Purpose The increasing scarcity of sand for construction is driving up the cost of sand, which in turn is affecting overall construction works in Asian countries. Therefore, it is essential to go for an alternative material to reduce the load on the traditional sand in underdeveloped nations. The purpose of this paper is to examine the influence of e-waste (0–25%) as an alternate for fine aggregate on the thermal and residual mechanical performance of cement concrete (CC) and geopolymer concrete (GC) mixes exposed to elevated temperatures following the International Organization for Standardization 834 fire curve. Design/methodology/approach Concrete specimens with varying proportions of e-waste were incorporated for both CC and GC mixes. These specimens were subjected to elevated temperatures (30–120 min) to simulate real fire conditions. The properties of the concrete were evaluated (density, porosity, crack width and residual compressive strength). The comparative performance of CC and GC was analyzed using experimental results. Findings Results showed that a decline in density and compressive strength, alongside an increase in porosity and crack width with an increase in exposure duration. Moreover, GC outperforms CC mixes in the case of thermal resistance. GC mixes exhibited higher residual strength (up to 17.2 MPa after 30 min and 4.5 MPa after 120 min), lower porosity (0.03%) and reduced crack width (0.02 mm), demonstrating improved fire resistance. The addition of e-waste (EW) had a marginal effect on mechanical strength at room temperature but contributed to enhanced thermal performance. GC showed 20–30% higher residual strength than CC after exposure to 1,029 °C. Originality/value This study introduces a sustainable approach to concrete production by utilizing e-waste as an alternative to fine aggregate and evaluating thermal resilience in both CC and GC. The results show that the incorporation of e-waste is a positive alternative to conventional sand, thereby reducing the need and demand for it (especially in the case of GC), which paves the way for sustainable construction practices.

Purpose This paper aims to provide a comprehensive and structured overview of the current state of research on fire-exposed industrial steel halls, with a focus on numerical simulations. Despite the frequent use of steel structures in industrial buildings, a lack of summarizing literature exists regarding their fire performance under standardized conditions. This systematic review closes this gap by analyzing relevant studies from the year 2000 onward that apply the ISO standard fire definition to typical one-bay, one-storey steel halls. By synthesizing modelling approaches, structural behavior, and failure mechanisms, this review offers a valuable reference for engineers and researchers seeking to improve fire-resistant design strategies for steel halls. Design/methodology/approach The study follows the PRISMA methodology to systematically select and evaluate peer-reviewed studies using numerical methods to simulate the fire behavior of steel structures. Only studies based on ISO standard fires and relevant hall geometries were considered. Findings The review reveals a clear correlation between failure mode and structural parameters such as column stiffness, boundary conditions, and load utilization. Two main failure types—outward and inward collapse—are repeatedly observed, with inward collapse being more desirable for safety. Moreover, typical load factors under fire conditions were identified as ranging between 0.15 and 0.30. Galvanisation and section geometry significantly influence temperature rise and thus fire resistance. Originality/value This paper is the first to offer a state-of-the-art review specifically focused on fire-exposed steel halls under standardized fire conditions. It bridges the gap between isolated research results and practical application, providing guidance for realistic and efficient fire design of industrial steel structures.

Purpose The purpose of this study is to assess structural damage mechanisms and evaluate fire resilience strategies following the 2021 Manavgat wildfire in Turkiye. Through detailed on-site inspections of 210 damaged structures, the research critically compares observed damage with recommendations from the National Guide for Wildland–Urban Interface Fires (NRC-2021), highlighting practical challenges, regional adaptability, economic feasibility and policy integration. The study provides targeted recommendations to enhance building resilience, improve wildfire mitigation strategies and inform future building codes, aiming ultimately to safeguard communities from similar wildfire incidents. Design/methodology/approach The study employed a detailed on-site investigation of 210 wildfire-affected buildings in Manavgat, Turkiye, including masonry, reinforced concrete (RC), steel and mixed structures. Structural damage and failure mechanisms were systematically identified, documented and categorized based on severity and construction materials. Observations from site inspections were then critically compared with the Canadian National Guide for Wildland–Urban Interface Fires (NRC-2021), assessing compliance levels, highlighting gaps and evaluating the effectiveness, practicality and adaptability of recommended resilience strategies to regional conditions. Findings The study identified that structural failures following the wildfire were primarily due to inadequate fire resilience measures, with timber components highly vulnerable to ignition, RC experiencing significant spalling and steel structures prone to rapid strength loss and buckling. Comparative analysis showed low compliance rates with NRC-2021 guidelines, especially concerning external walls, roofs, doors and windows. Results highlighted practical implementation challenges, economic limitations and gaps in regional adaptability, underscoring the critical need for comprehensive integration of fire-resistant construction strategies, effective vegetation management, regular maintenance and improved community-level preparedness planning. Originality/value This study offers original insights by providing a comprehensive field-based assessment of structural damage and resilience strategies from a major wildfire incident in Turkiye, critically benchmarking observed outcomes against the NRC-2021 guidelines. Its uniqueness lies in systematically evaluating implementation challenges, economic constraints, regional adaptability and policy integration gaps. The research contributes valuable, evidence-based recommendations to enhance fire-resilient construction, improve existing standards and inform future wildfire management policies, benefiting parties involved in disaster risk reduction, emergency planning and sustainable urban development.

Purpose Concrete is widely utilized in the construction industry. The concrete-making process requires the hydration of cement, resulting in carbon footprints. Additionally, a significant quantity of natural aggregates are mined illegally, causing ecological imbalance and major environmental problems. granulated blast furnace slag (GBFS) and fly ash (FA), the commonly available industrial by-products, are utilized as fine aggregate and binding material, respectively, for improving the heat-resistance performance of sustainable concrete. Design/methodology/approach M40-grade concrete has been cast with GBFS and FA as alternative natural fine aggregate and binder material, respectively. The uniaxial compression behaviour of the sustainable concrete after exposure to 200°C, 400°C, 600°C and 800°C was examined, including mass loss, failure modes, initial elastic modulus, peak strain, stress–strain behaviour and microstructural analysis. Findings Deterioration of compressive strength and elastic modulus has been observed, but deterioration was 12–23% and 5–14% higher for elastic modulus at 600°C and 800°C, respectively. FA-based blends exhibited higher residual compressive strength and energy absorption capacity up to 600°C. Substitution by GBFS only reduces peak strain and compression toughness, while the combination of GBFS and FA enhances the same. The microstructure and mineralogical phase have improved owing to the combination of FA and GBFS at elevated temperatures due to more peaks of CSH and insignificant micro-cracks. Originality/value This article demonstrates the strength and potential of concrete incorporating GBFS and FA for application in adverse environmental conditions with higher thermal gradients. In the authors’ opinion, test results are in favour of the design and practical implementations of such industrial waste-based sustainable concrete mixes under elevated temperatures.

PurposeThe aim of the paper is to propose a simple and effective calculation method for a three-side protected steel beam temperature field.Design/methodology/approachThe calculation model is based on temperature increment equation of EN1993-1-2 and the Fourier's law to calculate the conductive heat flux. The ABAQUS heat transfer simulation is used to establish temperatures and heat flux database at the joints. The ratio of simulation and calculated heat flux is predicted by evolutionary regression and gradient boosting method.FindingsCombined evolutionary regression analysis (CERA) including both linear and polynomial regression reduce the residual of mean square error (MSE) by 7.1% compared to linear regression analysis (linear evolutionary regression analysis (LERA)). The evolutionary regression analysis (ERA) effectively reduces the temperature discrepancy with increase of evolution numbers. Gradient boosting predicts the k value and temperatures with the least residual of MSE. The average residual of MSE is 53.23 °C for the upper flange, 16.18 °C for the web and 19.44 °C for the lower flange.Originality/valueThis paper proposed an effective and fast temperature distribution model for the three-side protected steel beam combining machine learning methods to converge the conductive heat flux between specimens. A novel ERA able to fit output data with multiple inputs with explainable equations is proposed and validated by effectively converging the conductive heat flux to simulation results.

PurposeAlthough separate studies on the influence of corrosion and fire exposure on the constitutive relationship of concrete and steel have been done, there is still a gap in knowledge on the influence of corrosion-temperature superimposition as nonlinear phenomenon. The current study is focused to investigate the response of hot-rolled steel bars subjected to corrosion-temperature superimposition.Design/methodology/approachUsing the accelerated corrosion-impressed-current technique, hot-rolled specimens with different levels of corrosion were obtained. The hot-rolled rebars were first corroded to target levels such as (6, 12, 18, 24, 30 and 36%) and subsequently subjected to target temperatures (250 °C, 400 °C, 550 °C, 800 °C and 950 °C), before tensile tests were carried out to evaluate the residual mechanical response.FindingsThe outcomes showed a significant decline in the parameters governing the mechanical properties of steel reinforcement due to the combined damage due to corrosion and fire. Corroded reinforcement still showed ductile failure after exposure to fire. Moreover, the combined loss of load-bearing characteristics due to corrosion and fire has little influence on the modulus of elasticity. The outcomes of this investigation provide a theoretical database for the assessment of aged structural elements exposed to combination after exposure to fire.Originality/valueThe information concerning structural material's response to corrosion-temperature combined damage is still limited. The cover of the reinforcement is designed to safeguard the reinforcing bars from foreign agencies but is often damaged and spalled off due to corrosion, rendering the reinforcing bars directly exposed. The study aims at the experimental production of fire conditions in a corrosion-damaged infrastructure to cover the aforementioned research gap. The effects of corrosion being superimposed by exposure to elevated temperatures on key parameters affecting mechanical behavior were examined.HighlightsInfluence of corrosion-temperature superimposition on the mechanical properties of hot-rolled rebars.Influence of corrosion-temperature superimposition on the macro and microstructure properties of hot-rolled rebars.Influence of corrosion-temperature superimposition on stress-strain curves of hot-rolled rebars.Influence of corrosion-temperature superimposition on tensile strength, modulus of elasticity and elongation of hot-rolled rebars.

PurposeBased on the known positive effects of conventional hot-dip galvanizing under fire exposure and indicative results on zinc–aluminum coatings from smallscale tests, a series of tests were conducted on zinc-5% aluminum galvanized test specimens under fire loads to verify the previous positive findings under largescale boundary conditions.Design/methodology/approachThe emissivity of zinc-5% aluminum galvanized surfaces applied to steel specimens was determined experimentally under real fire loads and laboratory thermal loads in accordance with the normative specifications of the standard fire curve. Both large and smallscale specimens were used in this study. The steel grade and surface conditions of the specimens were varied for both test scenarios.FindingsLargescale tests on specimens with typical steel construction dimensions under fire loads showed that the surface emissivity of zinc-5% aluminum galvanized steel was significantly lower than that of the conventionally galvanized steel. Only minor influences from the weathering of the specimens and steel chemistry were observed. These results agree well with those obtained from smallscale tests. The design values of zinc-5% aluminum melt (Zn5Al) required for the structural fire design were proposed based on the obtained results.Originality/valueThe novel tests presented in this study are the first ones to study the behavior of zinc-5% aluminum galvanized largescale steel construction components under the influence of real fire exposure and their positive effect on the emissivity of steel components galvanized by this method. The results provide valuable insights and information on the behavior in the case of fire and the associated savings potential for steel construction.

PurposeThis study focused on identifying critical factors governing the fire response of prestressed hollow-core slabs. The hollow-core slabs used as flooring units can be subjected to elevated temperatures during a fire. The fire response of prestressed hollow-core slabs is required to develop slabs with greater fire endurance. The present study aims to determine the extent to which the hollow-core slab can sustain load during a fire without undergoing progressive collapse under extreme fire and heating scenarios.Design/methodology/approachA finite element model was generated to predict the fire response of prestressed hollow core slabs under elevated temperatures. The accuracy of the model was predicted by examining thermal and structural responses through coupled temperature displacement analysis. A sensitivity analysis was performed to study the effects of concrete properties on prediction of system response. A parametric study was conducted by varying the thickness of the slab, fire and heating scenarios.FindingsThermal conductivity and specific heat of concrete were determined as sensitive parameters. The thickness of the slab was identified as a critical factor at a higher load level. Asymmetric heating of the slab resulted in higher fire resistance compared with symmetric heating.Originality/valueThis is the first study focused on studying the effect of modeling uncertainties on the system response by sensitivity analysis under elevated temperatures. The developed model with a parametric study helps in identifying critical factors for design purposes.

PurposeThis study aims at designing consistent and durable concrete by making use of waste materials. An investigation has been carried out to evaluate the performance of conventional and optimal concrete (including 5% GP) at high temperatures for different exposure times.Design/methodology/approachAn experimental work is carried out to compare the conventional and optimal concrete with respect to weight loss, mechanical strength characteristics (compressive, tensile and flexural) after exposed to 100, 200 and 300 °C with 1, 2 and 3 h duration of exposure followed by cooling in furnace for 24 h and then air cooling.FindingsThe workability of granite powder modified concrete decreases as percentage of replacement increases. Compressive, tensile and flexural strengths all increased at 100 °C when compared to strength characteristics at normal temperature, regardless of the exposure conditions, and there was no weight loss noticed. For 200 and 300 °C, the strengths were decreased compared to normal temperature and an elevated temperature of 100 °C, as weight loss of concrete specimens are observed to be decreased at these temperatures. So, the optimum elevated temperature can be concluded as 100 °C.Originality/valueIncorporating pozzolanic binder (granite powder) as cement replacement subjecting to elevated temperatures in an electric furnace is the research gap in this area. Many of the works were carried out replacing GP for fine aggregate at normal temperatures and not at elevated temperatures.

PurposeIn the analysis of structures in a fire situation by simplified and analytical methods, one assumption is that the fire resistance time is greater than or equal to the required fire resistance time. Among the methodologies involving the fire resistance time, the most used is the tabular method, which associates fire resistance time values to structural elements based on minimum dimensions of the cross section. The tabular method is widely accepted by the technical-scientific community due to the fact that it is safe and practical. However, its main criticism is that it results in lower fire resistance times than advanced thermal and thermostructural analysis methods. The objective of this study was to evaluate the fire resistance time of reinforced concrete beams and compare it with the required fire resistance time recommended by the tabular method of NBR 15200 (ABNT, 2012).Design/methodology/approachThe fire resistance time and required fire resistance time of reinforced concrete beams were evaluated using, respectively, numerical models developed based on the finite element method and the tabular method of NBR 15200 (ABNT, 2012). The influence of the following parameters was investigated: longitudinal reinforcement cover, characteristic compressive strength of concrete, beam height, longitudinal reinforcement area and arrangement of steel bars.FindingsAmong the evaluated parameters, the covering of the longitudinal reinforcement proved to be more relevant for the fire resistance time, justifying that the tabular method of NBR 15200 (ABNT, 2012) being strongly and directly influenced by this parameter. In turn, more resistant concretes, higher beams and higher steel grades have lower fire resistance time values. This is because beams in these conditions have greater resistance capacity at room temperature and, consequently, are subject to external stresses of greater magnitude. In some cases, the fire resistance time was even lower than the required fire resistance time prescribed by NBR 15200 (ABNT, 2012). Both the fire resistance time and the required fire resistance time were not influenced by the arrangement of the longitudinal reinforcements.Originality/valueThe present paper innovates by demonstrating the influence of other important design variables on the required fire resistance time of the NBR 15200 (ABNT, 2012). Among several conclusions, it was found that the load level to which the structural elements are subjected considerably affects their fire resistance time. For this reason, it was recommended that the methods for calculating the required fire resistance time consider the load level. In addition, the article quantifies the security degree of the tabular method and exposes some situations for which the tabular method proved to be unsafe. Moreover, in all the models analyzed, the relationship between the span and the vertical deflection associated with the failure of the beams in a fire situation was determined. With this, a span over average deflection relationship was presented in which beams in fire situations fail.