified constitutive material model with implicit creep consideration in EN 1993-1-2 [1] for the benchmark structure. The results of this paper highlight the necessity of including thermal creep in the state-of-the-art advanced structural fire design in engineering practice.

Fire risk assessment of bridges: from state of the art to structural vulnerability mitigation

In recent years, due to the rapid urbanization, the fire risk in transport infrastructures is becoming more critical. These fires, typically caused by highly flammable materials, can significantly compromise the stability of the structure, as well as cause significant economic and social losses. However, in current regulations, no fire design or verification criteria are provided for bridges and the buildings prescriptions are not directly applicable due to the significant differences among the fire conditions. Therefore, starting from a deep literature review, different performance levels for bridges’ structural fire resistance were proposed. These levels were linked to the fire risk classification suggested by Kodur et al., for identifying the most vulnerable bridges to fire. This methodology was applied both to the prescriptive and performance-based approaches, using nominal and natural fire curves derived by advanced zone models of several bridge fire scenarios. To better investigate the structural fire performance of bridges, parametric analyses of a typological bridge were conducted for identifying the most critical structural systems and fire scenarios. One of the most relevant finding is that the use of performance-based approach allows to consider more realistic fire conditions, to satisfy higher performance levels with an optimization of the fire protection design. Therefore, the proposed approach can be useful both for designers and industrial category to assess the bridge performances in fire, not only according to prescriptive approach but also considering the performance-based one.

The Ignition Frequency of Structural Fires in Australia from 2012 to 2019

Appropriate estimates of ignition frequency derived from fire statistics are crucial for quantifying fire risks, given that ignition frequency underpins all probabilistic fire risk assessments for buildings. Rahikainen et al. (Fire Technol 2004; 40:335–53) utilized the generalized Barrois model to evaluate ignition frequencies for different buildings in Finland. The Barrois model provides a good prediction of the trend of the ignition frequency; however, it can underestimate the ignition frequency depending on the building type. In this study, an analysis of the Australian fire statistical data from 2012 to 2019 was performed and compared with studies from Finland. A new coefficient is proposed to improve the Barrois model for a better fit for buildings in Australia. Several categories, such as hotels and hospitals, which were absent in previous studies, have been included as separate categories in this study. Office and retail spaces in Finland have an ignition frequency one order of magnitude lower than in Australia. On the other hand, other buildings (retail and apartments in particular) are much more prone to fire ignition in Australia than in Finland. The improved generalized Barrois model based on the Australian fire statistical data will be useful for determining ignition frequency for risk quantification in the Australian context.

Development of a job-exposure matrix (JEM) for exposure to smoke particle mass among firefighters of the Fire Department of the City of New York (FDNY)

ObjectivesA refined job exposure matrix (JEM) based on incident types and severities and response characteristics was developed for firefighters to estimate quantities of smoke particles emitted during structural and non-structural...

Graduate program reform in one department of physics and astronomy: From tragedy to more progressive policies and an evolving culture

In 2017 the University of Utah experienced a tragedy which catalyzed already active changes in the department. In the aftermath, admissions to the graduate program was paused while new policies were developed and implemented. This article outlines this change process through the perspectives and accounts of those involved. Through in-depth interviews with students, staff, faculty, and administrators the process of change was found to be a complex path that involved robust practices of gathering input. This input was considered by a centralized group (the executive committee) advising the department chair and administrators. Findings indicated that the collective desire to reopen the program inspired most faculty to work together to find solutions, while some stakeholders did not fully buy in to large-scale programmatic changes. Further, interviews revealed the persistence of deep cultural challenges after the development and implementation of new policies. A new metaphor for this change is suggested to be a bonfire, as a tragedy sparked the fire of change structures which had already been built, and continual fuel is needed to sustain these changes. Moving forward the department is extending their graduate reform into undergraduate initiatives and normalizing evidence-based teaching practices. Content warning: This paper discusses the death by suicide of a graduate student.Received 17 June 2021Revised 19 May 2022Accepted 19 September 2022DOI:https://doi.org/10.1103/PhysRevPhysEducRes.19.010102Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.Published by the American Physical SocietyPhysics Subject Headings (PhySH)Research AreasEducational policyProfessional TopicsGraduate studentsPhysics Education Research

Addition of Phosphogypsum to Fire-Resistant Plaster Panels: A Physic–Mechanical Investigation

Gypsum (GPS) has great potential for structural fire protection and is increasingly used in construction due to its high-water retention and purity. However, many researchers aim to improve its physical and mechanical properties by adding other organic or inorganic materials such as fibers, recycled GPS, and waste residues. This study used a novel method to add non-natural GPS from factory waste (phosphogypsum (PG)) as a secondary material for GPS. This paper proposes to mix these two materials to properly study the effect of PG on the physico-mechanical properties and fire performance of two Tunisian GPSs (GPS1 and GPS2). PG initially replaced GPS at 10, 20, 30, 40, and 50% weight percentage (mixing plan A). The PGs were then washed with distilled water several times. Two more mixing plans were run when the pH of the PG was equal to 2.4 (mixing plan B), and the pH was equal to 5 (mixing plan C). Finally, a comparative study was conducted on the compressive strength, flexural strength, density, water retention, and mass loss levels after 90 days of drying, before/after incineration of samples at 15, 30, 45, and 60 min. The results show that the mixture of GPS1 and 30% PG (mixing plan B) obtained the highest compressive strength (41.31%) and flexural strength (35.03%) compared to the reference sample. The addition of 10% PG to GPS1 (mixing plan A) improved fire resistance (33.33%) and the mass loss (17.10%) of the samples exposed to flame for 60 min compared to GPS2. Therefore, PG can be considered an excellent insulating material, which can increase physico-mechanical properties and fire resistance time of plaster under certain conditions.

Fire design of steel columns through second-order inelastic analysis with strain limits

A structural steel fire design approach through second-order inelastic analysis with strain limits is proposed and applied to the fire design of steel columns as a first step in the establishment of a novel fire design framework for steel structures in this paper. The proposed method is carried out using beam finite elements, utilising their computational efficiency. In the proposed design approach, the strength and stiffness deterioration of steel in fire, the spread of plasticity, global instability effects, indirect fire actions and thermal expansion are fully taken into account through second-order inelastic analysis, while strain limits are employed to consider the deleterious influence of local buckling on the ultimate resistance. Ultimate capacity of a steel member or system is determined by (i) the load or temperature level at which the predefined strain limit is attained or (ii) the peak load or critical temperature observed during the analysis, whichever occurs first. A systematic numerical parametric study is carried out through nonlinear shell finite element modelling, taking into account a high number of I-section and hollow section steel columns whose response is considered (i) using isothermal and anisothermal analysis techniques and (ii) with and without axial and rotational end-restraints. It is demonstrated that the proposed fire design approach consistently furnishes significantly more accurate capacity and limit temperature predictions for steel columns in fire relative to EN 1993-1-2 [1] design provisions.

Fire risks in electrical installations: the review

In India, fire poses a significant risk to a variety of industries. Media outlets across the nation report on fires virtually every day. Not only these fires result in the loss of numerous lives and injury to a large number of people, but they also caused extensive property damage. During the past two decades, India's construction industry has flourished, notably for highrise structures. As a result of their special character, fires in residential structures, particularly high-rise buildings, become more complicated and salvaging activities more difficult, sometimes resulting in a large number of fatalities and substantial property losses. The scenario has become more complex due to the fast modernization of Indian industry. A fire is a mishap may at times result in loss of life and property. We have strong regulatory measures, standards, good material specifications and national building construction codes. However, we are facing fire accidents on regular basis. After the investigation fire authorities are concluded that 80% of fire accidents happened due to electric short-circuits. Fire safety norms mandated by National Building code (Ref Indian National Building code 2016 part 4) is not given any significance of fire loads related to electrical installation and its components. More over National building code given lesser importance to the quality aspects of materials and components which can play a significance role of origination of fire accidents. The National building code considering only fire load related to cable and insulation failures. During my recent survey and analysis of few fire accidents pointing out that the failure in the electrical components and equipment’s are related to the appliances are the major cause of fire. This review intends to understand the gap in the existing system and extend to further studies to find out a proper solution.

Numerical analysis of a steel frame in a fire situation

In the paper, the stages of modelling of a steel frame under fire conditions were discussed. Numerical computations were performed using SIMULIA Abaqus software. The way of defining and developing the computational model was described. In the numerical procedure adopted in the paper, much attention was paid to formulas related to various types of the model parameters that depend on the fire temperature. The results were shown in a graphic form. They were compared with the results obtained from the analysis, in which the impact of elevated temperatures was disregarded. Based on numerical simulation results, an attempt was made to assess the effect of fire on the steel frame components. The paper is exploratory in character and provides an introduction to the issues related to the modelling of steel structure fires. The numerical modelling of the structure fire described in the paper can have practical potential for structural engineers.

Application of neural networks for light gauge steel fire walls

This research study evaluates the applicability of neural networks to determine the fire-resistance rating of Light gauge Steel Frame walls, made of cold-formed steel studs and lined with gypsum plasterboard.Many full-scale tests and numerical studies were conducted to determine the fire-performance of LSF walls, but these studies were expensive and time consuming. Therefore, an alternative option of using machine learning to predict the fire performance was proposed. The actual fire performance data from FEA and full-scale tests of previous research studies were used as inputs in the machine learning. Separate sets of training and test data were used; thus, test data is not used to calibrate the machine learning-based analysis. Here LSF walls made of different wall configurations and different steel profiles were considered. Training and testing of the artificial neural network are performed by combining different parameters such as loss function, keep probability factor, learning rate, the number of layers, and neurons to determine the optimal and accurate solution. The structural fire capacity of LSF walls obtained from machine learning was compared against the test data to evaluate its accuracy. Based on the findings, suitable neural network models with two hidden layers and suitable loss functions were recommended.

Structural Fire Analysis of Beams and Slabs Using ANSYS and FEAST Software Program

In recent years, building fire has become more frequent event and fire accidents have increased all over the world. Major problem with fire is it provides very less time to handle the situation and due to elevated temperature, reduction in strength of structural member with increase in fire exposure time has been observed. To evaluate this reduced strength of structural members and design for fire load, it is necessary to have the parameters such as fire load, fire exposure time and temperature variation across the structural members. In this paper, evaluation of fire load, equivalent time of exposure and temperature distribution of beams and slabs using finite element analysis software FEAST and ANSYS has been done. For temperature variation, transient heat thermal analysis, in which temperature is increasing continuously over the time, is used. For this analysis, beams and slabs are exposed to surface fire on different surfaces and the temperature distribution of cross section has been evaluated. The results are compared and found to be matching with the European Standard procedure.

CONCRETE'S RESISTANCE TO FIRE

The world's most popular building material is concrete. A civil engineer can accomplish heights they never thought possible.when this concrete is made into reinforced cement concrete by adding steel bars. However, reinforced concrete is vulnerable to the good powers of nature, specifically "FIRE," just like every other material on Mother Earth.This essay discusses how fire and reinforced concrete interact.What does "Fire Rating" signify in terms of the procedure is explained. How exactly are Fire Ratings obtained? R.C.C. members have a natural fire resistance. the physical and chemical processes a R.C.C. member experiences as a result of being around fires and their high temperatures. This paper finishes with recommendations for improving structural concrete's fire resistance as well as information on the rules set forth by IS 456:2000 for ensuring a specific level of fire resistance in concrete

Study on Residual Life of Concrete Structural Beams and Plate after Fire

Fire has great influence on the durability of buildings, so it is necessary to predict the remaining life of structures after fire. Taking the concrete structure fire of a large shopping mall in a city as an example, the prediction model of the residual life of the concrete structural members was established based on the concrete carbonization mechanism, and the residual life of the beam and plate members was predicted, which could provide a basis for the later reinforcement design or evaluation.

Shear resistance and design of stainless steel plate girders in fire

In this paper, the shear resistance and design of stainless steel plate girders at elevated temperatures are investigated. A broad range of parameters influencing the structural response of stainless steel plate girders in fire are taken into account, considering (i) austenitic and duplex stainless steel grades, (ii) rigid and non-rigid end posts, (iii) different aspect ratios for the unstiffened portions of the plate girders, (iv) various web slendernesses and (v) different elevated temperature levels. The influence of these parameters on the behaviour of stainless steel plate girders at elevated temperatures is considered. Currently, there is an absence of specific design rules on the fire design of stainless steel plate girders in the European structural steel fire design standard EN 1993-1-2. Considering this, an accuracy assessment of the room temperature stainless steel plate girder design recommendations of the European structural stainless steel design standard EN 1993-1-4 applied with the elevated temperature material properties of stainless steel is performed. The results indicate that this approach leads to unsafe and scattered ultimate strength estimations for stainless steel plate girders in fire. New fire design recommendations for stainless steel plate girders that are in accordance with the existing design provisions of EN 1993-1-2 and EN 1993-1-4 are proposed. The accuracy and safety of the proposed new design recommendations are comprehensively verified against the results from nonlinear finite element modelling.