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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.

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.

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.

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 purpose of this paper is the production of fire retardant and smoke suppressant rigid polyurethane foam (RPUF) with lower toxicity by using several fire-retardant combinations.

Fire-retardant additives with cooling effect, barrier ash formation effect, gas-phase inhibition effect and smoke suppressant effect combined to produce an optimum outcome on RPUF. The additive amount and burning time correlation were studied to find out the minimum amount of fire-retardant to obtain fire-retardant polyurethane foam.

Zinc borate powder was coated with 1.5 wt % of stearic acid and hydroxy stearic acid. Polyammonium diborates (PABs) were synthesized and used as a fire-retardant and smoke suppressant for rigid PU foam. Fire-retardant rigid polyurethane foams (FR-RPUF) composites formed by using several combinations of zinc borate, aluminum trihydroxide, trischloroisopropyl phosphate (TCPP), PABs, zinc borate coated with stearic acid and hydroxy stearic acid. Produced FR-RPUF were horizontal burning grade, and burning time was in the range of 1–10 s.

There were limitations during the mixing of fire-retardant powders with polyol due to the high viscosity of the mixture.

FR-RPUF foam with lower toxicity can be produced industrially with these fire-retardant combinations.

FR-RPUF could be produced by using non-toxic additives. During a fire, these additives do not evolve toxic gases. The TCPP content of RPUF foam was reduced, and fire-retardant PU with lower toxicity was produced.

Coated zinc borate and the combinations of the fire-retardants were successful in producing non-toxic fire-retardant and smoke suppressant PU foam.

The purpose of this paper is to investigate different types of fire on structural steel members with damaged fireproofing. Two types of fire scenarios are considered, ASTM E119 fire and Hydrocarbon fire. In industrial facilities such as oil refineries, certain units maybe subjected to hydrocarbon fire, and its effect might be different than standard fire. The purpose of this study is to compare both types of fire scenarios on steel beams with damaged fireproofing and determine the fire rating of the damaged beams under each fire scenario.

The study is performed using computational methods, thermal-stress finite element analysis that is validated with experimental results. The results of practical beam sizes and typical applied loads in such structures have been plotted and compared with steel beams with non-damaged fireproofing.

The results show significant difference in the beam fire resistance between the two fire scenarios and show the fire resistance for beam under each case. The study provides percentage reduction in fire resistance under each case for the most commonly used cases in practice under different load conditions.

Extensive literature search has been performed by the authors, and few studies were found relevant to the topic. The question this study answers comes up regularly in practice. There are no standards to codes that address this issue.

The purpose of this paper is to compare two elements of lay-off costs in a dynamic model of the labor market and analyze the differences for business cycle dynamics and welfare.

The paper builds a general equilibrium Real Business Cycle model and introduces firing costs and severance payments. Labor market frictions are assumed to follow the famous search and matching approach.

The paper finds that firing costs imply a higher volatility over the cycle and have stronger negative welfare effects. Severance payments have a lower volatility, reduce unemployment, and reduce welfare by a smaller amount.

Policy reforms should be aimed to use severance payments and reduce the ring cost component of lay-off costs.

Increasing welfare and a more stable business cycle could be supported by using severance payments instead of firing costs.

In literature, previous studies have focused on analyzing rienforced concrete (RC) columns with idealized end conditions when subjected to fire. In nature, full fixity or free rotation at column ends is not attained. Such ends may be considered partially restrained in rotation. This paper aims to shed a new light on the effect of different degrees of rotational restraint on the lateral deformation behavior of slender heated RC columns subjected to non-linear strain distributions produced by a time-dependent temperature history.

To find the strain distribution on the cross section, an iterative technique is adopted using Newton–Raphson method. By introducing a reliable calculation procedure, the lateral deformational behavior is expressed using numerical and searching techniques. A methodology is presented to calculate the effective length factor for RC columns at elevated temperature.

The results of the proposed model showed good agreement with available experimental test results. It was also found that the variation of rotational end restraint level has a considerable effect on the lateral deformation behavior of heated slender RC columns. In addition, the effectiveness and the validity of an analytical model should be verified by simultaneously validating the axial and lateral deformations. Moreover, the effective length factor for heated column is higher than that for the corresponding column at ambient temperature.

This paper shows the impact of different boundary conditions on the behavior of heated slender RC columns. It suggests powerful techniques to determine the lateral deflection and the effective length factor at high temperatures.

Fire protection regulations are difficult to comply with in the case of wooden structures because of the fact that wood is a combustible material. The fire protection of wood can be solved with coatings or by the application of flame retardants.

The standard of MSZ EN 1995‐1‐2 currently does not allow the consideration of fire retardants in case of scaling the fire load. In spite of the aforementioned, today there are many types of retardants on the market that are reliable and allow us to achieve a better fire protection classification.

The question is how sensitive a wood preservative is to a construction fault, or what would be the result of the erroneously applied fire retardant to the fire protection characteristics of timber used in constructions.

During the research, five different fire retardants were tested on three types of wood and their behaviour was monitored under controlled laboratory circumstances. When selecting the wood, it was important to take the wood species that are most commonly used in the construction industry, and their density should be as different as possible. During the tests, the wood preservative was applied incorrectly, modelling the following cases: applying less or more wood preservatives, and creating small and large faults.

This paper aims to present the findings of a numerical investigation into the performance of the steel-concrete composite floor involved in Broadgate Phase 8 fire.

The investigation is conducted by carrying out a 3-D thermomechanical analysis of a composite floor similar to the one involved in the fire using ANSYS. Four fire scenarios are investigated, with each producing a unique stress – strain pattern. The results obtained are compared with the observations made after the fire and inferences drawn.

The results obtained are found to be correlated with the observations made after the fire. The performance of the composite floor is found to be dominated by development of large strains, leading to large deflections. Furthermore, colder parts of the structure, through redistribution of forces, are found to have a profound impact on the ability of a composite floor to resist heating effects. From the findings, it is concluded that connections’ design, occurrence of membrane action and thermal restraints were the key reasons the floor did not fail.

The study takes a more forensic approach. This is a departure from majority of published literature, where comparison is usually between experimental and numerical results. By comparing the findings from a real fire with those of a numerical investigation, the study provides an insight into the accuracy of applying numerical models for the prediction of effects of fire on structural behaviour.

The purpose of this study is to investigate the transport phenomena of smoke flow in a semi-open vertical shaft.

The large eddy simulation (LES) method was used to model the movement of fire-induced thermal flow in a full-scale vertical shaft. With this model, different fire locations and heat release rates (HRRs) were considered simultaneously.

It was determined that the burning intensity of the fire is enhanced when the fire attaches to the sidewall, resulting in a larger continuous flame region in the compartment and higher temperatures of the spill plume in the shaft compared to a center fire. In the initial stage of the fire with a small HRR, the buoyancy-driven spill plumes incline toward the side of the shaft opposite the window. Meanwhile, the thermal plumes are also directed away from the center of the shaft by the entrained airflow, but the inclination diminishes as HRR increases. This is because a greater HRR produces higher temperatures, resulting in a stronger buoyancy to drive smoke movement evenly in the shaft. In addition, a dimensionless equation was proposed to predict the rise-time of the smoke plume front in the shaft.

The results need to be verified with experiments.

The results could be applied for design and assessment of semi-open shafts.

This study shows the transport phenomena of smoke flow in a vertical shaft with one open side.

The 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.

A 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.

The major challenges of lightweight claddings are rapid fire spread, smoke production and toxicity and inconsistency in fire testing.

The review highlights the current challenges in cladding fire, smoke toxicity, testing system and regulation to provide some research recommendations to address the identified challenges.

RC columns are very susceptible to fire, as besides the detrimental effects due to this action, second‐order effects play a significant role. In this work, the aim is to consider the ISO834 standard fire, and the focus is put on checking the proper use of a simplified method suggested on Annex B.3 of EC2 to account for the second‐order effects in RC columns.

The use of Annex B.3 of EC2 is obscure in what concerns the peak strain to be considered at the most deformed cross‐section concrete fibres, and this affects the evaluation of the second‐order moment installed in the RC column during the fire. Two hypotheses are analysed in the paper, and validated against the calculations from the advanced code SAFIR: the one where the classical limit of 3.5‰ is assumed for the peak concrete strain in compression, and a more refined compatibility of the section total strains.

The simulations demonstrate that using the simplified method with hypothesis H1 leads to unsafe conclusions. Conversely, hypothesis H2 compares much better with SAFIR predictions, and it can be rather easily adopted in real applications.

The indications provided here for the proper application of the simplified method are very useful for practical use. They overcome an unclear aspect on its implementation, not yet previously addressed.