Journal of Structural Fire Engineering最新文献

{"title":"Fire behaviour and resistance of cold-formed steel beams with sigma cross-sections","authors":"F. Arrais, N. Lopes, P. Vila Real","doi":"10.1108/jsfe-11-2020-0037","DOIUrl":"https://doi.org/10.1108/jsfe-11-2020-0037","url":null,"abstract":"PurposeSigma cross-section profiles are often chosen for their lightness and ability to support large spans, offering a favourable bending resistance. However, they are more susceptible to local, distortional and lateral-torsional buckling, as possible failure modes when compared to common I-sections and hollow cross-sections. However, the instability phenomena associated to these members are not completely understood in fire situation. Therefore, the purpose of this study is to analyse the behaviour of beams composed of cold-formed sigma sections at elevated temperatures.Design/methodology/approachThis study presents a numerical analysis, using advanced methods by applying the finite element software SAFIR. A numerical analysis of the behaviour of simply supported cold-formed sigma beams in the case of fire is presented considering different cross-section slenderness values, elevated temperatures, steel grades and bending moment diagrams. Comparisons are made between the obtained numerically ultimate bending capacities and the design bending resistances from Eurocode 3 Part 1–2 rules and its respective French National Annex (FN Annex).FindingsThe current design expressions revealed to be over conservative when compared with the obtained numerical results. It was possible to observe that the FN Annex is less conservative than the general prescriptions, the first having a better agreement with the numerical results.Originality/valueFollowing the previous comparisons, new fire design formulae are analysed. This new methodology, which introduces minimum changes in the existing formulae, provides at the same time safety and accuracy when compared to the numerical results, considering the occurrence of local, distortional and lateral-torsional buckling phenomena in these members at elevated temperatures.","PeriodicalId":45033,"journal":{"name":"Journal of Structural Fire Engineering","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2021-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49666761","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Examination of the effect of fire retardant materials on timber","authors":"É. Lublóy, L. Takács, D. Enczel, Zsolt Cimer","doi":"10.1108/jsfe-11-2020-0036","DOIUrl":"https://doi.org/10.1108/jsfe-11-2020-0036","url":null,"abstract":"PurposeThe fire safety of structures is an existing and important design aspect, which is assured by strict regulations. As a means to adhere to the strict requirements, fire protection has become a core problem. It is particularly difficult to comply with these regulations in the case of timber, which is a combustible material. These problems could be solved by enveloping the wood in fire retardant materials. MSZ EN 1995-1-2 currently does not take into consideration the fire-retardant materials charring rate under fire exposure.Design/methodology/approachHowever, currently these fire retardants are proving to be reliable and depending on their application can achieve better reaction-to-fire classifications. During the research, the authors used five different fire-retardant materials on three different types of wood and tested their behaviours in a laboratory. When selecting them, it was important to choose the species that are most commonly used in the building industry but which have significantly different densities. Our choice fell upon spruce (360 kg/m3), Scots pine (540 kg/m3) and oak (650 kg/m3). During the tests, we examined the weight reduction and the process of burning on the specimens treated with the fire retardant material. In addition, the authors also performed tests by derivatography on both untreated and treated specimen.FindingsThe question is whether the effects of the fire retardants should be taken into consideration when calculating the extent of the burn. The Eurocode (MSZ EN 1995-1-2) does not provide any opinions. On the market, there are manufacturers who are already discussing the possibilities of reducing the burn rate during the qualification of paints. In this paper, based on the results we received, we discuss the beneficial effects of the fire retardants which can be taken into account while measuring cross-sections.Originality/valueBy using fire retardants, a high proportion of cross-sectional area gain is only possible in case of small cross-sections; therefore, it is advisable to use them here as well. This can be effective for example in many smaller cross-sections, when there is a little space and therefore requires a small cross-section. Thus, if a larger cross-section without protection is not possible, it can be replaced by a smaller cross section, treated with a fire retardant.","PeriodicalId":45033,"journal":{"name":"Journal of Structural Fire Engineering","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2021-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42928561","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Travelling fire experiments in steel-framed structure: numerical investigations with CFD and FEM","authors":"M. Charlier, A. Glorieux, Xu Dai, Naveed Alam, S. Welch, Johan Anderson, O. Vassart, A. Nadjai","doi":"10.1108/JSFE-11-2020-0034","DOIUrl":"https://doi.org/10.1108/JSFE-11-2020-0034","url":null,"abstract":"\u0000Purpose\u0000The purpose of this paper is to propose a simplified representation of the fire load in computational fluid dynamics (CFD) to represent the effect of large-scale travelling fire and to highlight the relevance of such an approach whilst coupling the CFD results with finite element method (FEM) to evaluate related steel temperatures, comparing the numerical outcomes with experimental measurements.\u0000\u0000\u0000Design/methodology/approach\u0000This paper presents the setup of the CFD simulations (FDS software), its corresponding assumptions and the calibration via two natural fire tests whilst focusing on gas temperatures and on steel temperatures measured on a central column. For the latter, two methods are presented: one based on EN 1993-1-2 and another linking CFD and FEM (SAFIR® software).\u0000\u0000\u0000Findings\u0000This paper suggests that such an approach can allow for an acceptable representation of the travelling fire both in terms of fire spread and steel temperatures. The inevitable limitations inherent to the simplifications made during the CFD simulations are also discussed. Regarding steel temperatures, the two methods lead to quite similar results, but with the ones obtained via CFD–FEM coupling are closer to those measured.\u0000\u0000\u0000Originality/value\u0000This work has revealed that the proposed simplified representation of the fire load appears to be appropriate to evaluate the temperature of steel structural elements within reasonable limits on computational time, making it potentially desirable for practical applications. This paper also presents the first comparisons of FDS–SAFIR® coupling with experimental results, highlighting promising outcomes.\u0000","PeriodicalId":45033,"journal":{"name":"Journal of Structural Fire Engineering","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2021-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45214568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study on fire resistance of a prefabricated reinforced concrete frame structure","authors":"Shufeng Li, Zhang Jiaolei, D. Zhao, L. Deng","doi":"10.1108/JSFE-12-2020-0039","DOIUrl":"https://doi.org/10.1108/JSFE-12-2020-0039","url":null,"abstract":"\u0000Purpose\u0000This study aims to further study the fire resistance of prefabricated concrete beam-column joints with end-plate connection. This paper aims to analyze the fire resistance of this joint in prefabricated reinforced concrete frame structure (PRCS).\u0000\u0000\u0000Design/methodology/approach\u0000First, the accuracy of the model is verified by using the test data. Based on this, a refined finite element model of PRCS structure with two stories and two spans is established. The influence of four working conditions with different fire floors (positions) and different axial compression ratios on the deformation, failure and fire resistance of PRCS structure are analyzed.\u0000\u0000\u0000Findings\u0000The results show that under the four working conditions, the fire resistance of the PRCS structure under Condition 1 and Condition 2 is smaller. It shows that the beam deformation develops slowly in PRCS structure under four kinds of fire positions, and the large displacement emerges 60 min later, which is poles apart from that of prefabricated beam column members. With the increase of the fire time, the material is damaged and deteriorated, which leads to the eccentricity of the axial load, so that the column top appears large lateral displacement. Under the Conditions 1 and 3, the lateral displacement of the column gradually decreases as the axial compression ratio rises.\u0000\u0000\u0000Originality/value\u0000It is found that there is a distinct lack of researching on the fire resistance of prefabricated joints, and the existed research studies are limited to the fire resistance of members. Thus, it is necessary to strengthen the first floor and side column design of prefabricated frame structure.\u0000","PeriodicalId":45033,"journal":{"name":"Journal of Structural Fire Engineering","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2021-05-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45730448","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Properties of quenched and self-tempered reinforcing steel subjected to high temperature and different cooling conditions","authors":"I. Hager, S. Kańka, M. Maślak","doi":"10.1108/JSFE-08-2019-0030","DOIUrl":"https://doi.org/10.1108/JSFE-08-2019-0030","url":null,"abstract":"\u0000Purpose\u0000The study presents test results concerning the impact of high temperature and different cooling conditions on the mechanical properties of quenched and self-tempered reinforcing steel. The purpose of this paper is to clarify the extent of the history of the material’s temperature development profile, the course and the intensity of fire exposure and how cooling conditions determines its properties.\u0000\u0000\u0000Design/methodology/approach\u0000Each specimen series was heated to the temperatures of T = 200°C, 400°C, 600°C, 700°C, 800°C and 1,000 °C. The specimens were either slowly cooled down or subjected to rapid cooling with water quenching, which can be encountered during a firefighting operation. Additionally, stress–strain relationships, microhardness and structural observations were also performed.\u0000\u0000\u0000Findings\u0000The results of the presented experiments have shown that the steel bars previously heated in fire conditions were very sensitive to the cooling intensity. The test results from the steel specimens – that were heated and quenched with water – demonstrate an increase in tensile strength but a significant reduction in material plasticity.\u0000\u0000\u0000Originality/value\u0000The presented piece of work provides a contribution for fire safety engineering giving insight into the fire behaviour of reinforcing steel under fire conditions and subjected to rapid or slow cooling. This study has shown the threats arising from thermally induced changes in steel microstructure because of high-temperature exposure. It should also be noted that structure changes may have a local character and refer to steel rebars that are exposed because of fire spalling of concrete cover.\u0000","PeriodicalId":45033,"journal":{"name":"Journal of Structural Fire Engineering","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2021-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46788248","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Residual shear capacity of cold-formed steel-to-sheathing screwed connections at elevated temperatures","authors":"Kun Liu, Wei Chen, Jihong Ye, Jian Jiang, Wenwen Chen, Mingyu Zhao","doi":"10.1108/JSFE-07-2020-0024","DOIUrl":"https://doi.org/10.1108/JSFE-07-2020-0024","url":null,"abstract":"\u0000Purpose\u0000Most previous thermal-mechanical modeling of cold-formed steel (CFS) walls did not consider the failure of screwed connections under fire conditions because of the limited data of such connections at elevated temperatures.\u0000\u0000\u0000Design/methodology/approach\u0000In this study, 285 steady-state tests are conducted on CFS screwed connections with single-layer gypsum plasterboard (GPB) and Bolivian magnesium board (BMB) sheathing at ambient and elevated temperatures. The failure of these connections is described as the breaking of the loaded sheathing edge.\u0000\u0000\u0000Findings\u0000For the BMB sheathing screwed connections, hydrochloric acid gas is generated and released above 300°C, and the shear strength becomes much less than that of the GPB sheathing screwed connection above 370°C. Hence, BMB may not be suitable for use as the face-layer sheathing of CFS walls but is still recommended to replace GPB as the base-layer sheathing. The major influencing parameters on the shear strength of screwed connections are identified as the type of sheathing material and the loaded sheathing edge distance.\u0000\u0000\u0000Originality/value\u0000Based on the previous and present test results, a unified expression for the residual shear strength of screwed connections with GPB and BMB is proposed at ambient and elevated temperatures with acceptable accuracy. It can be used as the basic input parameter of the numerical simulation of the CFS structures under fire conditions.\u0000","PeriodicalId":45033,"journal":{"name":"Journal of Structural Fire Engineering","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2021-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49091047","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Flame behaviour, fire hazard and fire testing approach for lightweight composite claddings – a review","authors":"Delwar M. Hossain, Kamrul Hassan, A. Yuen, Yaping He, Swapan Saha, Waseem Hittini","doi":"10.1108/JSFE-09-2020-0027","DOIUrl":"https://doi.org/10.1108/JSFE-09-2020-0027","url":null,"abstract":"\u0000Purpose\u0000The purpose of this study is to review and summarise the existing available literature on lightweight cladding systems to provide detailed information on fire behaviour (ignitibility, heat release rate and smoke toxicity) and various test method protocols. Additionally, the paper discusses the challenges and provides updated knowledge and recommendation on selective-fire mechanisms such as rapid-fire spread, air cavity and fire re-entry behaviours due to dripping and melting of lightweight composite claddings.\u0000\u0000\u0000Design/methodology/approach\u0000A comprehensive literature review on fire behaviour, fire hazard and testing methods of lightweight composite claddings has been conducted in this research. In summarising all possible fire hazards, particular attention is given to the potential impact of toxicity of lightweight cladding fires. In addition, various criteria for fire performance evaluation of lightweight composite claddings are also highlighted. These evaluations are generally categorised as small-, intermediate- and large-scale test methods.\u0000\u0000\u0000Findings\u0000The major challenges of lightweight claddings are rapid fire spread, smoke production and toxicity and inconsistency in fire testing.\u0000\u0000\u0000Originality/value\u0000The review highlights the current challenges in cladding fire, smoke toxicity, testing system and regulation to provide some research recommendations to address the identified challenges.\u0000","PeriodicalId":45033,"journal":{"name":"Journal of Structural Fire Engineering","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2021-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45748875","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Performance of fire protective coatings on structural steel member exposed to high temperature","authors":"H. Mahmud, A. Mandal, S. Nag, K. Moinuddin","doi":"10.1108/JSFE-07-2020-0025","DOIUrl":"https://doi.org/10.1108/JSFE-07-2020-0025","url":null,"abstract":"","PeriodicalId":45033,"journal":{"name":"Journal of Structural Fire Engineering","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2021-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46413423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Post-thermal properties of Portland cement concrete made with copper slag as fine aggregates","authors":"N. Suresh, M. Manjunatha","doi":"10.1108/JSFE-06-2020-0018","DOIUrl":"https://doi.org/10.1108/JSFE-06-2020-0018","url":null,"abstract":"\u0000Purpose\u0000The purpose of this paper is to investigate the effect of elevated temperature on mechanical and physical properties of concrete specimens obtained by substituting the river sand with copper slag (CS) at proportions of 25%, 50%, 75% and 100%. The specimens were heated in an electric furnace up to 100, 200, 300, 400, 500 and 600 C and kept at these temperatures for 2 h duration. After the specimens were cooled in the furnace, mass loss, ultrasonic pulse velocity (UPV), compressive strength, split tensile strength (STS), flexural strength (FS) and modulus of elasticity (MOE) values were determined. No spalling occurred in the specimens after subjected to elevated temperature. The surface cracks were observed only in specimens exposed to 600 C. The maximum reduction in compressive strength and STS at 600C is 50.3% and 36.39% for referral mix (NC), 18% and 16% for specimens with 100% CS (MCS4). The reduction in MOE of specimens is observed to be high as copper slag content increases with increasing temperature. Scanning electron microscopy (SEM) studies are carried out to examine the changes in micro-structures of specimens after exposed to elevated temperatures.\u0000\u0000\u0000Design/methodology/approach\u0000After casting of concrete specimens, it is cured for 28 days. After attainment of 28 days age, the concrete specimens is taken out from the curing tank and allowed to dry for 2 days to remove any moisture content in the specimens to prevent explosive spalling during the time of heating. The prepared concrete specimen is subjected to temperatures of 100°C, 200°C, 300°C, 400°C, 500°C and 600°C up to 2 h duration. The physical test, mechanical test and SEM studies are carried out after cooling of specimens to room temperature (RT). The quality of concrete specimens is measured by conducting UPV test after cooling to RT.\u0000\u0000\u0000Findings\u0000The post-thermal strength properties of concrete specimens with copper slag contents are higher than referral mix concrete. The reduction of MOE of concrete specimens is more with incremental in copper slag content with increase in temperatures. Furthermore, the quality of concrete specimens is ranging from “good to medium” up to 500C temperatures based on UPV test.\u0000\u0000\u0000Originality/value\u0000In this research work, the natural sand is fully replaced with copper slag materials in the concrete mixes. The post-thermal strength properties like residual compressive strength, residual STS, residual FS and residual MOE is higher than referral mix after subjected to elevated temperature conditions. Higher density and toughness properties of copper slag materials will contribute to concrete strength. The effect of elevated temperature is more on MOE of concrete specimens having higher copper slag contents when comparing to specimens compressive strength.\u0000","PeriodicalId":45033,"journal":{"name":"Journal of Structural Fire Engineering","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2021-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42325712","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fire resistance of 3D printed concrete composite wall panels exposed to various fire scenarios","authors":"T. Suntharalingam, I. Upasiri, P. Gatheeshgar, K. Poologanathan, B. Nagaratnam, Heshachanaa Rajanayagam, S. Navaratnam","doi":"10.1108/jsfe-10-2020-0029","DOIUrl":"https://doi.org/10.1108/jsfe-10-2020-0029","url":null,"abstract":"\u0000Purpose\u0000Fire 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.\u0000\u0000\u0000Design/methodology/approach\u0000The 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).\u0000\u0000\u0000Findings\u00003DPC 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.\u0000\u0000\u0000Research limitations/implications\u0000To 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.\u0000\u0000\u0000Originality/value\u0000At 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.\u0000","PeriodicalId":45033,"journal":{"name":"Journal of Structural Fire Engineering","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2021-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49556347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}