Pub Date : 2025-09-06DOI: 10.1016/j.firesaf.2025.104532
Farnaz Beygi Khosroshahi, Fernando Raffan-Montoya, Stanislav I. Stoliarov
A new method for the measurement of the heat release rate and products of combustion at constant global equivalence ratios (GERs) was developed. This method was based on a modified Fire Propagation Apparatus (FPA) equipped with O2, CO2, CO, total hydrocarbons (THC), particulate matter (PM), NO, and HCN sensors. The control of GER was achieved by administering precisely calibrated, time-varying air flow to the combustion zone. To demonstrate this method's capabilities, the combustion of poly(methyl methacrylate) (PMMA) was investigated at GER ranging from 0.63 to 1.96. The CO2 yield, expressed as mass of species per mass of pyrolyzate, and heat of combustion were found to monotonically decrease from 2.04 to 1.05 and from 23.6 kJ g−1 to 15.1 kJ g−1, respectively, with increasing GER. Conversely, CO, PM, and THC yields increased from 0.019 to 0.263, from 0.015 to 0.051, and from 0.006 to 0.301, respectively, with increasing GER. Good carbon balance, within ±5 %, was achieved across the entire GER range. The characteristic time the combusting mixture spends in the FPA's test section was identified as another key parameter, alongside GER, that affected both species production and heat release. An empirical model was developed and validated to fully capture these dependencies.
{"title":"Characterization of flammability and species yields for PMMA burning at constant equivalence ratios in a fire propagation apparatus","authors":"Farnaz Beygi Khosroshahi, Fernando Raffan-Montoya, Stanislav I. Stoliarov","doi":"10.1016/j.firesaf.2025.104532","DOIUrl":"10.1016/j.firesaf.2025.104532","url":null,"abstract":"<div><div>A new method for the measurement of the heat release rate and products of combustion at constant global equivalence ratios (<em>GER</em>s) was developed. This method was based on a modified Fire Propagation Apparatus (FPA) equipped with O<sub>2</sub>, CO<sub>2</sub>, CO, total hydrocarbons (THC), particulate matter (PM), NO, and HCN sensors. The control of <em>GER</em> was achieved by administering precisely calibrated, time-varying air flow to the combustion zone. To demonstrate this method's capabilities, the combustion of poly(methyl methacrylate) (PMMA) was investigated at <em>GER</em> ranging from 0.63 to 1.96. The CO<sub>2</sub> yield, expressed as mass of species per mass of pyrolyzate, and heat of combustion were found to monotonically decrease from 2.04 to 1.05 and from 23.6 kJ g<sup>−1</sup> to 15.1 kJ g<sup>−1</sup>, respectively, with increasing <em>GER</em>. Conversely, CO, PM, and THC yields increased from 0.019 to 0.263, from 0.015 to 0.051, and from 0.006 to 0.301, respectively, with increasing <em>GER</em>. Good carbon balance, within ±5 %, was achieved across the entire <em>GER</em> range. The characteristic time the combusting mixture spends in the FPA's test section was identified as another key parameter, alongside <em>GER</em>, that affected both species production and heat release. An empirical model was developed and validated to fully capture these dependencies.</div></div>","PeriodicalId":50445,"journal":{"name":"Fire Safety Journal","volume":"158 ","pages":"Article 104532"},"PeriodicalIF":3.3,"publicationDate":"2025-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145050687","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-01DOI: 10.1016/j.firesaf.2025.104522
Konstantinos Chotzoglou , Talal Fateh
In the aftermath of the Grenfell Tower tragedy, the fire performance of external wall systems (EWS) and the timber crib fire source specified in BS 8414 have come under increasing scrutiny. This study presents a comprehensive experimental investigation into the burning characteristics and heat exposure effects of the BS 8414 timber crib. A two-scale approach was employed, combining bench-scale calorimetry (ISO 1716) and large-scale testing in both free-burn and chamber configurations, to evaluate the consistency, intensity, and thermal output of the fire source. Key parameters such as heat release rate (HRR), mass loss rate (MLR), temperature evolution, and incident heat flux on an inert façade were measured. The results demonstrate good repeatability and reveal that the actual heat output often exceeds the standard's prescribed values, exposing the façade to high-intensity thermal loads sufficient to ignite many cladding materials. The findings also indicate that the BS 8414 setup more closely resembles an external fire scenario rather than a post-flashover room fire, due to the chamber's geometry and fuel placement. This research provides valuable benchmark data that may inform regulatory bodies, standardization committees, and engineers, contributing to improved testing methodologies and the development of safer façade fire standards for high-rise buildings.
{"title":"Revisiting the BS 8414 timber crib: An experimental investigation for enhancing facade fire safety","authors":"Konstantinos Chotzoglou , Talal Fateh","doi":"10.1016/j.firesaf.2025.104522","DOIUrl":"10.1016/j.firesaf.2025.104522","url":null,"abstract":"<div><div>In the aftermath of the Grenfell Tower tragedy, the fire performance of external wall systems (EWS) and the timber crib fire source specified in BS 8414 have come under increasing scrutiny. This study presents a comprehensive experimental investigation into the burning characteristics and heat exposure effects of the BS 8414 timber crib. A two-scale approach was employed, combining bench-scale calorimetry (ISO 1716) and large-scale testing in both free-burn and chamber configurations, to evaluate the consistency, intensity, and thermal output of the fire source. Key parameters such as heat release rate (HRR), mass loss rate (MLR), temperature evolution, and incident heat flux on an inert façade were measured. The results demonstrate good repeatability and reveal that the actual heat output often exceeds the standard's prescribed values, exposing the façade to high-intensity thermal loads sufficient to ignite many cladding materials. The findings also indicate that the BS 8414 setup more closely resembles an external fire scenario rather than a post-flashover room fire, due to the chamber's geometry and fuel placement. This research provides valuable benchmark data that may inform regulatory bodies, standardization committees, and engineers, contributing to improved testing methodologies and the development of safer façade fire standards for high-rise buildings.</div></div>","PeriodicalId":50445,"journal":{"name":"Fire Safety Journal","volume":"157 ","pages":"Article 104522"},"PeriodicalIF":3.3,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144996692","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-01DOI: 10.1016/j.firesaf.2025.104520
Hyewon Kim , Jun-ichi Yamaguchi , Hyun-woo Park , Yoshifumi Ohmiya
Currently, in two-zone models, smoke flow is calculated based on the assumption that the fire plume, which develops directly above the fire source, depends solely on the amount of entrained surrounding air. However, in large flat spaces, which have been growing larger in recent years, the horizontal travel distance of ceiling jet flow is long, and it is possible that the amount of smoke due to entrainment of air during the horizontal spread process is underestimated. In this study, we performed experiments that reproduced an unconfined ceiling without a vertical wall soffit and determined the amount of entrainment in the ceiling jet flow by analyzing the gas concentration of ceiling jet flow at various flow distances. Next, we formulated the ceiling jet flow rate by expressing this in terms of dimensionless flow rate and dimensionless flow distance. Furthermore, we derived a simple prediction equation for ceiling jet flow arrival time based on the model equation. Finally, we validated the proposed equation and range of applicability through comparison with the results of several experiments.
{"title":"Simple prediction equation for ceiling jet flow arrival time in space without vertical wall soffit","authors":"Hyewon Kim , Jun-ichi Yamaguchi , Hyun-woo Park , Yoshifumi Ohmiya","doi":"10.1016/j.firesaf.2025.104520","DOIUrl":"10.1016/j.firesaf.2025.104520","url":null,"abstract":"<div><div>Currently, in two-zone models, smoke flow is calculated based on the assumption that the fire plume, which develops directly above the fire source, depends solely on the amount of entrained surrounding air. However, in large flat spaces, which have been growing larger in recent years, the horizontal travel distance of ceiling jet flow is long, and it is possible that the amount of smoke due to entrainment of air during the horizontal spread process is underestimated. In this study, we performed experiments that reproduced an unconfined ceiling without a vertical wall soffit and determined the amount of entrainment in the ceiling jet flow by analyzing the gas concentration of ceiling jet flow at various flow distances. Next, we formulated the ceiling jet flow rate by expressing this in terms of dimensionless flow rate and dimensionless flow distance. Furthermore, we derived a simple prediction equation for ceiling jet flow arrival time based on the model equation. Finally, we validated the proposed equation and range of applicability through comparison with the results of several experiments.</div></div>","PeriodicalId":50445,"journal":{"name":"Fire Safety Journal","volume":"158 ","pages":"Article 104520"},"PeriodicalIF":3.3,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145050695","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-08-31DOI: 10.1016/j.firesaf.2025.104511
Junjie Wei , Chao Zhang
This paper presents a theoretical model to calculate the radiative heat fluxes from localized fires to vertical surfaces. The fire volume is modeled as a series of concentric hollow cylinders (CHCs), each treated as an isothermal graybody with uniform height and width. New methods for determining the emissivity of individual CHC elements, as well as the view factors and transmissivity between each CHC and the target surface, are introduced. The radiative contributions from each CHC element using a simplified view factor approach and incorporating transmissive radiation losses through Beer's law and Kirchoff's law to account for medium absorption. The proposed model is validated against experimental data from the literature and verified through three-dimensional (3D) simulations using the Fire Dynamics Simulator (FDS). Comparisons with experimental data and simulation results indicate that the model provides conservative and reliable predictions for vertical surfaces both inside and outside the flame. Compared to the other classic flame models, the proposed model demonstrates improved accuracy outside the flame. Furthermore, the model fills a critical methodological gap by enabling the calculation of radiative heat fluxes not only on vertical surfaces within the flame but also on vertical surfaces with arbitrary normal directions at any position in space. This makes the model a valuable tool for advancing structural fire engineering design and risk assessment in localized fire scenarios.
{"title":"A theoretical model to calculate the thermal radiation from localized fire to vertical surfaces located inside and outside the flame","authors":"Junjie Wei , Chao Zhang","doi":"10.1016/j.firesaf.2025.104511","DOIUrl":"10.1016/j.firesaf.2025.104511","url":null,"abstract":"<div><div>This paper presents a theoretical model to calculate the radiative heat fluxes from localized fires to vertical surfaces. The fire volume is modeled as a series of concentric hollow cylinders (CHCs), each treated as an isothermal graybody with uniform height and width. New methods for determining the emissivity of individual CHC elements, as well as the view factors and transmissivity between each CHC and the target surface, are introduced. The radiative contributions from each CHC element using a simplified view factor approach and incorporating transmissive radiation losses through Beer's law and Kirchoff's law to account for medium absorption. The proposed model is validated against experimental data from the literature and verified through three-dimensional (3D) simulations using the Fire Dynamics Simulator (FDS). Comparisons with experimental data and simulation results indicate that the model provides conservative and reliable predictions for vertical surfaces both inside and outside the flame. Compared to the other classic flame models, the proposed model demonstrates improved accuracy outside the flame. Furthermore, the model fills a critical methodological gap by enabling the calculation of radiative heat fluxes not only on vertical surfaces within the flame but also on vertical surfaces with arbitrary normal directions at any position in space. This makes the model a valuable tool for advancing structural fire engineering design and risk assessment in localized fire scenarios.</div></div>","PeriodicalId":50445,"journal":{"name":"Fire Safety Journal","volume":"157 ","pages":"Article 104511"},"PeriodicalIF":3.3,"publicationDate":"2025-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144931732","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-08-31DOI: 10.1016/j.firesaf.2025.104517
G.M. Montagna , P.L. van den Berg , V. Oskam , C.J. Jagtenberg , V. Oosterveen , R.D. van der Mei , J. Klooster
Fire department response times are often used as a measure of their performance, even though its influence on the outcome is not well understood. In this study, we investigate the effect of the response time on the final damage to a building after a fire. We use a partial proportional odds model to measure how one extra minute of response time influences the probability of the damage exceeding a certain threshold, using data on building fires in the Netherlands from 2018 to 2022. Our results show that the probability of large damage increases almost linearly with the response time. As a rule of thumb, the probability of large damage increases with an average of 1% with each additional minute of response time. Furthermore, to minimize the probability of total loss each minute after a response time of about 10 min becomes increasingly more valuable.
{"title":"Effect of fire department response time on fire damage in the Netherlands","authors":"G.M. Montagna , P.L. van den Berg , V. Oskam , C.J. Jagtenberg , V. Oosterveen , R.D. van der Mei , J. Klooster","doi":"10.1016/j.firesaf.2025.104517","DOIUrl":"10.1016/j.firesaf.2025.104517","url":null,"abstract":"<div><div>Fire department response times are often used as a measure of their performance, even though its influence on the outcome is not well understood. In this study, we investigate the effect of the response time on the final damage to a building after a fire. We use a partial proportional odds model to measure how one extra minute of response time influences the probability of the damage exceeding a certain threshold, using data on building fires in the Netherlands from 2018 to 2022. Our results show that the probability of large damage increases almost linearly with the response time. As a rule of thumb, the probability of large damage increases with an average of 1% with each additional minute of response time. Furthermore, to minimize the probability of total loss each minute after a response time of about 10 min becomes increasingly more valuable.</div></div>","PeriodicalId":50445,"journal":{"name":"Fire Safety Journal","volume":"157 ","pages":"Article 104517"},"PeriodicalIF":3.3,"publicationDate":"2025-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144988496","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-08-28DOI: 10.1016/j.firesaf.2025.104518
Nieves Fernandez-Anez , Isabel Amez , Bjarne C. Hagen , Alberto Tascon , Blanca Castells
The use of solid organic fuels is expected to continue increasing during the near future, requiring bigger facilities and storage units. It is known that one of the main risks associated to these materials is the risk of fire and explosion. While flammability parameters and testing standards have been adapted from fossil fuel research, these adaptations often fail to account for the unique properties and behaviour of organic dusts. This study aims to critically evaluate the applicability of current flammability testing standards to organic solid fuels, identify inconsistencies in parameter determination, and propose improvements to enhance safety assessments. Special attention is given to the influence of particle size, moisture content, and composition on ignition sensitivity. A comprehensive literature review was conducted alongside experimental thermogravimetric analysis (TGA) of wood pellet dusts under varying conditions. The study examined how methodological variables (such as crucible size, heating rate, and gas atmosphere) affect thermal decomposition profiles and ignition-related parameters. The results reveal that current standards often overlook critical variables such as sample preparation, dispersion method, and equipment configuration, leading to inconsistent or non-representative results. TGA parameters like maximum weight loss temperature and induction temperature were found to be sensitive to test conditions. The study underscores the need for more detailed and standardized testing protocols tailored to organic dusts. It advocates for a shift beyond worst-case scenario assumptions toward more realistic, scenario-specific assessments. These improvements are essential for enhancing the reliability of flammability data and ensuring safer industrial practices involving combustible dusts.
{"title":"Beyond the worst-case scenario: Inconsistencies in dust flammability parameter determination for organic solid fuels","authors":"Nieves Fernandez-Anez , Isabel Amez , Bjarne C. Hagen , Alberto Tascon , Blanca Castells","doi":"10.1016/j.firesaf.2025.104518","DOIUrl":"10.1016/j.firesaf.2025.104518","url":null,"abstract":"<div><div>The use of solid organic fuels is expected to continue increasing during the near future, requiring bigger facilities and storage units. It is known that one of the main risks associated to these materials is the risk of fire and explosion. While flammability parameters and testing standards have been adapted from fossil fuel research, these adaptations often fail to account for the unique properties and behaviour of organic dusts. This study aims to critically evaluate the applicability of current flammability testing standards to organic solid fuels, identify inconsistencies in parameter determination, and propose improvements to enhance safety assessments. Special attention is given to the influence of particle size, moisture content, and composition on ignition sensitivity. A comprehensive literature review was conducted alongside experimental thermogravimetric analysis (TGA) of wood pellet dusts under varying conditions. The study examined how methodological variables (such as crucible size, heating rate, and gas atmosphere) affect thermal decomposition profiles and ignition-related parameters. The results reveal that current standards often overlook critical variables such as sample preparation, dispersion method, and equipment configuration, leading to inconsistent or non-representative results. TGA parameters like maximum weight loss temperature and induction temperature were found to be sensitive to test conditions. The study underscores the need for more detailed and standardized testing protocols tailored to organic dusts. It advocates for a shift beyond worst-case scenario assumptions toward more realistic, scenario-specific assessments. These improvements are essential for enhancing the reliability of flammability data and ensuring safer industrial practices involving combustible dusts.</div></div>","PeriodicalId":50445,"journal":{"name":"Fire Safety Journal","volume":"158 ","pages":"Article 104518"},"PeriodicalIF":3.3,"publicationDate":"2025-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145107899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-08-27DOI: 10.1016/j.firesaf.2025.104509
C. Álvarez , N. Correa , F. Valenzuela , M. Reveco , J. Ferrer , R. Demarco , A. Fuentes , A. Simeoni , P. Reszka
This work focuses on evaluating the effectiveness of fire retardants, using bench-scale flammability apparatuses to test Pinus radiata D. Don needles. Two devices entirely developed in Chile, representative of continuous and discontinuous ignition modes, were used. The product tested was Phos-Chek LC65A-Fx, commonly used in wildfire fighting operations in Chile. The retardant was applied on the pine needles at different concentrations in order to study the effect of retardant concentration () on different flammability parameters. Notable findings include a modification in flame behaviour in treated samples, with reduced smouldering and prolonged flame duration. As expected, the ignition delay times increase with the amount of retardant, showing a similar behaviour as the heat release rates (HRR). Interestingly, the critical heat flux () corresponding to spotting ignition was not affected by the addition of retardants, although an increase in ignition times () was noticeable. Experimental observations underscore distinct flame dynamics, highlighting the potential of retardants to impede fire propagation. This study highlights the crucial role of retardants in fire management strategies and emphasizes the need for optimal application, especially in urban areas adjacent to forests.
{"title":"Bench-scale flammability testing to optimize the effectiveness of fire retardant treatment of wildland fuels","authors":"C. Álvarez , N. Correa , F. Valenzuela , M. Reveco , J. Ferrer , R. Demarco , A. Fuentes , A. Simeoni , P. Reszka","doi":"10.1016/j.firesaf.2025.104509","DOIUrl":"10.1016/j.firesaf.2025.104509","url":null,"abstract":"<div><div>This work focuses on evaluating the effectiveness of fire retardants, using bench-scale flammability apparatuses to test <em>Pinus radiata</em> D. Don needles. Two devices entirely developed in Chile, representative of continuous and discontinuous ignition modes, were used. The product tested was Phos-Chek LC65A-Fx, commonly used in wildfire fighting operations in Chile. The retardant was applied on the pine needles at different concentrations in order to study the effect of retardant concentration (<span><math><msub><mrow><mi>σ</mi></mrow><mrow><mi>r</mi><mi>e</mi><mi>t</mi></mrow></msub></math></span>) on different flammability parameters. Notable findings include a modification in flame behaviour in treated samples, with reduced smouldering and prolonged flame duration. As expected, the ignition delay times increase with the amount of retardant, showing a similar behaviour as the heat release rates (HRR). Interestingly, the critical heat flux (<span><math><msubsup><mrow><mover><mrow><mi>q</mi></mrow><mrow><mo>̇</mo></mrow></mover></mrow><mrow><mi>c</mi><mi>r</mi><mi>i</mi></mrow><mrow><mo>′</mo><mo>′</mo></mrow></msubsup></math></span>) corresponding to spotting ignition was not affected by the addition of retardants, although an increase in ignition times (<span><math><msub><mrow><mi>t</mi></mrow><mrow><mi>i</mi><mi>g</mi></mrow></msub></math></span>) was noticeable. Experimental observations underscore distinct flame dynamics, highlighting the potential of retardants to impede fire propagation. This study highlights the crucial role of retardants in fire management strategies and emphasizes the need for optimal application, especially in urban areas adjacent to forests.</div></div>","PeriodicalId":50445,"journal":{"name":"Fire Safety Journal","volume":"157 ","pages":"Article 104509"},"PeriodicalIF":3.3,"publicationDate":"2025-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144931731","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In Taiwan, the non-combustibility test for building materials has been changed from CNS 6532 (based on JIS 1321) to CNS 15694 (based on ISO 1182), but the non-combustibility performance is still ranked using the “old” criteria of CNS 6532. There consequently exists a need to evaluate the feasibility of existing criteria. This study analyzed the differences of the two non-combustibility test methods, i.e. CNS 6532 and CNS 15694, and discussed the criteria applying ISO 1182 in other countries. A series of experiments is conducted to evaluate whether the current criteria can adequately rank the non-combustibility performance of building materials. Ten specimens selected from laminated and decorated building materials are tested for the comparative experiment since their “reaction to fire” performance may be complicated.
Our analysis demonstrates that the thermal environment in CNS 6532 and CNS15694 are different. CNS 15694 specifies that no automatic thermostatic can be used to control the furnace during testing but CNS 6532 does not. The temperatures for CNS 6532 tests return closer to the furnace setting temperature. Accordingly, the criteria for CNS 6532 cannot be used for CNS 15694. Additionally, the experimental results show that there is no significant difference in mass loss percentage. Further, for ensuring better confirmation of fire safety, a stricter assessment is recommended. Conclusively, this study recommends that the criteria for a non-combustibility test should comply with the Japanese standard, although the duration of flame is not included.
{"title":"Criteria for non-combustibility tests for class 1 laminated and decorated building materials","authors":"Tzu-Yan Tseng , Ming-Yuan Lei , Chen-Ming Hsiao , Kuang-Chung Tsai","doi":"10.1016/j.firesaf.2025.104519","DOIUrl":"10.1016/j.firesaf.2025.104519","url":null,"abstract":"<div><div>In Taiwan, the non-combustibility test for building materials has been changed from CNS 6532 (based on JIS 1321) to CNS 15694 (based on ISO 1182), but the non-combustibility performance is still ranked using the “old” criteria of CNS 6532. There consequently exists a need to evaluate the feasibility of existing criteria. This study analyzed the differences of the two non-combustibility test methods, i.e. CNS 6532 and CNS 15694, and discussed the criteria applying ISO 1182 in other countries. A series of experiments is conducted to evaluate whether the current criteria can adequately rank the non-combustibility performance of building materials. Ten specimens selected from laminated and decorated building materials are tested for the comparative experiment since their “reaction to fire” performance may be complicated.</div><div>Our analysis demonstrates that the thermal environment in CNS 6532 and CNS15694 are different. CNS 15694 specifies that no automatic thermostatic can be used to control the furnace during testing but CNS 6532 does not. The temperatures for CNS 6532 tests return closer to the furnace setting temperature. Accordingly, the criteria for CNS 6532 cannot be used for CNS 15694. Additionally, the experimental results show that there is no significant difference in mass loss percentage. Further, for ensuring better confirmation of fire safety, a stricter assessment is recommended. Conclusively, this study recommends that the criteria for a non-combustibility test should comply with the Japanese standard, although the duration of flame is not included.</div></div>","PeriodicalId":50445,"journal":{"name":"Fire Safety Journal","volume":"157 ","pages":"Article 104519"},"PeriodicalIF":3.3,"publicationDate":"2025-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144911992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-08-25DOI: 10.1016/j.firesaf.2025.104514
Rwayda Kh.S. Al-Hamd , Asad S. Albostami , Holly Warren
The bond between steel and concrete in reinforced concrete (RC) and fibre-reinforced concrete (FRC) structures is a multifaceted and intricate phenomenon. It refers to the adhesion and mechanical interlock between the steel reinforcement bars and the surrounding concrete matrix. The bond becomes more complex at elevated temperatures; however, having an accurate estimate is a crucial factor in design. Therefore, this paper employs advanced machine learning (ML) techniques to predict bond strength (Tb) at both ambient and elevated temperatures from a 394-point experimental database, which includes additional variables such as fibre content, geometric ratios, and thermal parameter conditions. Seven models were built and assessed, including Linear Regression (LR), Gradient Boosting (GB), Extreme Gradient Boosting (XGBoost), Artificial Neural Network (ANN), k-nearest Neighbours (KNN), Decision Tree (DT), and Deep Learning (DLearning) Regressors. The GB, XGBoost, and DT models offered the best prediction results with R² above 0.95 for the testing datasets, lowest error metrics (mean absolute error (MAE) between 0.8 and 1.1 MPa), and highest reliability (a30%-index ≥ 90%), all outperforming those reported in earlier literature. According to SHapley Additive exPlanations (SHAP) analysis, the length-to-diameter ratio () and failure surface temperature () dominated as the predictors, followed by concrete compressive strength (), and cover-to-diameter ratio (), which is according to the existing mechanics of bond and thermal degradation. This study presents resolutions regarding the promise of data-driven models to accurately, reliably, and interpretably predict bond strength in post-fire conditions, which is of great merit in terms of resilient design practice. Future work may investigate hybrid ML–mechanistic frameworks and the integration of full-scale fire testing to further enhance engineering applicability.
{"title":"Data-driven and explainable AI models for evaluating bond strength in reinforced concrete at elevated temperatures","authors":"Rwayda Kh.S. Al-Hamd , Asad S. Albostami , Holly Warren","doi":"10.1016/j.firesaf.2025.104514","DOIUrl":"10.1016/j.firesaf.2025.104514","url":null,"abstract":"<div><div>The bond between steel and concrete in reinforced concrete (RC) and fibre-reinforced concrete (FRC) structures is a multifaceted and intricate phenomenon. It refers to the adhesion and mechanical interlock between the steel reinforcement bars and the surrounding concrete matrix. The bond becomes more complex at elevated temperatures; however, having an accurate estimate is a crucial factor in design. Therefore, this paper employs advanced machine learning (ML) techniques to predict bond strength (<em>T<sub>b</sub></em>) at both ambient and elevated temperatures from a 394-point experimental database, which includes additional variables such as fibre content, geometric ratios, and thermal parameter conditions. Seven models were built and assessed, including Linear Regression (LR), Gradient Boosting (GB), Extreme Gradient Boosting (XGBoost), Artificial Neural Network (ANN), <em>k</em>-nearest Neighbours (KNN), Decision Tree (DT), and Deep Learning (DLearning) Regressors. The GB, XGBoost, and DT models offered the best prediction results with R² above 0.95 for the testing datasets, lowest error metrics (mean absolute error (MAE) between 0.8 and 1.1 MPa), and highest reliability (a30%-index ≥ 90%), all outperforming those reported in earlier literature. According to SHapley Additive exPlanations (SHAP) analysis, the length-to-diameter ratio (<span><math><mrow><mfrac><mi>l</mi><mi>d</mi></mfrac></mrow></math></span>) and failure surface temperature (<span><math><mrow><mi>T</mi></mrow></math></span>) dominated as the predictors, followed by concrete compressive strength (<span><math><mrow><msub><mi>f</mi><mi>c</mi></msub></mrow></math></span>), and cover-to-diameter ratio (<span><math><mrow><mfrac><mi>c</mi><mi>d</mi></mfrac></mrow></math></span>), which is according to the existing mechanics of bond and thermal degradation. This study presents resolutions regarding the promise of data-driven models to accurately, reliably, and interpretably predict bond strength in post-fire conditions, which is of great merit in terms of resilient design practice. Future work may investigate hybrid ML–mechanistic frameworks and the integration of full-scale fire testing to further enhance engineering applicability.</div></div>","PeriodicalId":50445,"journal":{"name":"Fire Safety Journal","volume":"158 ","pages":"Article 104514"},"PeriodicalIF":3.3,"publicationDate":"2025-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145050694","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-08-25DOI: 10.1016/j.firesaf.2025.104513
Y. Moorthamers, A. Snegirev, G. Maragkos, J. At Thabari, B. Merci
The recently proposed sub-grid combustion model (SCM) for weakly turbulent buoyant diffusion flames is applied to simulate 10 and 15 kW flames produced by a circular porous burner in an oxidizer co-flow with normal and reduced oxygen concentrations. Turbulence is modelled by the large eddy simulations technique. Soot production and radiative emission is predicted based on local resolved species concentrations and temperature, eliminating the need to prescribe soot yield and global radiative fraction. Finite-rate chemistry is incorporated via a single-step global reaction of fuel oxidation with temperature-dependent effective kinetic parameters, which are derived to fit the autoignition delay times predicted by detailed chemical mechanisms. When the oxidizer co-flow is ambient air, good agreement between the predicted and the measured spatial distributions of mean temperatures and soot volume fractions is demonstrated. In flames with reduced oxygen concentrations in the co-flow, the experimental combustion efficiency and radiative fraction are replicated in the simulations, and the critical oxygen concentration causing complete flame extinguishment is predicted well by the SCM. The predictions are shown to be weakly dependent on the values of model constants. Adequate representation of the flame shape requires the large turbulent fluctuations to be sufficiently resolved by the computational grid.
{"title":"Large eddy simulations of weakly turbulent diffusion flames in an oxygen-reduced co-flow using a new subgrid combustion model","authors":"Y. Moorthamers, A. Snegirev, G. Maragkos, J. At Thabari, B. Merci","doi":"10.1016/j.firesaf.2025.104513","DOIUrl":"10.1016/j.firesaf.2025.104513","url":null,"abstract":"<div><div>The recently proposed sub-grid combustion model (SCM) for weakly turbulent buoyant diffusion flames is applied to simulate 10 and 15 kW flames produced by a circular porous burner in an oxidizer co-flow with normal and reduced oxygen concentrations. Turbulence is modelled by the large eddy simulations technique. Soot production and radiative emission is predicted based on local resolved species concentrations and temperature, eliminating the need to prescribe soot yield and global radiative fraction. Finite-rate chemistry is incorporated via a single-step global reaction of fuel oxidation with temperature-dependent effective kinetic parameters, which are derived to fit the autoignition delay times predicted by detailed chemical mechanisms. When the oxidizer co-flow is ambient air, good agreement between the predicted and the measured spatial distributions of mean temperatures and soot volume fractions is demonstrated. In flames with reduced oxygen concentrations in the co-flow, the experimental combustion efficiency and radiative fraction are replicated in the simulations, and the critical oxygen concentration causing complete flame extinguishment is predicted well by the SCM. The predictions are shown to be weakly dependent on the values of model constants. Adequate representation of the flame shape requires the large turbulent fluctuations to be sufficiently resolved by the computational grid.</div></div>","PeriodicalId":50445,"journal":{"name":"Fire Safety Journal","volume":"157 ","pages":"Article 104513"},"PeriodicalIF":3.3,"publicationDate":"2025-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144988497","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号