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This work aims to present an experimental study of steel fibre-reinforced concrete (SFRC) subjected to high temperature, especially focusing on residual behaviour.

Compressive strength and split tensile strength of SFRC cubes and ultimate bending strength of prisms were evaluated under ambient and elevated temperatures. The specimens were heated by ceramic heaters and then repacked for testing.

The results showed that a compressive strength of SFRC is reduced by 38 and 66 per cent, tensile strength is reduced by 25 and 59 per cent and ultimate bending force is reduced by 33 and 56 per cent in case of 400°C and 600°C, respectively, comparing with ambient temperature.

The developed testing procedure could be used for determination of material properties of SFRC under elevated temperatures.

This study aims to propose a new design value, based on experimental and numerical studies, for surface emissivity of zinc hot-dip galvanized members exposed to fire.

The paper sums up experiments, used specimens and also shows results. Four experiments were performed in a horizontal furnace and one test in a fire compartment of the experimental building. Several tests were carried out for determination of the surface emissivity of galvanized steel structures in fire. The experimental and numerical studies were used for preparation of new generation of the structural steel fire standard Eurocode EN 1993-1-2:2025.

Hot-dip galvanizing is one of the most widely used processes for corrosion protection of steel products. The new design value for surface emissivity of zinc hot-dip galvanized members exposed to fire is determined using experimental results as 0.35. The value is proposed for next generation of EN 1993-1-2:2025. If hot-dip galvanization additionally can contribute beneficially to the fire resistance of unprotected steel members, it would be a huge economic advantage.

Experimental studies in the past years have indicated the influence of hot-dip galvanizing on the heating of steel members. This study suggests 50% reduction of the surface emissivity of a carbon steel member. This amendment will be incorporated in future versions of Eurocodes 3 and 4 and has already been implemented in some fire design tools for steel members in order to consider the beneficial contribution of hot-dip galvanized for fire-resistance requirements of less than 60 min.

This paper provides a summary of the issues in the passive fire protection of steel structures. Types of passive fire protection and the material properties of protection members and steel members are described. The paper deals with the possibility of partial fire protection for secondary steel beams, in cases where, due to possible membrane action, it is not necessary to apply passive protection to the entire beams.

Studies of partially fire-protected steel structures are compared, and results from studies with different input data are summarized. A fire experiment was conducted to investigate the effect of partial passive protection in a small-scale furnace. Based on the findings of the experiment, numerical models were prepared using Ansys Mechanical.

The results are summarized, and a partial fire protection length of 500 mm is recommended. Various partial fire protection lengths were compared, and the temperature development of the steel contactors was compared using a protection length of 500 mm. At the end of the paper, options for partial passive protection of steel beams are presented.

Extended paper from ASFE2021 based on selection.

The aim of this paper is to determine the thermal conductivity of a protective layer of alkali-activated cement and the possibility of performing fire protection with fireclay sand and Lightweight mortar. Unprotected steel structures have generally low fire resistance and require surface protection. The design of passive protection of a steel element must consider the service life of the structure and the possible need to replace the fire protection layer. Currently, conventional passive protection options include intumescent coatings, which are subject to frequent inspection and renewal, gypsum and cement-based fire coatings and gypsum and cement board fire protection.

Alkali-activated cements provide an alternative to traditional Portland clinker-based materials for specific areas. This paper presents the properties of hybrid cement, its manufacturability for conventional mortars and the development of passive fire protection. Fire experiments were conducted with mortar with alkali-activated and fireclay sand and lightweight mortar with alkali-activated cement and expanded perlite. Fire experiment FE modelling.

The temperatures of the protected steel and the formation of cracks in the protective layer were investigated. Based on the experiments, the thermal conductivities of the two protective layers were determined. Conclusions are presented on the applicability of alkaline-activated cement mortars and the possibilities of applicability for the protection of steel structures. The functionality of the passive fire layer was confirmed and the strengths of the mortar used were determined. The use of alkali-activated cements was shown to be a suitable option for sustainable passive fire protection of steel structures.

Eco-friendly fire protection based on hybrid alkali-activated cement of steel members.

Sandwich construction has developed and has become an integral part of lightweight construction. In the recent projects, it has been shown that by using sandwich panels as stabilizing members, a considerable amount of savings of steel can be achieved for structural members at ambient temperature. These stabilizing effects may also help to achieve similar savings in case of fire.

The response of a sandwich single panel as well as the behaviour of the whole structure at ambient temperature and in case of fire is influenced by joints between the sandwich panels and the sub-structure. The fastenings used to fix the sandwich panels to a sub-structure may be loaded by shear forces caused by self-weight, live loads or diaphragm action. Therefore, an experimental investigation was conducted to investigate the shear behaviour of sandwich panel joints in fire.

This paper summarized briefly the experimental results, numerical simulations and analytical models on the shear behaviour of sandwich panel joints at ambient and elevated temperatures.

The work is limited to studied types of screws and sandwich panels which are generally used in current sandwich construction.

These stabilizing effects in sandwich construction help to achieve savings in case of fire.

Sandwich construction has developed and has become an integral part of lightweight construction. In the recent projects, it has been shown that by using sandwich panels as stabilizing members, a considerable amount of savings of steel can be achieved for structural members at ambient temperature. These stabilizing effects help to achieve similar savings in case of fire.

This paper summarized briefly the experimental results, numerical simulations and analytical models on the shear behaviour of sandwich panel joints at ambient and elevated temperatures, which were not published yet.

This paper aims to present a part of a coupled numerical model for prediction the fire resistance of elements in a horizontal furnace. Temperatures calculated inside the timber beam are compared to measured values from the fire test.

The paper presents a part of a coupled numerical model for prediction the fire resistance of elements in a horizontal furnace. The presented part lies in a virtual furnace which simulates temperature environment around tested elements in the furnace. Comparison of results show good agreement in the case when burning of timber is included in the numerical model.

The virtual furnace presented in this paper allows to calculate temperature environment around three timber beams. After validation of the fire dynamics simulator (FDS) model, the temperature conditions are passed to the FE model which solves heat transfer to the tested element. Temperatures inside the timber beam which are solved in software Atena Science are compared to measured temperatures from the fire test. The comparison of temperatures in three control points shows good accuracy of the calculation in the point closer to the heated edge. An inaccuracy is shown in points located deeper in the beam cross-section – below the char layer.

In conclusion, the virtual furnace has a great potential for investigating the thermal behaviour of fire-resistance tests. A huge advantage inheres in the evaluation of the thermal effect throughout the volume of the furnace, which allows an accurate prediction of fire-resistance tests and evaluation of large number of technical alternatives and boundary conditions. However, passing the temperature field from the FDS model into FE model may decrease the level of accuracy. The solution lies in a coupled CFD-FE model. A weakly coupled model including fluid dynamics, heat transfer and mechanical behaviour is under development at Faculty of Civil Engineering, Czech Technical University in Prague. The fluid dynamics part which is presented in this paper is solved by FDS and the thermo-mechanical part is computed by object-oriented finite element model (OOFEM). The interconnection of both software is made owing to MuPIF python library.

The virtual furnace takes advantage of great possibilities of computational fluid dynamics code FDS. The model is based on an accurate representation of a real fire furnace of fire laboratory PAVUS a.s. located in the Czech Republic. It includes geometry of the real furnace, material properties of the furnace linings, burners, ventilation conditions and tested elements. Gas temperature calculated in the virtual furnace is validated to temperatures measured during a fire test.

The virtual furnace has a great potential for investigating the thermal behaviour of fire-resistance tests. A huge advantage inheres in the evaluation of the thermal effect throughout the volume of the furnace, which allows an accurate prediction of fire-resistance tests and evaluation of large number of technical alternatives and boundary conditions.

The virtual furnace has a great potential for investigating the thermal behaviour of fire-resistance tests. A huge advantage inheres in the evaluation of the thermal effect throughout the volume of the furnace, which allows an accurate prediction of fire-resistance tests and evaluation of large number of technical alternatives and boundary conditions. However, passing the temperature field from the FDS model into FE model may decrease the level of accuracy. The solution lies in a coupled CFD-FE model. A weakly coupled model including fluid dynamics, heat transfer and mechanical behaviour is under development at Faculty of Civil Engineering, Czech Technical University in Prague. The fluid dynamics part which is presented in this paper is solved by FDS and the thermo-mechanical part is computed by OOFEM. The interconnection of both software is made thanks to MuPIF python library.

The purpose of this paper is to present a complex pyrolysis computational fluid dynamics (CFD) model of timber protection exposed to fire in a medium size enclosure. An emphasis is placed on rarely used temperature-dependent thermal material properties effecting the overall simulation outputs. Using the input dataset, a fire test model with oriented strand boards (OSB) in the room corner test facility is created in Fire Dynamics Simulator (FDS).

Seven FDS models comprising different complexity approaches to modelling the burning of wood-based materials, from a simplified model of burning based on a prescribed heat release rate to complex pyrolysis models which can describe the fire spread, are presented. The models are validated by the experimental data measured during a fire test of OSB in the room corner test facility.

The use of complex pyrolysis approach is recommended in real-scale enclosure fire scenarios with timber as a supplementary heat source. However, extra attention should be paid to burning material thermal properties implementation. A commonly used constant specific heat capacity and thermal conductivity provided poor agreement with experimental data. When the fire spread is expected, simplified model results should be processed with great care and the user should be aware of possible significant errors.

This paper brings an innovative and rarely used complex pyrolysis CFD model approach to predict the behaviour of timber protection exposed to fire. A study on different temperature-dependent thermal material properties combined with multi-step pyrolysis in the room corner test scenario has not been sufficiently published and validated yet.

This paper presents ongoing research in behaviour of laterally unrestrained beams (I or H section) of Class 4 cross-sections at elevated temperatures, which is based on the RFCS project FIDESC4 - Fire Design of Steel Members with Welded or Hot-rolled Class 4 Cross-sections. Despite the current EC3 contains a number of simple rules for design of slender Class 4 cross-sections at elevated temperature, based on recent numerical simulations they were found to be over-conservative. Therefore, new well representing design models, which simulate the actual behaviour of the structures exposed to fire, are crucial. These design rules should be based on extensive numerical simulation validated on experimental data. Within this task, several tests were carried out to study lateral torsional buckling of Class 4 beams in fire. The design of the test set-up and description of the experiment is given, as well as verification of numerical model.