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The complex responses of the building under fire condition lead to difficult realization of structural fire-resistance design. By identifying the weakness areas, the defined most adverse scenario of the structural fire-resistance design has practical significance. In this paper, the characteristics of fire load, steel at elevated temperature and failure modes of steel beam and column in fire test, were discussed to determine that the damage consequences of steel components under fire were equivalent to component fracture. Meanwhile, the calculation method of joint well-formedness after component failure was given to recognize the failure mode of steel frame structure under fire condition based on structural vulnerability theory (SVT). Then, the most adverse fire scenario of the steel frame structure fire-resistance design under the conditions of single component failure and component failure continuously were analysed. The calculation method of the most adverse fire scenario based on the structural SVT was proposed. According to the failure mode identified by the SVT, the most adverse fire scenario was that the component with the minimum damage pattern subjected to fire in the condition of a single component failure occurred. When the component failed continuously, the components induced the maximum damage pattern (the vulnerability index was the largest) were the key components and such components exposed to fire was the most adverse fire scenario. Finally, two calculation models-6-story 4-span planar steel frame and 3D CFS composite shear wall structures-were selected to verify the proposed calculation of the most adverse fire scenarios. It was concluded that the proposed calculation method could reduce the number of fire scenarios that need to be calculated for design and was suitable for application to performance-based fire resistance design.

The Modular Building System (MBS) is increasingly popular and promoted due to the inherent advantages over conventional construction. Fire performance of a building has become a crucial design consideration because of the recent detrimental fire accidents. However, for modular buildings, there has been less previous evidence of research on the fire performance. Investigations become necessary since double skin wall and floor modular panel systems are involved in MBS in contrast to conventional buildings. Therefore, this work investigates the fire performance of Light-gauge Steel Framed (LSF) modular wall panels with different configurations through numerical analyses. Heat transfer numerical models were developed and validated against the full-scale fire test results comparing the time–temperature response. The validated numerical models were subsequently extended to analyse the fire performance of conventional and modular LSF wall panels. This includes 16 modular wall configurations with single and double fire resistance plasterboard linings and three different insulations, namely rock wool, glass fibre and mineral wool. The structural fire resistance time was determined using the established Load Ratio (LR) vs critical Hot-Flange (HF) temperature correlation. The results demonstrated that there is no noticeable difference in the structural fire resistance time between the modular and the corresponding mapped conventional LSF wall configurations. However, modular wall panels experience enhanced insulation fire resistance up to 170% for single-lined plasterboards and up to 80% for double-lined plasterboard configurations. The analysis also yields that there is no significant influence of the choice of insulation material between rock-wool, glass-fibre and mineral-wool on structural fire resistance.

PurposeFire door should withstand a high temperature without deforming. In the current paper, the challenges of improving the behaviour of the conventional fire door were described using various internal stiffeners in pair swinging-type fire door.Design/methodology/approachThe temperature distribution on the outside door surface was measured with distributed eight thermocouples. Subsequently the internal side was cooled with pressurized water hose jet stream of 4 bar. The transient simulation for the thermal and structure analysis was conducted using finite element modelling (FEM) with ANSYS 19. The selected cross sections during numerical simulation were double S, double C and hat omega stiffeners applied to 2.2 m and 3 m door length.FindingsDuring the FEM analysis, the maximum deformations were 7.2028, 5.4299, 5.023 cm for double S, double C and hat omega stiffeners for 2.2 m door length and 6.57, 4.26, 2.1094 cm for double S, double C and hat omega stiffeners for 3 m door length. Finally, hat omega gives more than three times reduction in the deformation of door compared to double S stiffeners which provided a reference data to the manufacturers.Research limitations/implicationsThe research limitation included the limited number of fire door tests due to the high cost of single test, and the research implication was to achieve an optimal study in fire door design.Practical implicationsAchieving the optimum design for the internal door stiffeners where the hat omega stiffener gives minimum door deformation compared to the other stiffeners was considered the practical implication. The work included two experimental fire door tests according to the standard fire test (ANSI/UL 10C – Positive Pressure of Fire Tests of Door Assemblies) for a door of 2.2 m length with double S stiffeners and a door of 3 m length with hat omega stiffeners, which achieved minimum deformation.Originality/valueThe behavior and mechanical response of door leaf were improved through using internal hat omega stiffeners under fire testing. This study was achieved using FEM in ANSYS 19 for six cases of different lengths and stiffeners for fire doors. The simulation model showed a very close agreement with the experimental results with an error of 0.651% for double S and 1.888% for hat omega.

Purpose Fire safety of a building is becoming a prominent consideration due to the recent fire accidents and the consequences in terms of loss of life and property damage. ISO 834 standard fire test regulation and simulation cannot be applied to assess the fire performance of 3D printed concrete (3DPC) walls as the real fire time-temperature curves could be more severe, compared to standard fire curve, in terms of the maximum temperature and the time to reach that maximum temperature. Therefore, this paper aims to describe an investigation on the fire performance of 3DPC composite wall panels subjected to different fire scenarios. Design/methodology/approach The fire performance of 3DPC wall was traced through developing an appropriate heat transfer numerical model. The validity of the developed numerical model was confirmed by comparing the time-temperature profiles with available fire test results of 3DPC walls. A detailed parametric study of 140 numerical models were, subsequently, conducted covering different 3DPC wall configurations (i.e. solid, cavity and rockwool infilled cavity), five varying densities and consideration of four fire curves (i.e. standard, hydrocarbon fire, rapid and prolong). Findings 3DPC walls and Rockwool infilled cavity walls showed superior fire performance. Furthermore, the study indicates that the thermal responses of 3DPC walls exposed to rapid-fire is crucial compared to other fire scenarios. Research limitations/implications To investigate the thermal behaviour, ABAQUS allows performing uncoupled and coupled thermal analysis. Coupled analysis is typically used to investigate combined mechanical-thermal behaviour. Since, considered 3DPC wall configurations are non-load bearing, uncouple heat transfer analysis was performed. Time-temperature variations can be obtained to study the thermal response of 3DPC walls. Originality/value At present, there is limited study to analyse the behaviour of 3DPC composite wall panels in real fire scenarios. Hence, this paper presents an investigation on the fire performance of 3DPC composite wall panels subjected to different fire scenarios. This research is the first attempt to extensively study the fire performance of non-load bearing 3DPC walls.

Проаналізовано способи та досвід застосування різних методів щодо приведення межі вогнестійкості будівельних конструкцій у випадку відхилення температурного режиму вогневого випробування від стандартного температурного режиму пожежі. На основі проведених теоретичних та експериментальних досліджень виконано співставлення реальних та стандартних температурних впливів з використанням методу співставленні площ, що знаходяться під кривою пожежі та обмежених ординатою температури, при якій досягнуто один з критеріїв вогнестійкості та віссю абсцис. Перевірено за допомогою аналітичного розрахунку з використанням функції Гріна адекватність методу приведення межі вогнестійкості. Встановлено, що метод приведення реальної температури отриманої в результаті проведення вогневого випробування до стандартного температурного режиму пожежі, є адекватним і може застосовуватись при інженерних розрахунках який забезпечує точність в межах 10-15%.

The A60 class deck penetration piece is a fire-resistance apparatus installed on the deck compartment to protect lives and to prevent flame diffusion in the case of a fire accident in a ship or offshore plant. In this study, the sensitivity of the fire-resistance performance and approximation characteristics for the A60 class penetration piece was evaluated by conducting a transient heat-transfer analysis and fire test. The transient heat-transfer analysis was conducted to evaluate the fire-resistance design of the A60 class deck penetration piece, and the analysis results were verified via the fire test. The penetration-piece length, diameter, material type, and insulation density were used as the design factors (DFs), and the output responses were the weight, temperature, cost, and productivity. The quantitative effects of each DF on the output responses were evaluated using the design-of-experiments method. Additionally, an optimum design case was identified to minimize the weight of the A60 class deck penetration piece while satisfying the allowable limits of the output responses. According to the design-of-experiments results, various approximate models, e.g., a Kriging model, the response surface method, and a radial basis function-based neural network (RBFN), were generated. The design-of-experiments results were verified by the approximation results. It was concluded that among the approximate models, the RBFN was able to explore the design space of the A60 class deck penetration piece with the highest accuracy.

The present study provides an overview of the terminology and concepts of fire safety with particular emphasis on the workplace setting. Various issues, such as fire protection codes, standards, and regulations, fire safety fundamentals, features of building construction related to fire protection and employee response to emergencies have been examined. Keywords: the National Fire Protection Association (NFPA); OSHA regulations; fire dynamics; fire drills; design; fire scenarios; heat release rate (HRR); performance-based file safety design

Fire and elevated temperature are important considerations for design of concrete structures, for both normal and nuclear facilities. In India, the present design guidelines for concrete subjected to fire and elevated temperature are limited to prescriptive minimum dimension and minimum cover. The other approach suggested is fire test based, and being resource intensive, is considered only for special cases of design. The various provisions of Indian standards are discussed and compared to the international standards. Fire test data for concrete/reinforcement properties at elevated temperature for Indian materials are scarce, and hence, the calculation methods are difficult to apply for Indian concrete. Validation of such methods for India is required, which again can only happen after generation of adequate database. The article highlights the present research needs for fire design of Indian concrete, along with development of analysis methodologies/guidelines for fire design of concrete structures, assessment of fire-affected concrete structures, and combination of the fire/temperature load with other extreme loads such as impact, seismic load, or missile load using advanced approaches. This article could serve as reference for designers as well as the starting point for several research initiatives in India and thereby is expected to improve the state of the art of fire design of concrete structures in India in the long term.

The paper presents results of numerical simulation and fire tests of multi-layered structures carried out under real fire conditions. It has been shown that fire test carried out according to ISO 834 standard differs from fire test conducted under real fire conditions. A new fire test methodology has been proposed. It is suggested to use real fire temperatures during fire tests to avoid accidents and allow occupants to evacuate the building safely. The ISO fire test standard should be improved visibly. Structural solutions to reduce temperatures and temperature deformations of multi-layered structures during fire are also reviewed. It was established that the gypsum layer should be placed in the middle of multi-layered structure in order to cool the structure more efficiently during fire.

The key objective of the analysis is to investigate the impact of damage on fire resistance of reinforced concrete structures under normal fire conditions. For this study, a two-dimensional non-linear load deflection curve analysis for selected reinforced concrete beams is carried out in simply supported condition. From this curve, we found out the load required for damage of beams in terms of deflection. After the damaging effect, such beams are exposed to fire from three sides and the beam’s top surface has to be loaded at a fixed point before it fails. In one case of FET, three RC-beams are exposed to fire for an hour. In the second case a fire test, the impact of pre-damaged fire resistance was tested using reinforced concrete beams. The results of these analyses contrast with the results of other simpler analytical approaches, and some assumptions and suggestions for fire construction of concrete reinforced beams are put forward.

The research on the fire resistance design of cold-formed steel (CFS) load-bearing composite walls, as the main vertical load-bearing and space-dividing components of the CFS structure, has received widespread attention. The purpose of this article is to propose a formula for calculating the fire resistant temperature of CFS composite walls in order to simplify the design method. Three different configurations for composite wall lined with gypsum plasterboards which commonly used were chosen as research objects. According to the temperature-rise rule and heat transfer mechanism, the temperature-rise curves at hot flange of the studs were obtained. Then a heat transfer model was established with considering both the heat conduction and cavity radiation where obtained temperature load was applied at hot flange of the stud to calculate the temperature distribution of the wall cross-section. The improved heat transfer model not only considered the effect of cavity radiation, but also simulated the direct exposure of the stud to high temperature due to the falling-off or losing of insulation for sheathed board. Then the heat transfer calculation results were imported into a simplified mechanical model for thermal–mechanical coupling numerical simulation. Integrity, insulation, and the load bearing capacity of the stud cross section were taken as the comprehensive consideration criteria for composite wall failure. The temperature at hot flange of the stud was defined as fire resistant temperature when the composite wall damaged. Finally, load ratio and fire resistance temperature related calculation formulas were fitted from the results of transient thermal–mechanical coupling simulation with varying load ratios. The comparison of fire resistance temperature between fitting formula and fire test results verified the applicability of the proposed fire resistance temperature calculation formula. Compared with the fire resistance temperature calculation formulas in the existing literature, the calculation formula proposed in this paper was more accurate and reasonable.

В статье приведены основные статистические данные по судебно-экспертной, исследовательской, испытательной деятельности и состоянию кадров судебно-экспертных учреждений федеральной противопожарной службы «Испытательная пожарная лаборатория» за 2019 год. Проведено сравнение основных показателей деятельности за 2019 год с аналогичными показателями за 2018 год. There are presented basic statistics relating to judicial-expert, research and testing activities as well as mastering new types of equipment, the state of personnel in judicial-expert establishments of the Federal Fire Service Fire-Testing Laboratory for 2019. Comparison between the basic indices of laboratories activities for 2019 and similar indices for 2018 is carried out.

This paper presents a numerical method for damage evaluation of steel structures under fire conditions based on degraded material property values. As the measure of structural damage to fire, a damage index is proposed which indicates how much a structure loses its material strength when exposed to fire. The index is formulated with the ratio of a volume-weighted average of material strength at elevated temperatures to that of the strength at room temperature. To investigate the feasibility of proposed damage index, fire testing and the corresponding structural fire analysis of steel–concrete composite beams are performed using a design fire load. The fire is modeled using a standard fire curve proposed in American Society for Testing and Materials E119. A regular real-scale composite beam and the beam protected by a fire-resistant material layer, the latter of which is typical of structural members used in nuclear power plant buildings in Korea, are considered for the fire damage evaluation. The damage state of the composite beams is evaluated using the fire damage index at each time the fire progresses, and it is compared with the value of the post-fire damage index of the beams. By the use of the proposed damage index, the effect of fire-resistant materials on structural integrity is quantified, and it is investigated whether the damage state of each beam at the end of the fire load satisfies the design performance of composite beams used for nuclear power plant structures.

Continuous monitoring of carbon monoxide and other fire-related parameters by means of an atmospheric monitoring system (AMS) has been used by the mining industry for early fire detection in underground mines. The National Institute for Occupational Safety and Health (NIOSH) initiated a project to integrate real-time AMS sensor data with NIOSH’s mine fire simulation program, MFIRE 3.0, to simulate and predict the spread of smoke that would provide assistance to mine fire emergency response personnel. Determining the heat release rate of a fire using the monitored sensor data was a critical component of the successful completion of this project. NIOSH researchers developed a direct method to calculate the heat release rate when a fire is within close range of sensors. However, this method is only applicable to the case where a fire occurs in AMS-monitored airways. This paper presents an improved method for determining the fire heat release rate for complicated scenarios where a fire is distant from sensors and airflow splits and merges are present. The method was validated using a full-scale diesel fuel fire test conducted in the Safety Research Coal Mine at the Pittsburgh Mining Research Division and can help mine operators and safety personnel make informed decisions during a fire emergency.

Purpose This study aims to evaluate the feasibility of a hybrid fire testing by real-time subdivision of physical and numerical substructures (NSs) on simplified structures as a milestone in the development of the method. Design/methodology/approach An interface where the data was exchanged between a finite element software and a hydraulic jack regulator using text files has been developed and applied to perform two experimental campaigns of nine tests on simple steel frame structures with different thermal loading conditions. In the first experimental campaign, the physical substructure (PS) was assumedly protected by insulating material, while the NS was uniformly exposed to ISO 834 fire on all sides. The difference of the second experimental campaign from the first one was that the PS was heated on one side. Findings The experimental results showed how a gap between the determined equilibrium position and the “real” position caused by the time lag, as well as an overshoot phenomenon due to the non-synchronized action of both substructures, may occur. From the identification of the overshoot, two paths of development spring to mind to reduce the delay of the NS. Originality/value In the context that the number of proposal theoretical algorithms continues to increase with the absence of real experimental adjustments, such experimental results and the associated analysis constitute additional understandings to identify possible paths of improvements that might have been missed or could not be accessed through previous studies.

Purpose This paper aims to present a part of a coupled numerical model for prediction the fire resistance of elements in a horizontal furnace. Temperatures calculated inside the timber beam are compared to measured values from the fire test. Design/methodology/approach The paper presents a part of a coupled numerical model for prediction the fire resistance of elements in a horizontal furnace. The presented part lies in a virtual furnace which simulates temperature environment around tested elements in the furnace. Comparison of results show good agreement in the case when burning of timber is included in the numerical model. Findings The virtual furnace presented in this paper allows to calculate temperature environment around three timber beams. After validation of the fire dynamics simulator (FDS) model, the temperature conditions are passed to the FE model which solves heat transfer to the tested element. Temperatures inside the timber beam which are solved in software Atena Science are compared to measured temperatures from the fire test. The comparison of temperatures in three control points shows good accuracy of the calculation in the point closer to the heated edge. An inaccuracy is shown in points located deeper in the beam cross-section – below the char layer. Research limitations/implications In conclusion, the virtual furnace has a great potential for investigating the thermal behaviour of fire-resistance tests. A huge advantage inheres in the evaluation of the thermal effect throughout the volume of the furnace, which allows an accurate prediction of fire-resistance tests and evaluation of large number of technical alternatives and boundary conditions. However, passing the temperature field from the FDS model into FE model may decrease the level of accuracy. The solution lies in a coupled CFD-FE model. A weakly coupled model including fluid dynamics, heat transfer and mechanical behaviour is under development at Faculty of Civil Engineering, Czech Technical University in Prague. The fluid dynamics part which is presented in this paper is solved by FDS and the thermo-mechanical part is computed by object-oriented finite element model (OOFEM). The interconnection of both software is made owing to MuPIF python library. Practical implications The virtual furnace takes advantage of great possibilities of computational fluid dynamics code FDS. The model is based on an accurate representation of a real fire furnace of fire laboratory PAVUS a.s. located in the Czech Republic. It includes geometry of the real furnace, material properties of the furnace linings, burners, ventilation conditions and tested elements. Gas temperature calculated in the virtual furnace is validated to temperatures measured during a fire test. Social implications The virtual furnace has a great potential for investigating the thermal behaviour of fire-resistance tests. A huge advantage inheres in the evaluation of the thermal effect throughout the volume of the furnace, which allows an accurate prediction of fire-resistance tests and evaluation of large number of technical alternatives and boundary conditions. Originality/value The virtual furnace has a great potential for investigating the thermal behaviour of fire-resistance tests. A huge advantage inheres in the evaluation of the thermal effect throughout the volume of the furnace, which allows an accurate prediction of fire-resistance tests and evaluation of large number of technical alternatives and boundary conditions. However, passing the temperature field from the FDS model into FE model may decrease the level of accuracy. The solution lies in a coupled CFD-FE model. A weakly coupled model including fluid dynamics, heat transfer and mechanical behaviour is under development at Faculty of Civil Engineering, Czech Technical University in Prague. The fluid dynamics part which is presented in this paper is solved by FDS and the thermo-mechanical part is computed by OOFEM. The interconnection of both software is made thanks to MuPIF python library.

To investigate the shear capacity of indirectly loaded reinforced concrete beams under and after fire exposure, load tests were conducted on eight full-scale specimens exposed to fire testing in a furnace chamber, and the effects of additional transverse reinforcement in the junction region between the primary and secondary beams on the shear capacity, fire resistance, failure modes and deflection were analysed. The results indicate that the slopes of the diagonal cracks in post-fire tested reinforced concrete beams without additional transverse reinforcement were shallower than those of a similar reference beam not exposed to fire, and that the ultimate capacities of reinforced concrete beams with additional transverse reinforcement decreased obviously after fire exposure. However, beams with additional transverse reinforcement exhibited increased fire resistance times and reduced strains in their reinforcement, indicating the benefit of conservatively providing such reinforcement. The findings of this study are expected to provide a reference for the improved fire-resistant design of indirectly loaded beams.

This paper investigates the post-fire seismic performance of steel reinforced concrete (SRC) beam to SRC column frames. Five SRC column to SRC beam planar frame specimens were tested in a program including a loaded fire test and a following horizontal cyclic loading test. Test parameters included heating time and column load ratio. The temperature development, deformation, post-fire hysteretic and skeleton curves, stiffness, ductility and damping coefficient of SRC frames are recorded, calculated and analyzed. The measured post-fire hysteretic curves indicates that the SRC frames exhibit very good energy dissipation capacity after fire exposure. The horizontal load capacity and viscous damping coefficient of SRC frames increase with the increase of column load ratio. However, column load ratio has an adverse influence on ductility as anticipated at normal temperature. One SRC frame specimen failed during the cooling phase, which demonstrates the importance of considering the cooling phase during the fire safety design.

Purpose of research. The purpose of this work is to study the effectiveness of the use of electronic educational resources and their demand for students. The availability of digital technologies and readiness of students and lecturers to study in the electronic educational environment ensure the active development of this form of educational process organization. To assess the effectiveness and demand for electronic educational resources, data on the parameters of operation and user interaction with educational material are required.Materials and methods. To obtain data on the operating parameters and users’ work in the electronic educational environment, it is proposed to use a multi-level automated system for training, monitoring and analysis of theoretical knowledge – the Fire Test program, which is designed to organize and implement training in higher education programs of the specialty 20.05.01 – Fire Protection, 40.05.03 – Forensic Examination, the direction of training 20.03.01 – Technosphere Safety and the educational program of secondary vocational education 20.02.04 – Fire Protection. The Fire Test program is available on the Internet and allows you to conduct independent testing on specialties, disciplines, subjects of disciplines, as well as to carry out self-monitoring and knowledge control by lecturers online. As a tool for evaluating the effectiveness and relevance of the Fire Test program, it is proposed to use the web analytics service – Yandex.Metrica. To monitor the Fire Test program, we have selected key parameters that characterize the number of users and their activity in the electronic educational environment, which include demographic parameters, parameters of activity and loyalty of trainees, and technology parameters.Results. Based on the results of monitoring demographic parameters, which included the age of the audience during the study period of 1 month, the Fire Test program received an average of 27 visits from lecturers and 15 visits from trainees. Visitors from the number of students were 87%, from the number of Faculty Members – 13%. Monitoring user activity by time spent in the Fire Test program showed that students spent an average of 8 minutes 57 seconds on the site, and lecturers – 10 minutes 32 seconds. The largest number of visits of trainees was made during classes from 8-00 to 14-00 (55%), during the period outside of training sessions and self-training from 17-00 to 22-00 (23%), there was a uniform appeal of trainees to the Fire Test program. According to the monitoring of the loyalty parameter, during the study period, 12% of users accessed the site only 1 time, the largest number of users (48%) worked in the Fire Test program from 16 to 127 times, and more than 128 times 13% of users accessed the site. Monitoring of the technology parameter showed that smartphones are used as the main device for working in the Fire Test program, the share of which is 88.2%. The main operating systems used on smartphones are iOS (51%) and Google Android (37%), while the most popular browsers are Mobile Safari (44%).Conclusion. The results of the study allow us to conclude about the effectiveness and relevance of the electronic educational environment implemented by the Fire Test program among the trainees of Ivanovo Fire and Rescue Academy of the State Fire Service of the Ministry of Emergency Situations of Russia, as evidenced by their loyalty and activity in remote operation with the educational material.

Purpose During the building designing, it is very important to deal with the fire resistance of the structures. The designed materials for escape routes should be selected to ensure the usability of the structures until the time of escape. Planning affects the glass structures similarly, so these can also be partition walls and load bearing structures, although the latter is less applied on escape routes. The heat protection of the glasses can be improved with heat-protective foils, while fire protection is provided by gel intumescent material. Design/methodology/approach To research the topic of fire resistance, laboratory experiments were carried out on small-scaled glass elements with thermal protection foil at Budapest University of Technology and Economics at the Department of Construction Materials and Technologies. Findings Fire protection of small model specimens was tested with blowtorch fire and furnace heat load. During the experiments, six foils were tested. Single pane glass, double layered and triple glazed specimens were tested with blowtorch fire. Originality/value Fire protection of small model specimens was tested with blowtorch fire and furnace heat load. During the experiments, six foils were tested. Single pane glass, double layered and triple glazed specimens were tested with blowtorch fire. In case of heat-protected glazing, the foils on the “protected” side of the single pane glass do not have a fire protection effect based on blowtorch fire test. For double glassed specimens, the P35 foil has a perceptible effect, even for the requirements of the flame breakthrough (E, integrity), when the foil is placed on the inner side (position 3) of the second glass layer. The stratification of each triple glazed specimens was effective against blowtorch fire load (3 M, S4&P35), so (EI, integrity and isolation) it can meet the requirements of flame breakthrough and thermal insulation.

The aim of this paper is to present a fire test database on the collapse of a full-scale steel stiffened plate structure without passive fire protection under lateral patch loading. Steel plate pan...

The fire performance of reinforced reactive powder concrete (RPC) beams has raised much concern due to the sensitivity of these beams to high temperature and relatively lower fire resistance. To achieve the fire-resistance ratings as specified in building design codes, a fire insulation layer is often required. However, very limited research has been conducted on the effect of fire insulation on the fire resistance of reinforced RPC beams. Hence, using the commercial software ABAQUS, a three-dimensional sequentially coupled thermal-stress finite element (FE) model was developed to simulate the response of insulated reinforced RPC beams to fire. Comparisons between the FE predictions and the existing fire test results are presented to demonstrate the accuracy of the proposed FE model. In addition, the validated FE model was used to study the effect of fire insulation parameters, including the thermal properties, thickness, height, setting mode, and local fire insulation damage, on the fire response of reinforced RPC beams. The results showed that the failure of reinforced RPC beams with partial loss of fire insulation occurred at the area of missing fire protection. Additionally, the effect of the following important parameters on the fire resistance of insulated reinforced RPC beams was investigated: compressive strength of RPC, reinforcement ratio, load ratio, thickness of RPC cover, beam width, and span-depth ratio.

Purpose This paper aims to investigate the need for active boundary conditions during fire testing of structural elements, review existing studies on hybrid fire testing (HFT), a technique that would ensure updating of boundary conditions during a fire test, and propose a compensation scheme to mitigate instabilities in the hybrid testing procedure. Design/methodology/approach The paper focuses on structural steel columns and starts with a detailed literature review of steel column fire tests in the past few decades with varying axial and rotational end restraints. The review is followed with new results from comparative numerical analyses of structural steel columns with various end constraints. HFT is then discussed as a potential solution to be adapted for fire testing of structural elements. Challenges in contemporary HFT procedures are discussed, and application of stiffness updating approaches is demonstrated. Findings The reviewed studies indicate that axial and rotational restraints at the boundaries considerably influence the fire response of steel columns. Equivalent static spring technique for simulating effect of surrounding frame on an isolated column behavior does not depict accurate buckling and post-buckling response. Additionally, numerical models that simulate fire performance of a column situated in a full-frame do follow the trends observed in actual test results up until failure occurs, but these simulations do not necessarily capture post-failure performance accurately. HFT can be used to capture proper boundary conditions during testing of isolated elements, as well as correct failure modes. However, existing studies showed cases with instabilities during HFT. This paper demonstrates that a different stiffness updates calculated from the force-displacement response history of test specimen at elevated temperature can be used to resolve stability issues. Originality/value The paper has two contributions: it suggests that the provision of active boundary conditions is needed in structural fire testing, as equivalent static spring does not necessarily capture the effect of surrounding frame on an isolated element during a fire test, and it shows that force-displacement response history of test specimen during HFT can be used in the form of a stiffness update to ensure test stability.

Cold-formed steel (CFS) composite exterior walls are made of cold-formed, thin-walled steel lipped channel studs with board linings on both sides. There are limited data on the structural and thermal performance of CFS composite exterior walls under fire conditions, especially from simulation analysis, in contrast with the data available for interior walls. Therefore, a new simplified model was proposed in this paper to accurately simulate exterior walls exposed to fire on one side; in this model, spring elements were applied to provide out-of-plane constraints different from the constraints of the simplified model for interior walls previously proposed. A discussion of the numerical simulation results of studs with different parameters, including temperature-rise curves, vertical load ratios, screw spacings, steel grades and cross-sectional sizes, was conducted to determine the range of the spring stiffness. Finally, the developed model was validated using the fire test results of two CFS exterior walls, where one had an external panel made of oriented strand boards and the other had an external panel made of autoclaved lightweight concrete boards.

Tubed-reinforced-concrete (TRC) columns are gaining increasing popularity in engineering constructions, however, research on their fire performance is still limited and mainly focused on concentrically-loaded columns. In this study, extensive numerical analysis was carried out to investigate the performance of square and rectangular TRC columns under eccentric loading and exposed to ISO 834 standard fire. A sequentially-coupled thermo-mechanical finite element analysis (FEA) model was developed in ABAQUS and validated well against fire testing results. The high-temperature overall deformations, internal bending moments and cross-sectional load redistributions of square TRC columns with different load eccentricities were analysed. Parametric studies were conducted to investigate the influences of load eccentricity ratio, sectional aspect ratio, bending direction, fire protection thickness, sectional dimension, load ratio and slenderness ratio on the fire resistance of square and rectangular TRC columns. Load eccentricity was found to have a greater effect on the fire resistances of columns of lower slenderness than those of columns of higher slenderness. Rectangular TRC columns of sectional aspect ratios no larger than 2 could generally achieve identical buckling resistance as that of the equivalent square sections. The influences of sectional aspect ratio and bending direction on the column fire resistance were insignificant. A design method was then proposed for both the ambient-temperature and high-temperature designs of eccentrically-loaded square and rectangular TRC columns. The fire design method could cover both protected and unprotected TRC columns. The design method has been thoroughly validated against detailed FEA modelling and yields excellent agreements with the modelling results.

This paper presents the results of experimental research on the fire response of steel beams and their end-plate connections in column-tree moment-resisting frames (CMRFs). Using subframe a...

To advance understanding of the multihazard performance of midrise cold-formed steel (CFS) construction, a unique multidisciplinary experimental program was conducted on the Large High-Perf...

Complementing a companion paper that summarizes the building global response and physical damage of a midrise cold-formed steel (CFS) framed building during an earthquake and postearthquake...

The construction and building sector is responsible for a large share of energy and material used during the life cycle of a building. It is therefore crucial to apply a circular economy model within the process wherever possible to minimize the impact on the environment. In this paper, the possibility of producing thermal and acoustic boards from industrial nonwoven waste textile is studied and presented. The nonwoven polyester textile obtained directly from the production line in the form of strips and bales was first shredded into smaller fractions and then in the form of pile compressed with a hot press to form compact thermal insulation boards. The first set of specimens was prepared only from waste polyester nonwoven textile, whereas the second set was treated with sodium silicate in order to check the material’s reaction to fire performance. The experimental work was conducted to define the acoustic properties, reaction to fire behavior and thermal conductivity of the produced specimens. The obtained results show that the thermal conductivity coefficient of specimens without added water glass dissolution is near to the values of conventional materials used as thermal insulation in buildings. The reaction to fire testing proved that the addition of water glass actually propagates the progressive flame over the entire product. It can be concluded that the presented thermal insulation can be used as an adequate and sustainable solution for building construction purposes.

The results of experimental research on lateral-torsional buckling of steel plate girders with slender web subjected to fire conditions are presented in this paper. The scope of the research covers four girders, three of which have been tested under high temperature conditions. The fourth girder has been used to determine the critical load resulting in lateral-torsional buckling of the considered element at room temperature. All the considered elements had identical cross sections and lengths; however, they differed in external temperatures applied and magnitude of measured geometrical imperfections. It has to be highlighted, that the experiments have been conducted subject to the anisothermal conditions, taking into account the uneven distribution of temperature in the cross section. An approach of this type represents a more accurate modelling of the structural component behaviour, when subjected to fire, as compared to the experiments conducted under isothermal conditions. Complete information on the development of research stand, conduct and results of particular tests are presented in this paper. The temperature–time curves for girder components, results of imperfection measurements and mechanical properties of steel are presented. The obtained critical temperatures and graphs of girder top flange horizontal deflection versus temperature are also included. The computer models developed for analysed girders are described in the paper as well. The results obtained with these models have been compared with experimental results. The computational models validated in this way constitute a basis for further parametric studies of lateral-torsional buckling in the domain of steel plate girders with slender web when subjected to fire conditions.

Tubed-reinforced-concrete columns are gaining increasing usage in engineering practices, whereas research on their fire behaviour is still limited and mainly concentrated on unrestrained columns. Since end-restrained columns might behave differently in fire as compared to the unrestrained columns, the fire behaviour of square tubed-reinforced-concrete columns with end restraints was investigated via numerical modelling in this study. The axial and rotational restraints were modelled using linear springs and then validated against fire test results. The effects of end restraints on the failure mode, axial force and buckling length at failure and fire resistance, and on the evolution of deformations, internal force and bending moment during heating, of end-restrained columns were systematically analysed through parametric studies. The axially-restrained columns mostly undergo axial contraction only in fire; their typical failure mode is uncontrolled overall axial deformation, except for those columns of relatively high axial restraints. An increase in axial restraint leads to a nearly linear decrease of axial force at failure and a linear increase of fire resistance. For rotationally-restrained columns, the typical failure mode is also uncontrolled overall axial deformation. As the rotational restraint increases, the bucking length at failure decreases and the fire resistance increases, which is particularly significant when the rotational restraint is relatively low. A practical design method is proposed for the fire resistance design of square tubed-reinforced-concrete columns with either axial, or rotational, or combined axial and rotational restraints. Both constant and temperature-dependent end restraints have been adopted and the outcome is that they provide very similar results.

With the increasing use of stainless steel elements in construction, the need for comprehensive rules to enable their efficient structural design is clear. To date, the fire behaviour of stainless steel I-section beam–columns has been the subject of relatively little research. In particular, there is an absence of experimental data. To address this gap in knowledge, full-scale anisothermal fire tests on six grade 1.4301 austenitic stainless steel I-section beam–columns have been carried out; the test procedure and results are reported herein. The test specimens were subjected to eccentric axial compression with two eccentricity values so as to achieve different combinations of axial compression and uniform minor axis bending. Complementary initial local and global geometric imperfection measurements, room temperature tensile coupon tests and room temperature beam–column tests were also carried out. Based on the obtained experimental results, together with additional numerical results from a previous study, the existing design rules in the European structural steel fire design standard EN 1993-1-2 and the new design method of Kucukler et al. (2021) for stainless steel beam–columns in fire, which will be incorporated into the next version of EN 1993-1-2, are assessed.

Purpose Perforated composite beams are an increasingly popular choice in the construction of buildings because they can provide a structurally and materially efficient design solution while also facilitating the passage of services. The purpose of this paper is to examine the behaviour of restrained perforated beams, which act compositely with a profiled slab and are exposed to fire. The effect of surrounding structure on the composite perforated beam is incorporated in this study using a virtual hybrid simulation framework. The developed framework could also be used to analyse other structural components in fire. Design/methodology/approach A finite element model is developed using OpenSees and OpenFresco using a virtual hybrid simulation technique, and the accuracy of the model is validated using available fire test data. The validated model is used to investigate some of the most salient parameters such as the degree of axial and rotational restraint, arrangement of the openings and different types of fire on the overall fire behaviour of composite perforated beams. Findings It is shown that both axial and rotational restraint have a considerable effect on time-displacement behaviour and the fire performance of the composite perforated beam. It is observed that the rate of heating and the consequent development of elevated temperature in the section have a significant effect on the fire behaviour of composite perforated beams. Originality/value The paper will improve the knowledge of readers about modelling the whole system behaviour in structural fire engineering and the presented approach could also be used for analysing different types of structural components in fire conditions.

The aim of this study is to examine the behavior of protected and unprotected steel–concrete composite I-beams with large cell diameters (D0/H = 0.7) and closely spaced cell configurations under the ISO 834 fire curve. Previous studies on experimental full-scale fire performances of cellular beams have been somewhat limited under vertical service loads and different insulation properties. To address this limitation, a total of four composite beams, two unprotected (one beam with a solid web, and one cellular beam) and two protected cellular beams (60 min fire resistance with implementation of water and solvent-based intumescent coatings) were tested. As outputs of the tests, the failure modes observed, such as web buckling, the Vierendeel effect, the slab behavior, including the mechanism of concrete cracking, the overall displacement behavior (i.e., deflected shapes) up to collapse at very large deflections, and temperature changes in the steel elements are discussed. It was concluded that the quality of the intumescent coating applied is crucial in achieving the desired fire resistance. Experiments showed that unprotected trapezoid deck voids did not have a decisive influence on the behavior of the beams for up to 60 min of fire testing. At high temperatures, similar crack patterns occurred in the composite slabs of the protected and unprotected steel–concrete composite cellular beams. In the protected beams, the behavior of reactive coatings was significant and resulted in a non-uniform temperature distribution in these beams’ web and flanges.

Purpose The occurrence of multiple hazards in extreme conditions is not unknown nowadays, but the sustainability of the reinforced concrete structures under such scenarios form competitive challenges in civil engineering profession. Among all, fire following earthquake (FFE) is categorized under multiple extreme load scenarios which causes sequential damages to the structures. This paper aims to experiment a full-scale RC frame sub-assemblage for the FFE scenario and assess each stage of damage through the nondestructive testing method. Design/methodology/approach Two levels of simulated earthquake damages, i.e. immediate occupancy (IO) level and life safety (LS) level of structural performance were induced to the test frame and then, followed by a realistic compartment fire of 1 h duration. Also, the evaluation of damage to the RC frame after the fire subsequent to the earthquake was carried out by obtaining the ultimate capacity of the frame. Ultrasonic pulse velocity and rebound hammer test were conducted to assess the structural endurance of the damaged frame. Cracks were also marked during mechanical damages to the test frame to study the nature of its propagation. Findings Careful visual inspection during and after the fire test to the test frame were done. To differentiate between concrete chemically affected by the fire or physically damaged is an important issue. In situ inspection and laboratory tests of concrete components have been performed. Concrete from the test frame was localized with thermo-gravimetric analysis. The UPV results exhibited a sharp decrease in the strength of the concrete material which was also confirmed via the DTA, TGA and TG results. It is important to evaluate the residual capacity of the entire structure under the FFE scenario and propose rehabilitation/retrofit schemes for the building structure. Research limitations/implications The heterogeneity in the distribution of the damage has been identified due to variation of fire exposure. The study only highlights the capabilities of the methods for finding the residual capacity of the RC frame sub-assemblage after an occurrence of an FFE. Originality/value It is of find kind of research work on full-scale reinforced concrete building. In this, an attempt has been made for the evaluation of concrete structures affected by an FFE through nondestructive and destructive methods.

Purpose The Southern African Institute of Steel Construction has developed a novel cellular beam structure (CBS) for multi-storey buildings that is entirely devoid of concrete. Channel sections between the cellular beams support a complex sandwich flooring system, which contains a fire-resistant ceiling board, metal sheeting, an interior fibre-cement board and an access-flooring system. As for all structures, the CBS requires a fire rating. This paper aims to investigate the thermal behaviour of the CBS using numerical modelling and experimental fire testing, as it has a unique setup. Design/methodology/approach Experimental fire tests on the flooring system were conducted to validate finite element models, which were developed in ABAQUS. These models were then extended to include floor beams and the structural steelwork. Findings Good correlations were found between the experimental and numerical results, with temperature variations typically in the range of 0-5%, although with localised differences of up to 20%. This allowed larger finite element models, representing the sandwich floor system of the CBS, to be developed and analysed. A 1-hour rating can be obtained by the system in terms of insulation and integrity requirements. Practical implications The CBS allows for more economical steel structures, due to the rapid construction of its modular panels. A suitable fire resistance will ensure the safety of the occupants and prevent major structural damage. Steelwork and flooring temperatures are determined which has allowed for global structural analyses to be carried out. Originality/value The originality of this study lies in thermal analysis and testing of a new cellular beam flooring system, through determining behaviour in fire, along with beam temperatures.

In order to obtain the degree of damage in reinforced concrete (RC) beams exposed to fire, using the equivalent fire exposure time as the damage index, a new method of damage identification based on the support vector machine technology was proposed. Firstly, the feasibility analysis was conducted based on finite element models of simply supported beams. Thereafter, four RC simply supported beams were designed for fire test and vibration test, which were used to amend the finite element model and the SVM-based identification method. Fire tests were carried out on 4 beams for 60, 90, 120, and 150 min, respectively. During and after the fire tests, structural modal information were recorded. The first two order modal information, as SVM input paraments, was used to predict the equivalent fire exposure time based on SVM. The predicted results were very close to the actual fire exposure time. The residual bearing capacities of the beams after fire were calculated according to the predicted fire exposure time, which were close to experimental results. It indicated that the equivalent fire exposure time as the output parameter for damage identification was reliable. Finally, on the basis of damage identification method for simply supported beams, a new three-step positioning method was established for identifing the degree of damage in continuous beams. The method was applied to a thress-span continuous beam. The numercial situlation results revealed that the three-step positioning method was accurate.

This paper describes a full-scale natural fire test to investigate the collapse behaviour of a single storey cold-formed steel (CFS) building, designed to behave in a specified way in a severe fire, with roof venting and partial wall collapse. The test building had a span of 8 m, height-to-eaves of 2.15 m, and length of 10 m. The walls of the CFS building were constructed from cantilever ‘stud & track’ panels, with stud spacing of 0.6 m. The roof of the building comprised CFS trusses pinned to the wall connection plates at the top. In this fire test, walls on two adjacent sides were lined internally with fire resistant lining to achieve a structural fire resistance of 30 min (R30) and the calculated fire load was provided to generate a structural fire severity of 30 min, taking into account roof venting. Thus the two protected walls were expected to remain vertical throughout the fire; the roof was expected to collapse first, followed by pulling in of the unprotected walls. The CFS cantilever wall/roof truss system collapsed with an inwards asymmetrical collapse mechanism at a truss temperature of 622.5 °C, with collapse being due to member buckling of the non-fire rated wall rather than failure of the screws or joints. A non-linear finite-element (FE) model is then described. The collapse temperature predicted using the FE was 628.2 °C, with a deformed shape similar to that observed in the fire test. The FE model has matched the experimental behaviour, thus making this model useful in understanding and predicting the behaviour of CFS cantilever wall/truss system in severe fire conditions.

In the residential sector single stud LSF walls are commonly used as load bearing and non-load bearing walls. But in situations where higher acoustic insulation levels and load bearing capacities are required, double stud LSF walls are used. However, fire performance of double stud LSF walls has not been investigated adequately unlike in the case of single stud LSF walls. There is insufficient research data on the fire performance of double stud wall systems. Therefore, this research investigated the fire performance of double stud walls under standard fire conditions using full scale test panels (3 m × 3 m) made of 90 mm lipped channel studs. Three full-scale fire tests were conducted to investigate the fire performance of load bearing double stud LSF walls. The fire test results of double stud LSF walls were then compared with those of single stud LSF walls with varying stud depth. The results revealed the presence of a unique heat transfer mechanism, resulting in an enhanced fire performance for double stud walls. The discontinuous stud arrangement within the cavity of double stud LSF walls was identified as the main contributor for the delayed heat transfer mechanism. This paper presents the details of this research and its results. It has also shown that the Direct Strength Method (DSM) based fire design equations developed for single stud LSF walls can be used to predict the failure times of double stud LSF walls exposed to fire.

The performance of light timber frame wall and floor assemblies in fire depends on their composition. The assemblies' ability to form fire-separations between building compartments (separating function) can be assessed by full-scale fire testing or calculation methods. Calculations are the low cost and more flexible alternative. The component additive method is a commonly used calculation method for fire design of timber structures. The method considers the insulation ability of the material layers present in the assembly. The component additive method described in this article is developed to be flexible to implement different materials and products of different dimensions. However, the amount of different materials currently included in this method is rather limited and there is no generally accepted procedure to implement new materials. This paper presents a common agreement of the procedure to implement new materials which comprises of: (1) the design and execution of model-scale fire tests; (2) determination of the modified thermal properties needed for simulations; (3) thermal simulations of assemblies in fire conditions; (4) development of design equations and; (5) verification by one or more full-scale fire test(s). The abovementioned steps have been clearly presented in this paper and supported by examples.

This paper presents a generic algorithm designed to identify aerodynamic factors among the data specified in firing tables and projectile flight parameter data recorded during live fire tests. The algorithm and the concept of live fire testing shown here allow developing a mathematical model of projectile trajectory in the form of a modified motion model of a point mass. Potential applications of the model include fire control systems.

An emerging composite flame retardant has been prepared by sodium modification of natural mineral rectorite (REC), and waterborne intumescent fire retardant coating (IFR-Na-REC) containing sodium-modified rectorite (Na-REC) was successfully fabricated. The flame retardancy, morphology, structure, chemical composition and mechanical property of the intumescent coating were in detail investigated. The results showed that Na-REC could greatly promote the heat insulation effect of waterborne intumescent coatings. The temperature of the backside of steel plate for the IFR-Na-REC coating with 10% Na-REC was recorded to be 202 °C after 60 min of fire test, 24 °C lower than that of the control coating, and the flame retardant time reached up to 119 min. The enhanced fireproof performance could be attributed to the increased adhesion of the coating to the substrate and the formation of ceramic-like protective layer between rectorite and components in intumescent coating, which acted as a fire barrier to protect the internal matrix. Our work could offer a more benign approach to the general production of composite flame retardant coatings for fire protection.

A novel fire testing method, named the Heat-Transfer Rate Inducing System (H-TRIS), is presented and described in this paper. The method directly controls the thermal boundary conditions imposed on a test specimen by controlling a specified time-history of incident radiant heat flux at its exposed surface. Accounting for the absorptivity and thermal losses at the exposed surface of the test specimen, H-TRIS can be programmed to control the net heat flux at the exposed surface; thus controlling the in-depth time dependent temperature distributions within the test specimen. H-TRIS can be used for imposing a wide range of time-histories of incident radiant heat flux (e.g. constant, linear, stepped), or in-depth time dependent temperature distributions (i.e. specified thermal gradients). Notably, this enables simulation of thermal boundary conditions experienced by materials or structures exposed to any source of heat – during a conventional fire test (e.g. standard furnace test), a large-scale fire test, a real fire, or some other thermal boundary conditions calculated using a fire model (e.g. zone or computational fluid dynamics model). H-TRIS enables complementary experimental studies with excellent repeatability at comparatively low economic and temporal costs relative to traditional furnace test methods, thus permitting multiple repeat tests and statistical studies of response to heating. Application of H-TRIS within a research project studying heat-induced concrete spalling is briefly presented and discussed, to illustrate the significance and novelty of the new fire testing method.